Common y-chromosome ancestor, 60K yr ago

[SCOOTER93]

Has any one been to the dentist office lately and read the October 04 National Geographic article about the Phoenicians? They claim in that article that all modern males trace their ancestory back to a common ansector who lived 60,000 years ago.

 

This seems surprising to me because modern people were supposed to be migrating out of Africa (by the replacement theory) by 110K years ago. So our intrepid ancestor would have had to rack up a lot of milage on his frequent flier card. Also, there seems to be too much genetic variation in the human genome to have a common ancestor as recently as 60K years ago.

 

National Geographic is not exactly a super market tabloid so I have to give it some credence, but it seems strange with accepted thinking on human evolution.

 

SCOOTER93

[Sorcerer]

Yes and the aborigines were supposed to be in aussie already by ~60kya.

 

I think perhaps the sample size of the DNA they used wasn't large enough, this combined with the ethnicity not being sufficiently mixed and an incorrect assumption of the rate of mutation would all cause the estimate to be wrong.

[Ophiolite]

This seems surprising to me because modern people were supposed to be migrating out of Africa (by the replacement theory) by 110K years ago. SCOOTER93

There is hot debate in the field of anthropology at present' date=' brought on by just such conflicting evidence as this.

 

Also, there seems to be too much genetic variation in the human genome to have a common ancestor as recently as 60K years ago.

SCOOTER93

I understand that there is less genetic variation in humans than in most animal species. I seem to recall this is due to a 'choke point' around 80kya when we almost went the way of the dodo. Perhaps one of our biology savants can comment on these two points.

 

Has any one been to the dentist office lately and read the October 04 National Geographic article about the Phoenicians? SCOOTER93

In the UK, following a long established tradition, this issue will not appear in dentist's waiting rooms till April 2017.

[SCOOTER93]

There is hot debate in the field of anthropology at present' date=' brought on by just such conflicting evidence as this.

 

I understand that there is less genetic variation in humans than in most animal species. I seem to recall this is due to a 'choke point' around 80kya when we almost went the way of the dodo. Perhaps one of our biology [i']savants [/i]can comment on these two points.

 

In the UK, following a long established tradition, this issue will not appear in dentist's waiting rooms till April 2017.

I thank you and Sorcerer for your comments.

 

Just by looking at people and comparing variation of general apperance with the variation of other species, (In the wild, I mean, not species that man has genetically messed with), it would seem there should be more genetic variation with people. Think about lions, tigers, zebras, deer elk ect. These all look much more alike each other than people look like each other.

 

Sorry about your UK traditions for dentist's office waiting rooms. Do you have to wait that long for treatment, too?

[Sorcerer]

Thats a pretty anthropocentric veiw scooter, we can distinguish each other well because it is necessary as a social animal, there isnt a need for us to distinguish between wild animals as such though. Its kind of like the old racist remark "they all look alike to me"..... maybe if you spent time studying them the differences would begin to become apparent.

[ed84c]

Well wasn't it all pangea in those days?

[Sorcerer]

No, pangea existed ~245 million years ago, gondwana and laurasia split about 135 mya.

 

We are talking 60 thousand years ago, not million, this is a very short time on a geological time scale, the continents were basically in the positions they are today.

 

Anyway, what does pangea have to do with it?

[ed84c]

well i thought that was the reason behind the spread of the human race. He was asking about how they walked so far from ethiopia (well i thought he was) and hence in pangea the lebanon and ethiopia would have been much closer, i prosume.

[Sorcerer]

Well the migration from africa took place over several thousand years, it wasn't a once off trek across the globe. During this time the earths climate was changing, at the peak of the last ice-age the sea level was much lower than it is today, due to the water being locked up in ice sheets, this allowed crossing of passages such as the bering straight which let Humans into america, and also possibly through the indonesian islands to australia, maybe only required a short swim. Also passage across from north africa to spain via gibralta may have been possible.

 

I think you may also need to re-read the thread, he wasn't asking anything about how they walked so far.

[ed84c]

oh sorry, to waste your time and all. Also your point is why Humans are in the UK, but how did they get to easter island?

[Ophiolite]

oh sorry, to waste your time and all. Also your point is why Humans are in the UK, but how did they get to easter island?

It's worth emphasising a point Sorcerer made, but I don't think you picked up on. This movement is occuring over thousands of years. The average distance moved each year is of the order of one or two miles on average. This is not a matter of great treks by a small band of humans over thousands of miles, it is a case of a gradual extension of hunting territory over decades, probably punctuated by a more serious move of the order of tens or even hundreds of miles when confronted with some natural catastrophe.

