Humans have approximately 25000 genes. Why are these genes on 46 chromosomes? Why not 40 or 50?

  • $\begingroup$ In general, the chromosome number has to be even because each set of chromosomes comes from 1 parent, so 2 x N is always even. But different species have different chromosome numbers. No real reason why humans have to be at 46. There are plenty of people who survive with 47. $\endgroup$
    – user137
    Commented Dec 23, 2015 at 11:59
  • 1
    $\begingroup$ Chromosome rearrangements are just a type of mutations, hence the process is stochastic. Some chromosomes split, some merge, some duplicate etc. These events are very rare, though. Like all mutations these influence fit to some extent, since karyotype structure is known to play important role in epigenetic regulation. $\endgroup$ Commented Dec 23, 2015 at 12:20
  • $\begingroup$ user137 and @EliKorvigo I think one of you can extend your comment into an answer. $\endgroup$
    – Remi.b
    Commented Dec 23, 2015 at 17:18


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