Mailbag: Neandertal backbreeding

In your blog, you have commented on the prospect of re-creating a neandertal from a "completed" genome.....I agree with your views and predictions. However, given the apparent widespread occurrence of small pieces of the neandertal genome in contemporary humans, there should be a large variability in the fraction of each person's genome which he/she shares with at least the small number of neandertals whose DNA has been sampled. And though one could argue that ethics would be trampled, one could selectively breed exisiting humans to enhance their complement of neandertal genes. Not that I am suggesting this should be done, but such breeding could be entirely voluntary, may have already occurred, and would overcome at least some "Jurassic Park" and Frankensteinian objections to the enterprise??

You bet – that’s not only plausible in principle, it’s exactly what people are trying to do with cattle to backbreed something like aurochsen.

The success (not withstanding the time required) hangs on the distribution of Neandertal variation in the current genome. We don’t know yet how clustered it is – is it a 3 percent average, but people have random parts, or is it that most people share the same 3 percent? If it’s more scattered, then a larger representation of the Neandertal genome still exists, distributed among many people; if not, we may not be able to get more than a few percent of a Neandertal by backbreeding.