The Evolution of and/or Creation of Life

[Thorgrimm]

Ashmo Wrote:

Darwinism proposes that all life started with one very simple event (likely enough to have occurred on ONE planet in a vast universe full of billions of billions of planets) and went on from there through RANDOM mutation and NON-RANDOM natural selection. Not in major jumps, but on a slow, gradual slope.

Ashmo, hate to break it to ya bud, but was NOT a slow, gradual slope. So I started this thread to see just how much folks do know about Natural Selection. I orginally posted this material on the Radiated Society, but comments like making their heads hurt from the information makes me want to see just how much of a good non-flaming debate I can get here on NMA.


Being the utter rebel and non-conformist that I am, I thought I would present a lil' dissertation on some of my thoughts on the evolution/creation debate.


4.6 Billion B.C. Debris from the initial formation of the solar system, in the form we now encounter as meteorites, some still extant after billions of years began to occasionally drop into our atmosphere more or less unexpectedly. These meteorites have been radiocarbon dated to an age of 4.5 to 4.7 billion years in age. Importantly, these same meteorites were found to contain carbonaceous chondrites rich in amino acids and at least three of the four nucleotides required to make up DNA and/or RNA, those ingredients essential for life as we know it.

4.0 Billion B.C. Life seems to have rather quickly appeared on Earth. In this regard, “life” is defined as the ability to absorb nutrients (of any kind) and to replicate (not just to exist). But why on Earth did life appear?

As it turns out, it’s not altogether clear how Life on Earth came about. Evolutionary Theory certainly does not explain how life began, even if it has been occasionally successful in explaining how life on Earth evolved all the way from the earliest, one-celled creatures to Homo sapiens. (Of course, evolutionary theory has not been all that successful in explaining a whole host of life style innovations scattered about in the geologic and anthropologic records, but it is the reigning theory.

But such theories do not answer the question of how life began on Earth. Clearly the evidence suggests that life currently exists on Earth, but after that, the theories get a bit more sticky.

An important point is that the Earth has a relative abundance of elements that does not reflect the same combinations in other parts of the solar system. For this and other reasons, it is believed by some scientists that the present earthly atmosphere is not Earth’s original one. Evidence also exists to suggest that the Earth experienced a 'thermal episode' sometime around the period from 4.0 to 3.8 billion years ago. By and large, most scientists now believe that Earth’s atmosphere was reconstituted initially from the gases spewed out by the volcanic convulsions of the Earth in its birth pangs.

As clouds thrown up by these eruptions shielded the Earth and it began to cool, the vaporized water condensed and came down in torrential rains. Oxidation of rocks and minerals provided the first reservoir of higher levels of oxygen on Earth; and eventually, according to theory, life began to take shape. Scientific theory, for example, suggests that plant life added both oxygen and carbon dioxide to the atmosphere and with the aid of bacteria started the nitrogen cycle. But where did the plants, and the bacteria, come from? Ah yes, the initial-most conditions!

Modern science has been able to 'duplicate' conditions on a very early Earth; a primordial, watery soup subjected to electrical sparks (in lieu of primordial lightning bolts), and in carefully controlled experiments, has been able to make organic compounds from inorganic elements (the latter being essentially the proverbial rock pile). Yet, so far, they have not been able to learn how the organic compounds could organize themselves into a replicating cell, complete with the all-important ability to reproduce. There is a 'made of clay' hypothesis that suggests it is possible, but no such experiment has been able to replicate the organization into neucliotides.

In this clever scenario, researchers have found that the nickel in certain clays selectively hold onto the twenty kinds of amino acids that are common to all living things on Earth (while ignoring any other amino acids not common to these same life forms). Meanwhile traces of zinc in the same clay help link together the nucleotides, which results in a compound analogous to a crucial enzyme (called DNA-polymerase) that links pieces of genetic material in all living cells.

In effect, the clay has the two basic properties essential to life:
(1) the capacity to store, and
(2) the ability to transfer energy. In the primordial conditions, according to this hypothesis, clays might have acted as chemical laboratories where inorganic raw materials were processed into more complex molecules. Funny enough, the ability of the clays to trap and transmit energy was due to defects in the clay’s microstructure, essentially 'mistakes' in the formation of clay crystals. According to one scientist, “It would seem that an accumulation of chemical mistakes led to life on Earth.” On the other hand, I’ve got some good news for modern science theories, and some bad news.

The good news is that the combined murky-soup and life-from-clay hypotheses combine rather nicely. The bad news is that in the case of the Earth, a problem of timing occurs. Essentially all problems encountered in life are timing problems. For the question is not can it happen (as described by the murky-life-from-clay-soup theory), but how did it happen here on Earth?

For life as we have it on Earth to happen, two basic molecules are necessary: Proteins, which perform all the complex metabolic functions of living cells; and nucleic acids, which carry the genetic code and issue the instruction for the cells’ processes. Both function within a unit called a cell, a cell capable of triggering the replication not only of itself but of the whole animal of which the single cell is but a minuscule component. In order to become proteins, amino acids must form long and complex chains. In the cell they perform this task according to instructions stored in one of the nucleic acids (DNA -- deoxyribonucleic acid) and transmitted by another nucleic acid (RNA—ribonucleic acid). Well, Skippy, I have bad news, so far science has not been able to replicate the formation of nucleic acids.

3.8 Billion B.C. Life appears on Earth.

Sediments found off the coast of Greenland bear chemical traces that indicate the existence of photosynthesis as early as 3.8 billion years ago. Based on this and other evidence, Norman Sleep of Stanford University [Nature, November 8, 1989] concluded that the “window of time” when life on Earth began was just the 200 million years between 4.0 and 3.8 billion years ago. “Everything alive today evolved from organisms that originated within that Window of Time.”

Other scientists have concluded that no matter how life began on Earth, it did so about 4.0 billion years ago, and probably by some 'momentus event'. Nobel prize winner Manfred Eigen [Science, May 12, 1989] concluded that a primordial gene appeared 3.89 billion years ago (plus of minus 600 million).

The essence of these ideas is that the murky-soup or life-from-clay hypotheses are not the most likely reason for life on Earth (although the methods would still have been feasible if there had been more time and energy). But alas, that ole timing thing again, just can't get around it.

3.75 Billion B.C. First appearance of archaeo-bacteria, dated to between 3.5 and 4.0 billion years ago. Bacteria appears to have preceded algae and other primeval forms of life.

3.5 Billion B.C. The end of Precambrian I. Geologic Eras are subdivided into Periods, based primarily on the sequence of sedimentary rocks (and their contents of fossils, etcetera). Precambrian I is assumed to have begun 4.0 billion years ago. The first notable change in the sedimentary sequence occurs approximately 0.5 billion years later.

Fossil remains of algae found in Australia have been dated to 3.5 billion years ago. Other fossil remains, found in 1977 in South Africa have been dated to between 3.1 and 3.4 billion years ago. These algae were organisms already possessing both amino acids and complex nuclei acids; indicating not the beginning of life on Earth, but an already advanced stage of it.

Finally, for the most part, the Early Precambrian (aka the Archean Period) was characterized by crust formed on a molten Earth and a very disturbed crystalline rock strata. Psychotic rock? Isn't that the name of some Death Metal band?

3.136 Billion B.C. Beginning of Precambrian III. A continuation of the mind-numbing, eon-after-eon, biological simplicity. Or as the media might phrase it: a minimal news epoch.

2.704 Billion B.C. Beginning of Precambrian IV.

2.272 Billion B.C. Beginning of Precambrian V.

1.840 Billion B.C. Beginning of Precambrian VI. Coincident with this latest Precambrian Era is the appearance of a variety of metamorphosed sedimentary rocks, lava flows and granite. This epoch also marks the beginning of the Late Precambrian, also known as the Algonkian Period.

For more complex lifeforms to evolve (i.e., lifeforms a bit more exciting than the mind-numbing oceanic algae which has ruled for some two billion years), oxygen is needed. This oxygen became available only after algae or proto-algae began to spread upon the dry land. Essentially, it was time for 'everybody out of the pool' to which only a few intrepid algae responded. But for these adventuresome green plant-like forms to utilize and process oxygen, they needed an environment of rocks containing iron with which to “bind” the oxygen. Without this critical ingredient, these algae would have been destroyed by oxidation; free oxygen still being a poison to these life forms. But there it was, something on the order of two billion years ago, 'green herbage' beginning to increase the atmosphere’s oxygen. In this regard, it is extremely important to note that the covering of the lands with green algae had to precede the emergence of maritime life (maritime life other than the floating green scum).

The Bible says the same thing, which when you think about it, is really quite remarkable in that the Bible is being used in this clever way to substantiate evolutionary theory!. For example, according to Genesis 1: 11-23, green herbage was created on Day Three, but maritime life not until Day Five.

“Let the Earth bring forth green herbage, and grasses that yield seeds, and fruit trees that bear fruit of all kinds in accordance with the seeds thereof.”

This was the all important evolution from asexual reproduction to sexual reproduction. But before 'creatures' could appear (in the water, air or dry land), Earth had to set the pattern of the biological clocks that underlie the life cycles of all living forms on earth. In effect we had to have the cycles of light and darkness. This, the Bible knocked out on the Fourth Day events, and thereby maintained its scientific accuracy. It also filled a gap of about 1.3 billion years; from about 1.8 billion years to some 544 million years ago, about which little is known otherwise because of the paucity of geological and fossil data.

