How did the first human reproduce when it's chromosome count went from 48 to 46.?

Question

According to the human genome project chromosome #2 is a product of 2 fused chromosomes from a common ancestor of chimps and humans.
When this occurred how would the offspring be able to reproduce?
As a matter of fact how can this happen in any species when the chromosome count changes?

I appreciate the answer and I read through the website, but it was unclear whether this was normal or the horse and wild horse relationship was unusual.
It spoke of our ancestors having to breed with siblings when the chromosome count changed. I thought this was a mutation that would occur in the zygote. Is it possible for the parents to consistently alter the count to their offspring.

Answer 1

This is called change in ploidy.

What matters is not the number of chromosomes, but the compatibility of the matching DNA within those chromosomes.

Two individuals with different numbers of chromosomes can mate, and this is not necessarily fatal for the resulting offspring.

For example, wild horses have 33 pairs of chromosomes (66 chromosomes), and domestic horses have 32 pairs (64 chromosomes). Not only can they interbreed, but the resulting offspring are fertile.

In other words, horses are currently undergoing the type of chromosome fusion event that the human branch went through when it went from 24 pairs to 23.