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Author | Topic: Question about evolution, genetic bottlenecks, and inbreeding | |||||||||||||||||||||||||||
Taq Member Posts: 9973 Joined: Member Rating: 5.7 |
Thats all well and good, but I am talking about the ancestors of individual creatures, not of individual genes. Then let's use you and your cousins as an example. You share a common ancestor--your shared set of grandparents. For you and your cousins, your grandparents are your most recent common ancestor. However, you and your cousins carry DNA from ancestors other than your most recent common ancestor.
I am now saying a MRCA can not be a group of individuals and i am inviting someone to disprove me. Being that humans are dioecious, it would seem that it is impossible for ONE person to be the common ancestor of an entire species. This is possible in a bacterial colony, but not so much for humans.
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harry Member (Idle past 5468 days) Posts: 59 Joined: |
quote: I showed you how its possible in my flow chart. Read it, and then we can talk, its on page 4 Edited by harry, : No reason given.
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Stagamancer Member (Idle past 4916 days) Posts: 174 From: Oregon Joined: |
Being that humans are dioecious, it would seem that it is impossible for ONE person to be the common ancestor of an entire species. This is possible in a bacterial colony, but not so much for humans. This actually not at all impossible. Common ancestor does not mean progenitor, it just means if you go back far enough, you can find an individual that is a part of everyone's family tree. Humans are not that diverse genetically, either, which makes it even more probable. Of course, because of the relatively large numbers of alleles we have, trying to figure out when such a person existed is very time consuming because we'd have to take all of the histories of all our genes into account. This doesn't mean that this common ancestor is responsible for all our genes, simply that he/she has contributed genetic material (or genetic material derived from his/hers) to everyone. So it may be that my gene A is derived from the MRCA and your gene B is derived from that same individual. Doing all this work is probably not even worth it, which is whywe search for mitochondrial-Eve and Y-Adam instead. This cuts down on time and effort and still gives us the information we're searching for, such as where in the world Homo sapiens originated. "There are three kinds of lies: lies, damned lies, and statistics."
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harry Member (Idle past 5468 days) Posts: 59 Joined: |
Staga
Do you agree that every species has an inevitable single most recent common ancestor with another species? That also there is one within species, such as homo sapiens? Do you agree that it is a logical inevitability? Despite being impossible to find the exact individual? I have decided I am wrong to apply most recent common ancestor to a great grandparent tree like I have been shown. However I am still right in applying it to overall species, and large sections of species, as I have in my flow chart. Edited by harry, : No reason given.
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Taq Member Posts: 9973 Joined: Member Rating: 5.7 |
I showed you how its possible in my flow chart. Read it, and then we can talk, its on page 4 I was thinking more in terms of genetics. Yes, I can see in those terms that it is not impossible. Genetically, the two groups would not share a common X chromosome ancestor that is the single male ancestor, which is what I was going for. Edited by Taq, : No reason given.
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Dr Adequate Member (Idle past 285 days) Posts: 16113 Joined: |
'Concestor 0 is the most recent ancestor that unites the geograpahically divided population' Dawkins, page 45 ancestors tale. See graph on page 49 of the book to see how ONE PERSON is the most recent common ancestor of all mankind. But the graph does not show that this must be a unique distinction. Nor does Dawkins say so.
However, if we consider not just our all-female and all-male lines, but our ancestors along all parental lines, it turns out that everyone on earth may share a common ancestor who is remarkably recent....that the common ancestor of everyone alive today very likely lived between 2,000 and 5,000 years ago. That we have a common ancestor is not in doubt. That we have a unique MRCA will never be withing our power to prove, and Douglas Rhode does not say so. --- As my diagram has shown, there can be more than one MRCA. This is by-the-by. We may or may not have had a unique MRCA. Do you understand now why that person did not constitute a bottleneck? ---
If we assume the top two people on the chart are Y-adam and M-Eve ... That can't be M-Eve unless she had some daughters.
If anyone here can draw me a tree disproving that there must have at some point been someone who is the ancestor of all humans. I'll shut up. That's not being disputed.
But I am 99% sure that a Most recent common ancestor is an individual A most recent common ancestor is an individual. --- Please note once again that even if there was a unique MRCA, neither M-Eve nor YN-Adam need have been that individual. The odds are aginst it.
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harry Member (Idle past 5468 days) Posts: 59 Joined: |
quote: Do you actually read my posts or do you just skip over them. I have re-iterated since my like 4th post I know its not a bottle neck now.
quote: Fine throw a daughter into the mix to go off and breed of the line
quote:quote: So why are people going against me on this. People have said the MRCA can be a group of people, which if we are talking about grandparents fine, I will accept. But if they think as a species we don't have one, they are off the bat.
quote: quote: Are you contradicting yourself? I don't know if I have understood you properly.
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Taq Member Posts: 9973 Joined: Member Rating: 5.7 |
I have decided I am wrong to apply most recent common ancestor to a great grandparent tree like I have been shown. However I am still right in applying it to overall species, and large sections of species, as I have in my flow chart. The one problem with the chart is that it assumes the all the other lineages will die off. It's not as if one son goes to Asia and finds the continent full of women and no men. It's not as if I can have two sons by two mothers, send one to Africa and one to Asia, and then proclaim myself the common ancestor of all humanity. At each point in time there may very well be a single MRCA, but that MRCA will change through time as lineages die off. Surely, the MRCA 100,000 years ago was different from the modern MRCA.
