Question about evolution, genetic bottlenecks, and inbreeding

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I know I am correct. I think I'll play dumb for a little bit. First, you disagreed with me. Then you said I was correct. I think you have an integrity issue here. I think you are caught in a web of lies that you've resorted to contradicting yourself. Do you lie often?

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Interesting. The person who admits they used to be a creationist, first to get overtly rude, first to 'KNOW' they are right. A poor outlook to take in this subject.An interesting psychology experiment it would make, to study how confident one is their opinions, and whether or not these people correlate with religiousity.Don't like that? How about we drop the insults then and talk about the subject.

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What is magical or special about Y-adam that makes him the MRCA?

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There is nothing magical about him, that is just the definition. IN THIS CONTEXT.I may have misreprestned myself, I am saying that for this example Y-adam and M-eve are the most recent common ancestors. I realise they are all the most recent, but as a definition it is A and H??No one has dealt with the fact that all the definitions I have found refer to the MRCA as an individual, not a group. If you can address this the conversation is complete. IF I am reading the definition wrong, what do they mean by individualHowever you have shown me you can have more than one equal generation common ancestor. So what makes one THE most recent common ancestor, there must be something because all these defintions I find refering to a single person would be baseless.These definitions that the MRCA is an individual must be based on something, no one has said yet.Edited by harry, : No reason given.

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Secondly, on a more practical level, we can't find individuals from genetic data. Eve and Adam are both traced by unmodified genetic data passed by the maternal and paternal lines (respectively) so the only modifications in these lines are mutations, however we only get data when a modification occurs, so there is no way to distinguish between a small population that had the same markers and a single individual.

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I know, but I am talking purely theoritically

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Oh, and another very important point: even if you consider y-chromosome Adam and mitochondrial Eve to represent individuals, this does not mean that they were the only individuals alive at that time,

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I am also aware of that

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only that the very narrow piece of genetic material being tested hails from them MRCA was a couple who only had children together in which case both parents are equally recent ancestors

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Ok so this is my point. If we reach this point, where we have narrowed down the most recent common ancestor down to two people in our quest to find one (if my definition is correct). Plenty of others could have contribured to the gene pool, but these are the direct ancestors.However we still need to go further back to find the one person these 2 people are directly descended from. Because, and this is the crux of it, (Althought I am note sure. If the common ancestor of everyone today, had kids with only one woman as you suggest, they would both the M-Eve and Y-Adam, as they are both the most recent examples of where everyone got their chromosomes.Now we are pretty sure this isnt how it goes. How do I upload an image to show what I mean?

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can all be individuals

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All the definitions I find say they ARE. not can can be

When we discuess scientific definitions things do not always mean what they say though do they. IF they did, we wouldnt need defintions.I have found these definitions, and you are saying they do not matter. Ofcourse they matter, the are written by emininent biolgists for a reason.You can not just brush aside these defintions, there must be a way to reconcile/disprove why an individual is not guarenteed to be an MRCA at some point down the line.How do I upload pictures?

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No. You have found TWO common ancestors. The most recent common ancestor *might* be the most recent of these two or (more likely) is another more recent individual.

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Yeah sorry I worded that wrong. I will get back later tonight with a diagram to help explain what I mean

Okie kokieFirst

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Quote these eminent biologists:

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'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.(I will deal with this again later)You can go on natural journals if you have access and see references.

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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.

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Douglas Rhode, On the Common Ancestors of All Living HumansIf you guys are so sure of yourself, you should be doing research yourself.Now looky here I have drawn this in response to

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No. You have found TWO common ancestors. The most recent common ancestor *might* be the most recent of these two or (more likely) is another more recent individual.

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If we assume the top two people on the chart are Y-adam and M-Eve, we have our two common ancestors. Now their son (their can be any period of time in between the Adam and Eve and the son I have drawn, it does not matter. However, now, say we are descended from people living in Asia. Who is the whole human races Y adam? They guy at the top, assuming his other son survived and passed on his genes and did not interbreed with the population on the chart.However who is the MOST Recent common ancestor of all the asian and african populations? Adam's skip however many generations son!Now all you need to do, is extropolate this to where one son split off to be a chimpanzee, and another split off to become humans.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. But I am 99% sure that a Most recent common ancestor is an individualEdited by harry, : No reason given.Edited by harry, : No reason given.Edited by Adminnemooseus, : change image to thumnail.

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One point, the MCRA of both humans & chimps would also be the MRCA to any other chimpoid species (no fossils have been found as of yet) and to the hominid genera, Sahelanthropus, Orrorin, Ardipithrcus, Australopithicus, Parantropus, Kenyanthropus & Homo.

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Agreed

Thats all well and good, but I am talking about the ancestors of individual creatures, not of individual genes.

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Ok so this is my point. If we reach this point, where we have narrowed down the most recent common ancestor down to two people in our quest to find one (if my definition is correct). Plenty of others could have contribured to the gene pool, but these are the direct ancestors.

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Disregard it, I phrased it badly and it was wrong anyway. I think my most recent post explains my position well enough.I am now saying a MRCA can not be a group of individuals and i am inviting someone to disprove me.

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The existence of common ancestors does not in itself apply bottlenecks.

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Yeah I got that, staga explained it. However I am uneasy with people saying a Most Recent Common ancestor can be a group of people.Can we confirm there must a single most recent individual common ancestor to all humans? Or do we disagree on that to?

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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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I showed you how its possible in my flow chart. Read it, and then we can talk, its on page 4Edited by harry, : No reason given.

StagaDo 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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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?

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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.

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That can't be M-Eve unless she had some daughters.

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Fine throw a daughter into the mix to go off and breed of the line

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But I am 99% sure that a Most recent common ancestor is an individual

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A most recent common ancestor is an individual.

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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.

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A most recent common ancestor is an individual.

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That we have a unique MRCA will never be withing our power to prove

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Are you contradicting yourself? I don't know if I have understood you properly.

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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.

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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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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.

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 questionWas 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?

Yeah I didnt think you could

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We have more than one ancestor.

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We have at least one MRCA.

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We may have more than one MRCA.

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The definition of MRCA is THE MOST RECENT COMMON ANCESTOR.

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Oh, you believe me now?

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You clearly take me for an idiot and have not been reading any of my posts.I have repeatedly stated it is the most recent common ancestor. Yuo say you have not memorised my posts word for word, you have not even read the basic points of them either.

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Bet?

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Look once more at the diagram from the SkepticWiki. Individuals A through H are all contemporaries, and all common ancestors of the present generation.

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Your argument cannot be "logically inevitable" if it is possible to conceive of a counterexample. And that is a counterexample.

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THIS IS NOTHING TO DO WITH THAT DIAGRAM. I HAVE NOW SAID REPEATEDLY, IAM NOT REFFERING TO GRANDPARENT MODELS ETC I AM TALKING ABOUT MRCA'S FOR GEOGRAPHICALLY DIVIDED POPULATIONS OR WHOLE SPECIES

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How would I know?

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Go back, re read everything I have said, then answer the question on what you think is the most likely answer to this questionDo we have a single MRCA that is related both chimpanzees and humans, yes or no?