My searches so far for info on animal instinct have resulted in huge number of hits about rock bands, songs, pet shops and everything but what am looking for.
How instinctive behavior is passed to new generations fascinates me, but am wondering if there is any research showing the mechanism for this.
It came to mind as am re-reading Darwin who discuses examples in detail. Since then there must have been some advances in biology, but wonder if anybody realy knows. Is it in the DNA, in the brain, or what?
Any pertinent links?
Instinctive (or “fixed action”) behavior is one of the most curious topics of interest in neurophysiology. We have a vary strong, if primitive, grasp on how learned behavior is encoded via strengthening preferred connections (synapes) between neurons, so that certain paths are more readily stimulated by lower potentials. (See Hebbian theory.) The same general mechanism is also responsible for instinctive behavior (hence, the notion that it is “hardwired in”), and with an animal with a very simple nervous system like the sea slugs of genus Aplysia (with which Eric Kandel demonstrated the learning mechanism of memory storage in neurons) it’s pretty easy to see how it would evolve an instinctive behavior, as even minor differences between its literally few and very discrete sensory and motor neurons would result in behavioral changes which give rise to selective differentiation.
With more complex animals displaying sophisticated behavior, however, it’s far more difficult to identify and study the specific cellular structure in the brain that controls a behavior, must less establish differences between like members of a species and track development. It seems almost impossible that an an inate behavior that requires intricate manipulation and judgement–building a nest or a dam, or identifying one penguin out of a thousand seemingly identical birds–could be the result of selective mechanicms. But you have to realize that a complex behavior is simply a collection of less complicated behaviors, and so forth. The genome (built of DNA) provides the recipe from which the brain (and other organs) are built is one significant component of this, but it’s wrong to think that it’s all “in the DNA”, as if you could unravel a strand and find a program for said behavior; the genome dicates how and when neurophysiological development occurs, but also indirectly controls instinct by coding for the manufacture of neutrotransmitters, enzymes, et cetera which play a role in defining the resultant behavior from an instinctual impulse.
So…it’s complicated. So complicated, in fact, that any professional neurologist or neuroscientist worth his salt will own up to not really understanding how little electrical impulses in the brain turn into juggling balls, much less orchestral symphonies or the Collected Works of William Shakespeare.
There is also the highly discredited pseudoscientific theory or racial memory popularized by Jungian disciples, in which acquired memories and associated behaviors are shared between generations as a “collective unconscious”. No physiological mechanism for this has ever been demonstrated, and the theory itself has fallen by the wayside, though if you took a sufficiently broad view I suppose you could considered memes to be a kind of collective social unconscious memory.
Stranger
Wow, stranger, thank you for that fascinating treatise! Most enlightening.
And so ends this thread, as can’t think of anything more pertinent that possibly could be added. 