Toumai confirmed as "human ancestor"

Adam Khor

http://blogs.scientificamerican.com/observations/2013/04/04/brain-shape-confirms-controversial-fossil-as-oldest-human-ancestor/

Black Swan

Any other artifacts for Sahelanthropus tchadensis, or just this skull? If this is in fact a hominin ancestor, pushing back origins 7 million years is hugely significant.

Adam Khor

Black Swan wrote: »

Any other artifacts for Sahelanthropus tchadensis, or just this skull? If this is in fact a hominin ancestor, pushing back origins 7 million years is hugely significant.

According to Wikipedia, a femur may have been found along with the skull but no one ever said anything about it

steddyeddy

I'm finding it very hard to believe all of our ancestors were confined to Africa at this stage.

Black Swan

steddyeddy wrote: »

I'm finding it very hard to believe all of our ancestors were confined to Africa at this stage.

Perhaps there were several (somewhat random) attempts that occurred for the origin of our species in different environments over millions of years, and the African environment held the greatest probability for success, while others were variably less and suffered extinction? In any case, there were fossil records of other related hominin ancestors about the world, but not 7 million years old.

Galvasean

7 million years, that was the long speculated 'divergence point' between humans and the other modern great apes wasn't it?

Personally, I think pointing and saying, "Look how big the brain is!" and concluding that it is a human ancestor is a very flawed way of thinking. The brain of Sahelanthropus tchadensis is of similar size to a chimp, so having a large brain is not necessarily a direct result of walking upright, as many are claiming.
The "forward position of his foramen magnum (the spinal cord opening in the base of the skull), which is associated with upright walking" strikes me as being far more critical in figuring out that Sahelanthropus is related to us. However, this seems to be something of a footnote in reports.

PS: Toumai!

Adam Khor

Galvasean wrote: »

7 million years, that was the long speculated 'divergence point' between humans and the other modern great apes wasn't it?

Personally, I think pointing and saying, "Look how big the brain is!" and concluding that it is a human ancestor is a very flawed way of thinking.
PS: Toumai!

Haha I agree

Galvasean

Elaborated thoughts (from me) here:
http://www.krank.ie/category/main/toumai-confirmed-human-ancestor/

Wibbs

More of the usual "confirmed" spin that comes out from time to time and not just in the tabloids. Both nutjobs and scientists look for "the missing link". I'm with you G, there's little that confirms much of anything in this story. We simply don't have the fossil resolution to build a picture of what was going on back then. This guy could have been the only bipedal ape, or he may have been one of many. There were certainly many living at the same time later on down the line. All we can say is he was likely a bipedal chimp like dude but that's about it.

IMHO we'll likely never nail the earliest human ancestor down as it's just to fuzzy a picture and even too fuzzy a definition. For me Erectus is the first definite human and human ancestor, before that it gets real vague.

Black Swan

Thanks to this OP, yesterday I checked out from the locale library the Last Ape Standing (2013) by Chip Walter, that discusses "The Seven-Million-Year Story." He suggests that there may have been 26 different hominin ancestor evolutionary attempts over the past 7 million years, all but one having become extinct by the present date. He further suggests that there may be more such natural attempts discovered to add to this number as research continues.

Galvasean

Interesting. I'll have to check that one out!

steddyeddy

I don't think we will have a real idea until we can successfully reconstruct ancient DNA.