Post: #1

It made the international news cycle today, but I haven't seen it posted yet so thought I'd create a new thread.

Scientists revealed that they have discovered a single site at the Cradle of Humankind near Joburg holding fossils of more than 15 individuals of a newly discovered species of human ancestor they have called Homo Naledi. Naledi means "star".



They have concluded, after considering but rejecting the other possibilities, that the site must be a burial site, thus pushing back the date human ancestors started burying their dead. Actually "burying" isn't an accurate term. The bodies were found placed in a remote and inaccessible cave.

Quote:The fossils were found in a chamber so remote it appears no other species was able to access it, bar a few birds and mice. The team’s hypothesis that the H. naledi bodies were deliberately placed there arose from eliminating other possible explanations, said Prof Berger.

The fossil bones bore no marks of scavengers or carnivores that might have dragged them there, and there was no evidence of a natural process such as moving water that might have deposited them in the cave, he said.

It appears the bodies were intact when they were placed in the cave, and began to decompose there. Some of the skeletal remains were found in articulation and include a hand missing only one of its 27 bones.

“We explored every alternative scenario, including mass death ... and were left with intentional body disposal by Homo naledi as the most plausible scenario,” he said.

http://www.bdlive.co.za/national/science...n-ancestor

While I don't share the view that there is some sort of weird conspiracy trying to convince people of the "Out of Africa" hypothesis against the evidence, this sort of discovery does concern me. Or rather, it concerns me that broad generalisations are made form only a few discoveries. The place this discovery was made is quite close to Johannesburg, nice and close to the academics at the University. I always feel that people look in certain places because they are convenient. And you don't normally find things where you are not looking. Obviously this is an oversimplification, but factors unrelated to the underlying reality affect where most people look for fossils. So generalisations from fossils found at such a convenient site make me "nervous".

But anyway, the find is regarded as very significant. It is very rare to find the kind of volume of fossils that was discovered in one place. They have not been dated yet (not sure why), but I think they have placed the species in some sort of slot.

Post: #2

Searching in natural caves is the most logical place.
For anyone interested, https://en.wikipedia.org/wiki/Rising_Star_Cave and https://en.wikipedia.org/wiki/Cradle_of_Humankind

Post: #3

(09-10-2015 03:19 PM)void Wrote:  Searching in natural caves is the most logical place.
For anyone interested, https://en.wikipedia.org/wiki/Rising_Star_Cave and https://en.wikipedia.org/wiki/Cradle_of_Humankind

Oh, it's not that they were found in caves that "concern" me, but that the caves are so close to Joburg. i.e They are too convenient. There are likely many other caves systems that are either undiscovered or explored in much less detail because they are more difficult to get to. This may result in conclusions being somewhat biased by overeliance on certain data.

Post: #4

I love discoveries like this. The book of mankind is being rewritten every 50 years, as more and more discoveries and conclusions come about.

Post: #5

I once did a work course in Oklahoma, and as part of the safety stuff they were talking about tornadoes, and they showed a by county map of where the most tornadoes struck. Now they said that why should two adjacent counties, have perhaps a 100% difference in the number of tornadoes, and why should more tornadoes always strike the most populous counties?

The point was that they don't. But in order to report a tornado, someone needs to see it, and it's a similar phenomenon here. Why is it when they accidentally find an archaeological site during construction, it's near other built up areas? Simply because that's where they build stuff. Near other buildings, and near infrastructure. I sort of see what you're saying, but it seems like the most sensible way of doing this is to go after the 'low hanging fruit' near established centers. While it may be slightly biased since they're not looking at every square mile on the continent equally, it still helps fill in the blanks.

Post: #6

What is the significance of this? It's a cool discovery but what is this going to teach us about the history of mankind?

Post: #7

(09-14-2015 09:13 PM)monster Wrote:  What is the significance of this? It's a cool discovery but what is this going to teach us about the history of mankind?

I went to a paleontology lecture a few months ago, although it was before this discovery, it did reveal the current trend in paleontology thinking.

Basically, there is more and more evidence that all the different 'species' of human were not really species at all. Homo Erectus, Neanderthalis, Habilis, Rudolfiensis, Sapiens, and many of the other Homo types and maybe even pre-Homo types were not separate species, but rather different racial types of the same species.

In this day and age we have relatively few races which look reasonably similar to one another in appearance. In those ancient days there were a lot of races who looked very different from one another in terms of body types.

The old thinking was that there was a precursor human race who spread across the world and that then there was genetic drift that allowed certain racial types to evolve. The new thinking is that there were dozens if not hundreds of racial types that evolved first, then spread over the world, then intermixed or died off, and the few left today are the 'survivors' of a racial arms race, as it were.

So as I understand it, the discovery of Homo Naledi supports this hypothesis in that it further blurs the line between what exactly can be defined as 'human' and 'pre-human' and suggests that the evolution of the human was not a straight linear path of apelike creature -> less ape-like -> humanish -> human but rather a peculiar steaming pot of DNA mixing that makes little logical sense, and made a lot of variation possible in early humans and pre-humans (imagine there being as many human races as dog types).

Post: #8

(09-14-2015 11:44 PM)Thomas the Rhymer Wrote:  ...

So as I understand it, the discovery of Homo Naledi supports this hypothesis in that it further blurs the line between what exactly can be defined as 'human' and 'pre-human' and suggests that the evolution of the human was not a straight linear path of apelike creature -> less ape-like -> humanish -> human but rather a peculiar steaming pot of DNA mixing that makes little logical sense, and made a lot of variation possible in early humans and pre-humans (imagine there being as many human races as dog types).

Great point. Which is why I think that the most productive line of biological research right now is to sequence as many genomes as possible. All animals (including human) and plants. My view is that a deep analysis of this data will answer many questions regarding the splitting of various species and sub species that cannot current;y be answered by looking at the fossil record.

This is certainly already being done, but it seems that there is still a lot of data to collect to really enable firm conclusions to be drawn.

Post: #9

At the risk of getting sidetracked, I saw an excellent Nat Geo documentary about 6 months ago called "The Search for Adam".

https://www.youtube.com/watch?v=LS2FMS87DE8

Essentially it is all about males will pass on a DNA marker to offspring, and based on where it is, you can tell how far back it goes. Now some of the more successful chains/conquerors from thousands of years ago (Ramses the Great or Genghis Khan for instance) will be present in a large percent of people, and working backwards, they were able to identify a single marker from ~60k years back that is present in everyone today. While obviously there were many ppl back then breeding, their ancestral lines eventually died out or blended in, which perhaps gives more credence to the "many breeds" hypothesis.