BillHoyt said:
You didn't read that page, did you? Go back to that page, sir, and read it. For understanding this time.
Here is the link.
Here's another example, Peter
"Squares with yellow dots represent relatives that share the same Y-chromosome"
And another
"Family historians researching their own dynasties will take heart from this, since men sharing surnames (passed from father to son in many societies) might also share Y chromosomes."
"share Y chromosomes," Peter. The phrase is everywhere. And everywhere it is shorthand for "share copies of essentially the same Y chromosome code."
Do you want more, Peter?
You still haven't given anything that contradicts my original statement.
From your own link:
This is why the Y chromosome is so widely used in human population studies. As it passes from father to son down paternal lineages, the only changes occurring are due to mutation, and the molecular record of the past is therefore relatively easy to interpret compared to the recombining X chromosome and autosomes.
Findings support the hypothesis that modern humans originated in Africa about 150 000 years ago.
The simplest and slowest kind of mutation alters a single base in DNA, for example from a ‘C’ to a ‘T’. A rich resource of these binary DNA markers has now been discovered on the Y chromosome, and in combination these define signatures of different Y-chromosomal types called ‘haplogroups’. Haplogroups can be arranged into a well-resolved genealogical tree, representing the branching order in which the different mutations occurred since all modern Y chromosomes had a common ancestor (sometimes known as ‘Y-chromosomal Adam’, although he was only one of many men in a population, rather than the solitary forefather of the Book of Genesis).
Your own link shows that men with the same ancestor have different Y-chromosomes due to mutation.
The human race DOES have a common male ancestor, the Y-chromosomal Adam. Yet they don't have the same Y-chromosome because of mutation.
Which is what I said originally.
I erred when I said the common ancestor lived several million years ago. From your link, he lived 150,000 years ago. On that point I stand corrected.
Randi's column contained the words "By rights, this means that all men throughout the world should share the same Y chromosome, and we don't."
Well, you might want to believe that the word "same" means "the same apart from mutations". Fair enough.
So, in your opinion, Randi meant to say "all men throughout the world should share the same Y chromosome apart from mutations, and we don't."
The trouble is that even in your interpretation is correct, Randi is still wrong. Because, by YOUR definition of "same" we DO share the same Y-chromosome.
Randi is wrong either way.