@save the frogs https://youtu.be/bpWPAnK9E1I?is=xedq0jdgJW-8UOFY Human chromosome 2 is a large human chromosome that formed from the head-to-head fusion of two separate ancestral primate chromosomes. This major genetic event explains why humans have 23 pairs of chromosomes while other great apes, such as chimpanzees, gorillas, and orangutans, have 24 pairs. Evidence for the Fusion Matching DNA: Human chromosome 2 lines up cleanly with two separate ape chromosomes Timeline: The fusion event occurred in the human lineage after splitting from the common ancestor shared with chimpanzees, estimated by various studies to be between roughly 1 to 5 million years ago. Speciation: This chromosomal reduction may have helped create a reproductive barrier between early human ancestors and other primate populations https://pmc.ncbi.nlm.nih.gov/articles/PMC187548/