SMOKINCHOICES (and other musings)

April 16, 2013

2 mil yr bones tell mixed story

(I get really excited when scientists give us something new to think about which has been hidden away from prying eyes,  left undisturbed and pure – – pretty much as it once was.  It is the way it was made, back in the beginning!  No one has been able to reach in and contaminate it or modify it and all those  things  present day laboratory scientists like to do. 

It is a glorious window of opportunity to ponder and imagine and dream.  And we can let our minds free-float and try to contemplate the magical paths our ancestors took.  How I loved Jean Auel’s series of books – the  “EARTH CHILDREN”   with the Clan of the Cave Bear.  

So please try to understand, I can’t just pass on something as rare as this.  Since I love it so much, just have to share – –  you know how I am.   Jan)

Latest study

Ape, human traits mixed in old bones


OHIO STATE UNIVERSITY Australopithecus sediba

Two-million-year-old bones from an extinct South African creature display a mix of human and ape traits, according to a series of studies published yesterday.

Where this ancient primate fits on humans’ evolutionary tree is unknown and remains a subject of intense disagreement among researchers.

Scientists generally agree that humans sprang from a group of ancient species called australopithecines. This includes Australopithecus sediba, the subject of six papers published online yesterday in the journal Science.

  • A. sediba climbed in trees and walked upright. Its remains were discovered in a South African cave in 2008. It was first described in journals in 2010.

Debbie Guatelli-Steinberg, an Ohio State University anthropologist, was among a team of scientists who have found similar traits between the teeth of A. sediba and those of the first humans.

“It’s providing additional evidence to suggest they are closer relatives to us,” Guatelli-Steinberg said.

Among the other new analyses, the ribs show that the creature’s upper trunk resembled an ape’s, while the lower part looked more like a human’s.

Arm bones other than the hand and wrist look primitive, reflecting climbing ability, while earlier analysis of the hand had shown mixed traits.

LEE BERGER UNIVERSITY OF WITWATERSRAND    This image released by the journal Science shows the right hand of the adult female Australopithecus sediba. The hand lacks three wrist bones and four terminal phalanges but is otherwise complete. The skeleton’s arm bones other than those in the hand and wrist look primitive.

Another paper said there is a mix of human and apelike traits in the leg bones. The heel was narrow like an ape’s, which would seem to prevent walking upright, but the more human-like knee, pelvis and hip show that A. sediba did just that.

The papers follow the initial examination of two partial skeletons and an isolated shinbone.

The studies already have stirred objections from anthropologists who argue that A. sediba is not the evolutionary link to humans.

“I would say there is unusually exceptional skepticism as to whether they are direct relations to human,” said C. Owen Lovejoy, a Kent State anthropologist.

  • At the heart of the debate is which region of Africa should be considered the “cradle of humanity.”

Many anthropologists say our ancestry can be traced to eastern Africa. That’s where the bones of “Lucy” were discovered in 1974. Lucy’s species, Australopithecus afarensis, lived in Ethiopia 4 million to 3 million years ago.

For her part of the research, Guatelli-Steinberg traveled to museums in South Africa, Tanzania, Ethiopia and Kenya to study teeth from 340 fossilized remains. After examining their cusps, grooves and ridges, she found that sediba teeth shared 13 traits with those of Homo erectus, an early human species.

“They are less similar to Lucy and other forms,” she said.

A big problem for both the eastern Africa and South Africa camps is a lack of solid evidence — a smoking gun, if you will. Fossilized bones of early humans and pre-humans are rare, and theories are based on a few partial skeletons.

“It’s one thing to find a humerus or a femur, but it’s something special to find a humerus associated with a femur,” Love-joy said. “You can test hypotheses with those kinds of things.”

Although Lovejoy agreed that the partial sediba skeletons are significant, he called the researchers’ conclusions “extraordinary.” Lovejoy’s past research includes studies of A. afarensis.

  • Guatelli-Steinberg said this dental study doesn’t try to declare that A. sediba is humanity’s “missing link.”

“We can’t say who is ancestral to whom,” she said. “We can say who seems to be more closely biologically related.”

Information from the Associated Press was included in this story.



1 Comment »

  1. Its having good description regarding this topic.It is informative and helpful.I have known many information from this.

    Comment by DENTAL IMPLANTS IN HOUSTON TX — December 19, 2013 @ 9:11 am | Reply

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