Orrorin itself could be discussed amicably (the formal description is due out in late February 2001). Instead, the personal chemistry among the current bunch of paleoanthropologists has set off an undignified, unethical fight. Paleoanthropologists are the worst-behaved of paleontologists, in any case, and they have been for so many decades that it is deeply embedded in their culture; and Richard Leakey seems to be a world-class example. I've been on the receiving end of his tongue myself, and I'm not even in the field! (I think he insulted me just to keep in practice!) "A gentleman never offends unintentionally" (Oscar Wilde).
Ardipithecus, Australopithecus anamensis.
A new, complete(?), australopithecine skeleton from Sterkfontein, discovered by Ronald Clarke, shows every sign of being very old and very important, when it is finally excavated and cleaned and described and interpreted. Here are some sites to gather what information is available now:
Here are some images of robust australopithecines:
A news update: A new skull of A. boisei may show that it is not a separate species. If it is not, it should be called A. robustus.
Claim that Australopithecus robustus used tools. In January 2001, a report suggested that A. robustus used specially selected bone tools to dig into termite mounds. (Termites are very nutritious, it is said: twice the calories of steak!). Here are Web-available reports:
However, if you read the actual research paper (Blackwell and d'Errico 2001, see new references for Chapter 22, you will find two separate lines of thought.
Tools of Homo erectus
In 1999 the Discovery Channel aired a series on research at a site in Eritrea, northeast Africa, about 1 million years old, which has yielded an enormous collection of tools probably made by Homo erectus. I did not watch the series. Here are Web pages for the first three episodes:
Homo erectus and wood-working
Discovery that stone tools associated with Homo erectus were being used to chop wood. Archaeology OnLine, January 2001.
Homo erectus and fire:
Asian Homo erectus.
Here are some images:
Evidence from Germany around 400,000 BP suggests that H. heidelbergensis must have been formidable people. Beautifully crafted hunting spears were made by H. heidelbergensis in Germany around 400,000 BP. They are throwing spears, up to 3.2 m long (10 feet), carved to angle through the air like modern javelins, and they are associated with butchered horses and other bones from elephant, rhino, deer and bear. Here are two news articles on the spears:
Many anthropologists have cited "art" as a modern human characteristic. Obviously, these new discoveries show that that idea is just plain wrong. Either the older story of human evolution is right, and "archaic" Homo sapiens was evolving this early, or we have to recognize that Homo heidelbergensis (call it what you like) was capable of art and sculpture well as the design and manufacture of exquisite spears in Germany. This is more evidence, in my opinion, that something is radically wrong with the current emphasis on recent origin or radical innovation, or both, for Homo sapiens.
Around 200,000 BP, it is suggested, a population of H. heidelbergensis in Africa evolved into what we would now recognize as Homo sapiens. Meanwhile, Homo heidelbergensis in Europe and the Middle East were evolving into Neanderthals.
Here is a vivid article by Jerold Lowenstein on the Klasies River people of South Africa, clearly modern humans, and perhaps the earliest non-controversial modern humans.
While we're worrying about what really happened, and trying to decide who is descended from whom, it's just as well to keep in mind that we should not let emotion, especially political correctness, hide that fact that we are trying to do science. See the essay "The Third Man", by Matt Cartmill, from Discover.
See this site for detailed information on localities, ages, and for images of many important specimens. Updated to 2001.
However, there is a new claim that the hands of Neanderthals and modern humans were different enough to make a big difference.
Maybe the hands are different. Does that mean that Neanderthals could not make decent tools, indistinguishable from the Mousterian tools that modern humans were making? No, you can't say that for sure: you can only suggest it. If Neanderthals made flutes and played them (see next topic), and it is an "if", then I don't worry too much about their hands being unable to perform delicate tasks.
A typically forthright essay by Valerius Geist, laying out his image of Neanderthal hunters. 2000.
Cannibalism was an every-year pastime in Papua New Guinea within living memory (see Tim Flannery's book, Throwim Away Leg), and among the New Zealand Maori last century.
And those inferences depend on the assumption that in studying mitochondrial DNA, we are looking at DNA that is not subject to much, or any, selective influence. Instead, changes in mitochondrial DNA are selectively neutral. It is only if you accept this assumption that mitochondrial DNA would change in a clock-like manner.
The analogy is with radioactivity. Radioactive decay proceeds randomly as far as each atom is concerned, but as a whole, a rod of radioactive fuel produces energy by atomic fission in an entirely predictable, clock-like fashion. That's why nuclear power plants don't randomly explode. Molecular biologists would love to have the same sort of predictable change-through-time that is provided to geologists by radioactive age dating (Chapter 2).
So a whole mini-industry has developed, producing "divergence dates" based on analyzing mtDNA in living organisms, always using the assumption that changes in mtDNA are mostly or completely attributable to non-selective changes.
The entire mini-industry would collapse, and its "divergence dates" along with it, if the assumption were faulty.