 

I'm not sure where you picked up the reference to how humans reached the UK. The only UK reference I can find in this thread to the presence of National Geographic in dentist's waiting rooms, and the authorities are all prety much in agreement that they arrive by post and do not actually walk themselves!

 

Easter Island is an easy one. The Polynesians discovered and settled it around 400AD. By that time they were skilled sailors and ocean navigators. It is only 1600 years ago.

[ed84c]

I meant that you made a point that the sea levels were lower which is why we have a ninhabited UK

[Sorcerer]

Homo ergaster lived in the UK hundreds of thousands of years before Homo sapiens, I think, but am not sure, that there was lower sea levels at this time, a few hundred thousand years is also enough time for continental plates to drift so perhaps the UK was slightly closer to the mainland at this time.

 

If the sea level wasnt sufficiently low for humans to get to the UK via the english channel before the invention of boats, then they may have walked across the sea ice, perhaps they were out here looking for seals or something and came across the island.

 

Im not sure what the earliest record of human activity in the UK is, I will do a search now.

[ed84c]

according to Mr Titchmarsh who seems to be an expert on these things now (i am of course refering to the TV series 'the natural history of britain') that is how the UK became inhabiteted

[Sorcerer]

Ooops I meant heidelbergensis.

Heres a nice link: http://www.open.ac.uk/StudentWeb/s292/

Having trouble finding out about human history in the UK though.

[ed84c]

heidelbergensis? Try the BBC site if you want more info

[Sorcerer]

according to Mr Titchmarsh who seems to be an expert on these things now (i am of course refering to the TV series 'the natural history of britain') that is how the UK became inhabiteted

 

Which way?

Swam the english channel when it was lower sea level?

Walked over the sea ice?

Crossed in boats?

 

Havent seen the series, New Zealand public TV is crap.

[ed84c]

lol, walked across the sand beds of the non existant channel, the channel was still frozen up in the north of the UK

[Ophiolite]

Which way?

Swam the english channel when it was lower sea level?

Walked over the sea ice?

Crossed in boats?

.

No English channel (and in the interests of European harmony: La Manche? Non!) No white cliffs. The Thames a tributary of the Rhine. Human settlement on the now deluged Dogger bank in the North Sea. Separation didn't occur till sea levels rose at the end of the last glacial retreat and the present channel was eroded.

But thereafter there was probably periodic settlement by boat.

 

Referring back to an earlier post of yours in this thread. The UK is on the same plate as nearby Europe, so no closer proximity there I'm afraid.

[swansont]

Has any one been to the dentist office lately and read the October 04 National Geographic article about the Phoenicians? They claim in that article that all modern males trace their ancestory back to a common ansector who lived 60' date='000 years ago.

 

This seems surprising to me because modern people were supposed to be migrating out of Africa (by the replacement theory) by 110K years ago. So our intrepid ancestor would have had to rack up a lot of milage on his frequent flier card. Also, there seems to be too much genetic variation in the human genome to have a common ancestor as recently as 60K years ago.

 

National Geographic is not exactly a super market tabloid so I have to give it some credence, but it seems strange with accepted thinking on human evolution.

 

SCOOTER93[/quote']

 

Y-chromosome "Adam" and Mitochondrial "Eve" are massively misunderstood phenomena. This is a common y-chromosome ancestor, which does not mean that it's the "father of all humans" or anything like that. For one thing, the y-chromosome is male-only. This isn't the common ancestor of women. It would be incorrect to interpret the existence of Y-Adam to mean that he was the only male alive at the time. Here is more on M-Eve and Y-Adam. Read the mathematical argument carefully.

[SCOOTER93]

Y-chromosome "Adam" and Mitochondrial "Eve" are massively misunderstood phenomena. This is a common y-chromosome ancestor, which does not mean that it's the "father of all humans" or anything like that. For one thing, the y-chromosome is male-only. This isn't the common ancestor of women. It would be incorrect to interpret the existence of Y-Adam to mean that he was the only male alive at the time. Here[/url'] is more on M-Eve and Y-Adam. Read the mathematical argument carefully.

 

Your link to the Y-chromosome Adam and the Mitochondrial Eve were very interesting and explain a lot of the things that I have been puzzling over, well, I'm still puzzling, but perhaps in a little more informed way.

 

Thank You

 

Scooter93