Modern Darwinian evolutionary theory is proud that it has cast off the quaint Aristotelean notion of teleological cause, causa finalis. Instead, it sticks to the strict scientificity of efficient cause. Or so it claims. Evolution is said to proceed via natural selection that selects the successful living species that are generated by chance mutations of genes. The criterion of success is simply that a species survives, for there is a so-called 'struggle of survival' among the species.
Teleological explanation, by contrast, is said to 'explain' the successful features of living beings that allow them to survive in terms of their purposeful design by some maker or other. For instance, the beaks of certain species of finches would be designed to be adapted specifically to a certain environment, thus enabling the finches to successfully survive to the point of reproduction. (If you don't believe this is how teleology in evolution is thought about, listen to the reputable philosopher of science, Michael Ruse, in his recent lecture on the Gaia Hypothesis.) Evolutionary theory pooh poohs the 'ridiculous' idea of teleological design.
But is evolutionary theory too quick to assume airs of superiority?
First of all, its claim to stick to efficient causality is shaky, since the mutation of species relies essentially on chance, i.e. contingency. In Aristotle's thinking this is change _kata symbebaekos_, i.e. change that just 'comes along' (from _symbainein_ 'to go along with'). Mutations just 'happen', without any cause at all being able to be named, let alone any efficient cause. Contingent being, i.e. the mode of being _kata symbebaekos_, is opposed in Aristotle to being _kath' auto_, i.e. being according to itself, or being in itself, intrinsic, essential being. Thus e.g. human being is 'according to itself' being that 'has the logos, language', whereas whether a human being is white is contingent; whiteness just 'comes along' as an accidental attribute to human being.
Second of all, and more importantly, that life has a _telos_ does not boil down to the notion that each species were purposefully designed. Purpose (_hou heneka_) in Aristotle is not to be equated with _telos_, since it is only one kind of _telos_. The scientists miss this. Furthermore, they overlook that they already unwittingly name the _telos_ of life, of course, without thinking at all about it, for they say there is a 'struggle for survival'. This means life is essentially a will to live. According to Aristotle (and today, modern science is by no means beyond Aristotle, but abysmally ignorant of his thinking), life is that mode of being characterized essentially by _metabolae kath' auto_, i.e. by movement/change from within itself. Living beings move/change by themselves, rather than having to be moved by something else. Aristotle has four kinds of movement/change according to i) where (locomotion), ii) how much (growth and decay) iii) how (qualitative change, such as when a dog learns a new trick or a tree's leaves change colour) and iv) what (reproduction). The last named is a synonym for survival of the species. Life is that mode of being that strives to perpetuate itself.
Now, the evolutionary scientists' next move is to pooh pooh the idea that life could be characterized as essentially a will to live. Where's the will? they ask. Have you asked a plant lately what it wants? But there are different levels of will. Will that sees what change it wants and strives to get it is purposeful will. Wishing is a will that doesn't strive. Urge or drive is blind will, but nevertheless directed toward some end, some _telos_. Living beings are essentially characterized by the urge to survive. This urge includes the drives to flee or otherwise avert life-threatening danger, to nourish themselves, to reproduce.
So scientific evolutionary theory, albeit implicitly, smuggles in from the outset the _telos_ of all life: the urge to survive. Life is that mode of being with the urge to perpetuate its own self-movement. All living beings strive essentially to bring themselves into presence and maintain this self-moving presence for as long as possible. One aspect of life's self-movement is reproduction itself, through which the species itself is propagated.
Evolutionary theory is at a loss to account for the essence, the nature of life itself as self-movement. Its apparatus of efficient causality must capitulate before this self-presencing of life itself. This does not prevent it, however, from blindly and vainly seeking the efficient causes of life itself through, say. molecular biology, thus maintaining the efficient causal hierarchy for the ultimate scientific explanation of the cosmos from physics through chemistry to biology (and then on to explaining human consciousness itself as some complicated kind of neuronal processing).
Modern science is in its essence wedded to efficient causality, i.e. to effectiveness, and it will defend to the bitter end this betrothal to the will to effective power -- that is, until there is an historical occasion for an alternative way of thinking to make inroads against its dogma. Modern science's arrogant over-self-confidence is the present-day form of superstition that reigns in the universities right through the media to everyday prejudices.