1.408 Billion B.C. Precambrian VII begins.

0.976 Billion B.C. Precambrian VIII begins with its only claim to fame being the fact that this is the last Precambrian epoch.

Actually, there was, in fact, an event of some importance in this epoch. For three billion years, from soon after the Earth cooled sufficiently to the current period, the highest form of life was the single cell. A degree of complexity then emerged about a billion years ago, when cells developed packaged nuclei which included mitochondria DNA.

The mitochondria were (and continue to be) cellular organelles that convert food into a form of energy that the rest of the cell could use. Unlike the DNA of the nucleus, which form bundles of long fibers, each consisting of a protein-coated double helix, the mitochondrial DNA come in small, two-strand rings. And where nuclear DNA encode an estimated 100,000 genes (most of the information needed, for example, to make a human being) mitochondrial DNA encodes only 37 genes. Never-the-less, in its own way, this was a momentous occasion.

544 Million B.C. Following the biological simplicity of the Precambrian Era, the Earth was suddenly beset with the initiation of the Paleozoic Era (“Old Life Era”). It was a period of large faunas of marine invertebrates.

At the outset of the Cambrian Period (the first, and in some ways, the most notable Period of the Paleozoic Era), the dominant species was unquestionably the Trilobites. For of all the wondrous delights of this bygone era, the Cambrian’s most famous residents were a species which blanketed the fossil records of some 500 million years ago with a vengeance (in other words, they was everwhere!). As marine anthropods, these little jewels of multi-cellular innovation had a body divided by two furrows into three parts.

The extensive fossil record left behind by Trilobites (and the less dominant, the brachiopods) is due in part to the fact that shallow seas covered large parts of the continents. In fact, at the beginning of the Paleozoic Era, the main event was known as the Cambrian Explosion. (The name Cambrian, incidentally, comes from the region in Wales where the first geologic data for this period was obtained. The word "explosion" references here a sudden, enormously expanding proliferation of species.)

From a geological perspective, “three billion years of mind-numbing biological simplicity was replaced overnight by burgeoning complexity.” This ultimate “phase transition” occurred with the advent of single-celled organisms evolving into multicellular organisms (a primordial “In unity there is strength” scenario). Suddenly, and with spectacular effect, the trick of cellular differentiation and aggregation into multicellular organisms occurred. An explosion of new forms of life resulted, with a bewildering variety of complexity.

This is perhaps best demonstrated by reference to the Phyla of the Cambrian. Biologists created a vast hierarchy for life and its many forms. The broadest of the categories are referred to as Kingdoms, essentially animals, plants.

Immediately below Kingdoms are Phyla (but just above Classes, e.g. mammals and reptiles). Phyla are discrete body plans, upon which many variations may be created. Phylum Arthropoda, for example, the most populous of all Phyla, have jointed appendages (insects, centipedes, spiders, crabs). Phylum Chordata include vertebrates such as humans.

There are 30 major Phyla in today’s world, just as there have been for much of the past 500 million years. This is a striking continuity of anatomical designs, upon which as many as 50 billion variants have come and gone. However, in the aftermath of the Cambrian explosion, there may have been as many as 100 Phyla! The majority of these, however, became extinct in short order.

The Cambrian Explosion, meanwhile, was a geologically brief moment (less than a hundred million years) of tremendous evolutionary experimentation, followed by a severe sorting process; particularly severe in terms of species, with whole Phyla, which includes a whole swath of species, going extinct in the twinkling of an eye. The shape of today’s world was influenced to a large extent by which Phyla survived 500 million years ago!

458 Million B.C. The Ordovician Period begins. The first primitive jawless fishes appeared. This is also a time for mountains being elevated in New England and volcanoes along the Atlantic Coast.

415 Million B.C. The Silurian Period begins with the earliest small land plants and animals. Great mountains are formed in northwest Europe. Corals appear, building reefs in far northern seas, shelled cephalopods are abundant, the first jawed fish appears, and the Trilobites go into serious decline preparatory to their vanishing from the scene.

370 Million B.C. The Devonian Period arrives with amphibians, and an abundance of primitive fishes and the first sharks. Insects begin as land plants evolve, even to the extent of large trees appearing. The Brachiopods reach their pinnacle of success.

328 Million B.C. The Carboniferous Period begins. This period is primarily known for the Carboniferous Period being split into two distinct epochs: The Lower Carboniferous (also known as the Mississippian), famous for an abundance of relatively modern types of sharks, and the Upper Carboniferous (also known as the Pennsylvanian), where some 300 million years ago, reptiles appeared. Land plants became more diversified, including many ancient kinds of trees. Crinoids, flowerlike in form and anchored by a stalk opposite the mouth, achieved their greatest development.

285 Million B.C. Then came the great Permian Period, known to oil and gas men the world over as one of the premier stratus to find oil, gas, and other profitable hydrocarbons. Ah yes, abundant conifers and developing reptiles all struggling to fulfill their destinies to fill our gas tanks some 250 to 285 million years later. With the end of the Permian, we also closed the Paleozoic (“old life”) Era, and species after species ended their own species' Wheel of Life.

Modern seas contain twice as many species as in the Cambrian world. But the increase in the number of species was no steady march from ancient to modern times. The evidence, on the contrary, shows interruptions and occasional catastrophic collapses in diversity; mass extinctions that felled huge percentages of existing species within a single geological instant. Five such events punctuate the history of life on Earth. Many lesser collapses, not big enough to deserve the appellation 'Mass Extinction', but never-the-less devastating on a continent-wide scale, also took their toll. As a result, 99.9 percent (which is a significant percentage) of all species that have ever lived are now extinct!

If the Cambrian Explosion is the single most spectacular phenomenon in the fossil record for the advent of life, the Permian Extinction, when no less than 96 percent of all then-existing species perished, is one of the most notable K-Mart specials on discontinued species. The Permian close-out special occurred some 250 million years ago, and began a virtual trend in mass elimination. Even so, with the end of the Paleozoic, there were fish in the waters as well as sea plants. Amphibians had made their transition from water to dry land, and may even have spawned the ancestors of crocodiles.

250 Million B.C. The Mesozoic Era (“Middle Life”) begins, with the most notable 'vacant ecology' since the end of the Precambrian Era. In the process, the new state of affairs continues with the Permian-initiated trend, fad, fashion, whatever, of periodic mass extinctions. These clearance opportunities have continued to this day.

With the advent of the Mesozoic Era, we also began the Triassic Period, with the first appearance of dinosaurs. I could spend a lot of time talking about dinosaurs; Tyrannosaurus Rex, Triceratops, Apatosaurus, and the like, but instead will accede to the true connoisseur of dinosaurs, Calvin and Hobbs.

Biblically... (A strange place for biblical ramblings, but there you have it!) Biblically, the Mesozoic Era is contained succinctly in Genesis 1: 20-23. The Hebrew term for what has been translated as 'great whales' is Taninim (plural of Tanin). The later term is used to mean 'sea serpent', 'sea monster', even 'crocodile'. The latter, of course, is in the line with dinosaurs, ancestors of crocodile having appeared in the Permian Period and managing to survive as a species to modern day.

155 Million B.C. The beginning of the Jurassic Period, where Movieland Parks predominated, populated with a variety of inmates from primitive birds, sophisticated dinosaurs, and the first small mammals. This was the zenith for the dinosaurs; implying it was all downhill from there. Closer to home, the Sierra Nevada Mountains were uplifted.

130 Million B.C. The Cretaceous Period! About all the Cretaceous is known for is the appearance of floras with modern aspects and the disappearance of the dinosaurs by the end of the Cretaceous. The end of the BIG Guys is widely believed to have come about by the impact of a particularly aggressive asteroid; circa 62 - 65 million B.C. This is as good a theory as any. But one should keep in mind that it was not only the fall of Dino the Dinosaur, but there were a lot of other saurs to bite the dust as well. The mass extinction at the end of the Cretaceous was, on the basis of numbers of species that went extinct, the most severe yet discovered in the fossil record.

68 Million B.C. The Beginning of the Cenozoic Era 'current life', most of which the Bible summarizes in a mere two verses of Genesis (1: 24-25). The Cenozoic Era is then subdivided into two Periods, the first of which is the Tertiary Period. The Tertiary Period is then further subdivided into five 'cenes' (also known as Epochs). The first is the Paleocene, where the first placental mammals appeared. Primitive mammals were definitely on the rise.

58 Million B.C. The Tertiary continues blithely along with the advent of the Eocene Epoch (or Eocene Epic, depending on your druthers). The time was marked with mountain building in the Rockies, Andes, Alps and Himalayas. There was a continued expansion of early mammals, and the primitive horse appeared.

35 Million B.C. The Oligocene Epoch arrives, and with it mastodons, monkeys, and apes. At the same time, many older types of mammals became extinct.

Well kiddies, that brings us up to where all the 'monkey' business begins. So in my next post I will expound on a lil' known species and its debated origins. Till then have as much fun reading this as I have in making it.




