Is Y-chromosomal Adam younger than Mitochondrial Eve?

Question

A Christian claimed to me that: the Y-chromosomal Adam is way younger than the Mitochondrial Eve.

Is this true?

He argued that this was consistent with the biblical account: that Noah is Y-Chromosomal Adam and Eve is Mitochondrial Eve.

Is this result really consistent with that claim?

These Christian sites repeat the claim:

• Molecular History Research Center
• Evidence for Christianity

I think I read somewhere that the most recent universal human ancestor might be less than 5,000 years old. That's younger than Chinese civilization. But, hey, could it be true?

Some said I am missing the point that Y-Adam is not the partner of m-Eve.

Actually that's the point. Sons of Noah had wives and those wives are decendant of Eve, not Noah. Hence, mitocondrial eve is older than than y chromosome Adam. The m-eve is Eve, and the Y-adam is Noah. Y chromosome adam is actually Noah. That seems to be what the Christians are trying to point out.

Now, I am a half-way atheist; I don't know which one is true.

Answer 1

Yes, it is true to the extent that we can date accurately (see the Wikipedia links you provided, or this summary article). The best estimates right now are that Mitochondrial Eve lived 200+-13 kya, while Y-chromosomal Adam lived 142+-15 kya.

It is also true that Genesis describes Noah and his three sons (one Y chromosome) and his wife and sons' wives (4 different mitochondria) as the human passengers on Ark.

However, this is just about exactly meaningless. The genetic data doesn't agree very well with this sort of arrangement, especially since there would need to be a massive population expansion after the ark, which means that many male lineages would trace back to a common choke-point; the lineage would look more like a comb than a tree. Instead, the branching pattern seems like a typical tree expected from a more stable population size (see picture on Wikipedia, for example). But so much other genetic data profoundly disagrees with this (e.g. the genetic age of pretty much any allelic variation in humans should be no more than the mitochondrial age of Eve, more or less, and this is absolutely not what is found) that Biblical literalists can only rationally accept such drastically different processes than we observe now that one can draw no conclusions about what happened back then.

Answer 2

No, most recent studies give an equal or slightly older date for the Y Chromosome.

An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree (full text pdf)

We report the discovery of an African American Y chromosome that carries the ancestral state of all SNPs that defined the basal portion of the Y chromosome phylogenetic tree. We sequenced ~240 kb of this chromosome to identify private, derived mutations on this lineage, which we named A00. We then estimated the time to the most recent common ancestor (TMRCA) for the Y tree as 338 thousand years ago (kya) (95% confidence interval ¼ 237–581 kya). Remarkably, this exceeds current estimates of the mtDNA TMRCA, as well as those of the age of the oldest anatomically modern human fossils.

The numbers presented here may be an overestimate for the age of this haplotype, this paper estimates:

The ‘extremely ancient’ chromosome that isn’t: a forensic bioinformatic investigation of Albert Perry’s X-degenerate portion of the Y chromosome

We show that the authors ignored previously inferred Y-specific rates of substitution, incorrectly derived the Y-specific substitution rate from autosomal mutation rates, and compared unequal lengths of the novel Y chromosome with the previously recognized basal lineage. Our analysis indicates that the A00 lineage was derived from all the other lineages 208 300 (95% CI=163 900–260 200) years ago.

This 2013 paper summarizes:

Low-Pass DNA Sequencing of 1200 Sardinians Reconstructs European Y-Chromosome Phylogeny

The evolution of human populations has long been studied with unique sequences from the nonrecombining, male-specific Y chromosome (see the Perspective by Cann). Poznik et al. (p. 562) examined 9.9 Mb of the Y chromosome from 69 men from nine globally divergent populations—identifying population and individual specific sequence variants that elucidate the evolution of the Y chromosome. Sequencing of maternally inherited mitochondrial DNA allowed comparison between the relative rates of evolution, which suggested that the coalescence, or origin, of the human Y chromosome and mitochondria both occurred approximately 120 thousand years ago. Francalacci et al. (p. 565) investigated the sequence divergence of 1204 Y chromosomes that were sampled within the isolated and genetically informative Sardinian population. The sequence analyses, along with archaeological records, were used to calibrate and increase the resolution of the human phylogenetic tree.