Homo naledi is only 250,000 years old

The accumulation of small heritable changes within populations over time.

Moderators: Calilasseia, ADParker

Homo naledi is only 250,000 years old

#1  Postby Shrunk » Apr 26, 2017 12:56 am

In 2013, Lee Berger at the University of the Witwatersrand in Johannesburg and his colleagues made an extraordinary discovery – deep inside a South African cave system they found thousands of bones belonging to a brand new species of early human — and now we finally may know when this species lived and how it fits into our evolutionary tree.

By 2015 it was becoming clear that the new species, which was named Homo naledi, was unlike anything researchers had discovered before. Although parts of its skeleton looked identical to our modern human anatomy, it had some features that were strikingly primitive – including a skull that was only slightly larger than that of a chimpanzee.

But Berger and his colleagues had trouble establishing how old the H. naledi fossils were. Without that piece of information, most other researchers agreed that the true significance of H. naledi for understanding human evolution was unclear. Guesses have varied from as old as 2 million years to as young as 100,000 years.

Today, news broke that Berger’s team has finally found a way to date the fossils. In an interview published by National Geographic magazine, Berger revealed that the H. naledi fossils are between 300,000 and 200,000 years old.

“This is astonishingly young for a species that still displays primitive characteristics found in fossils about 2 million years old, such as the small brain size, curved fingers, and form of the shoulder, trunk and hip joint,” says Chris Stringer at the Natural History Museum in London....

https://www.newscientist.com/article/21 ... AU.twitter


Among the implications of the dating is that there were at least five distinct species of Homo alive at the same time.
"A community is infinitely more brutalised by the habitual employment of punishment than it is by the occasional occurrence of crime." -Oscar Wilde
User avatar
Shrunk
THREAD STARTER
 
Posts: 26170
Age: 56
Male

Country: Canada
Canada (ca)
Print view this post

Ads by Google


Re: Homo naledi is only 250,000 years old

#2  Postby zulumoose » Apr 26, 2017 9:23 am

I am quite naive in these things, but isn't the defining point of the species barrier the inability to interbreed and have fertile offspring?

How is this determined from fossils alone, wouldn't aged fossils of modern dogs or even humans show enough variation such that they would be determined by the same limited means of investigation to be different species instead of races or breeds of the same species?
User avatar
zulumoose
 
Posts: 3625

Country: South Africa
South Africa (za)
Print view this post

Re: Homo naledi is only 250,000 years old

#3  Postby juju7 » Apr 26, 2017 9:49 am

It was an evolutionary dead end.
User avatar
juju7
Banned Sockpuppet
 
Posts: 905

Country: South Africa
South Africa (za)
Print view this post

Re: Homo naledi is only 250,000 years old

#4  Postby Shrunk » Apr 26, 2017 10:25 am

zulumoose wrote:I am quite naive in these things, but isn't the defining point of the species barrier the inability to interbreed and have fertile offspring?

How is this determined from fossils alone, wouldn't aged fossils of modern dogs or even humans show enough variation such that they would be determined by the same limited means of investigation to be different species instead of races or breeds of the same species?


Fair point, I think. I wasn't using the term "species" in such a strict sense here. If I understand correctly, it is still an open question whether there was interbreeding between H. sapiens and H. neanderthalis.
"A community is infinitely more brutalised by the habitual employment of punishment than it is by the occasional occurrence of crime." -Oscar Wilde
User avatar
Shrunk
THREAD STARTER
 
Posts: 26170
Age: 56
Male

Country: Canada
Canada (ca)
Print view this post

Re: Homo naledi is only 250,000 years old

#5  Postby DavidMcC » May 01, 2017 2:07 pm

zulumoose wrote:I am quite naive in these things, but isn't the defining point of the species barrier the inability to interbreed and have fertile offspring?

How is this determined from fossils alone, wouldn't aged fossils of modern dogs or even humans show enough variation such that they would be determined by the same limited means of investigation to be different species instead of races or breeds of the same species?

