|Feature Article - November 2009|
|by Do-While Jones|
Evolutionists scramble to fit Ardi into their evolutionary model.
Last month, the mainstream news media was filled with exciting announcements of the discovery of a new “human ancestor.” Since you probably saw them, we won’t quote some of them. 1 2 3 But, in case you missed them all, the Associated Press report was typical. It’s subtitle was,
‘Ardi’ predates Lucy by a million years, changes scientific view of origins 4
The article said,
This older skeleton reverses the common wisdom of human evolution, said anthropologist C. Owen Lovejoy of Kent State University. Rather than humans evolving from an ancient chimplike creature, the new find provides evidence that chimps and humans evolved from some long-ago common ancestor — but each evolved and changed separately along the way.
“This is not that common ancestor, but it’s the closest we have ever been able to come,” said Tim White, director of the Human Evolution Research Center at the University of California, Berkeley. 5
This is remarkable! Just one discovery “changes [the] scientific view of origins” and “reverses the common wisdom of human evolution!” Humans didn’t evolve from a chimp-like creature! Scientists have been wrong all along!
Let’s be clear. Evolutionists still believe that humans and modern apes share a common ancestor. They just don’t believe that the common ancestor was as chimp-like as previously believed, and the split between humans and modern apes happened at least a million years earlier than previously believed. So, what’s the big deal? The big deal is that there are genetic implications which are likely to cause more arguments between DNA researchers and paleontologists.
Up until now, evolutionists have claimed that chimps are (figuratively speaking) our cousins. It was as if we and chimps shared a common grandfather. But now they claim we share a common great-great-great-great-…-great-great grandfather. If a generation is 20 years (or less), then moving back the common ancestor 1 million years adds another 50,000 (or more) generations between us and chimpanzees. The number of generations is important because it has previously been used to calibrate the molecular clock.
This change in timing has serious ramifications for the already troublesome (to evolutionists) analysis of the differences between human DNA and chimp DNA. Evolutionists are conflicted about just how similar human and chimp DNA is. 6 On the one hand, they need to prove that our DNA is almost exactly the same because we haven’t evolved very much from a common ancestor. On the other hand, they have to prove that our DNA is significantly different because we evolved significantly from a common ancestor. In their minds, similarity is proof of evolution, and difference also is proof of evolution. So, to the casual observer it would seem that no matter how you slice it, there is proof of evolution. But when you start thinking about it closely, it really does matter how you slice it. There has to be just enough similarity, and just enough difference, for the argument to be valid. For a while, 98% seemed like the magic number. More recently, some evolutionists have thought that number is too high. If humans and chimps aren’t as closely related as previously thought, then the 98% figure is certainly too high, and must be revised lower. This means the DNA analysis has to be “corrected” somehow.
Changing the time when humans split with apes will necessarily affect the calibration of the so-called “molecular clock.” Evolutionists believe that differences in so-called “junk DNA” are the result of irrelevant mutations which happen at a fixed rate. How do they know this fixed rate? Well, they have compared chimp DNA to human DNA and determined the average number of differences in particular stretches of junk DNA. “Knowing” the number of generations since the presumed split between apes and humans, they have calculated the mutation rate. Using that mutation rate, they “confirm” the date of the split. (The confirmation is bogus, of course, because they have simply used invalid circular logic.)
If they don’t change the presumed mutation rate, then the DNA analysis of when apes and humans split will not match the new time suggested by the discovery of Ardi. So, they will use circular logic to realize that the mutation rate is actually slower than previously thought, and using the new clock rate, the DNA analysis will again match the paleontologists’ analysis.
The popular press tells us this interesting fact:
The fossil puts to rest the notion, popular since Darwin's time, that a chimpanzee-like missing link—resembling something between humans and today's apes—would eventually be found at the root of the human family tree. Indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior—long used to infer the nature of the earliest human ancestors—is largely irrelevant to understanding our beginnings. 7
That’s right! Evolutionists are now telling us that studies of chimpanzee anatomy and behavior are irrelevant to understanding the origin of human beings. We suspect that won’t go over well with some anthropologists!
Before we talk about what bones were actually found, let’s do some thought experiments to appreciate what was actually found.
Suppose you buy a 1000-piece jigsaw puzzle. You take seven pieces from that puzzle and give them to a friend who has not seen the picture on the box. How much could that friend tell you about the puzzle? Probably not much—especially if the pieces all happened to be pieces of sky.
We mention this because the “type fossil” for Ardipithecus ramidus is ARA-VP-6/1. By definition, a type fossil is the fossil to which all other fossils are compared to see if they came from the same species. ARA-VP-6/1 is just a few teeth. Donald Johanson’s excellent book, From Lucy to Language, shows pictures of many of the hominid fossils. For Ardipithecus ramidus, he chose a picture of ARA-VP1/129, which is a single tooth, because “this right mandible fragment proved to be a critical feature in distinguishing this new species.” 8 Figuratively speaking, Ardipithecus ramidus had previously been known from just a few pieces of sky.
