Chimpanzees have 24 pairs of chromosomes. Humans have 23 pairs. It turns out that our chromosome number 2 is composed of two chimp chromosomes linked end-to-end. You can see the evidence of this under a microscope. All chimp chromosomes have two telomeres, one at each end, and a centromere somewhere near the middle. All but one one of the 23 human chromosome pairs also have two telomeres and one centromere. The exception is our chromosome number two (the second longest of the bunch); it has 4 telomeres and two centromeres. Bam! And if you do DNA analysis, you find that the human genes and chimpanzee genes are 98.8% identical. Bam! Anybody who denies that humans and chimps are cousins is full of shit.