Cheers, Þórgrímr

 

[xdarkyrex]

http://scienceweek.com/2005/sw050429-1.htm

An article on RNA replication in the origin of life

 

[Thorgrimm]

http://scienceweek.com/2005/sw050429-1.htm

An article on RNA replication in the origin of life

@Dopamine, hurt your head did it?

@xdarkyrex, good article, but from the artilce here is the kicker:

Even if both sequences had well determined secondary structures, the perfect complementarity of the Watson-Crick pairing would act as a sink, leading to a sterile population of double-stranded molecules.

Thus possibly ruling out an RNA ruled Earth. So back to the good ole Protien DNA ruled Earth.



Cheers, Þórgrímr

 

[xdarkyrex]

That was my point, sorry for not elaborating, I'm doing a lot of multitasking right now with schoolwork.

I'm a big proponent of the protein theory.

 

[Thorgrimm]

That was my point, sorry for not elaborating, I'm doing a lot of multitasking right now with schoolwork.

I'm a big proponent of the protein theory.

Lol, np, I am also a proponent of the metabolism first theory. Of note a recent model by Chrisantha Fernando suggests that the enclosure of an autocatalytic non-enzymatic metabolism within protocells may have been one way of avoiding the side-reaction problem that is typical of metabolism first models. It is quite interesting, but a little 'heady' if you are not into microbiology.

Here is the link for you to DL the PDF of the model. First entry in the list.

http://www.cogs.susx.ac.uk/users/ctf20/dphil_2005/publications.htm



Cheers, Þórgrímr

 

[Ashmo]

I never claimed the original beginning was gradual. Evolution is, relatively speaking.

It's slow and gradual in comparison to creationism which proposes that all modern life was spawned in an instant (or the course of a week). It's certainly not slow in comparison to astronomic time scales.

The point is that the way evolution works (and the speed with which it works) makes sense. It is fast enough to allow for empirical observation (e.g. experiments with fish across several decades) and slow enough to be somewhat stable across the centuries and millenia ("somewhat" as the process doesn't just "pause").

Nobody is claiming that all accounts in the bible are completely random. The point is that the factual truth in it is interwoven with fictitious accounts and questionable moral advice in a manner which renders it useless as a primary source for any historical information at all.

Yes, the parallel between the creation of earth in the bible and the actual beginnings of life is less or more accurate, but that hardly makes the bible a useful alternative to, say, the Encyclopaedia Britannica. Quite possible the bible (originally a number of distinct texts, most of which lacked a standardised content) was used to transport some world-knowledge, like many other religious traditions or concepts (entire cultures based their religions around astronomic insights, for examples, even though their methods could be hardly called scientific).

As for macro-mutations. Yes, there were those, too (and everybody knows that the larger the population becomes the more likely certain mutations are to occur). But for the most part macro-mutations are destructive. The number of macro-mutations that actually resulted in an advantage (or rather: resulted in no disadvantage and then, through successive micro-mutations, eventually created an advantage) is dwarfed by the number of macro-mutations that didn't make the cut because it resulted in horrible freaks of nature, unable to survive after birth.
Again, no miracle, just statistic probability.

It's quite simple: it may have been very unlikely, but the fact we exist proves that we were the ones to have exactly the right circumstances for the event to occur.

Being struck by lightning isn't something you generally need to worry about, but some people end up on the wrong side of the statistic. Improbable doesn't equal impossible.

 

[Thorgrimm]

Good job at sidestepping the main point, part of what I quoted you on;
Ashmo Wrote:

Not in major jumps, but on a slow, gradual slope.

Evolution was anything but smooth. It was a jagged ride with very high peaks and very low depths. There were 5 mass extinctions and a host of lesser contintental extinctions.

The whole point of this thread was to find out just how much folks on NMA really know of evolution, or if what most folks think is true or not. Your misperceptions and error-filled statements are just as bad as a creationist statement.


Ashmo wrote:

It's slow and gradual in comparison to creationism which proposes that all modern life was spawned in an instant (or the course of a week). It's certainly not slow in comparison to astronomic scales

I see you missed my other point I was trying to make, Creationists are using a flawed timescale. But are saying basically the same thing.

Just to clear up something I am neither a a blind follower of Creationism or a blind follower of its spiritual opposite, Evolution. I believe in the third way.

In my next major post I will continue the 'timeline' and you will see why I say evolution is neither slow or on a gradual slope.



Cheers, Thorgrimm

 

[Ashmo]

Would you be happy if I added the words "for the most part" in my statement?

I'm not doubting there are certain boosts in evolutionary history. I'm just saying that those boosts are not in any form "weird" or logically impossible.

EDIT: Mind you, I'm not saying anything about evolution has to be "slow" on an absolute time scale. I'm merely saying that this is how evolution works on an individual level -- a monkey won't suddenly give birth to a human.

Except for the very few macro-mutations I talked about, micro-mutations and natural selection pressure can explain the evolutionary process rather nicely. I wouldn't claim to know that there has not been any other influence (although alien gene fiddling or divine intervention remain rather unlikely), but unless you can show me something evolution (on a genetic level, not the original Darwinian species/individual-level) can't explain, I stand by my words.

 

[Thorgrimm]

Would you be happy if I added the words "for the most part" in my statement?

I'm not doubting there are certain boosts in evolutionary history. I'm just saying that those boosts are not in any form "weird" or logically impossible.

Nah, and sorry to badger you, but the point I wanted to make is that any broad over-arching statement on natural selection from either side is detrimental to the process of finding out what actually did occur and brought life from lifelessness. If folks spent as much energy to try and find out what actually happened as they do to trying to 'convince' the other side to their way of thinking we prolly would have the answer by now.

Btw you may want to read that model report I linked to. Looks promising for possible protocell generation.



Cheers, Thorgrimm

 

[Ashmo]

Contrary to what I may have led you to believe, I'm not actually particularly well-versed, nor very interested, in biology or biochemistry.

I'm more interested in the general high-level perspective than the low-level detail. Judging by experience, that seems to suffice for most discussions, though.

I hope I haven't misled you, as I don't try to claim in-depth knowledge where I have none.

I may have a certain talent of understanding abstract relations outside my normal field of knowledge, but I'm not too well-versed in (nor do I enjoy) the art of bullshitting my way through.

 

[Thorgrimm]

Contrary to what I may have led you to believe, I'm not actually particularly well-versed, nor very interested, in biology or biochemistry.

I'm more interested in the general high-level perspective than the low-level detail. Judging by experience, that seems to suffice for most discussions, though.

I hope I haven't misled you, as I don't try to claim in-depth knowledge where I have none.

I may have a certain talent of understanding abstract relations outside my normal field of knowledge, but I'm not too well-versed in (nor do I enjoy) the art of bullshitting my way through.

NP bud, I always saw you as a very smart person, so I figured you had a good working knowledge of the subject and was a wee bit miffed at the broad statement. And if I seem a bit harsh I apologize for that, just this is one subject I have studied and followed most of my adult life. So I may not have a degree in the subject, but I feel I can hold my own in a debate on the subject.

By the way, the slow growth curve had been the prevailing theory until Bob Bakker and his Dinosaur Heresies Book hit the streets in 1986. The idea may have been around for a while before then, but I remember the storm of controversy his book provoked. It kicked evolution in the nuts and brought in some fresh ideas that caused scientists to re-examine other parts of natural selection.

Some of Bakker's reconstructions have proved remarkably accurate in the light of more recent evidence. Deinonychus, the "two-hundred-pound Cretaceous predator with a wickedly enlarged hind claw for disembowelling prey" is drawn on page 312 with feathers. This was indeed heresy when the book was published. Bakker based this reconstruction on its "incredibly birdlike anatomical structure" which strongly indicated "it is probable that they had already evolved feathers".

When Bakker's book was first published, many scientists were sceptical that meat-eating dinosaurs really were the ancestors of birds. They wanted to see proof that dinosaurs had feathers. In the last few years the fossilized remains of feathered dinosaurs have been discovered in the 124 million year old lake sediment of Liaoning, China. These dinobirds are preserved in remarkable fine detail firmly confirming Bakker's theory about the connection between birds and dinosaurs.

Anybody interested in the Big Guys should have this book in their collection.



Cheers, Thorgrimm

 

[Ashmo]

I actually read about the feathered dinosaur thing and it makes sense. Feathers can provide an advantage even if the creature is not capable of true flight.

I'm not arguing that all of Darwin still holds true in 2007, but rather that Core Darwinism prevails.

 

[Thorgrimm]

I actually read about the feathered dinosaur thing and it makes sense. Feathers can provide an advantage even if the creature is not capable of true flight.

I'm not arguing that all of Darwin still holds true in 2007, but rather that Core Darwinism prevails.

Yes it certainly does make sense to us now, but back when Bakker proposed it, it was literally a heresy against the 'holy of holies' to science. Man, I remember the shitstorm it created.

I whole-heartedly agree. Its core tenets are certainly sound, but IMO, I think it needs an update. But a LOT of scientists and normal folks are getting to the point where you suggest something like a revision of the 'holy of holies' you almost automatically get slapped with the tag of creationist and they close their mind to debate. To me this is just as bad, in not worse than what any religion would do. Since science is supposed to question their theories if something does not fit.


