Neanderthal DNA

[Digit]

If HSN only interbred with HSS but rarely and is responsible for our large brains, then no matter how frequently or infrequently the two species made it to the altar, we must all be hybrids of the two species. Either that or there must be a lot of half empty skulls around. If we are all hybrids, as I have long argued, then both Neandertal Man AND Cro-Magnon are extinct, superseded by their hybrid offspring, us!
Sorry for the two posts, my computer is still showing its independence.

[Cognito]

If HSN only interbred with HSS but rarely and is responsible for our large brains, then no matter frequently or infrequently the two species made it to the altar, we must all be hybrids of the two species. Either that or there must be a lot of half empty skulls around. If we are all hybrids, as I have long argued, then both Neandertal Man AND Cro-Magnon are extinct, superseded by their hybrid offspring, us!

But you need to realize that there might not have been enough cross breeding in the population to overcome genetic drift during countless generations from here to there. Some alleles may be lurking, but those that made it might only have been those alleles that conferred a positive selection benefit.

[Minimalist]

Either that or there must be a lot of half empty skulls around

There is a fabulous political observation there!

[Digit]

We talk of a species going extinct, but as I understand Darwin, within a species, for what ever reason, a mutation occurs, or has previously occurred, that a new situation causes that mutation to be in some manner advantageous to that particular animal, i.e. to a single individual or small number in a brood, not the whole of the species.
That advantageous mutation will then spread throughout the breeding population untill the new species has entirely superseded the parent species, which is now extinct.
Equally well, the human race is popularly said to be descended from a single African 'Eve', again, one individual. If we are accept this viewpoint then again, if our large brain is down to Neandertal man, the possibility of infrequent matings or otherwise is at least mathematically unimportant.
Once would have been enough if the hybrid obtained a sufficient advantage over his bretheren, and remained a desirable mate, he must have become the new 'Adam'.
I look forward to a very lively debate.

[Cognito]

We talk of a species going extinct, but as I understand Darwin, within a species, for what ever reason, a mutation occurs, or has previously occurred, that a new situation causes that mutation to be in some manner advantageous to that particular animal, i.e. to a single individual or small number in a brood, not the whole of the species.
That advantageous mutation will then spread throughout the breeding population untill the new species has entirely superseded the parent species, which is now extinct.

Equally well, the human race is popularly said to be descended from a single African 'Eve', again, one individual. If we are accept this viewpoint then again, if our large brain is down to Neandertal man, the possibility of infrequent matings or otherwise is at least mathematically unimportant.

Once would have been enough if the hybrid obtained a sufficient advantage over his bretheren, and remained a desirable mate, he must have become the new 'Adam'. I look forward to a very lively debate.

Digit, I believe we are saying the same thing in a roundabout way. The allele located could be one of many lurking alleles left behind by archaic species that confer an advantage in some manner that has yet to be determined. The brain-size allele may have given selective advantage as a result of brain reorganisation in addition to maintaining a larger size. Whether it still provides selective advantage today or not is questionable, but once isolated science can test that hypothesis on my neighbor who is obviously part Neanderthal.

[Digit]

Cognito, on the basis that a part of our brain seems able to make intuitive leaps, and that we can do what we are doing now and reason forward and backwards, and that we are, as far as I know, the only species capable of these acts, then I must argue that a large brain will confer some advantage over those that cannot do these things. As to how much of our oversize brain would be necessary to achieve an advantage over other competing species I must pass.
Have you ever read Jean Auel's Clan of the Cave Bear series? In a fictional background she shows again and again how we are capable of taking advantage of serendipidous, hope that's the correct spelling, events. I can't believe that someone set out to smelt copper ores, or to heat flint to improve their control of it, but I can accept that we were able appreciate what was happening and so take advantage of it.

[Cognito]

Cognito, on the basis that a part of our brain seems able to make intuitive leaps, and that we can do what we are doing now and reason forward and backwards, and that we are, as far as I know, the only species capable of these acts, then I must argue that a large brain will confer some advantage over those that cannot do these things. As to how much of our oversize brain would be necessary to achieve an advantage over other competing species I must pass.

Have you ever read Jean Auel's Clan of the Cave Bear series? In a fictional background she shows again and again how we are capable of taking advantage of serendipidous, hope that's the correct spelling, events. I can't believe that someone set out to smelt copper ores, or to heat flint to improve their control of it, but I can accept that we were able appreciate what was happening and so take advantage of it.

Digit, I understand where you are going but you also need to take into consideration fissures and folding in the human brain. If you expanded the human brain to be "smooth" (similar to dog's brains, etc.) the size would be huge. In other words, a very large brain has already been compressed into a small area by folding over multiple times. Although size does matter in the sexual arena, the brain still needs to pass through a birth canal and there are limitations (just ask any mother).

