Misconceptions about evolution exist due to humans’ inability to comprehend the enormousness of time. That leads to common misconceptions such as, “I haven’t seen a monkey giving birth to a human”, “if humans evolved from monkeys, why do monkeys still exist?” etc.
Firstly, monkeys did not evolve into humans. In the evolution tree (remember: it’s a tree and not a line), monkeys are not our ancestors; they are cousins. In other words, the common ancestors of monkeys and humans (apes) existed about 30 million years ago. The monkeys we see today had a trajectory from that time to the present, just like their distant cousin, humans, in that period.
The same goes for chimpanzees and humans. Chimpanzees are our closest cousins, and that branch goes back 5-7 million years ago. A rough sketch of the branching business is shown below.
Understanding Evolutionary Trees: Evo Edu Outreach (2008) 1:121–137