Alright ladies and gents, I now present the portion of the timeline I call 'Monkey Business'.



32 Million B.C. The first appearance of a fox-sized creature called Aegyptopithecus, which was half-ape and half-monkey and possessed a tail. It is conjectured that the creature probably ran along tree branches instead of swinging below them. According to paleoanthropologists (that curious breed between paleontologists, anthropologists, and an occasional archeologist), this is the first appearance of an ape-like creature.

25 Million B.C. The beginning of the Miocene Epoch, a time of renewed uplift of the Rockies and other mountains, great lava flows in the Western United States, and mammals beginning to acquire modern characteristics. For the most part, the mountain building phase occurred predominantly toward the end of the Miocene.

16 Million B.C. The Pliocene Epoch (and the final act of the Tertiary Period of the Cenozoic Era) begins with a bang, Ramapithecus appeared. Theorists later determined that while Rama Baby was probably in the ancestral closet of the orangutan, he was not a direct ancestor of man. In any case, orangutans had left the man-line. Unfortunately, as chance would have it, Ramapithecus, that portion of the species not following the orangutan destiny, was extinct by about 7 million B.C.

At roughly the same time as Ramapithecus was roaming about, Proconsul, a genus ancestral to the chimpanzee, arrived with no tail at all from the ape-rich epoch of the Miocene. Proconsul was quite possibly the rootstock of any number of later anthropoids. Many scientists consider this to be the first appearance of a hominid, one capable of revealing a possible transition to manlike apes.

10 Million B.C. The gibbon splits off from the ancestral monkey-ape-man line.

9 Million B.C. Gorillas split from the family tree.

6 Million B.C. Man and chimpanzee go their separate ways, ancestrally speaking.

5.8 Million B.C. First appearance of Ardipithecus ramidus kadabba, an innovative creature which decided to walk on two legs instead of four. This was big news. "That kadabba walked upright at all is hugely significant. Paleontologists have suspected for nearly 200 years that bipedalism was probably the key evolutionary transition that split the human line off from the apes." [Michael D. Lemonick and Andrea Dorfman, "One Giant Step for Mankind", Time Magazine, July 23, 2001.]

4 Million B.C. First appearance of Australopithecus anamensis, supposedly man’s predecessor. This followed Ardipithecus ramidus ramidus which made a brief appearance (i.e. there are few if any remains) in the 4.5 million B.C. time period.

3.5 Million B.C. A discontinuity occurs, a gap in the fossil record, that obscured the period before, during, and just after the theorized split between gorillas, chimpanzees, and pre-humans. According to Becky Cann, “What walked the Earth before the first humans were creatures different from anything that has been seen on the planet or is on the planet today.” This may be the area where the 'missing link' became missing in the fossil record.

3.3 Million B.C. The life and times of Lucy, an Australopithecus, who left the most complete skeleton of any man-ape ancestor to date, a skeleton to be eventually discovered by the Leakeys. Incidentally, 'Lucy' was so named because,
(1) the skeleton was female, and
(2) at the beer celebration that night, the paleoanthropologists had played the Beatles’ song, Lucy in the Sky with Diamonds. This kind of nostalgia sort of makes you feel warm and fuzzy all over, doesn’t it?

Following in Lucy's footsteps was Australopithecus africanus, Australopithecus aethiopicus, Australopithecus boisei, and Australopithecus robustus. The latter two, however, seemed to stumbled into a evolutionary dead end and made no further contribution.

2.2 Million B.C. The Taung child lived in South Africa, a being which is currently the best candidate for the title of the 'missing link' between man and ape. Taung was a man-ape (an ape with some characteristics of a human, but with less than half the brain size). It was the true intermediate or transitional creature between the gorilla and Homo. Taung was a primate that walked upright, thus giving paleontologists a reason to allow it to slip into the vague category of “hominid”. Ultimately, it was classified as Australopithecus Africanus.

Bridging the gap between the various camps of Australopithecus and the latter ancestors was Homo rudolfensis.

2.1 Million B.C. Another contender for the crown of 'missing link' is Homo habilis, possibly a descendant of Australopithecus. This first 'human' more humanoid than ape, was as close to the dividing line, the intermediate stage between man-apes and Homo sapiens, as has yet been uncovered.

2.0 Million B.C. First appearance of Advanced Australopithecus and Homo Erectus. In any case, Homo Erectus was the first truly man-like creature (in terms of skeletal appearance) to arrive on the scene. It was these creatures who were, according to theory, the progenitors of the first primitive men. Well, maybe. But it’s not all that simple. The history of Erectus is about to take us into some wholly new territory.

1.9 Million B.C. A slight diversion. Remember the mitochondrial DNA? Something strange happened between the common chimpanzees and the pygmy chimpanzees, some 1.9 million years ago. It turns out that mitochondrial DNA can be transmitted genetically only through the female line. In what is the ultimate matriarchal paradigm, all of the genes of the mitochondrial DNA hail from the female. And while the nucleic DNA and its genes are a combination of the male father and female mother of an offspring (those that carry the preponderance of the physical characteristics of an individual), the mitochondrial DNA, which determine the species’ ability to convert and utilize energy within a cell is purely an attribute provided by good old mom.

The split between the common and pygmy chimpanzee would not occur for another 600,000 years. However, geneticists, studying the mitochondrial DNA of living chimpanzees, along with the inevitable mutations over the eons, have traced the entire chimpanzee line back to ONE SINGLE FEMALE chimpanzee that lived 1.9 million years ago! Is science wonderful, or what? More later!

1.5 Million B.C. Homo Erectus demonstrates the success of the species by extending its reign throughout Africa, the Middle East, Europe and Asia.

800,000 B.C. 'Java Man', shows up on the scene and is identified as human, Homo, but classified as Homo erectus. He had apish traits in the skull, but would ultimately be accepted as a rough draft or prototype for both Neanderthals and modern humans.

600,000 B.C. Climatic variations began with the ebb and flow of glaciers encroaching on Europe and Asia; periodically driving the ancestors of man to take refuge in Africa, the Middle East, and perhaps India. Glaciation peaked about every 100,000 years, thereafter, one ice expansion after the other.

This was also the beginning of the Pleistocene Epoch, the last of the geologic time scales and the one to take us up to about 11,000 B.C, when the Current Epoch began. About this time, Homo heidelbergensis made a brief appearance (roughly 400,000 years).

500,000 B.C. 'Peking Man' was an erectus who may have been a cannibal. A slightly modern version of Java Man, this creature may have been using tools.

400,000 B.C. The appearance of Archaics, semi ape-men, and the first suggestion of Homo sapiens.

250,000 B.C. Homo erectus had been the most successful human-like species (up until the modern type), originating in Africa, and spreading around much of the world including the Middle East, Europe and Asia. It was in the latter where its characteristics had first been defined in Java and Peking Man.

Then about 250,000 years ago, Homo erectus suddenly gave way to a new breed of humanity. It was the new and improved version, as if the species had been replaced totally. According to geneticist/anthropologist Becky Cann, “We don’t understand what happened with Homo erectus.” Initially, as early as 800,000 years ago, our walking tall boys had gone from Africa into Europe and Asia, leaving their mark on Java and Peking Man, and evolving eventually into archaic Homo sapiens. At the same time, we have another species, Homo Neanderthalensis. There was probably 1.3 million or so of Homo erectus on three continents, when 250,000 years ago, the appearence of a superior species began and erectus found itself being totally replaced. It is a curious fact that Asian Homo erectus apparently contributed little if anything to the gene pool of anatomically modern Homo sapiens.

In the wild, an extraordinarily small number of individuals within a species actually do the reproducing for the population. This turns out to be important for the evolvement of the human species as well, particularly when the suddenly appearing precursors of modern Homo sapiens sapiens began their invasion. For when some 250,000 years ago, the first modern Homo sapiens sapiens rose from a uniquely advanced band of archaic sapiens in Africa, they replaced the unevolved descendants of erectus without breeding with them. The takeover may have taken 3,000 generations to complete, but it was more like outliving than invading; the new guys on the block possessing some adaptive advantage to put them over the top. Human populations were constantly branching out (searching for greener pastures as it were), but most didn’t make it. According to Becky Cann: “It may have been just a random chance that this group from Africa did essentially make it and make it for a long period of time. It might have been a benign environment, it might have been superior cultural advantage, who knows? Something.”

According to Richard Leakey: “Certainly the archaeological evidence would suggest that there was a remarkable homogeneity of the known population, which was presumably late erectus / early sapiens across most of Africa, a good part of Europe, and a good part of Asia and the Far East until between 200,000 to 300,000 years ago, and thereafter you seem to get new technologies, new ways of doing things. It’s very difficult to interpret that, but it does suggest that something happened about then. Prior to firearms, humans didn’t have the capability of annihilating any species.” One might argue that the new technology was blade tools, but “nowhere was there evidence of warfare.” There was, in effect, little chance for Java Man to write the book, Bury My Heart at Wounded Zhoukoudian. Oh... Zhoukoudian is the site where Java Man’s final remains were found.