Yes, I have read all of Jean Auel's books and seen the movie; however, she fell for the "biger brain -- bigger birth canal" idea. So did Erik Trinkaus initially, but it was proved to be wrong about six years ago. I cannot put my fingers on that reference, but will do so should you wish. To wit, HSN birth canals were essentially the same size as HSS.

My conclusion? A better organized brain is more important than brain size when it comes to being intelligent, creative, intuitive, etc. Beagle believes HSNs were just as, if not more intelligent than HSS. I don't agree with all of that position because of their foraging behavior, but they could have had different abilities/intelligence that was not as usefull as those traits possessed by HSS and mentioned above.

[Digit]

I agree with what you say about a better organised brain, Cognito, but that begs the question of how much brain is neede for that better organisation. Using a computer as an analogy, possibly totally wrongly, the peripherals of a computer have much greater volume than the 'brain, so untill we have a greater understanding of our own brain I would not like to have any of mine removed just to find out how much I can manage without. We have this large brain, we are the most intelligent species we know of, by Occam's Razor, a large brain had an adavantage.

[Beagle]

http://www.johnhawks.net/weblog/reviews ... _2006.html

This is Hawks addressing the issue of the the Broca area of the brain. That and the Wernickes' area were both as well developed in Neandertal as in HSS.

Considering that HN also had a hyoid bone that is indistinguishable from HSS, it seems incredible to me that some experts maintain that Neandertal was incapable of complex speech. The bones just don't lie.

[Cognito]

Beags, I was led to this article in John Hawkes site about the recent discovery of the D-Allele for brain size:

http://www.seedmagazine.com/news/2006/1 ... ge=all&p=y

I am really surprise to read Paabo's comments at the end with regard to Lahn's paper as "... the most compelling case to date showing a genetic contribution of Neanderthals to modern humans," and said he plans to to seek confirmation of Lahn's findings in his own work on the Neanderthal genome."

That statement could change the future of evolutionary genetics since Paabo is in charge of the Neanderthal Genome Project that seeks completion of the genome in two years. If he substantiates the find, the "Club" will need a new residence.

[Charlie Hatchett]

Heck, mix in a little Erectus, and Min's psychiatric practice, specializing in Club induced psychosis, will be making big bucks!!

Min is the world's leading psychoanalyst on Club induced psychosis...it's usually terminal, but some have been known to recover...

...some have been known to recover...

but scarred for life.

[Cognito]

Svante Paabo's name is too big in molecular genetics right now to revoke his Club Card. He expressed an opinion and dropped a turd into the punchbowl at the same time. He has my vote for the Brass Balls Award 2006.

[Digit]

Hi Cognito, I can't go with you on your surmise that HSN may have been less intelligent than HSS because of their foraging life style. IF we assume that we are a hybrid of HSN and HSS, and are perhaps more intelligent than either, why did a foraging life style continue for so long after the assumed demise of HSN? I know of at least two peoples who currently pursue such a life style, and many that gave it up in recent times did so reluctantly, so it must have had something going for it.

[Cognito]

IF we assume that we are a hybrid of HSN and HSS, and are perhaps more intelligent than either, why did a foraging life style continue for so long after the assumed demise of HSN? I know of at least two peoples who currently pursue such a life style, and many that gave it up in recent times did so reluctantly, so it must have had something going for it.

Digit, the way I read the article the difference between HSN and HSS was the manner in which each group foraged. HSN tended to remain in a defined geographical area and wait for the food to come to them. As an example, when herds stopped coming through their territory, they tended to switch their diet to something else that was available (water fowl, rabbits, etc.). However, if the herd didn't come to HSS, they went in search of the herd. Subtle difference, but that difference alone could end HSN's era over time, especially in times of climactic stress (i.e. LGM).

[Beagle]

Beags, I was led to this article in John Hawkes site about the recent discovery of the D-Allele for brain size:

http://www.seedmagazine.com/news/2006/1 ... ge=all&p=y

I am really surprise to read Paabo's comments at the end with regard to Lahn's paper as "... the most compelling case to date showing a genetic contribution of Neanderthals to modern humans," and said he plans to to seek confirmation of Lahn's findings in his own work on the Neanderthal genome."

That statement could change the future of evolutionary genetics since Paabo is in charge of the Neanderthal Genome Project that seeks completion of the genome in two years. If he substantiates the find, the "Club" will need a new residence.

Wow - what a statement. This report was posted earlier by myself and by Min. from two sources, but neither one had that quote in it from Paabo. Plus I noticed someone else called the study "bulletproof". I rarely see words like that from these guys. If it truly holds up then the implications are obvious. Thanks Cogs!