In the case of pet dogs, humans play a large role in their phenotypic evolution (through selective breeding), making it seem that they were separate species. Humans don't have anything like as much phenotypic variation as pet dogs (some height and skin colour variation, plus face shape details, etc.).
May The Voice be with you!
DavidMcC
 
Name: David McCulloch
Posts: 14913
Age: 67
Male

Country: United Kigdom
United Kingdom (uk)
Print view this post

Re: Homo naledi is only 250,000 years old

#6  Postby Shrunk » May 09, 2017 11:12 am

"A community is infinitely more brutalised by the habitual employment of punishment than it is by the occasional occurrence of crime." -Oscar Wilde
User avatar
Shrunk
THREAD STARTER
 
Posts: 26170
Age: 56
Male

Country: Canada
Canada (ca)
Print view this post

Re: Homo naledi is only 250,000 years old

#7  Postby Macdoc » May 09, 2017 11:44 am

Excellent topic ...thanks for that ...I think at this point it's the human bush rather than tree.
Travel photos > https://500px.com/macdoc/galleries
EO Wilson in On Human Nature wrote:
We are not compelled to believe in biological uniformity in order to affirm human freedom and dignity.
User avatar
Macdoc
 
Posts: 17156
Age: 73
Male

Country: Canada/Australia
Australia (au)
Print view this post

Ads by Google


Re: Homo naledi is only 250,000 years old

#8  Postby DavidMcC » May 09, 2017 12:46 pm

Macdoc wrote:Excellent topic ...thanks for that ...I think at this point it's the human bush rather than tree.

You mean we have several/many base stems?
I take it you refer to the occasional suspected hybridization event during hominid evolution, or just that there are many extinct evolutionary lines within homo.
May The Voice be with you!
DavidMcC
 
Name: David McCulloch
Posts: 14913
Age: 67
Male

Country: United Kigdom
United Kingdom (uk)
Print view this post

Re: Homo naledi is only 250,000 years old

#9  Postby Veida » May 09, 2017 9:37 pm

Shrunk wrote:If I understand correctly, it is still an open question whether there was interbreeding between H. sapiens and H. neanderthalis.

Er, no, that is not an open question. It is clear that there was such interbreeding. Shown by Pääbo and colleagues who sequensed the neanderthal genome and compared it to the Sapiens genome. Non-africans have a few percent neanderthal DNA.
Veida
 
Posts: 852

Sweden (se)
Print view this post

Re: Homo naledi is only 250,000 years old

#10  Postby DavidMcC » May 10, 2017 1:16 pm

Veida wrote:
Shrunk wrote:If I understand correctly, it is still an open question whether there was interbreeding between H. sapiens and H. neanderthalis.

Er, no, that is not an open question. It is clear that there was such interbreeding. Shown by Pääbo and colleagues who sequensed the neanderthal genome and compared it to the Sapiens genome. Non-africans have a few percent neanderthal DNA.

I don't trust anything Pääbo publishes, ever since he tried to use coding gene sequences for genetic dating, and got the predictable nonsense, yet didn't seem to realise why!
May The Voice be with you!
DavidMcC
 
Name: David McCulloch
Posts: 14913
Age: 67
Male

Country: United Kigdom
United Kingdom (uk)
Print view this post

Re: Homo naledi is only 250,000 years old

#11  Postby Wortfish » Jun 05, 2017 3:48 pm

Shrunk wrote:
Among the implications of the dating is that there were at least five distinct species of Homo alive at the same time.


Actually, the creationists predicted back in 2015 that H. naledi was likely very young: http://creation.com/homo-naledi

The Berger et al paper describing the geological context of their finds repeatedly refers to the remains as “bones” and only “partially mineralised”. They were not even excavated from lithified sediment but soil “composed of largely unconsolidated sediment … dominated by reworked orange mud clasts embedded in a brown muddy matrix.” Many of the bones required no excavation at all..... All this indicates that the bones may well be quite young, in which case the obvious dating method would be carbon-14.
User avatar
Wortfish
 
Posts: 971

United Kingdom (uk)
Print view this post

Re: Homo naledi is only 250,000 years old

#12  Postby newolder » Jun 05, 2017 4:13 pm

Wortfish, The half-life of carbon-14 is 5 730 years, give or take a few years. 10 half-lives, after which the original content has decayed such that approximately 0.1% remains, takes us to 57 300 years ago. A species a further 200 000 back in time would have virtually no 'time of death' C-14 remaining in a sample. The 'obvious' dating method would, therefore, not be carbon-14.
I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops. - Stephen J. Gould
User avatar
newolder
 
Name: Albert Ross
Posts: 7310
Age: 1
Male

Country: Feudal Estate number 9
Print view this post

Re: Homo naledi is only 250,000 years old

#13  Postby Wortfish » Jun 05, 2017 4:50 pm

newolder wrote:Wortfish, The half-life of carbon-14 is 5 730 years, give or take a few years. 10 half-lives, after which the original content has decayed such that approximately 0.1% remains, takes us to 57 300 years ago. A species a further 200 000 back in time would have virtually no 'time of death' C-14 remaining in a sample. The 'obvious' dating method would, therefore, not be carbon-14.