Homo sapiens neanderthaensis were also on the scene, and populating Europe, the Middle East, and Asia. It had previously been believed that Neanderthals first made their appearance around 125,000 years ago, but more recent discoveries have extended the date back considerably to around 400,000 years ago.

125,000 B.C. Neanderthals begin migrating northward out of Africa. Or at least this is the dating for the first evidence of such a migration. Unfortunately, there is no explanation as to why they began the migration, why they left Africa. All the anthropologists are willing to conclude is that the Neanderthals probably buried their dead in rituals, knew how to use herbs for healing as early as 60,000 years ago, and probably could speak, the latter which might have been useful for ritual burials.

92,000 B.C. Cro-Magnon Man, Homo sapiens sapiens, the first ancestor of man who might be able to ride a streetcar in downtown San Francisco without causing undue attention showed up in the Middle East. Cro-Magnon was once believed by anthropologists to have descended from Neanderthal Man, and furthermore, to have arrived on the scene much later, about 35,000 years ago. But recent discoveries in caves near Mount Carmel and another near Nazareth in Israel, date the oldest Cro-Magnon to some 92,000 years ago, and apparently not a neo-Neanderthal.

There’s just one problem. IT’S ALL HAPPENING TOO FAST!

Roughly 32 million years ago, a common ancestor of monkeys, apes, and Man appeared in Africa. Then about 16 million years later, Ramapithecus, a precursor of the Great Apes branched off the primate line, Proconsul. 11 million years later, about 5 million years ago, Australopithecus showed up with hominid aspects. Then around 4 million B.C.E., Homo erectus arrived to usher in the Old Stone Age. A gap appears from 1.5 million B.C.E. to 300,000 years ago, when there is little if any evidence of evolutionary-time-scale evolvement.

Then abruptly, circa 300,000 to 400,000 years ago, without any evidence of gradual change, Neanderthal arrives on the scene. A mere 100,000 years later, Cro-Magnon arrives, with this ultimate version of Homo sapiens sapiens probably having nothing to do with Neanderthals (in fact, the two lines of Homo sapiens probably lived side by side without interbreeding).

Anthropologists are absolutely amazed at the modern species’ accelerated rate of evolvement. Both Neanderthals and Cro-Magnon appear much too quickly on any kind of evolutionary time scale. With tens of millions of years leading up to Homo erectus, there is simply no explanation for the abrupt and sudden appearance of Cro-Magnon Man. It’s a puzzlement! The questions abound!

How in the world could the sudden appearence of a new species of man circa 250,000 B.C. 'outlive' the erectus they replaced? And as an offshoot of the same species, find a way to live much longer?

What 'new technologies, new ways of doing things' could have accounted for the invaders’ superiority. What does an advanced sapiens have over a good, old- fashioned erectus?

How does one account for Leakey’s suggestion that "something happened about then”? What did happen then? And why? In a nut shell, how does one account for the sudden appearance of Cro-Magnon Man?

Where in the world do you suppose they found the first fossils of Aegyptopithecus? Or Australopithecus?

I shall endeavor to answer some of these questions in the next section I call The Search for 'Eve'.



Cheers, Thorgrimm

 

[Ashmo]

Of course they are stupid. Nobody is claiming that scientists are infallible or that all scientists adhere to the scientific ideal. Bigotry and narcissism tends to get the best of them, as with any group of successful people (outsiders can be forgiven for being merely ignorant of the facts, though).

I am in no way trying to promote a view that the scientific body of established truth as it is now, or as it was, say, twenty years ago -- or only two -- is absolute. Science thrives on deprecation of old theories over new evidence and creation of new theories to fit new discoveries.

Scientific truth is only ever an approximation to absolute Truth -- but at least that's better than doing what religions do and pulling your facts out of your ass (or "visions" or subjective "insight" ignorant of real world facts).

Scientific truth may be, in part, at any given moment, "wrong" or "incomplete", but the scientific method is what DOES work. It works so astonishingly well that "Christian Scientists" have realised its potential harm for their dogma and repeatedly try to force it into obedience -- unsuccessfully, one might add.

As for the dazzling speed of evolutionary progress around the time of the development of Cro-Magnon man...

Firstly, evolution can still account for that. Some evolutions with seemingly overwhelming results are really much simpler than some changes on a much smaller scale. The original advent of Earthly life is most likely the most astonishing "mutation" there is. A rapid development further down the stream can usually still be split up into many many tiny consecutive mutations -- more of a question of quantity than quality.

We already know that selection pressure can have powerful impacts -- it's one of the core concepts of evolution. We are not superior to other animals in the absolute sense of the word.

Several proposed explanations for the drastic change from tree-dwelling monkeys to modern hunter-gatherers are based around the discovery of fire, the invention of man-made tools, the development of spoken language. All of them certain had some influence on the course of human evolution.

Most gaps in the fossil record don't mean a lack of transitional forms, they only mean a lack of transitional fossils.

Anyway. Go on, it's an interesting read already.

 

[xdarkyrex]

On the subject, this might be of interest for you guys to start following:

http://www.wired.com/science/discoveries/news/2007/12/dino_mummy
Rare Mummified Dinosaur Unearthed: Contains Skin, and Maybe Organs, Muscle

Scientists on Monday announced the discovery of what appears to be the world's most intact dinosaur mummy: a 67-million-year-old plant-eater that contains fossilized bones and skin tissue, and possibly muscle and organs.

Preserved by a natural fluke of time and chemistry, the four-ton mummified hadrosaur, a duck-billed herbivore common to North America, could reshape the understanding of dinosaurs and their habitat, its finders say.

"There is no doubt about it that this dinosaur is a very, very significant find," said Tyler Lyson, a graduate student in geology at Yale University who discovered the dinosaur in North Dakota.

"To say we are excited would be an understatement," said Phil Manning, a paleontologist at England's University of Manchester who is leading the examination. "When I first saw it in the field, (I thought) 'Shiiiit, that's a really well preserved dinosaur.' It has the potential to be a top-10 dinosaur, globally."

It's all over a bunch of news outlets right now, and a quick google search will get you some good details if you can sift through the bullshit.

 

[Mord_Sith]

Africa seems to be the hotbed for human evolution, including the Bering Strait transition for most native people of North America, however didn't the transition occur during the glacial periods of Erectus rather than the Sapien times, or am I mistaken in that thought process.

As for the expedited evolution of Sapien while Erectus is left in the dust, is it possible certain pairings between the Erectus could have produced the proper combination far before the standard evolutionary scale could have predicted.

Another thought, what if by chance a carrier virus modified their RNA/DNA pairings that caused the change to go into full kilt before it was expected to cope with the damages that the virus was incurring, also to double the effect, if the virus attacked the RNA/DNA but the Erectus could not evolve to face the virus head on could very easily have caused the loss of Erectus that much quicker.

There are already several attempts by human scientists now to modify viruses in order to become benign towards humans in a facility to cure things like cancer or other nasty things. To boot there's more benign bacteria in the human body than there are cells that make up the actual human being, it's very possible that our expedited evolution could be the result of the little beasties doing the work for us in our innards.

I have enjoyed the read quite thoroughly, although I dare not claim more than conjecture and guesswork at this point however, but at least I'm not screaming creationism.

 

[Thorgrimm]

Scientific truth is only ever an approximation to absolute Truth -- but at least that's better than doing what religions do and pulling your facts out of your ass (or "visions" or subjective "insight" ignorant of real world facts).

Scientific truth may be, in part, at any given moment, "wrong" or "incomplete", but the scientific method is what DOES work. It works so astonishingly well that "Christian Scientists" have realised its potential harm for their dogma and repeatedly try to force it into obedience -- unsuccessfully, one might add.

I agree wholeheartedly, thats why it is so frustrating that the 'scientist priest kings' are adopting dogmatic thinking over seeking the truth. Very frustrating. Bob Bakker is a classic example of what it takes to shake up that dogma.

As for the dazzling speed of evolutionary progress around the time of the development of Cro-Magnon man...

Firstly, evolution can still account for that. Some evolutions with seemingly overwhelming results are really much simpler than some changes on a much smaller scale. The original advent of Earthly life is most likely the most astonishing "mutation" there is. A rapid development further down the stream can usually still be split up into many many tiny consecutive mutations -- more of a question of quantity than quality.

We already know that selection pressure can have powerful impacts -- it's one of the core concepts of evolution. We are not superior to other animals in the absolute sense of the word.

All of that is a given, yet you have not offered any evidence as to how the sudden and rapid evolution, of not one but two species of humanity, occurred in a evolutionary blink of an eye. Even the paleoanthropologists do not know how it occurred. I am after facts, not 'dogmatic' repeating generalities.

Several proposed explanations for the drastic change from tree-dwelling monkeys to modern hunter-gatherers are based around the discovery of fire, the invention of man-made tools, the development of spoken language. All of them certain had some influence on the course of human evolution.

Every one of those items you mentioned made their appearance AFTER the appearence of Homo Sapiens Neanderthalis and Homo Sapiens Sapiens. So they had no affect on the cause of that sudden rise of two species of humanity.

Most gaps in the fossil record don't mean a lack of transitional forms, they only mean a lack of transitional fossils.