Well, folks, it IS faulty. Research published by Ballard late in 2000 reported an intensive study of the mtDNA in species and strains of the fruit-fly Drosophila (see summary by Rand 2001). Ballard has shown conclusively that mtDNA in Drosophila shows evolutionary change that is incompatible with the assumption of neutral or nearly-neutral selection. (The evolutionary change seems to be induced by strong natural selection associated with a parasite called Wolbachia that can entirely ruin the sex life of a fruit fly, but the specific source of the selection doesn't matter. What does matter is that mtDNA can undergo strong selection.)
So does this discovery ruin the conclusions based on mtDNA studies? No. Change in mtDNA can show evolutionary pathways and branches in the organisms that carry that DNA. What does become suspect is the idea that one can assign specific dates to ancient branching events. So in reading results based on mt DNA, or nuclear DNA for that matter, remember that any dates mentioned are likely to be wrong by some unknown factor: in other words, don't believe them for an instant. In my comments from now on, I have inserted [ ] around any dates offered from mtDNA analyses.
First, this shows that there are mtDNA lineages that have gone extinct, even though their possessors were fully members of modern Homo sapiens. So does the different mtDNA extracted from Neanderthals unequivocally bar them from membership in Homo sapiens? Some of the weasely answers quoted in these news stories suggests that the answer may be "NO." For example, some of the "Out-of-Africa" folks are hedging their position by talking about a little bit of potential inbreeding. I suppose that if Neanderthal women were carrying children of "modern humans" they were only a little bit pregnant!
Second, does this ancient Australian DNA suggest that modern humans arose in Australia? Of course not. But having said that, does DNA show that modern humans arose in Africa? No. The DNA evidence shows that most (perhaps all) the DNA in living humans arose in Africa. The question of how and when the African DNA was dispersed over the globe is still to be answered.
However, research published in 2000 looks at some of those genetic differences. The differences studied are certainly not random, since they affect sperm production. The pattern of differences cannot have arisen by random processes either. They are certainly adaptive, under natural selection, and they receive explanation that is to do with the different mating patterns of chimps and humans.
But what does it mean? The authors talked about a bottleneck early in the history of our species, when Homo sapiens passed through a very small population size. I suspect that scenario, though possible, has a more sinister alternative.
It is clear from the data from chimps and gorillas that a "natural" hominid species has a very much greater genetic variation than we do. It's therefore likely that Homo sapiens did too. What happened?
The molecular data (classical version) suggest that all living Homo sapiens are descended from a population that emerged in Africa, and expanded to populate Africa, and then, in the Out-of-Africa scenario, expanded to populate the world.
But other populations of Homo were living across the Old World. These included Homo neanderthalensis, which descended from Homo heidelbergensis in Europe and the Near East; and Homo erectus in Asia.
We now have some evidence that Homo sapiens interbred with Homo neanderthalensis in Spain, because we have found a "hybrid" child that was apparently living several thousand years after the "end" of the Neanderthals. See also a longer article in Discover, August 1999, by Robert Kunzig.
That suggests that the Out-of-Africa populations of Homo sapiens, with their restricted genetic variation, met other members of their own species who did not realize that they were supposed to be a separate species. The Neanderthals may have been outside the (narrow) genetic envelope that "living Homo sapiens" lies within, but they were inside the permitted, normal, genetic envelope of a normal hominid species that we should call Homo sapiens. And that means that Homo heidelbergensis belongs there too.
In turn, that suggests that in the end the Neanderthal contribution to ancient and modern Homo sapiens was lost, or it has not yet been sampled. (About 800 of the several billion living humans have been sampled for genetic studies like this.) One could ask about the Tasmanian islanders who were separated from Australia for 10,000 years yet retained complete interfertility with the rest of the species. (I do not know whether any Tasmanian genes have been examined, and there are no full-blooded Tasmanians left.)
And this leaves open the question of the Homo erectus populations of Asia...
So why has the Neanderthal contribution to the human genome been lost (or why has it not been detected?). Probably the narrow genetic range of living Homo sapiens is the result of 100,000 years of ethnic cleansing, which started with Neanderthals, and seems to have been a persistent behavior ever since (see the Old Testament and the newspapers, and historical records for every continent).
Eve Spoke, by Philip Lieberman, is a book that argues that language was the difference between modern humans and Neanderthals. Remember that I think language began with the control of fire (Homo erectus, probably). This book doesn't deny that Neanderthals could have had language. It argues that Neanderthals couldn't speak as well as H. sapiens, and the comparative lack of communication skills did them in. As you can imagine, it's terribly difficult to get any evidence that will test this suggestion (or mine, either). Here is a December 1998 review of Lieberman's book.
Links last checked March 9, 2001. All worked except a site from Cleveland State University, where many images of old skulls were posted. I shall have to find an alternative when I get time.
Page last updated by RC, April 27, 2001.
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