Talk:Australopithecine

From Academic Kids

A 2001 discovery and -- let's just say much more -- contradicts many conclusions in this entry.

First, two critiques about a portion of the first paragraph (copied in red below) -- one supporting the possibility of afarensis as an ancestor, and one against it:

“...since then, Hominid fossils have been found that are older than A. africanus, yet nevertheless seem to belong to the genus Homo. Thus, the genus Homo either split off from the genus Australopithecus at an earlier date (the latest common ancestor being A. afarensis or an even earlier form), or both developed from an as yet possibly unknown common ancestor independently. ... The fossil record seems to indicate that Australopithecus is the common ancestor...”

1. A recent discovery by those famous Leakey anthropologists (http://www.accessexcellence.org/WN/SUA14/newhominid.html|) shows that even afarensis had a non-Australopithecine competitor, so -- for the same reason that I agree with this Wikipedia entry when it says that we might not have descended from africanus, but from another, competing genus instead -- I think there's just as much reason that we should not state, with so much certainty as this author has, that afarensis is a "common ancestor" of ours. We can't be certain whether even afarensis is what we "developed from," especially given this 2001 discovery. This is why we still call these species the 'missing link(s)': We aren't certain; this part of our history is 'missing'. Also, since this other genus discovered in 2001 were contemporaries of afarensis, I also doubt that they "developed from" (to quote the red text) afarensis. And thus, this new genus brings up a very plausible scenario which the Wikipedia entry doesn't recognize the possibility of: that we descended from this other genus, Kenyanthropus, without them descending from any Australopithecines, which would contradict the two only scenarios which are recognized as possible in this "either...or" claim in red(that "genus Homo either split off from the genus Australopithecus at an earlier date...or...") ).

We can't even make an affirmative case that we descended from any Australopithecines: Basically, the claim of our ‘descent’ from afarensis was only a presumption to begin with: There wasn’t any actual evidence to merit this theory of descent from Australopithecines (or if there is evidence, I'd love to see it because I've been asking fruitlessly for years. ;-) ), but rather an assumption was made because (at the time, i.e. before 2001), "We know of no competitors to afarensis, nor species similar to us, like afarensis is, so we must have descended from them". Such presumptions are 'burden of proof' fallacies in the system of logic (i.e., A negative presumption, in logic, can never prove an affirmative conclusion, such as, "We did descend from...") : Or as we scientists would say, ‘Absence of evidence is not evidence of absence,’ as the 1972 and 2001 Leakey discoveries painfully pointed out because finally, that evidence was no longer absent, with 1972 as the demise of africanus being considered the only known (homonid) species of that era, and 2001 being the demise for our assumptions about afarensis being our only possible ancestor from their respective era -- and with scientists on both sides, ever since, arguing about which species was 'more human' in each era and thus more likely to be our ancestors, without either side really having incontrovertible evidence. And really, who's to say a third species of that era won't be discovered, which is more similar to us than these two? The only rational stance on this issue is agnosticism, and to simply admit that we don't posess enough knowledge to come to any hard-formed opinions. To assume things without affirmative evidence is simply bad science and bad logic (with science being called Logical Empiricism by philosophers for a reason ;-) ), which ironically seems to have been accepted by a large portion of my fellow ‘scientists’ until the 1972 and 2001 discoveries made them question their assumptions. Can we try parsing the word assumption, to bring some levity to this regarding us 'oh so smart' scientists: ass|u|me.

2. Note that I put emphasis on the word ‘either,’ in the above red text: There’s another, plausible option which has been ignored by the author of this Wikipedia entry (Is anyone starting to see his pattern? ;-) ): that afarensis did exist earlier than the genus Homo but we simply haven’t yet discovered fossils to prove it, just as we “didn’t yet discover” *any* fossils of Kenyanthropus until 2001... Just because we haven't discovered it, doesn't mean it didn't happen, as we found with Kenyanthropus and as the saying "Absence of evidence isn't evidence of absence" summarizes. We can’t ASSume whether or not we’ll find such fossils, and therefore we shouldn’t be falsely led into this ‘either/or’ false claim, nor that no possibilities exist besides those two simply because they were the only two which the author came up with as possibilities. This area of science, being so immature, still gives us very little evidence to back the claims of the Wikipedia author, especially given the certaintism with which some of these claims were stated; so of course I'm pleased that at some of the claims were stated with the appropriate amount of probabilism, but not certaintism, which is merited by the (lack of good) evidence.

And finally, a critique about this last bit:

“The existence of Australopithecus seems to have put firmly to rest the theory that human-like intelligence evolved first and bipedalism followed.”

3. Kenyanthropus platyops had a larger braincase than Australopithecus, and we can’t be sure whether these BOTH were evolutionary dead-ends because they might have competed with an even smarter species. We’re still discovering fossils, folks, and there might be a third, fourth, and so on as-yet-undiscovered species, one of which could have had human-like intelligence before any of these genera went bipedal, so no, the existence of Australopithecus proves nothing firmly; this is yet again non-sequitur logic from the author of this article.

Just a closing thought... History is like walking through fog: The further back we try to see, the harder it is to see much detail.

Oh, and if anyone wants to get more info on these two species of australopithecus and the newly-discovered species with whom they competed:

[1] (http://www.utexas.edu/courses/wilson/ant304/projects/projects97/weimanp/fossils.html) "The brain shape is also more humanlike and he likely was capable of rudimentary speech. The picture shown is of skull 1470, the most complete habilis skull ever found, found by Richard Leakey's team at Koobi Fora. Incidently, the stone tools made by habilis were a dramatic departure from what earlier hominids were able to do." [2] (http://www.utah.edu/unews/releases/01/mar/cranium.html) "Kenyanthropus platyops [the 2001 discovery listed above] resembles skull 1470 found in the eastern Turkana basin in the 1970s. Called Homo rudolfensis by some researchers and a member of genus Australopithecus by others, the Nature article suggests researchers now must consider if it instead descended from Kenyanthropus." [3] (http://www.guardian.co.uk/Archive/Article/0,4273,4156479,00.html) In the 1970s, Bernard Ngeneo, a member of Richard Leakey's field crew working the fossil beds on the eastern shore of Lake Turkana, found a skull known from its catalogue number - KNM-ER 1470. This skull, "1470 man" for short, looks very modern, and is generally assigned to Homo rudolfensis, a very early member of our own genus. Kenyanthropus has a very similar, flattened face, but is almost twice as ancient as 1470. [4] (http://www.theosophy-nw.org/theosnw/evol/ev-ibeld.htm) "The line of descent promoted till not long ago was roughly Ramapitbecus (fossil ape), Australopithecus, Homo habilis, Homo erectus, and finally ending up with Homo sapiens. In this sequence Australopithecus and Homo habilis were given rather humanlike characteristics, such as an apelike head or face on a modern looking human body. Paleoanthropological discoveries of the last 25 years have done much to undermine this fairly simple picture. Besides these, various other kinds of research on fossil hominids have disturbed the picture even more."