What degree of cousin is a chimpanzee (or some other animal)?

[misterW]

Has anyone ever tried to approximate what degree of cousin any nonhuman organism would be to a person? It seems there might be some trouble since the different species would have different generation lengths.... but has anyone ever tried to approximate this?

[Walloon]

From Wikipedia article on Hominini:

Hominini is the tribe of Homininae that comprises humans (Homo), chimpanzees (Pan), and their extinct ancestors. Members of the tribe are called hominins (cf. Hominidae, "hominids"). The subtribe Hominina is the "human" branch, including genus Homo and its close relatives, but not Pan.

The creation of this taxon is the result of the current idea that the least similar species of a trichotomy should be separated from the other two. Through DNA comparison, scientists believe the Pan/Homo divergence was completed between 5.4 to 6.3 million years ago, after an unusual process of speciation that ranged over four million years.

Assuming a median of 25 years per human generation (based on the median of a women's childbearing years), there have been 216,000 to 252,000 human generations since the divergence.

How many generations of Pan (chimpanzees and their extinct ancestors) there have been since the divergence, I would not even guess.

The maximum degree of cousinhood would be 252,000th cousin, but depending on how short a chimpanzee generation is, there could be a lot of "n removed" after that.

[puppygod]

With chimps achieving breeding age at 7 - 15 years, I think we can approximate chimp generation at 10 - 12 years. Roughly twice the human.

[Walloon]

All right, assuming a chimpanzee generation of 11 years, then the maximum degree of cousinhood between humans and chimps would be 252,000th cousin, 321,000 times removed. Minimum degree of cousinhood: 216,000th cousin, 275,000 times removed.

[Chronos]

Of course, both of those probably overstate the generational remove, since shortly after the split, the human and chimp lines probably had very close to the same generation length. To really do it properly, you'd need some way of estimating how long it took for human generation length to increase.

[Risha]

Would we have to calculate in that we're all heavily inbred once you go a number of generations back?

[ultrafilter]

No. All you need is the number of generations between the cousins in question and the last common ancestors.

[Little Nemo]

All you need is the number of generations between the cousins in question and the last common ancestors.

Exactly. You'd need to figure out who was the most recent creature that was the common ancestor of a living human and a living chimpanzee.

[Smeghead]

Richard Dawkins' The Ancestor's Tale takes sort of this approach to explaining life. It may interest you.