« I do not come from the monkey ». Children’s songs have been made with that letter. Those who proclaim this sentence usually attribute to Charles Darwin the claim that human beings “come from monkeys”. Phrase that we can read in The Origin of Man .
On the other hand, many biologists often reply that it is not that we are descended from the ape, but that we have common ancestors . Of course, that appreciation is true, although imprecise. We also have common ancestors with bison, cockles, aubergines or the bacteria in our intestines and there is no confusion with these examples.
What does “monkey” mean?
The statement “we come from monkeys”—assuming that “come” refers to “descend”—first raises a problem of terminology . And it is that in order to be able to speak precisely and accurately it is necessary to adequately define “mono”.
There is no scientific term that encompasses a group of animals under the term “monkey” . It is, on the contrary, a word of colloquial speech, and therefore, the expression “we come (or not) from monkeys” is not a scientific statement .
For Anglophones, according to the Oxford dictionary, the term ” monkey “ refers to all primates with a tail , such as the marmoset, baboon or macaque, and differentiates them from ” ape “ , which would be primates without a tail such as the gorilla. , the orangutan or the chimpanzee.
In Spanish , the definition in the dictionary of the Royal Spanish Academy is different: it calls “monkey” any primate that belongs to the ancient suborder of the anthropoids , an archaism that today would represent the members of the Simiiformes group. In it are found the Platyrrhini (platyrrhines), or «New World monkeys», such as capuchins, howler monkeys or marmosets, and the Catarrhini (catharrines), or «Old World monkeys», which include the cercopithecoids , such as baboons or mandrills, and hominoids , including gibbons, chimpanzees, gorillas… and also human beings . Darwin referred to these same groups in his famous book, in fact.
The importance of scientific language
In all these cases we are talking about a colloquial language. According to the RAE, “monkey” is synonymous with the scientific term Simiiformes, marked in blue in the image, and therefore, saying that we come from —or descend from— common ancestors with monkeys is true, since we are also included in it .
However, the English definition of ” monkey “ poses a problem. And it is that it includes in the definition all the platyrrhines and the cercopithecoids, but excludes the hominoids, as they do not have a tail . In the image, in orange. In phylogenetic terms, any group that is defined must include all the descendants of a common ancestor , it can neither leave descendants out, nor include organisms that do not descend from that ancestor. When a group meets this requirement, it is said to be monophyletic .
A group that includes the last common ancestor of a series of species, but excludes one or more species that do descend from that ancestor, is called a paraphyletic group in phylogeny, and is not valid in scientific terms. This is what happens with the English concept ” monkey “: it includes the common ancestor of all the Simiiformes, with the exception of a specific group, the hominoids.
But apart from its invalidity in scientific terms , we still have common ancestors with the animals that are considered ” monkey “ in English . Even under that definition, the expression “we have common ancestors with monkeys” is still true.
In a more correct scientific terminology, one should speak of Primates , Simiiformes or Catarrhini . And to say, therefore, that we have ancestors in common with primates, with simiiformes and with catarrhines . If, in phylogenetic terms, every group must include all the descendants of the same common ancestor, that is equivalent to saying that we are primates, we are simiiformes and we are catarrhines .
But we can go a little further.
What if the phrase “we came from monkeys” were true?
In any case, and going back to the origin of the question, regardless of the definition of “monkey” that we accept, the phrase “we come from monkeys” may not be as false as many biologists – and all creationists – think.
In neither case does the term “monkey” refer exclusively to modern animals. If we look at our phylogenetic tree —which is like the family tree of species—, we find among our ancestors a good number of prehistoric species that fit the definition of “monkey” in any of its versions.
The nuance is in time. Even if we exclude the human being from the definition —which the RAE does not do, by the way— and we take the Oxford definition for granted, where only primates with tails are monkeys, it is clear that we do not descend from any current monkey . However, we have a large number of ancestors that fit the definition of “tailed primate” . Animals like Aegyptopithecus, from 35 million years ago, have as much of an “ape” as, for example, Dent’s cercopithecus .
Namely. Although we do not come from any modern ape species, we do descend from a large number of ape species, all of them prehistoric . And it doesn’t matter which definition you choose.
To say that “we come from monkeys” is correct.
REFERENCES:
Perelman, P. et al. 2011. A Molecular Phylogeny of Living Primates. PLOS Genetics , 7 (3), e1001342. DOI: 10.1371/journal.pgen.1001342
