> In contrast, gene duplication at a large scale in any animal would probably fundamentally mess up body plan development in non-survivable ways. While unusual

> In contrast, gene duplication at a large scale in any animal would probably fundamentally mess up body plan development in non-survivable ways. While unusual, polyploidy in mammals is survivable, there's a species which is tetraploid: https://en.wikipedia.org/wiki/Plains_viscacha_rat https://en.wikipedia.org/wiki/Plains_viscacha_rat The wiki exaggerates the degree to which this claim is controversial, fwiw. Better than the alternative, probably.