OK. But they were right that the bones were relatively recent. It still might be interesting to a carbon-14 test just to make sure.
User avatar
Wortfish
 
Posts: 971

United Kingdom (uk)
Print view this post

Re: Homo naledi is only 250,000 years old

#14  Postby newolder » Jun 05, 2017 5:01 pm

Wortfish wrote:
newolder wrote:Wortfish, The half-life of carbon-14 is 5 730 years, give or take a few years. 10 half-lives, after which the original content has decayed such that approximately 0.1% remains, takes us to 57 300 years ago. A species a further 200 000 back in time would have virtually no 'time of death' C-14 remaining in a sample. The 'obvious' dating method would, therefore, not be carbon-14.


OK. But they were right that the bones were relatively recent. It still might be interesting to a carbon-14 test just to make sure.

Knock yourself out - and report back after you regain consciousness. :popcorn:
I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops. - Stephen J. Gould
User avatar
newolder
 
Name: Albert Ross
Posts: 7310
Age: 1
Male

Country: Feudal Estate number 9
Print view this post

Re: Homo naledi is only 250,000 years old

#15  Postby Wortfish » Jun 05, 2017 5:19 pm

newolder wrote:
Knock yourself out - and report back after you regain consciousness. :popcorn:


And what if the bones really are just 5,000 years old following a carbon-14 test? Dating can prove incorrect. H. rudolfensis was initially dated to 3 million years ago but was subsequently revised to 1.9 million years.
User avatar
Wortfish
 
Posts: 971

United Kingdom (uk)
Print view this post

Ads by Google


Re: Homo naledi is only 250,000 years old

#16  Postby newolder » Jun 05, 2017 5:21 pm

Wortfish wrote:
newolder wrote:
Knock yourself out - and report back after you regain consciousness. :popcorn:


And what if the bones really are just 5,000 years old following a carbon-14 test? Dating can prove incorrect. H. rudolfensis was initially dated to 3 million years ago but was subsequently revised to 1.9 million years.

I refer my interlocutor to my previous reply.
I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops. - Stephen J. Gould
User avatar
newolder
 
Name: Albert Ross
Posts: 7310
Age: 1
Male

Country: Feudal Estate number 9
Print view this post

Re: Homo naledi is only 250,000 years old

#17  Postby Shrunk » Jun 05, 2017 6:12 pm

Wortfish wrote:Actually, the creationists predicted back in 2015 that H. naledi was likely very young.


"Predicted" :point:
"A community is infinitely more brutalised by the habitual employment of punishment than it is by the occasional occurrence of crime." -Oscar Wilde
User avatar
Shrunk
THREAD STARTER
 
Posts: 26170
Age: 56
Male

Country: Canada
Canada (ca)
Print view this post

Re: Homo naledi is only 250,000 years old

#18  Postby Wortfish » Jun 05, 2017 7:51 pm

Shrunk wrote:
Wortfish wrote:Actually, the creationists predicted back in 2015 that H. naledi was likely very young.


"Predicted" :point:


Whatever you call it, they were more correct than the discoverer who thought they could be 2-3 million years old.
User avatar
Wortfish
 
Posts: 971

United Kingdom (uk)
Print view this post

Re: Homo naledi is only 250,000 years old

#19  Postby newolder » Jun 05, 2017 8:12 pm

Wortfish, From where did you extract that "3 million years old" figure? The OP includes that:
Guesses have varied from as old as 2 million years to as young as 100,000 years.

Whilst the newer dating work has:
In an interview published by National Geographic magazine, Berger revealed that the H. naledi fossils are between 300,000 and 200,000 years old.
I am, somehow, less interested in the weight and convolutions of Einstein’s brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops. - Stephen J. Gould
User avatar
newolder
 
Name: Albert Ross
Posts: 7310
Age: 1
Male

Country: Feudal Estate number 9
Print view this post

Re: Homo naledi is only 250,000 years old

#20  Postby Shrunk » Jun 05, 2017 8:40 pm

Wortfish wrote:
Shrunk wrote:
Wortfish wrote:Actually, the creationists predicted back in 2015 that H. naledi was likely very young.


"Predicted" :point:


Whatever you call it, they were more correct than the discoverer who thought they could be 2-3 million years old.


Proportionately, no, the creationists were still way off. Do the math, 250,000/6000 vs 3 million/250,000.
"A community is infinitely more brutalised by the habitual employment of punishment than it is by the occasional occurrence of crime." -Oscar Wilde
User avatar
Shrunk
THREAD STARTER
 
Posts: 26170
Age: 56
Male

Country: Canada
Canada (ca)
Print view this post

Next

Return to Evolution & Natural Selection

Who is online

Users viewing this topic: No registered users and 1 guest