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.


It’s all Greek to me

The world of science is full of terminology borrowed from dead languages such as Ancient Greek and Latin. This is the natural result of the fact that in the 17th and 18th century scientists tended to use Latin to communicate with each other.

While this tradition has now changed in favor of languages that are still very much alive, the legacy continues in the terms we use to classify plants and animals.

When we refer to modern humans, we call ourselves Homo sapiens sapiens, or the Latin expression for “Human, smart, smart.”

We owe this expression and many others to Carl von Linné,or, as he was known to his colleagues, “Linnaeus.”

This Swedish scientist, who lived in the 18th century, set out to classify and label plant and animal forms based on observable similarities in shape. Reflecting the thinking of his time, Linnaeus wanted to reveal the order that existed in God’s creation. His research resulted in a number of classificatory units that are still used today:

Domain
Kingdom
Phylum
Subphylum
Class
Subclass
Order
Family
Genus
Species
Subspecies

Linnaeus also initiated the custom of using two terms (a binomial) to refer to individual life forms.

Each of these binomials, such as Homo sapiens, is very specific and cannot be applied to anything but to members of that genus and species. Similarly, an Australopithecus afarensis refers to Lucy’s kind and nobody else.

Meet Lucy, Australopithecus afarensis. (What’s in a name?)

One trait that is inherently human is a desire to explain what we see. One aspect in which this desire expresses itself is the way in which we classify plant and animal life.  One of the first scientists to start this endeavor was a Swede by the name of Carl von Linné. He is also known as Linnaeus and was the main proponent of the “taxonomic system.”  Although some aspects of this system are no longer in use, what has survived until now is its method of hierarchical classification and custom of binomial nomenclature.

The terms “binomial nomenclature” refer to the use of two names to identify a plant or animal. For example, we are Homo sapiens. Lucy was an Australopithecus afarensis, meaning “Southern Ape from the Afar region.”  Within these two terms, “Australopithecus” refers to the genus, “afarensis” to what we call species. We belong to the genus “Homo” and the species “sapiens.”

Fossils do not come with nametags identifying the individual and the species they belong to. That job is left to paleoanthropologists, people who study early humans. That might explain why we have resorted calling ourselves Homo sapiens, or “Smart beings” – a not-so-subtle reflection of how we perceive ourselves.

Lucy is not the only representative of these Australopithecines we know, but she may very well be the most famous one. Other members of the Australopithecus afarensis species have been uncovered in Ethiopia. These Australopithecines lived between 3.9 and 3.0 million years ago. They tended to be small compared to modern humans like us; females were commonly substantially smaller than the males. Lucy lived around 3.2 million years ago.  She measured about three-and-a-half feet and probably weighed about 60 to 65 pounds.

The remains of these Australopithecines indicate that they were capable of walking upright as a means of getting around, but that they also had the ability to climb trees more easily than modern humans.