Having spent under a month haunting this particular forum, it has come to my attention that a lot of arguments concerning the validity of "the theory
of evolution" are actually based on a specific evolutionary hypothesis concerning human origins, namely that we are a member of the goup "primates",
also including the great and lesser apes, old world and new world monkeys, lemurs, tarsiers, and so on.
While the body of evidence supporting this particular hypothesis is sufficient to convince me that it is true, that is not my concern here. Rather, I
have noticed that a good many people, on both sides of the "evolutionist" argument, are misrepresenting our (hypothesized) position within the
primates. I intend to rectify this.
A Couple Of Words on Phylogeny
Just so you know what I'm talking about, there are a couple of terms that will need to be explained: First off, "monophyly" and "paraphyly". If a term
- for example, "monkey" is to be treated as monophyletic, it has to include all descendants of the most recent common ancestor of all groups
described as monkeys
. If it does not, it is considered to be "polyphyletic", which effectively makes it biologically invalid.
As a less obscure example, imagine a group of people known by the name of "The Smith-Joneses", who all share one great-great grandmother. For the term
to be monophyletic, everyone descended from this great-great grandmother must be included in the group known as "the Smith-Joneses". If those who
have, for example, married and changed their names, are not included, "the Smith-Joneses" becomes polyphyletic
Another issue is with the levels of phylogeny. Basically, every organism exists within a species, within a genus, within a family, within an order,
within a class, within a phylum, within a kingdom, within a domain.
Because evolution doesn't tend to happen in neat, regular units, a number of intermediate "clades" are added - those above gain the prefix "super-",
and those below gain either "Sub-", "Infra-" or "Parv" - giving us such terms as parvorders within infraorders within suborders within orders within
superorders, et cetera. The term "tribe", although not used here, is employed to describe a group between subfamily and genus.
What we are
- that's us - are in the subfamily Homoninae. Also within the Homoninae are the African Great apes - that is, members of the genus
(chimps and bonobos), and, at the base of the group, members of the genus Gorilla
Assuming the arrangement of the groups within the hominins is correct - with gorillas splitting off before chimps and humans diverged - the term
"african apes", to be monophyletic, would include humans. Our ancestry, at any rate, is considered to be with the group "african apes".
That is not to say that we evolved from chimpanzees, or that they evolved from gorillas. While the common ancestor was an african ape, it would not be
considered the same species as any one of the modern species.
Homonids, or "great apes", describes the members of the family Homonidae. Within this group are the subfamilies "Homoninae" and "Ponginae". "Ponginae"
currently includes only the genus "Pongo", the Orangutans.
To be monophyletic, as such, "great apes", including chimps, bonobos, gorillas and orangutans, must also include humans.
Hominoids, or "apes" describes members of the superfamily Hominoidea. Within this group are the families "Homonidae" - the great apes - and
"Hylobatidae" - the gibbons, or "lesser apes". To be monophyletic, therefore, "Apes" must include not only gibbons, orangutans, chimps, bonobos and
gorillas, but also ourselves.
The parvorder Catarrhini contains two groups - the previously discussed Hominoidea, and the Cercopithecoidea, or old world monkeys - old world monkeys
describing the - mostly tailed - monkeys native to Africa and Asia.
The infraorder Simiiformes, or simians, describes the "ape-like" primates, consisting of the two parvorders "Catarrhini" and "Platyrrhini (the new
What this means is that the two lineages currently known as "Monkeys" diverged before the old world monkeys separated from the apes.
What this, in turn, means is that "monkeys", from an evolutionary perspective, includes the apes. Certainly, the apes have an ancestor that would be
described as a "monkey".
The Haplorrhines, or suborder Haplorrhini, is made up of the infraorders "Simiiformes" and "Tarsiiformes", or tarsiers. Along with Strepsirrhini,
which includes the more divergent primates such as lemurs and lorises, it makes up the group primates.
My purpose in starting this thread is not to debate human origins. I am not a primatologist, and as far as the vertebrates go, I think the only group
I have less interest in are sheep. I do not definitively "know" if this phylogeny is correct - everything in science is always subject to change.
However, if people are going to discuss human evolution, I feel it that they will be best able to deny ignorance, wherever they find it, if they know
what we are actually said to have evolved from. We can be said to have evolved from a primate, we can be said to have evolved from a monkey, we can be
said to have evolved from an ape, we can be said to have evolved from a great ape, and we can be said to have evolved from an african ape.
We cannot, however, be said to have evolved from any modern species of any of these any more than they can be said to have evolved from us.
We are Homo sapiens
, a homonin, homonid, hominoid, catarrhine, simian, haplorrhine primate.
[size=-3]While it doesn't name all the nodes that I have discussed here, and does name a couple incorrectly, the basic structure of the described
phylogenetic tree can be found at the Tree Of Life Web project (primates)
24/12/2010 by TheWill because: (no reason given)