Such expressions as that famous one of Linnæus, and which we often meet with in a more or less concealed form, that the characters do not make the genus, but that the genus gives the characters, seem to imply that something more is included in our classification, than mere resemblance. I believe that something more is included; and that propinquity of descent,—the only known cause of the similarity of organic beings,—is the bond, hidden as it is by various degrees of modification, which is partially revealed to us by our classifications (Darwin, 1859, p. 413f).

Tuesday, 28 April 2009

Biology & Teleology

“Met the ghost of Stephen Foster at the Hotel Paradise
This is what I told him as I gazed into his eyes:
Rooms were made for carpets,
Towers made for spires,
Ships were made for cannonades to fire off from inside them ..."
(Squirrel Nut Zippers, 2002)

Findings of a recent study published in Cognition state that:
    "... college-educated adults display scientifically unwarranted teleological explanations with ease. Such findings highlight the challenges faced by educators in both the life and physical sciences. The source of popular resistance to scientific ideas appears to run deep" (Kelemen & Rosset, 2009: 143).
They certainly 'run deep' in biological systematics and in the philosophy of biology as a newly published article in the Journal of Biogeography by Heads (2009) clearly demonstrates.

According to Heads, Darwin's move away from teleological argumentation was rejected by neodarwinists who preferred purpose over structure:
    "... as his knowledge of biology and laws of growth deepened, Darwin learned to avoid teleology. Through this process he left his background behind and evolved into a modern (Renaissance) scientist. Nevertheless, Darwin's later work has been ignored whereas his earlier arguments have been co-opted as support for teleology, panselectionism and centre of originism." (Heads, 2009: Online)
Teleology and biology have been inseparable since Aristotle despite the attempts by Roger Bacon, Rene Descarte, Baruch Spinoza and Wolfgang von Goethe to undermine it completely. German idealists didn't help, neither did 19th century English naturalists, who like Kant sought to replace a theological or 'higher purpose' with Natural 'intention'.

Heads provides several excellent examples of natural teleology in systematic biology:
    "... many features of organisms are teleological, a bird's wings are for flying; eyes are for seeing ..." (Ayala, 2004:65).
    "A rock may not have a purpose but an eye does. Eyes and hands do not just happen for no reason" (Ruse, 2003:33).
Teleology, according to Heads, seems to be embraced by some philosophers of biology:
    "... a vitally important tool for looking into the organic world" (Ruse, 2002: 47).
The problem of teleology is rampant in systematics and biogeography, with few opposing it and others, like Ernst Mayr, using weak arguments:
    "[Mayr] recognized that the teleology in biology was a serious problem. His solution was to suggest that the modern synthesis is not really teleological, and that it uses teleological language but not teleological thinking" (Heads, 2009: Online).
I believe that Heads, like Kelemen & Rosset (2009), has pin-pointed the problem behind teleology, namely we start out as teleologists. Once we accept this fact, we have a lot of unlearning to do. I whole-heartily recommend Heads (2009) for students of systematics and biogeography.

Malte C. Ebach

Ayala, F.J. (2004) Design without designer: Darwin's greatest discovery. Debating design: from Darwin to DNA (ed. by W.A. Dembski and M. Ruse), pp. 55–80. Cambridge University Press, New York.
Heads, M. (2009). Darwin’s changing views on evolution: from centres of origin and teleology to vicariance and incomplete lineage sorting Journal of Biogeography DOI: 10.1111/j.1365-2699.2009.02127.x
Kelemen, D., & Rosset, E. (2009). The Human Function Compunction: Teleological explanation in adults Cognition, 111 (1), 138-143 DOI: 10.1016/j.cognition.2009.01.001
Ruse, M. (2002) Evolutionary biology and teleological thinking. Functions: new essays in the philosophy of psychology and biology (ed. by A. Ariew, R. Cummins and M. Perlman), pp. 33–62. Oxford University Press, New York.


Crawford Tillinghast said...

When the modified (apomorph) form of a pre-existent structure was subject to natural selection and acquired a function which was different from its original, it is not teleology. If wings are associated to flying, it is less presumptive to admit it is a consequence of natural selection, not a cause. Therefore, teleology demands the ad hoc assumption of underlying purpose.

As it can not be proved/disproved, It is reasonable to stay with the hypothesis which costs less. It seems that the teleological one is hardly the case.

That we think teleologically is one thing. That we admit nature and evolution to be so, is another.

Anti-teleologist said...

It seems to me that teleology in evolutionary biology is about two things. Thinking and language. There are those who think teleologically and use teleological language. And there are those who don't think teleologically but may resort to teleological language for simplicity.

I once wrote to a retired professor of zoology who I had the privilege of studying an elective subject (human population biology) under. I lamented the problem of teleology and suggested that it would be useful to have exercises in biology classes where students have to express evolutionary concepts in non-teleological language. This professor replied that in her day this was indeed done, but that evolutionary theory is now so well established that it is difficult to get it wrong.

I didn't really agree, but I didn't reply, as apart from raising the point for her comment, my main purpose had been to inform her how much I'd enjoyed the subject, and how much influence it continues to have on my thinking. (I will be sending her an email with a link to this comment, so she can read it and comment if she chooses).

But I do think there is an argument for introducing such exercises. If the esteemed professor uses teleological language, she does so knowingly and carefully. But just as there are now generations of people who don't know how to do maths in their heads because they've never had to, I think there is now ageneration of otherwise good biologists out there, who (a) don't recognise that they are using teleological language, and (b) even if they do, find it hard to frame sentences in non-teleological terms.

In evolutionary terms, NOTHING is teleological. Eyes AREN'T 'for' seeing. Wings AREN'T 'for' flying. Eyes facilitate seeing. Wings facilitate flying. But (for example) there are flightless birds whose wings don't faciliate flying. And for those organisms whose wings do facilitate flying, they are 'simply' (conceptually speaking) the fortuitous descendants of evolutionary processes in which some organisms had differential reproductive success as a RESULT of favourable morphology relative to prevailing environmental circumstances.

I provide below an exercise of the sort I'm suggesting. Which of the following descriptions is teleological? Why?

(A) Since bearing healthy offspring who will themselves survive to reproduce is the defining evolutionary by-product of motherhood...

(B) Since bearing healthy offspring who will themselves survive to reproduce is the defining evolutionary aim of motherhood...

(C) Since bearing healthy offspring who will themselves survive to reproduce is the defining evolutionary outcome of successful motherhood...

Carl said...

Interesting to read about the recent study published in Cognition,and about the references is good to read.

Biology Dissertation