If humans came from monkeys, then why are monkeys still around?

This is a question that one frequently encounters on various blogs. It expresses a desire to learn more about one’s origins, but reflects a misunderstanding of how science currently interprets these origins.

The question has the potential to confuse, but the answer is very simple: monkeys, apes and humans evolved from a common ancestor.

We are the only representative of the human lineage still around; the fossil record is replete with earlier hominids that did not survive. The same applies to the non-human portion of the Primate Order: some of them are around today, many more have become extinct.

So what is this business with a “common ancestor?” This expression refers to earlier forms we can trace our origins back to. Consider this image:

Starting at the bottom of the image, there are lines extending upwards, towards a number of branches, such as lemurs, New World monkeys, etc. The intersection of these lineages represents the place where speciation (or the evolution of a new species) occurred.

Let’s take humans and chimpanzees as an example.

At one point, there were no chimps or humans. This is where we place a common ancestor (in this example, we place its existence in the section following the branch leading up to gorillas and before the branching between chimps and humans).

Each of the animals identified is still with us today. As I mentioned in an earlier blog, we are all subject to continuous evolutionary pressures and development. As such, we can say that the monkeys with whom we share our world are not our ancestors, because we live side by side. However, we do share a common ancestor. From this common ancestor, branches lead to us and to other, non-human primates.

Go back to the image one more time. The further down the diagram you go, the further back in time you have traveled. So, looking at the image we can see that monkeys, apes and humans share a common ancestor, but that ancestor existed much earlier than the common ancestor between us and chimps.

Another way to address the question would be to point out that our “family history” is, in fact, “history.” It resides in the past. We cannot find ancestors among current (distant) relatives; we have to go back far in time to find them.

Monkey business

 When asked their opinion about human evolution, some people will answer: “I cannot accept that we came from monkeys.”

We should all agree with that sentiment. Humans are no monkeys. But we are part of the Primate Order.

In an earlier blog  I wrote about Carl von Linné to  and his way of classifying plants and animals using observable traits.

Under the Linnaean system, human beings belong to the Primate Order. Within this Order, there are two sub-units, referred to as suborders: the Prosimians and the Anthropoids.

Fans of the movie Madagascar ought to be very familiar with Prosimians, a family that includes lemurs and lorises.

Anthropoids include New World monkeys (such as marmosets, tamarins, capuchin monkeys, howler  and spider monkeys) as well as Old World monkeys, apes and humans (such as baboons, colobuses, gibbons, siamangs, orangutans, gorillas, chimpanzees, bonobos and humans).

All of the animals just mentioned are still with us. Each one of these is subject to evolutionary pressures and some (like us humans) are flourishing and others (like chimps and gorillas) face ever-diminishing natural habitats.

But this all relates to the present. How does it apply to the past?

Together with gibbons, siamangs, orangutans, gorillas, chimpanzees and bonobos, humans are members of the Superfamily of Hominoidea (a.k.a. apes and humans). The classification of humans and apes into this Superfamily reflects a common ancestor in a distant past.

Moreover, recent DNA studies comparing human genetic information with that of other non-human primates has shown a high degree of genetic similarity. For example, DNA from a modern human is close to 99% identical to that of contemporary chimpanzees. This further supports descent from a common ancestor.

Next time you hear a remark about humans evolving from monkeys, you can set the record straight: one species did not come from the other. Humans and apes simply share a common ancestor.

No monkey business required.