Submitted by Altruistic_Spirit_25 t3_zhk2lf in askscience
For example, a canine that will shake its prey around in its jaws. This probably disorients the prey. But how does that become a trait that a canine will have for generations?
Submitted by Altruistic_Spirit_25 t3_zhk2lf in askscience
For example, a canine that will shake its prey around in its jaws. This probably disorients the prey. But how does that become a trait that a canine will have for generations?
I think OP is referring to apparently inherited memories. The genome determines the physical characteristic, as a set of assembly guides for making the animal. Simplistically a long neck for a giraffe, fast muscles and running legs your a cheetah.
And there are reflexes like suckling.
But how does a very young animal have complex behaviours which suggests to me that they have inherited memories?
I don't think they actually have inherited memories, just inherited behaviors.
But a behaviour is a complex thing, probably requiring vision recognition of objects and choosing from a selection of actions. That would suggest, if the brain is anything like neural networks, it's already been trained with those functions.
We have several examples—at least in insects—that suggest that "learned" behaviors and "instinctive" behaviors use the exact same "hardware" in the brain. For example, take a fly encountering a smell for the first time. That "smell" goes through a number of structures in the fly's nervous system, from olfactory receptors to other nerve cell networks that identify those different inputs, filter out noise, and ultimately evaluate how to react. This network is capable of changing based on experience...if the is evaluated as "neutral" the first time, but then the fly gets hurt, perhaps the next time the same network will identify the smell as "dangerous," with an evaluation of "run away from that smell!" Running away from this smell based on prior experience would be a "learned" behavior.
Now take the same fly, and expose it to sex pheromones from its own species. The smell of sex pheromones goes through the exact same olfactory system as every other smell...receptors, identification, evaluation. But even the very first time the fly smells it, its identification/evaluation system connects that smell with sex. It doesn't need to experience sex a few times first to "learn" what that smell means...within that plastic, malleable olfactory system, a few connections came already pre-made, and those connections draw a bright line between sex pheromone olfactory receptors and sex, exactly as if the fly had learned to make that connection.
Separately from this, we also know that some species—like mice—can pass certain learned associations to their children and grandchildren through epigenetics. When a mouse makes a traumatic-enough association with a certain smell, that mouse's body is able to make alterations to how certain bits of DNA will be expressed in their offspring. Even when in-vitro fertilization is used (to rule out the mice somehow teaching their children about the truama), offspring show increased behavioral sensitivity to the same smell that traumatized their parent or grandparent, but not to other smells.
So between these lines of evidence (and some others), some scientists hypothesize that all instincts, from insects to mammals, are evolutionary hijacks of our "learned behavior" systems. Essentially, while animal brains (including ours) are often very flexible and adaptable, which lets us learn new behaviors over time, those same "teachable" systems are capable of developing with certain specific "learned" behaviors already built in.
It's an energy-efficient way to disorient and damage prey. As dogs develop and go through varied stages and random activities, most converge on shaking as one of their repertoire of preferred trajectories. Like most humans converge on walking, each in an idiosyncratic way.
What on earth does the length of a giraffes neck have to do with instincts?
> Important- The canine behavior you talked about is not learned and is inborn.
Source? Ive seen dogs raised alone do the head shaking thing. I don't buy that its a learned behaviour and not instinct.
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[deleted] t1_izr3v80 wrote
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