or in more scientific terms: Why are F1 hybrids so often sterile or lethal?
The Dobzhansky-Muller theory says that there is an incompatibility between genes with reduced fitness that have diverged between species. So far nobody has ever observed a D-M gene but a new Science paper describes two genes that separate D. simulans and D. melanogaster: lhr (lethal hybrid rescue) and hmr (hybrid male rescue).
Well, dogs have 78 chromosomes, arranged in 39 pairs, while cats have 38 chromosomes, in 19 pairs – so no viable embryo can be produced.
Yea, Yea.