Let’s continue the analogy. Suppose your teenage daughter, without your knowledge, buys a 1000-piece jigsaw puzzle and assembles it on the floor of her bedroom. After finishing the puzzle, she does not put it away, but just leaves it there on the floor. (We know this is unrealistic. Your teenage daughter always cleans up her room immediately. But work with us here—we are trying to make a point. ) Several weeks later, you pick up a pile of clothes lying in a heap in your daughter’s bedroom, and find the puzzle underneath them. The puzzle has broken into five big sections, and a few pieces are missing. (You will find them in the dryer after you have washed her clothes.) Despite the fact that the puzzle is broken, and a few pieces are missing, you can easily tell what the picture is.
Several Neanderthal skeletons were discovered mostly complete and generally intact. It is as easy to see what these mostly complete, generally complete puzzles looked like.
Now let’s try one more experiment. You buy five 1000-piece puzzles. From the first puzzle you take 400 pieces and put them in a plastic bag. You take 25 pieces from the second puzzle, five pieces from the third puzzle, 80 pieces from the fourth puzzle, and one piece from the fifth puzzle, and put them in the same bag, too. You shake the bag up, and give it to a group of friends who have never seen the pictures on the puzzle boxes. You tell them there are pieces from several puzzles in the bag, and you want them to assemble the pieces as best they can. Then they have to tell you (1) how many different puzzles are represented, and (2) everything they can about the pictures on those puzzles.
We leave it to your imagination to decide how many different puzzles they would think there are, and how much your friends would argue about how they go together.
This experiment represents the situation of most fossil finds in general, and the Ardipithecus discovery in particular. Ardi’s skeleton was largely complete, but it was not intact. That is, the bones were confined to a reasonable area, but were all jumbled up with bones of other critters as well. That made reconstruction hard. According to the popular press,
The first, fragmentary specimens of Ardipithecus were found at Aramis in 1992 and published in 1994. The skeleton announced today was discovered that same year and excavated with the bones of the other individuals over the next three field seasons. But it took 15 years before the research team could fully analyze and publish the skeleton, because the fossils were in such bad shape.
After Ardi died, her remains apparently were trampled down into mud by hippos and other passing herbivores. Millions of years later, erosion brought the badly crushed and distorted bones back to the surface.
They were so fragile they would turn to dust at a touch. 9
I can understand why it took 15 years. The Biblical Archeology and Anthropology Museum here in Ridgecrest has a museum-quality replica of the famous Lucy skeleton just like the ones you find in some of the bigger museums. 10 The curator is a friend of mine, and he asked me to help him move the skeleton for a temporary show at a public event. In the process of moving her (in her glass coffin), her bones all rolled to one end. When we set up the glass coffin at the event, I was given the task of putting her bones back in the proper place. Even with Johanson’s famous picture of how Lucy was supposed to look, I’m not sure I did it correctly. I’m not sure Johanson did it correctly, either. One small piece of a rib tends to look like any other small piece of a rib.
I have no doubt that a skilled anatomist can correctly identify and place bone fragments of modern humans and modern apes because we have many complete, intact skeletons of modern humans and modern apes to use as a guide. But how does one put together bones of a creature that one has never seen before?
The answer is that one uses knowledge from modern animals. Knowing how modern human bones (and modern ape bones) fit together, one can guess how Ardi’s bones went together. This introduces a subtle bias. If one uses the human model to assemble the bones, the final reproduction will naturally look human. If one uses the ape model to assemble the bones, the final reproduction will naturally look apelike.
Adrienne Mayor provides us an excellent example of this. She contends that legends of giants were based on mammoth bones which were mistaken for human bones. Her book includes a pair of pictures showing how mammoth bones can be assembled into a convincing giant human skeleton. 11 There is also a book telling how to build a miniature dinosaur out of chicken bones. 12
The same thing is true of the reconstruction of Ardi. They carefully measured Ardi’s bones, and realized that if Ardi were human, each bone would go in a certain place. That’s where they put the bones, and (no surprise) the reconstruction looks very human.
Here’s why we brought up the multiple puzzle analogy: They found lots of bones from lots of different individuals (including some monkeys) and tried to reconstruct a representative skeleton of a creature that has never been observed. When we say, “lots of bones,” we really mean lots of bones.
Instead, the skeleton and pieces of at least 35 additional individuals of Ar. ramidus reveal a new type of early hominin that was neither chimpanzee nor human. 13
At last count, the team had cataloged more than 110 specimens of Ar. ramidus, not to mention 150,000 specimens of fossil plants and animals. 14
Suwa spent 9 years mastering the technology to reassemble the fragments of the cranium into a virtual skull. "I used 65 pieces of the cranium," says Suwa, who estimates he spent 1000 hours on the task. "You go piece by piece." 15
Two initial seasons of stratigraphic and geochronological studies yielded 649 cataloged vertebrates, including a minimum number of 17 hominid individuals represented mostly by teeth. 16
What makes the problem worse is that there aren’t just bones from lots of different hominid individuals, there were monkey bones, too.