I certainly agree. Absence of evidence does not mean evidence of absence. But at the same time, if you are going to apply that to the scientific side, you must also apply that to the Judeo-Christian-Islamic point of view to.

@ xdarkyrex, Yeah I am following that development with great interest.

@Mord Sith, without any conclusive evidence anything is possible. All we know as of now is that for some unknown reason two species of humanity quite suddenly, in a blink of a geological eye, evolved from the base rootstock, Homo Erectus. As for myself, I have not ruled out anything. I need evidence to do that.

Ok kiddies, here is the last part of my lil' dissertation. I call this part the Search for 'Eve'.


For these purposes of our search for 'Eve' we are obliged to turn to such genetic anthropologists as Wes Brown, et al. In Wes' paper in the Journal of Molecular Evolution [June 1980] he suggested “the possibility that present-day humans evolved from a small mitochondrially monomorphic population that existed at that time.” The implication was that, based on mutation rates of mitochondrial DNA, there existed the possibility that 180,000 to 360,000 years ago, a solitary woman could have become the mitochondrial mother of every living being.

Importantly, Brown noted that while different mammals of the same species differed by 1.5% in their mtDNA, humans differed from one another by an “anomalously low” 0.18 to 0.4%, suggesting much less diversity and thus the possibility of a small founding group, even a single mutha. Furthermore, the smaller the founding group, the faster and more dramatic, perhaps, was the anatomical change.

Meanwhile, in order to do true justice to the search for Eve... and additionally, to buttress with current, relevant facts, our case for something funny going on in the evolvement of Neanderthal and Cro-Magnon Man... we must backtrack slightly in our dating of events. To wit...

200,000 B.C. Somewhen in the time frame of 140,000 to 290,000 years ago, a single, solitary woman living in sub-Saharan Africa became the world’s one common grandmother! In a revolutionary (and still highly controversial) article in Nature [January 1, 1987], Rebecca L. Cann, Mark Stoneking, and Allan C. Wilson asserted the following: “Mitochondrial DNA from 147 people, drawn from five geographic populations, have been analyzed by restriction mapping. All these mitochondrial DNAs stem from one woman who is postulated to have lived about 200,000 years ago.” This work effectively took the theoretical possibility of Wes Brown and put it to the acid test. The result was that, in all likelihood, there was an Eve. And probably dressed (or undressed) for the part.

Recall that mitochondrial DNA 'mtDNA' is the energy-eliciting compartments of the human cell, it is the task of these microscopic components to extract energy from food molecules floating in the sappy cytoplasm outside the nucleus of the cell. The energy of mitochondria is then synthesized as the universal energy currency, ATP. Without these organelles, our biological processes would shut down. These mtDNA lie outside the nuclear DNA, which is, in turn, responsible for the transmission of most physical characteristics. The DNA in a cell’s mitochondria contains 37 genes (as compared to perhaps 100,000 genes in the cell’s nuclear DNA).

The mtDNA is inherited only maternally, from the mother. It is thus passed intact from great-grandmother to grandmother to mother to daughter with virtually no input from males and thus no mixing, no blending of father’s and mother’s genes (mixing that could otherwise jumble, complicate, and thus obscure its history).

When the nuclear DNA in a male’s sperm unites with the DNA in the egg of a woman, there is a mixing together of genes like marbles in a tumbler. Characteristics from both parents are manifest in the baby, a unique human being with a mixture of the parent’s genes. But when sperm enters the ovum, only nuclear DNA is believed to enter the egg. So when a baby’s cells form and are duplicated, they contain nuclei possessing the genes of both the mother and father, but with the mitochondria containing the genes only of the female parent. It has been that way since the beginning of woman. And with no tumbling of the mitochondria marbles, mutation is basically the only kind of change that can occur in the mtDNA.

By considering the mutations in the genetic molecules (random, “neutral” ones which accumulate over time, with little or no effect on the functioning of our organisms), Becky, Mark and Allan reconstructed a branching diagram leading back to one mother by taking a count of the number of mutational differences among the twigs. Moreover, they were able to date backward (without studying paleontology, geology, or any other ology), for the mutational differences (or “divergences”) between people that occurred, which they calculated at a set rate of 2 to 4 percent every million years. The mutations, they claimed, accumulate at much the same rate in all organisms ranging from bacteria to plants to animals. The longer a population had been around, the more mutations. One could even identify Cleopatra’s mitochondrial genes in modern people and, at least theoretically, specify her entire mitochondrial genotype (assuming, of course, that she has an uninterrupted line of daughters since.)

Though mutations via mistakes or accidents in the DNA replicating itself may be a random mispairing of base-pairs during replication (i.e. a failure of DNA to exactly copy itself) they may also be the result of agents in the environment. Candidates for causing such alternations include naturally occurring radioactive compounds, environmental chemicals known as mutagens, ultraviolet radiation from a hot sun, highly penetrating and ubiquitous cosmic rays, or some other unknown agent. Others have gone so far as to speculate that agents in mud eaten by humans can alter DNA, and so can the chemical composition of burned meat.

At the time, the winter of our discontent, 198,005 B.C., there were glaciers slowly moving across parts of the globe, sheets of ice that grew like algae from the poles. But in Africa, according to Becky and the Boys, it was eminently hospitable, warm and lava-rich, a virtual vacation land festooned with garlands of flagrant (but sadly, not fragrant) flowers. (The authors, in describing the delights from Out of Africa, were apparently discounting the substantial possibility of being eaten by lions, trampled by elephants, gored by Rhinos, and dying of thirst, hunger, disease, and/or lack of multi-media intellectual stimulation.) Never-the-less, here, beginning several million years ago, the first two-legged hominids progressed into man-apes (and and presumably woman-apes), then into the ape-men known as Homo sapiens, and then to the first modern humans.

Though there were at least a million very primitive people living in the Old World, only from this small, isolated population in Africa, according to Becky, et al, did we all descend. These were the only Homo sapiens sapiens at the dawn of modern mankind, and when all their clans were counted, their number was less than 10,000. The rest of Africa and the world beyond was inhabited by far more archaic people who bore many resemblances to this new band in the sub-Sahara but who were still too much like the forerunning erectus... low-skulled and beetle-browed.

These archaics had spread throughout Africa and into Asia and Europe, many developing into what would be known as Neanderthals. But they were destined for extinction, and it was only the relatively small band of higher-skulled and gracile Africans, evolving much more swiftly out of the erectus stock, who would serve as our ancestors. They spread out of the sub-Saharan savannas and took control of the world, wrestling it from the archaics, some 30,000 years ago.

Thirty centuries after that, there would be 8 billion of us. The land of the ape-men had been overrun, conquered systematically (and perhaps brutally) by these fledgling humans from the sub-Sahara. For the conquerors had changed in a unique and fundamental sense. They were, according to the even more outlandish Wilson’s theories, now able to speak, make better weapons, and look the part; no longer ape-like or shambling or beetle-browed.

This African scenario, however, comes not from fossils (a fact which really riles the paleoanthropologists), but from DNA laboratories. Furthermore, 'Eve' was old, much older than many paleoanthropologists expected. Think of her as the 10,000th grandmother.

It must be admitted that this hypothetical woman was probably not the one and only mother of all subsequent humanity, as the biblical name of Eve implies, but simply one woman whose mitochondrial genes got passed along through an endless string of daughters. She was the only woman her age whose descendants included at least one female in every generation; our oldest known common ancestor. The mitochondrial 'Eve' was probably never the only woman on earth. There may have been thousands of others, but their mitochondrial lines have since gone extinct.

Anatomically, Eve may have been the very first modern female. But then again she may also have been part of a more archaic group of Homo sapiens. The population to which she belonged may have been very small, or put another way, a population that, at the point of Eve’s existence, had crashed to a very small number for some indefinable reason. She may have postdated the first modern Homo sapiens sapiens.

The reality is that Eve’s morphology can not be easily pinpointed. The population of which she was representative may have stayed in sub-Saharan Africa for some time, then gone up to some other area and then moved out. “In that movement, at some point, for some unknown reason, the actual transition from an archaic to an anatomically more modern woman took place. Many nuclear genes from earlier people will survive in modern humans, both male and female, and some of those could easily come from something that we wouldn’t recognize as Homo sapiens.” In other words, our genes didn’t come out of nowhere when Homo sapiens suddenly appeared.

The fossil record of Africa is such that it has led Mary Leakey to conclude that if nothing else, the basic premise of the Eve argument, a sub-Saharan origin 142,500 to 285,000 years ago remains, “as far as the evidence we have now, a reasonable assumption.” In fact, Mary and son Richard had both discovered fossils that lent great credence to the idea that a population of archaic Africans had evolved into the first anatomically modern humans before they had similarly evolved anywhere else.

“While the archaics in Europe had given way to Neanderthals, the similarly heavy- featured archaics in Africa such as Ndutu and Rhodesian Man had made way for a more gracile form of pre-modern man, who seemed more aligned to populations of today than virtually any fossils from Europe and Asia.” In one case the Leakeys found an archaic next to something that was just about modern (c. 130,000 to 100,000 B.C.). From the Leakeys’ viewpoint, there was a good chance that Eve was Tanzanian, South African, or Ethiopian. Meanwhile, Linda Vigilant (another geneticist, who used DNAs from Africans and not American blacks) calculated the common human ancestor as living 238,000 years ago, probably in Botswana, just north of South Africa.

