Is man just an animal?

Theodosius Dobzhansky

Modern biologists frequently say that man is not special, that we are just a species among many. Thus, for instance, Colin Tudge writes this:

Phylogenetically we are an outpost, a tiny figment of life, just as Earth is a cosmological nonentity that no other intelligent life-form in the Universe would bother to put in their celestial maps.

(The variety of life, Oxford University Press, 2000).

This is just the indiscriminate application of a pseudo-scientific dogma that few biologists would dare contradict, which can be expressed in one of the following equivalent ways:

• All species of living beings are equivalent; no one is superior to the others.
• There are no criteria that make it possible to compare the importance of different species.
• Man is not superior to chimps, ants, bacteria...
• Evolution has no direction.

Sex and species, two related concepts

Taxonomic categories

The species is the basic taxonomic category used by biologists to classify living things. The other categories (genus, family, order, class and phylum) are considered artificial and arbitrary. On the other hand, we tend to regard the species as natural, obvious, similar to a concept when the represented objects are living beings. But we will not enter here into the famous problem of universals, nor wonder on whether concepts (and species) really exist or are mere constructs of the human mind.

The classic definition of a species is: a set of living beings that share common characteristics and can interbreed, giving rise to fertile offspring. Notice that the use of the word interbreed implies that the living things in question use sexual reproduction. This leads us to ask whether the concept of a species should be restricted to living beings with this type of reproduction, or it can be extended to those that reproduce otherwise, such as prokaryotes and some eukaryotes. This question can be answered in several ways: