what would happen if the nucleus of a sex cell had the same amount of chromosomes as the original nucleus

Question

what would happen if the nucleus of a  sex cell had the same amount of chromosomes as the original nucleus

anonymous · Answer

you would get an organism that has double the chromosome number as its parents. see, when two haploid sex cells merge, you get one diploid intermediate which then does meiosis. is you merge two diploid sex cells, you get a tetraploid intermediate. and as you know from down syndrome, too many chromosomes is as bad as too few. the organism wouldn't evolve at all.

anonymous · Answer

But what would happen if the offspring gets double the number of chromosomes? Will it result in evolution?

preetha · Answer

If the progeny is viable and is able to transmit this to the next generation, maybe.

anonymous · Answer

So that's how humans came into existence.

anonymous · Answer

for an organism to be "suddenly tetraploid", you will need a MUCH bigger adaption. imagine what you do during meiosis...how do you put two identical chromosomes on each side if the apparatus is trimmed to one? how do you control protein expression if there is double the DNA material? you know as well as I do.

plus, diploidy isn't human-specific at all. all higher organisms are diploid. some annelids are even polyploid. the process of gaining diploidy must have lasted to a few 100.000 years because of all the adaptions that go along with it. and this is why you won't find evolution happening from one day to another. adaptions have to be made before a bigger jump can occur - and because of that, the jump isn't as big as one might think.