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harry Member (Idle past 5468 days) Posts: 59 Joined: |
quote: YES YES!! your getting what I mean. The MRCA will change as lineages die off. Now if we assume adam and eve had a daughter and a son as well as the MRCA son in the centre of the graph. They can go off and populate Asia and Africa, so their populations can await the arrival of the two sons of the MRCA. Now if we were to shift our perspective, and look at the son of Adam I didnt follow, then we may find that he is related in some way to the others. However, that does not remove The existance of an individual MRCA, it just changes their identity, and it could be a very different person. The other lineages do not HAVE to die off. Edited by harry, : No reason given.
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Dr Adequate Member (Idle past 285 days) Posts: 16113 Joined: |
Do you actually read my posts or do you just skip over them. I have re-iterated since my like 4th post I know its not a bottle neck now. I've not been memorizing your every word ...
Fine throw a daughter into the mix to go off and breed of the line That's not good enough ... she needs to be the female-line ancestor of every female on that chart with living female-line descendants.
So why are people going against me on this. People have said the MRCA can be a group of people, which if we are talking about grandparents fine, I will accept. But if they think as a species we don't have one, they are off the bat. We have at least one.
Are you contradicting yourself? No. A most recent common ancestor is necessarily an individual for the same reason that a pretzel vendor is necessarily an individual --- that's just grammar. However, the distinction need not be unique (see the diagram from the SkepticWiki).
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harry Member (Idle past 5468 days) Posts: 59 Joined: |
You are starting to bore me now. No one has come up with anything that proves we can not be from one ancestor.
The definition of MRCA is THE MOST RECENT COMMON ANCESTOR. All you are doing is talk talk talk. You can not show me one paper that says I am wrong. I am going to show the logical inevitability of my argument. Answer the question and only the question Was there one creature that was related to all living chimpanzees and all living humans? Yes or No? Eveything related to this creature, ie its parents etc, are also common ancestors, but not relevant. But is there only one creature that is the most recent common ancestor of you, and poopflinger the chimp?
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Stagamancer Member (Idle past 4916 days) Posts: 174 From: Oregon Joined: |
Do you agree that every species has an inevitable single most recent common ancestor with another species? Because of the dilution that occurs with every single generation, I'm not so sure this is true for every single pairing of species. I can't imagine, for example, that you could find an individual that has contributed genetic information to every human and every Escherichia coli bacterium. But, I'm going to have to research more on what the experts say about this. So, I honestly can't give you a definitive answer now.
Do you agree that it is a logical inevitability? Despite being impossible to find the exact individual? But yes, I agree, that according to the MRCA is defined, logically, it is possible, though perhaps not inevitable. "There are three kinds of lies: lies, damned lies, and statistics."
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Stagamancer Member (Idle past 4916 days) Posts: 174 From: Oregon Joined: |
At each point in time there may very well be a single MRCA, but that MRCA will change through time as lineages die off. Surely, the MRCA 100,000 years ago was different from the modern MRCA. This is true, and this is what differentiates a MRCA from a progenitor. The MRCA, by definition is really a product of the group that you are looking at. Obviously, the MRCA of me and my siblings is different from you and your siblings, and the MRCA for me, my siblings, you, and your siblings is different too.
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Dr Adequate Member (Idle past 285 days) Posts: 16113 Joined: |
Re: Would you Adam and Eve it? You are starting to bore me now. No one has come up with anything that proves we can not be from one ancestor. We have more than one ancestor. We have at least one MRCA. We may have more than one MRCA.
The definition of MRCA is THE MOST RECENT COMMON ANCESTOR. Oh, you believe me now?
All you are doing is talk talk talk. Well, this is the internet. If you would instead prefer me to whack you over the head with an inflated pig's bladder, I shall need traveling expenses.
You can not show me one paper that says I am wrong. This is because there is no such thing as the Journal of the Bleedin' Obvious.
I am going to show the logical inevitability of my argument. Bet? Look once more at the diagram from the SkepticWiki. Individuals A through H are all contemporaries, and all common ancestors of the present generation. Your argument cannot be "logically inevitable" if it is possible to conceive of a counterexample. And that is a counterexample.
Answer the question and only the question Was there one creature that was related to all living chimpanzees and all living humans? Yes or No? Eveything related to this creature, ie its parents etc, are also common ancestors, but not relevant. But is there only one creature that is the most recent common ancestor of you, and poopflinger the chimp? How would I know?
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Theodoric Member Posts: 9076 From: Northwest, WI, USA Joined: Member Rating: 3.7 |
You are starting to bore me now. No one has come up with anything that proves we can not be from one ancestor. Oh, are you trying to set us up here? Trying to worm around to some sort of creationist or ID bs.
I am going to show the logical inevitability of my argument. What? Is it some sort of secret? Show us the "logical inevitability" of your argument. That way we can tell you if it is a "logical inevitability" or not. My guess is you are going to present some sort of creationist or ID crap. Maybe I am wrong. I will wait patiently for your argument. Facts don't lie or have an agenda. Facts are just facts
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