Nature: no purpose to it

5

If one assumes, as I do, that there is no god that has given us, or can give us, a meaningful ‘purpose in life,’ could it be that there is some internal drive in life itself that can get this for us? And here I don’t mean ‘human life,’ because certainly humans can develop purpose for themselves (and I have previously suggested that this effort is itself what generates any sense sense of value we have). I mean, is there some principle inherent in any organic life that is somehow driving us towards some end, some greater perfection, some progress?

My answer to this is simply, no. All life exhibits a purposiveness in a base way – the drives for survival and for reproduction. But if we look at nature as a whole, what we see seems to be a kind of ebb and flow of generations coming and going, and not doing else but that. Life may be an expression of the physical tendency of atoms to come together in various compounds which then decay or fall apart over time; but it’s difficult to see any more in it than this.

I’m going to post here re-edited comments on the matter I made on another site, in order to clarify what was written too hastily and too loosely there. I hope the host of the other site will not begrudge me this.

Over at Scientia Salon, Massimo Pigliucci published a short, concise history of evolutionary theory, while providing a review of a current debate among biologists over whether recent studies in genetics, epigenetics, ecology, and development in environmental response demand a revision of the Modern Synthesis in evolutionary theory (which hinges on the assumption that the primary interest of evolutionary study is the transformation and inheritance of genes in the struggle of organisms to survive their environment). (http://scientiasalon.wordpress.com/2014/11/10/the-ongoing-evolution-of-evolutionary-theory/)

Having had a solid undergraduate education in biology; having read Darwin (while studying philosophy) as a graduate student; and having taken a course in microbiology while working in health care – I thought my knowledge of current evolutionary theory was fully up-to-date.

But reading books on evolution lately, while catching up on debates over the need for secular education in a religiously biased society, I have come to realize that there’s considerable gap between what one could learn as an undergraduate back then, and what researchers are exploring now.

Consequently, I resigned myself to making little or no comment on Pigliucci’s article, and reading it – and supplemental material it linked to – largely as part of my continuing education.

However, Patrice Ayme, with whom I’ve had an argument in the past, over whether ethology – the study of animal behavior – necessarily provides us with an ethics (reproduced here in a previous posting), published a comment that troubled me. The implications of her argument seemed to be that the very notion of a “Darwinian” evolutionary theory was somehow misguided, because the French scholar Lamarck had formulated an evolutionary theory first. (She also charged that there was a bias against Lamarck because he was French, and for Darwin because he was British – and from the propertied class. I’ve decided not to wrestle with that sort of political wrangling here.)

Here I have to say that I may simply be misunderstanding Patrice Ayme; her prose style is somewhat difficult, and suggests that English is not her native language, and that she has not yet become fluent – as a writer – in English. So there is a language difficulty I may not have overcome in my reading of her comments.

Nonetheless, given our previous disagreement on ethology and ethics, I developed the strong impression that Patrice Ayme was not only arguing for the valorization of Lamarck, but for classical Lamarckian evolutionary theory per se.

In his own historic context, Lamarck was something of a materialist, in that he believed that differentiation of species could be explained within organic life itself. But he was also a Deist, and a rather devout one, who believed some purposiveness had been instilled in life forms to the extent that species were driven – partly in response to the environment, but partly by some internal impulse – toward greater perfection of form, generation after generation.

One example of this, which comes up in discussion below, is the giraffe. Lamarck believed – and here I admit I am simplifying – that the giraffe achieved its long neck in evolution, by continually exercising its neck to reach leaves on trees, in an environment that challenged it with little low-level vegetation to feed on; this passed on generation after generation thus perfecting the form of the giraffe to this purpose.

Well, but this is not how it actually happened.

While Lamarck has left us an evolutionary theory, it is a theory lacking in essential knowledge that we’ve accumulated since; and it includes conjectures that Darwin’s more mechanistic view has discredited. It is simply not the case that giraffes grew longer necks by reaching for leaves on higher branches.

