Re: Lucy's current status -- in the fossil record or out?
HARRY R. ERWIN (herwin@osf1.gmu.edu)
27 Dec 1996 13:45:38 GMT
Susan S. Chin (susansf@netcom.com) wrote:
: "Michael J. Gallagher" <MIKEJOE@Prodigy.Net> wrote:
: : >Is the hominid fossil known as "Lucy" still considered a part of the
: : >fossil record of human evolution? If not, when did this change and why?
: I'm not sure I understand your question. Are you asking if Lucy is still
: considered a possible human ancestor, a part of the hominid lineage
: leading to modern Homo sapiens? The "fossil record of human evolution"
: encompasses all hominid lineages, including those which became extinct
: such as the robust Australopithecines and Neanderthals.
Well put.
: Al Curtis (alc@azotus.com) wrote:
: : "Lucy", a member of the species named Australopithecus afarensis is
: : still the subject of some controversy. Many paleoanthropologists
: : consider A. afarensis to be on the branch that led directly to H.
: : habilis (a species which itself is somewhat controversial) to H.
: : erectus to H. sapiens. However, there have been many different types
: : of hominid fossils found which have been assigned to the genus
: : Australopithecus and it is still not certain which of these diverse
: : types led to humans.
: : p.s. My money is on Lucy
: : -al=
: "From Lucy to Language" by Don Johanson and Blake Edgar (Simon &
: Schuster, 1996) is an excellent reference book documenting human
: evolution from Ardipithecus ramidus to Australopithecus anamensis all
: the way to anatomically modern humans. Along the way, you encounter a lot
: more hominid species than I've been exposed to... Homo ergaster, Homo
: rudolfensis, Homo heidelbergensis....
: What I'd like to know is, how valid are these new species designations?
: The discoverers of these specimens on the whole didn't assign them to the
: names above... so how does one even go about "officially" changing the
: designation if the original discoverers who published the finds are no
: longer around? Or is it just "the consensus is" therefore that's what
: we'll call it?
Johanson is a 'splitter,' although not as extreme as Groves. The following
are my opinions, based on a large character database: Ardipithecus
ramidus, Australopithecus anamensis, and A. afarensis are probably valid.
I suspect A. africanus splits, based on some cladistic analysis I've done.
A. robustus and A. boisei seem to be valid. There's an unnamed early
species of Homo dating to about 2.5 MYr BP. Homo habilis appears to split
into H. rudolfensis and H. habilis in the narrow sense, again based on my
analysis. H. ergaster appears to be an african subspecies of H. erectus
based on Rightmier. H. heidelbergensis appears to be transitional between
H. erectus and H. sapiens. H. neanderthalensis is difficult--the eastern
neanderthals hybridize with early H. sapiens, while the western and
levantine neanderthals don't. H. sapiens in the modern sense seems to
emerge about 100,000-200,000 BP in Africa, but it's not clear where and
when modern levels of artistic intelligence emerged (which seems to me to
be the most important specialization of modern H. sapiens).
Hope that helps.
--
Harry Erwin, Internet: herwin@gmu.edu, Web Page: http://osf1.gmu.edu/~herwin
49 year old systems analyst, PhD student in computational neuroscience
("how bats do it" 8), and lecturer for CS 211 (data structures and
advanced C++)
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