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Wokko 
Come and take it.
Joined: 04 Oct 2005
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David 
I dare you to try
Joined: 27 Jul 2003
Location: Andromeda
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Interesting (and, surprisingly for the Daily Mail, seems reasonably legit as far as I can tell, lol*). How does that evidence square though with findings that most humans have some traces of neanderthal in them? Yes, neanderthals went extinct around 40,000 years ago, but they also emerged hundreds of thousands of years prior to the time period referred to in the study, and so any further interbreeding would thus, you'd think, lead to an at least somewhat more diverse ancestry.
*Note that the claim to shared ancestry isn't mentioned in this article on the study (which nonetheless does include the most interesting and controversial findings mentioned above). Perhaps that suggestion is a bit of an embellishment, to say the least?
https://phys.org/news/2018-05-gene-survey-reveals-facets-evolution.html
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Last edited by David on Sun Nov 25, 2018 11:59 pm; edited 1 time in total |
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think positive
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Joined: 30 Jun 2005
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**** so we are all related?? dont do that to me!
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You cant fix stupid, turns out you cant quarantine it either! |
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watt price tully 
Joined: 15 May 2007
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think positive
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Joined: 30 Jun 2005
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WPT i need you to go to bed
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You cant fix stupid, turns out you cant quarantine it either! |
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David
I dare you to try
Joined: 27 Jul 2003
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It seems even that Phys.org paper may have been guilty of exaggeration (this is how science journalism can go wrong a fairly unremarkable finding gets sensationalised, and then extravagant conclusions can be drawn from that sensationalised report, and so on). Here's a response to some of the coverage:
https://biologos.org/blogs/archive/did-90-of-animal-species-appear-about-the-same-time-as-human-beings
| Quote: | Their conclusions are interesting (and to some extent unexpected) but they are not shocking, nor do they defy evolutionary theory. To see why, lets unpack what the authors have claimed. First, it is important to note that the authors never claim that most species came into existence within the past 200,000 years. Rather, what has come into existence within that time frame is the genetic variation observed in one gene in the mitochondrial genome. By tracing the mutations in that one gene, we can trace the origin of the gene back to the last common female ancestor of all living members of a certain species (the so-called mitochondrial Eve). But this discovery, at best, tells us the minimum age of the species. It tells us little to nothing about the maximum age of a species.
To understand the difference between minimum and maximum age for a species, consider the cheetah (Acinonyx jubatu). The cheetah has remarkably little genetic variation in both its nuclear and mitochondrial genome. Using the same methods employed by Stoeckle and Thaler, this species appears to be no more than 12,000 years old (unlike 90% of other mammal species, which are hundreds of thousands of years old). However, the fossil record of the cheetah species extends back several hundred thousand years. These two observations are not contradictory. The species is very old, but its mitochondrial DNA appears quite young. 12,000 years ago, at the end of the last Ice Age, cheetahs were migratingpresumably as a result of large climatic changesfrom their native Asian point of origin to their present home in Africa. It appears this move resulted in a significant population bottleneck, wherein only a small number of cheetahs made it to Africa; the ancestors of the present population. All other cheetahs in Asiaalong with their genetic diversitywent extinct. The mitochondrial genetic clock was reset by the genetic bottleneck. Examining mitochondrial DNA variation alone, we can only predict when the most recent bottleneck occurred for the mtDNA lineages found in cheetahs. We cannot predict the age of the cheetahs as a species.
The scenario above can be played out for most species. An examination of the mitochondrial genome of any species will only tell us when the common ancestor of all modern members of this species existed, which will almost invariably occur after the evolutionary origin of the species. What Stoeckle and Thaler have potentially discovered, by examining the variation of a single gene in the mtDNA, is that most species experienced a mitochondrial genetic bottleneck between 100 and 200 thousand years ago. |
So are we all descended from the same two people? Probably not, but it does look like there might have been a period 100,000 years or so ago in which the then human population thinned dramatically before expanding out again hence, the "bottlenecks" described above.
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think positive
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Joined: 30 Jun 2005
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cmon david, we lost the GF let me do it here! there is no way you believe in adam and eve - or the world is flat! if the world is flat, whats underneath?? is it jagged??
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You cant fix stupid, turns out you cant quarantine it either! |
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David
I dare you to try
Joined: 27 Jul 2003
Location: Andromeda
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The prevailing theory is that it's turtles all the way down. 
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All watched over by machines of loving grace |
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think positive
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Joined: 30 Jun 2005
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$$%^%%$ hal beat u to it!!
turtles?? ok thats just wierd!! im thinking clumps of mud and rocks, in HD
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You cant fix stupid, turns out you cant quarantine it either! |
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watt price tully
Joined: 15 May 2007
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| think positive wrote: | | WPT i need you to go to bed |
I'm open minded but how does your partner feel about it?
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“I even went as far as becoming a Southern Baptist until I realised they didn’t keep ‘em under long enough” Kinky Friedman |
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think positive
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Joined: 30 Jun 2005
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| watt price tully wrote: | | think positive wrote: | | WPT i need you to go to bed |
I'm open minded but how does your partner feel about it?
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 holy crap~i only had 2 drinks that night, im out of practice!
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You cant fix stupid, turns out you cant quarantine it either! |
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