Craig Holdrege has an interesting discussion on the giraffe issue (http://natureinstitute.org/pub/ic/ic10/giraffe.htm), wherein he discusses both Lamarck’s and Darwin’s views on the matter. An important moment in his quote from Darwin is when Darwin, while noting that long-necked giraffes would have an advantage in eating higher leaves, also remarks “the individuals, less favoured in the same respects will have been the most liable to perish….” The death/ non-reproducibility of organisms (including whole species extinction), that have no traits adaptive to environmental change is crucial to Darwinian theory. Lamarckian theory, taken to its logical limits, suggests that, barring environmental catastrophe, all species should be able to adapt and survive, and that hasn’t been the case. There have been catastrophes, but not all extinctions have occurred because of these, most simply occurred because a species could not develop adaptation to non-catastrophic environmental change.

This actually provides a stronger foundation to the development of complexity in species that do survive, than seemingly purposive tendencies to progress: Variation in populations develops a multitude of traits, some of which allow the population to survive in a given environment, others that may serve no immediate purpose at all, and still others that surviving organisms can use in a number of ways to improve chances of reproduction and hence species survival.

Holdrege makes the point that the giraffe’s neck, not only being long enough for eating, is almost too short for drinking. In other words, while well adapted to eating leaves off trees, the giraffe’s long neck makes drinking difficult. So why does this ungainly animal with such a difficulty reaching down to water sources have the neck it has? As Holdrege notes, the neck serves several purposes (e.g., it is used as a balance when galloping, and it is used by male giraffes in combat with other males over preferred potential female mates). But the simplest answer is that it survived, and its predecessors did not.

Like Patrice Ayme, Michael T. Ghiselin also believes that Darwin depended more on Lamarck than many think, that Lamarck is poorly represented in history (http://www.textbookleague.org/54marck.htm). But he makes a telling remark:

“Lamarck’s approach to evolution was that of a metaphysician rather than a natural scientist. It invoked a mystical assumption (the notion that organisms sought “perfection” and tended to become increasingly complex and man-like) which could not be treated scientifically (…).” “Darwin’s concept was a well articulated body of scientific thought that could be, and was, tested by recourse to facts. Lamarck’s was not.”

Unsurprisingly, Ghiselin remains a committed Darwinian.

Without belittling Lamarck, the fact remains that Darwin addressed evolution in a manner that articulated known facts and made possible further research and discovery of new data, and that is necessary for a scientific model that is not purely speculative.

But perhaps Patrice Ayme would prefer a more speculative evolutionary theory, one more truly Lamarckian. Perhaps it is the grim materialism of Darwinian theory (and its inheritors), as a negative ideology, that has mislead us?

Perhaps what is wanted is a theory of evolution that has proved – or could prove – that nature has a purposiveness and teleology; that evolution has been directed by nature toward improvement of species toward perfection, realized finally in the human species.

I’m sorry, but all the evidence stands against this. From everything it presents us with, nature is mindless, purposeless, and uncaring.

Let me clarify:

Mutations (by which I mean, those changes at the genetic level and above, that we also call adaptations*) occur randomly; then environment determines which of these survive, as continuance of the species, or in development of new species; and which get destroyed (this destruction is engineered through the failure to reproduce, for individuals with such doomed traits). The surviving traits may or may not be clearly adapted to the environment; they may have other uses, they may become vestigial, they may be squelched into disappearance.

“If we admit that the geological record is imperfect to an extreme degree, then the facts, which the record does give, strongly support the theory of descent with modification. New species have come on the stage slowly and at successive intervals; and the amount of change after equal intervals of time, is widely different in different groups. The extinction of species and of whole groups of species, which has played so conspicuous a part in the history of the organic world, almost inevitably follows from the principle of natural selection; for old forms are supplanted by new and improved forms. Neither single species nor groups of species reappear when the chain of ordinary generation is once broken. The gradual diffusion of dominant forms, with the slow modification of their descendants, causes the forms of life, after long intervals of time, to appear as if they had changed simultaneously throughout the world.” Darwin (Origin of Species, Chapter XV) (emphasis added).

