Chromosome Fusion
Chimps have 48 chromosomes, humans only 46. How can they be closely related? Despite the difference in chromosomes, chimp DNA is nevertheless closer to human DNA than it is to gorilla DNA. One Fusion Event First of we need to realise the chromosomes are paired, so this is a jump from 24 pairs to 23 pairs. What we are talking about is two pairs of chromosomes fusing - joining end to end - to produce one pair. It is like having two sections of string, tying the right end of one to the left end of the other, and ending up with one string approximately as long as the two originals combined. Imagine three consecutive strings: abcdefg + hijklmnop + qrstuvwxyz This is analogous to the ancestor with 24 chromosome pairs, but just looking at three of them. Some mutation happens, and joins two string together. Now there are only two consecutive strings: abcdef@hijklmnop + qrstuvwxyz This is analogous to the ancestor with 23 chromosomepairs, but just looking at two of them. If you look carefu...