The chimpanzee became its own species when it separated from bonobos about 2 to 3 million years ago

500 Words2 Pages
The chimpanzee became its own species when it separated from bonobos about 2 to 3 million years ago (Mitchell, and Gonder). According to the article “Chimps And Bonobos”, this most likely happened because of allopatric speciation which is the separation of a species through physical forces like mountains or rivers that isolate the two groups. The physical force that separated the two species was most likely Zaire River which is also called the Congo River in Sub-Sahara Africa. About 2 million years ago there was a drought south of the river and drove the gorillas that were living the area north. Without an apex predator in the area the common ancestor of the two animals crossed the river and became isolated from their relative the bonobo.…show more content…
According to Chimpanzee, an example of a homologous structure it shares with its descendants is its relatively large skull. As the animals became more evolved their skull shapes started to change to accommodate for a larger brain. This size difference is shown in Figure 2 because you can see the difference in the brain and skull size of the chimpanzees (bottom) and humans (top) (Chimpanzee). This is because Cranium size is determined by brain size and recent evidence by (Dumas, 2012) shows that this is likely determine by a protein domain called DUF1220. DUF1220 is a domain, a sub section of a gene, which is about 65 amino acids long and expressed mostly in neurons (DUF1220). Research (Dumas, 2012) shows that more copies present in the genome the larger the brain size is in that animal. Humans have 270 copies and the trend goes down from there with Chimps having 125, Gorillas 99 and marmosets 30 and mice just one (Dumas). This research shows the reasons hominids increased in brain size is because there was a mutation that increased the amount of DUF1220 in their lineage which led to gradually larger brain sizes. Since the Chimps split off (Figure 1) before this mutation their brains did not increase in size; hence the reason they are still similar to the common ancestor of both chimps and humans. Another homologous structure unique to apes that evolved from the

More about The chimpanzee became its own species when it separated from bonobos about 2 to 3 million years ago

Open Document