Teleology and Inheritance of Acquired Characteristics

The idea that creatures evolve their perfect and wildly imaginative forms for a predesigned reason is called teleology.

Teleology is thought to be easily disproved and has been relegated again and again to the dustbins of dumb ideas.

Fish did not, for example, hold a committee meeting and decide to grow fins so that they could swim.

A second, related idea about evolution was introduced by Jean Baptiste Lamarck in 1806. He believed physical (or mental) characteristics acquired during a creature's life could be passed one generation to the next. Back then nobody liked the idea of evolution at all and they were quick to disprove Lamarck with the snide but convincing argument that no uncircumcised male humans were born and foreskins have not even gotten shorter despite several thousands of years of lopping them off at birth.

In a way, both these debunked and ridiculed ideas are correct if you consider populations rather than individuals. Little boys may not be born without foreskins but they don't keep them long. And they lose them for a reason - to cull out hemophiliacs. Humans are special cases, we all agree. No other creature cuts off parts of the sex organ to cull hemophiliacs.

Fish evolved from earlier creatures that swam to chase prey or avoid being prey. They changed their behavior patterns to meet new challenges from predators, seek new prey, attract mates or hide from enemies, live in areas of strong currents or hide in tiny caves.

The change in behavior then gave slight advantages to populations of fish with fin characteristics best suited to that kind of behavior. In any population there were some fish that, by chance, happened to have better suited fins than their siblings.

The better endowed fish had more young and the improved fin shapes became more common within that population. Thus, over a period of hundreds, perhaps thousands of generations, the fins were shaped by the fish behavior into specific shapes and uses.

Try or Die

Behavior changes always leads the process of evolutionary selection. From this viewpoint, the specialized fins of a particular species of fish did evolve for a purpose - survival of the fish within a specific envelope of relationships. The difference is that the purpose was not determined in advance, but is a pre-set condition of life that demands that organisms try very hard to survive. This is a behavioral characteristic, not a morphological one. But it is still deterministic, especially when applied to the population as a whole.

As for aquired characteristics, while the adventures of a single fish may not be passed along to its progeny, there can be no doubt that behavior patterns acquired by a population of fish do indeed get passed along to the progeny, if only by the necessity of the progeny surviving in the new habitat or condition imposed by the behavioral shift. Eventually, behavior aquired by a small population of fish can spread to become common to a species if the characteristic improves its ability to survive.

Evolution is hardly a game of blind random chance. Creatures work hard to select themselves for survival. The more inventive and clever they are, the better their chances of having more young. And if they learn how to survive in difficult surroundings, advancing some behavior pattern that gives them an edge, moving perhaps into a new domain, their young must emulate this new behavior or perish. Those that succeed best have the most young, but they have to try or they die. What's more, there are as many, if not more, creatures that survive by cooperation than there are creatures that survive because they are more aggressive.

Teaching DNA new tricks