180,000 to 90,000 B.C. Eve’s descendants were moving right along, growing increasingly savvy and increasingly migratory, sloughing off old erectus traits and spreading out of Africa to take over the world. “There was little evidence,” said the geneticists, “that this advanced African population interbred with existing and more primitive populations in Asia and Europe. Instead, they simply outbred and outlived them. They must have possessed some vast superiority.”

This view of no hanky-panky (or at least none manifesting in the mtDNA of any derived offspring) between the Eve tribe and the whole of Erectusland inhabitants, constitutes in the minds of most paleoanthropologists, a severe liability of the Eve Theory. Added to this was the fact that the geneticists had taken the extreme view that there was, perhaps, ZERO reproductive exchange between Eve’s descendants and the Asian/European populations the invaders replaced. “Populations in Asia and Europe were not only overwhelmed but contributed virtually no genes to modern humanity.” Erectus was still the original founder, but the African erectus, not Java or Peking Man, turned into a modern form before the Asian erectus could do the same, and then overtook all the Java and Peking descendants, who left not a trace. More importantly,” it is alleged, “Java Man, Peking Man and all the Neanderthals made NO genetic contribution to modern man!"

When this particular debate in the scientific community had really heated up, Wilson then took another giant, extreme step for Eve’s mankind. He suggested that the “vast superiority” of Eve’s band derived from their ability to speak! (And supposedly, how to sing and dance and play the guitar.) This last assertion (by Wilson), which few if any believe, is that the ability to speak may have come from a mitochondrial (instead of an infinitely more likely nuclear) DNA mutation. According to Wilson, a mitochondrial mutation may have caused more oxygen to go into the Africans’ brains. That was, after all, what the mitochondrion was all about: oxygen and energy production.

The motivation for this radical concept by Wilson was to show “how a maternally inherited ability to use language or perform some other vital skill could have allowed modern humans to replace more ‘archaic’ species about 100,000 years ago with no intermixing.” In effect, it was a woman who managed to get in the first word!

In essence, Wilson believed that they had “found a mother who lived roughly 200,000 years ago and that she was one among many mothers living at that time, many thousands at least, and that she had two daughters, at least, one giving rise to Lineage I, which largely stayed in Africa, and the other Lineage II, which includes many Africans and all the non-Africans. And in one of those two lineages: the first to really speak.” It should be noted that this hypothesis was “data-free”. “Others dismissed it, no pun intended, as not worth talking about.” In academic circles Wilson was doing a “tap dance on the limb of a tree that other scientists, both geneticists and anthropologists, were sawing at the trunk.” But then, a Neanderthal in Israel was found with a bone structure near the larynx that is crucial to language and was identical to that of modern humans! Oops.

Never-the-less, the superiority that enabled Eve’s band of evolved erectus to replace all the other erectus without so much as a single paternity suit is still not clear to the vast majority of scientists in the field. Most of the paleoanthropologists even found it difficult to accept the one Eve idea. But a willingness to open one’s mind has never been a prerequisite for becoming prominent in the field of science. For the genetic mtDNA evidence is more than a little convincing.

For example, the Africans displayed the most diverse DNA types. The longer a lineage is around, the more mutations it collects, and thus the more diversity within such a population. The divergence of Africans was 0.47%, Asians 0.35%, Australian Aborigines, New Guineans, and finally Caucasians were 0.23%. The Aborigines of Australia actually appeared genetically closer to Europeans than they did to Africans. In fact, the Aborigines’ diversity suggested that fifteen lineages had found a way to cross from Asia to Australia. According to Becky, et al, the founding of Australia may have been made by a people “who knew exactly where they were going and had gone there time and time again.” In other words, it wasn’t just some clown in a big canoe, island-hopping. The primordial Aussies had thus come originally not from Asia, their next door neighbor, but from Africa?

The geneticists were also saying that there had been no distinct races until after much of the world was settled! Rather, the picture was a single population that had spread around the Old World before any permanently distinct racial or ethnic groups had been formed. The process of the formation of human races is one that happened after the founding of the population by multiple mothers.

Critical to Berkeley’s claim of Eve living circa 200,000 (or within the range from 142,500 to 290,000) years ago is the RATE of the molecular clock. Berkeley (Becky, et al) assumed a constant 2 to 4 percent rate of mutation. Brown had, on the other hand, assumed 1 to 2 percent per million years (implying a set of revised dates of 285,000 to 570,000). The key is that the slower the rate, the further back in time was any 'Eve'. Masatoshi Nei came up with 1.4%, i.e. 400,000 years ago. Two others at the University of Texas claimed that “The molecular clock runs more slowly in man than in apes and monkeys. There is no case in which the human lineage has evolved faster. This is true for both nuclear and mitochondrial sequences. When all the nuclear sequences are considered together, the rates in the orangutan, gorilla and chimpanzee lineages are, respectively, 1.3, 1.9 and 1.6 times faster than the rate of human lineage.” This comparison may be very important.

African apes and humans, for example, are genetically closer to one another than to other primates. We can think of primate evolution beginning with ratlike, insect-eating little mammals that had begun clinging to trees (picture the tree shrew); then transforming into something like a bushbaby or lemur, with eyes moving to the front of the head, a pre-monkey or “protosimian”; then, from the rootstock, a whole cacophony of monkeys in South America, along with Europe, Asia, and Africa once the continents floated apart. As evolution proceeded, there had been another major split, this time between monkeys and creatures developing into the large, tail-less, semi-erect apes. After millions more years there was yet another branching off that went in three directions: one toward the chimpanzee, one toward the chest-thumping gorilla, and another toward hominid man-apes and finally the furless erectus and Homo sapiens sapiens, who were all but nude.

With this in mind, we then can denote the genetic similarity of humans and other species. If a human is 100% human, for example, the chimp is 96-99%, Old World monkey (baboon) 70-75%, a New World monkey (spider monkey) 60%, a lemur 35-40%, a dog 25%, and a kangaroo 10%. Man, chimp and gorilla are as close to each other as zebra and horse! A pig is closer to a whale than a horse, a pigeon or penguin is closer to a turtle than a turtle to a snake, man is closer to mice than rabbits, and while the giant panda was a bear, the lesser panda was more of a raccoon.

There was also the question of the regular beat of the mitochondrial clock. Most scientists thought it was pretty regular, but there was no guarantee of that, especially over the millennia. One detractor of the Berkeley group, a professor Wolpoff, for example, figured that any mutation in mtDNA that had an evolutionary impact would provoke the forces of natural selection to act upon that molecule in such a way as to muck up its use as a clock. Alternatively, perhaps some force of natural selection reset the clock, then allowed it to operate in a regular, consistent manner.

It’s important to note that because we have Eve’s mitochondrial genes doesn’t mean we have more than an exquisitely small fraction of her nuclear genes. That is why she has been referred to, time and again as a 'mitochondrial Eve' and not a real one. The mtDNA that survived down the centuries represented more a 'Lucky Mom', if only one mom it was, than Adam’s fairest. While it was suggested that a group of women with identical mitochondrial DNA types, and not a single ancestor, may be the source of genetic diversity in modern humans, Stoneking and Cann argued back in their Cambridge paper that “this hypothetical group of women must be descended from a single common ancestor in a preceding generation. It is not biologically feasible to have multiple lines of descent without a common ancestor.”

140,000 B.C. Eve’s offspring begin arriving in the Middle East and Asia, as evidenced by the divergences in mtDNA which indicate a partitioning of lineages.

125,000 B.C. Eve’s offspring’s distant cousins, the Neanderthals, begin appearing on the European scene. (Call this period the Eurocene.) The Neanderthals had developed over the course of some fifty millennia, and then had kept essentially the same form for the next 35,000 years. Then overnight, geologically speaking, something drastic happened. The traditional view is that roughly 40,000 years ago, they evolved into a new subspecies, Cro-Magnon Man.

It is now believed that the Neanderthals, quite suddenly and mysteriously, disappeared (leaving only pockets that survived for a few thousand additional years). The Neanderthals had managed to survive in Europe and the Middle East for about 2,850 generations, making it through glacial weather, fending off woolly mammoths, life insurance salesmen, and other deadly creatures. And then all of sudden: curtains. Suddenly, the air was filled with the sound of music, i.e., “The Party’s Over.” In their place were the Cro-Magnon men decorating caves in the south of France, and who, unlike the Neanderthals, were anatomically modern.

Again, there were no signs of violence, no wars between Homo sapiens sapiens and Homo sapiens neanderthalensis, no Super Bowl between the Sapiens Sapsuckers and the Neanderthal Neanderthals. Instead, it was a matter of outcompetition taking a mere 5,000 years to accomplish. The Neanderthals left no genetic input, even though it is clear that they and modern man both descended from erectus-like archaics. (Actually, there is some evidence of Neanderthal traits existing in modern man, particularly in the thinking of many Republicans).