A diverse assemblage of large mammals is spatially and stratigraphically associated with Ardipithecus ramidus at Aramis. The most common species are tragelaphine antelope and colobine monkeys. 17
The fundamental problem evolutionists have is that new fossils don’t match the old evolutionary fable. For years, evolutionists have said that chimps and humans are so similar because they both evolved from a recent ancestor. Now they have fossils which indicate (to them) that the ancestor wasn’t so recent. Therefore, they need an explanation for how distantly related creatures (humans and chimps) could be so similar. They have faced this problem multiple times before, and so they trot out the same old explanation: convergent (a.k.a. parallel) evolution.
An additional implication of Ar. ramidus stems from its demonstration that remarkable functional and structural similarities in the postcrania of Pongo and the African apes have evolved in parallel, as have those of Pan and Gorilla. Until now, a myriad of characters shared among the extant African apes were presumed to have been present also in ancestral hominids (because they were presumed to have been the ancestral state). However, it now appears that many of these putative shared primitive characteristics have evolved independently. This highlights the alacrity with which similar anatomical structures can emerge, most likely by analogous selection operating on homologous genomes. The same genetic pathways can be repeatedly and independently coopted, resulting in convergent adaptations. Recent work on gene expression demonstrates that there are also multiple pathways that can produce similar but independently derived anatomical structures.
Work on deep homology shows that parallel evolution "must be considered a fact of life in the phylogenetic history of animals". 18
In other words, evolutionary history can’t be inferred from similarity because so many different evolutionary paths wind up close to the same place. This is the argument the geneticists use against paleontologists to explain why the DNA-based tree of life is right and the fossil-based tree of life is wrong.
So, what do we know for sure? We know that they found lots of bones, which probably belong to a previously unknown primate. Not all of the bones were recovered. Some of the bones were crushed and distorted. Some of the bones might actually belong to another individual of the same species, or perhaps even a different (but similar) species. These bones were carefully assembled into a nearly complete skeleton the way experts think they should look. Consequently, the skeleton does look like those experts think it should look.
They probably did a pretty good (but not perfect) job of recreating Ardi’s appearance. Some extinct creature that looked a lot like the recreation certainly existed at some time in the past.
Those are the facts. But what do the facts mean? Unfortunately, we have run out of space to tell you. So, you will just have to wait until next month’s newsletter for our analysis.
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Alleyne, Telegraph.co.uk, 01 Oct 2009, http://www.telegraph.co.uk/science/6251024/New-fossil-moves-story-of-mankind-back-one-million-years.html
2 Lemonick and Dorfman, Time, October 1, 2009, “Ardi Is a New Piece for the Evolution Puzzle”, http://www.time.com/time/health/article/0,8599,1927200,00.html?xid=newsletter-weekly
4 Schmid, AP, Oct. 1, 2009, “World’s oldest human-linked skeleton found”, http://www.msnbc.msn.com/id/33110809/ns/technology_and_science-science/ and also at http://news.yahoo.com/s/ap/20091001/ap_on_sc/us_sci_before_lucy_7
6 Disclosure, August 2007, “Forget Everything!”, http://www.scienceagainstevolution.org/v11i11f.htm#similar
7 Shreeve, National Geographic magazine, October 1, 2009, “Oldest Skeleton of Human Ancestor Found”, http://news.nationalgeographic.com/news/2009/10/091001-oldest-human-skeleton-ardi-missing-link-chimps-ardipithecus-ramidus.html
8 Johanson and Edgar, From Lucy to Language, 1996, page 116
9 Shreeve, National Geographic magazine, October 1, 2009, “Oldest Skeleton of Human Ancestor Found”, http://news.nationalgeographic.com/news/2009/10/091001-oldest-human-skeleton-ardi-missing-link-chimps-ardipithecus-ramidus.html
11 Mayor, The First Fossil Hunters, 2000, pages 122-123
12 McGowan, Make Your Own Dinosaur Out of Chicken Bones, 1997
13 Gibbons , Science, 2 October 2009, “A New Kind of Ancestor: Ardipithecus Unveiled”, page 37
14 Gibbons , Science, 2 October 2009, “A New Kind of Ancestor: Ardipithecus Unveiled”, page 38
16 White, et al., Science, 2 October 2009, “Ardipithecus ramidus and the Paleobiology of Early Hominids”, page 76
17 White, et al., Science, 2 October 2009, “Macrovertebrate Paleontology and the Pliocene Habitat of Ardipithecus ramidus”, page 87
18 White, et al., Science, 2 October 2009, “Ardipithecus ramidus and the Paleobiology of Early Hominids”, page 76 quoting N. Shubin, C. Tabin, S. Carroll, Nature 457, 818 (2009).