Recent example of natural selection:

“The peppered moth exists in both light and dark colors in the United Kingdom, but during the industrial revolution, many of the trees on which the moths rested became blackened by soot, giving the dark-colored moths an advantage in hiding from predators. This gave dark-colored moths a better chance of surviving to produce dark-colored offspring, and in just fifty years from the first dark moth being caught, nearly all of the moths in industrial Manchester were dark. The balance was reversed by the effect of the Clean Air Act 1956, and the darkmoths became rare again, demonstrating the influence of natural selection on peppered moth evolution.” (http://en.wikipedia.org/wiki/Natural_selection. Their source: Ken Miller, http://www.millerandlevine.com/km/evol/Moths/moths.html.)

Note the lack of any mention of some sort of trans-generational generational purposiveness here; that is, there is no effort on the part of the organism to improve its condition. Without the Clean Air Act, over the course of generations, the genetic coding for light-coloring would simply have been squelched; light-colored moths would go extinct; the survivors of this species would all be dark. The ‘pepper moth,’ as a species, would become another species, to which we would need to give a different name.

Returning to our giraffes:

Mutation occurred, and some giraffes grew long necks; long necked giraffes reproduced and survived, short-necked giraffes died out. Holdredge’s point is crucial; long-necks make it difficult to drink (and drinking is actually more immediately important to the organism than eating). Giraffes may be surviving despite of their long necks (not because of them), although finding other adaptive uses for it along the way. The survival of long-neck giraffes cannot be reduced to Lamarckian teleological simplicity.

Scientists make mistakes; Darwin made mistakes; Lamarck made fewer mistakes than, say, his arch-for Cuvier, but far more than Darwin. That’s why we refer to evolutionary theory as “Darwinian,” it’s simple as that. The history of science is about cooperation (sometimes hotly debated, but eventually reaching agreement), leading to greater knowledge, not ultimate purposes.

Again, I’m sorry: Evolution does not develop purposively or progressively. We are not descended from apes, we are simply a certain kind of ape, all the other contemporary apes are on exactly the same step of the ladder that we are, descending from the same fore-bearers we did. Because there is no ladder – there is no ‘going up,’ there is only ‘going on.’

Our evolutionary fore-bearers are all dead – as species, they didn’t make it. And it is still unclear that we will, in the coming centuries. In worse case scenarios of natural selection, the whole of a given species can simply be wiped out. Because nature doesn’t care. If we or our entire breed are wiped out, other life-forms will continue. If all life is wiped out, the planet will still spin about the sun. If all suns are extinguished, fields of forces will generate the next big bang – or they won’t. I was tempted to emphasize this with the stock closing line “end of story.” But there is no story here.

Except the one we humans tell. But that is not to nature’s purpose, but to ours.

————————–
* I am growing wary of using the word “adaptation” as inscription of surviving traits in species, because it does have a distinctively purposive ring to it, e.g., ‘let’s get warmer clothing to adapt to this cold winter we’re having.’

It should be remembered that a part of the function of the human brain, as an evolved organ of environmental response, is to find patterns and determine possible intentions in the environmental field of perception. (Can’t run away from a predator unless first recognizing it for it’s intention to attack.) Consequently, assuming purposiveness everywhere, may be the inherited assumption, that the use of reason needs sometimes to overcome, in order to develop greater knowledge and understanding of the world, just as it is.

“Research shows that students have a tendency to think in Lamarckian terms. That is, students often invoke the needs of organisms when accounting for change over time (Bishop and Anderson, 1990). The apparent confusion may be reflected in statements such as “leopards evolved their spots in order to survive better in their environment,” or “elephants evolved their large ears so that they could disperse their body heat better.” They may also often believe that evolution is goal-directed. Discussion of Lamarck’s ideas will provide a context in which a clear distinction can be made between these ideas and those of Darwin. In this lesson, students are asked to explain phenomena using both Lamarckian and Darwinian theories. In doing so, students will come to see that the Lamarkian explanation is unsatisfactory while the Darwinian mechanism of natural selection is plausible and consistent with our current knowledge of genetics.”

http://sciencenetlinks.com/lessons/comparing-theories-lamarck-and-darwin/

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