Dear GSW members:
This message is to inform you of a special evening session of the
Geological Society of Washington on TUESDAY (yes this is GSW blasphemy)
the 30th of March. Our scheduled regular meeting on March 24th is
cancelled in order that we may present Ardi night the following week –
in celebration of the recent spectacular discoveries of human origins
in Ethiopia. These findings were highlighted in Science magazine
in the October 2, 2009 issue, including an insightful editorial by past
GSW president Brooks Hanson.
For that issue Tim White and colleagues wrote an article titled
“Ardipithecus ramidus and the Paleobiology of Early Hominids.” To
provide you with more insight to the discovery, the abstract of that
article is reproduced below.
Hominid fossils predating the emergence of Australopithecus have been
sparse and fragmentary. The evolution of our lineage after the last
common ancestor we shared with chimpanzees has therefore remained
unclear. Ardipithecus ramidus, recovered in ecologically and temporally
resolved contexts in Ethiopia’s Afar Rift, now illuminates earlier
hominid paleobiology and aspects of extant African ape evolution. More
than 110 specimens recovered from 4.4-million-year-old sediments
include a partial skeleton with much of the skull, hands, feet, limbs,
and pelvis. This hominid combined arboreal palmigrade clambering and
careful climbing with a form of terrestrial bipedality more primitive
than that of Australopithecus. Ar. ramidus had a reduced
canine/premolar complex and a little-derived cranial morphology and
consumed a predominantly C3 plant–based diet (plants using the C3
photosynthetic pathway). Its ecological habitat appears to have been
largely woodland-focused. Ar. ramidus lacks any characters typical of
suspension, vertical climbing, or knuckle-walking. Ar. ramidus
indicates that despite the genetic similarities of living humans and
chimpanzees, the ancestor we last shared probably differed
substantially from any extant African ape. Hominids and extant African
apes have each become highly specialized through very different
evolutionary pathways. This evidence also illuminates the origins of
orthogrady, bipedality, ecology, diet, and social behavior in earliest
Hominidae and helps to define the basal hominid adaptation, thereby
accentuating the derived nature of Australopithecus.
The Discovery Channel has a wonderful hour-long film titled
“Discovering Ardi”, which aired last fall, and they have also created
an interactive website devoted to the discovery.
http://dsc.discovery.com/tv/ardipithecus/ardipithecus.html
Our expert speakers at this special GSW event include:
Gidday Woldegabriel (Los Alamo National Laboratory): “Human Origins in
the Midst of Chaos: Evidence from the Ethiopian Rift System”
Ray Bernor (Howard University and the National Science Foundation):
“Ardipithecus: Geologic and. Paleontologic Contexts”
and
Jay Matternes (Artist Naturalist): “Fleshing out Ardi”
We are especially happy to introduce Jay Matternes to the
society. More information about this remarkable artist may be
found at:
http://www.jay-matternes.com/
I hope that you all will be able to come to Ardi night. Mark your
calendars for TUESDAY, March 30th.
Sincerely,
Jay Kaufman
2010 GSW President