Neanderthals disappeared during the last period of Ice Age coldness. Most of these late Neanderthals were associated with the Mousterian culture of the Middle Paleolithic (which was still part of the Old Stone Age, where technology was measured on the basis of stone flakes and the crudest of tools). But some may have slipped into the Upper Paleolithic (perhaps from watching Cro-Magnons wield their blade tools). Some may even have developed rituals and a spiritual awareness far more definite than the dubious hints of ocher decoration in the archaics who had come before.

Then between 35,000 and 40,000 years ago, there was a marked increase in the complexity of sociocultural systems. There was, admittedly, the possibility of hybridization between Neanderthals and Moderns on the order of 35,700 to 36,900 years ago, but it’s only a possibility; while in Crete, there are archaic traits dated to more than 50,000 years ago.

The Cro-Magnon apparently had all the cards when it came to outcompeting the Neanderthals. For one, they had technology, which meant for the most part, better ways of cutting up meat and game (the latest stage of this evolutionary trait is the Cuisinart). The initial technology was found in South Africa, dating to 75,000 years ago. The Neanderthals were living in the Middle Paleolithic, using flakes and certain types of prepared cores, while the Cro-Magnons living in the Upper Paleolithic were basing their hopes on a blade technology and a whole range of blade tools, as well as bone/antler tools, even ivory. They may even have been carving turkeys on Thanksgiving Day, and finding ways to prepare and eat cranberries.

One scientist, Desmond Clark, has noted that: “A whole new technology arises between 40,000 and 30,000 years ago.” (Verrrry interesting.) In the Negev (southern Israel) you have true Upper Paleolithic technology, you can see it emerging out of the Middle Paleolithic technology around about 45,000 or more years ago, just before Europe.” Other precursors which suddenly appeared in Europe around the time of the Neanderthal disappearance were found in Sri Lanka and then to Israel, dated to about 40,000 years ago.

A second advantage of Cro-Magnon Man over the Neanderthal was that the Cro-Magnons had longer arms than Neanderthals. (This may also mean they came from a warmer climate, i.e., in cold climates short arms conserve heat). At the same time Cro-Magnon Man made warmer clothes, built better hearths, and had better locomotor efficiency. What this all amounts to is that the moderns had style. Style and grace.

They were also pregnant for a shorter period (not the 11 or 12 months for Neanderthals), and thus the more modern women were not as thoroughly fed up with being pregnant in those extra months! This latter fact is probably the single greatest advantage of the moderns over the Neanderthals. Small wonder that the Neanderthals faded from the scene. 12 month pregnancies!!!!? Dammnn!

115,000 B.C. The last resting place, in a place called la grotte de Qafzeh (kaf-sa) (mountain of the jump) in Israel, of the oldest anatomically modern population known to the world.

110,000 B.C. First indication that the Caucasian/Mongoloid races had split from the Negroid race. This suggests not only a prior movement out of Africa, but some sort of fundamental difference in the respective environments of what now constituted two branches of Homo sapiens sapiens.

95,000 to 60,000 B.C. The Wurm glaciation.

40,000 B.C. Official unveiling of the Cro-Magnon gene pool. The new model comes with genetic advantages that allows one to wear improved upholstery, pass every other evolving species on the evolutionary road without even having to shift into passing gear, and curse out every driver that gets in your way. So good were these genes that modern man was being allowed to expand at a previously unseen rate, migrating on a grand scale, or simply settling down to create nations and races (and thus dramatic conflict between the nations and races).

It was a time for Caucasians and Mongoloids to go their separate ways. Man was now being allowed to differentiate (find differences between him and others of the same, fairly uniform species), and begin calling himself by reference to his locale, as if where you’re from makes a great deal of difference. Obviously, it doesn’t (unless you’re from Iowa, an indication of automatic superiority). At the same time, Indians from North, Central and South America carried with them a number of rare Asian DNA types, but also had some unique polymorphisms found only in Amer-indians.

30,000 B.C. As Indians were settling the Americas, iron pyrite was showing up in Belgium, clay pots in China, Stone Age humans developing permanent communities even before the advent of agriculture, and Cro-Magnons adding last flourishes to the cave art in Europe. Even art! Home sapiens sapiens artis!

29,999 B.C. First evidence of the appearance of the deadly and degenerative species known as Homo neanderthalensis artis crticalis. DNA from this sub-sub-sub-species still crops up in the most modern of humans even today.

We’ve now arrived to within striking distance of history. Man and woman, Homo sapiens sapiens, and Eve’s offspring are now ready to start making waves (for better or worse). There are a few questions that need to be answered by science (and the reason I feel it needs an update). These questions are puzzlements that bedevil the state of the art theories that are relevant to the earliest times of the Earth and the life forms it has fostered (particularly in the form of human beings).

1. What caused the first life to spring from lifelessness?

2. The mtDNA’s ability to convert and utilize energy within the cell is incredibly important to life as we know it. But why is the mutation rate for humans so low, as compared to other species?

3. Why would Eve’s offspring be able, as so many paleoanthropologists / geneticists have phrased it, to 'outlive' Homo erectus? How does the first of the Homo sapiens sapiens line suddenly develop longevity (and apparently, seniority and tenure)? Just what happened 250,000 years ago that jump-started the Homo species?

4. Why did the Neanderthals and Cro-Magnon Man evolve so quickly?

5. Why was there no intermixing of Cro-Magnons and Neanderthals; no half breeds or Croanderthals? And why did the Cro-Magnon and Neanderthal shun their immediate predecessor, Homo erectus, from whom they allegedly inherited the family farm and all of their genes (mitochondrial as well as nucleic)? This zero intermixing is amazing! No hanky-panky, no slumming, no simple sexual curiosity, nothing!?

6. Developing an ability to speak is a profound evolutionary event. What happened some 200,000 years ago to Homo erectus to cause speech? Was it a necessary in order to evolve the earliest form of bridge clubs?

7. Why would Eve’s offspring have initially stayed in Africa, and then made the trek to the Middle East, and thereafter to the rest of the world? Did it take a few hundred generations for them to hone their conquering skills?

8. Becky Cann said that the founding of Australia was done by Eve’s offspring, people who knew “exactly where they were going and had gone there time and time again.” (see above) How could the archaic Homo sapiens sapiens, even with radically evolved tools, an ability to speak, and the other superiorities... know about Australia and “exactly where they were going”? Did they have maps? Does Rand-McNally go back that far? Was one of Eve’s brood a travel agent?

9. Why did the Neanderthals fall by the wayside with so little fanfare around 40,000 B.C., and so quickly, taking only 5,000 years to vanish from the scene? After such an auspicious beginning as a radically advanced species from Homo erectus, what did they find lacking? What distinguished them to the point that they and Cro-Magnon Man (who lived virtually side-by-side) never mixed? There were no wars, no Super Bowls between them. So why such a division? Was this the first and most extreme example of Sibling Rivalry? Exactly what happened 35,000 to 40,000 years ago?

Maybe one day we will have the answers to all these questions, then again, maybe not.

Thus endeth my lil' dissertation on Evolution of life on Planet Earth. I am still very interested in what folks know about the subject.




Cheers, Thorgrimm

 

[Wooz]

That's all nice and dandy, but I've still haven't quite grasped your idea of a "third way" besides 'blind evolutionism' and ' bible thumping creationism'.

That's one thing. The giant leaps in conclusions, and declarative matter-of-fact descriptions that scatter your otherwise interesting read are a nuisance.

 

[Mord_Sith]

What if the 'Eve' genes were dominant over the other Erectus Mitochondrial genes, causing the male genes in the Erectus force their own pattern over the weaker Erectus Female Mitochondrial genes?

Even if they interbred for any means of time if the genes were dominating the female genes of Erectus it would be not a conquering of battle, but a conquering of genetics in that case, the males of Eve's legacy would force it upon the unwitting Erectus Females not already graced with such a legacy causing the child to be more Eve-like than the mother herself.

Considering that the Male Mitochondrial genes are not as strong as the female genes, that would also account for the male not getting a say on the Mitochondria during conception, however if the genes are still stronger in the male Eve strain than in the Female of other Erectus, it could very well replace what natural selection would deem 'the weakest link'.

A pity the kid's not gonna have it's mother's eyes...

 

[Thorgrimm]

That's all nice and dandy, but I've still haven't quite grasped your idea of a "third way" besides 'blind evolutionism' and ' bible thumping creationism'.

That's one thing. The giant leaps in conclusions, and declarative matter-of-fact descriptions that scatter your otherwise interesting read are a nuisance.

Then my friend, you need to read the thread just a bit better because I plainly spelled it out once.

@ Wooz, if you have something intelligent to add, then by all means do so. If you think my highlighting of certain ucomfortable fact as a nuisance and if you think that I am jumping the gun then by all means present your counter evidence. That is what this thread is about. Otherwise, all you are doing is trolling this thread. Or as my daddy used to say, put up or shut up. I would love to see your take on the subject.

What if the 'Eve' genes were dominant over the other Erectus Mitochondrial genes, causing the male genes in the Erectus force their own pattern over the weaker Erectus Female Mitochondrial genes?

Thats just it, there is no such thing as male mitochondria DNA. Everything is passed from good ole mom. The only DNA passed on from the male is the Nuclear DNA. So there cannot be any mixing of the mtDNA.




Cheers, Thorgrimm