john hawks weblog

paleoanthropology, genetics and evolution

Mailbag: Zorse pigmentation

Wed, 2010-09-15 20:59 -- John Hawks

Re: Horse-zebra hybrids

I know you saw the picture of the zebra horse in the NYT this morning. Are we SURE that hasn't been photoshopped? I mean, I know it is the NYT, but it makes me thinkk that I don't understand ANYTHING about genetics at all!

Yeah, apparently this particular one is unique.

The stripes come from patterning genes that activate the melanin pathway; the pattern gradient inhibits expression of a gene that synthesizes melanin. White spots occur when a different gene is turned off, on the same pathway. So the two combine -- it's like a palomino that has stripes instead of splotches, I guess.

I have a slide that shows a cattle-bison hybrid with similar spots, like a cow.

Neandertals

For years, I've worked on their bones. Now I'm working on their genes. Read more about the science studying these ancient people.

Denisova

From a finger bone of an ancient human came the record of a completely unexpected population. My lab is working on the science of the Denisova genome.

Acceleration

The advent of agriculture caused natural selection to speed up greatly in humans. We're uncovering some of the ways that populations have rapidly changed during the last 10,000 years.

Malapa

Just outside Johannesburg, the Malapa site is producing some of the most exciting finds in human evolution. This site is the headquarters of the Malapa Soft Tissue Project.