I have issues with it on the basis of cause and effect i.e., with regards to the question: if humans have a disease, is it necessary for them to evolve it out? No, they could develop a medicide (not the same as eating medicinal leaves which are part of “nature” and hence the “metaphysically given”) and then cure it. Adaptation isn’t the automatic course of action for human beings. As Ayn Rand said, “The difference between animals and humans is that animals change themselves for the environment, but humans change the environment for themselves”. This implies that using natural selection for solving your problems is an appeal to the metaphysically given. Again, there is nothing wrong with artificial selection which is what is proper and required for man. Now, “Changing yourselves for the environment” runs contrary to the conceptual nature of man
Right. How could I have forgotten - Ayn Rand, evolutionary biologist and philosopher.
The issue here is that you’re not actually understanding what evolution is. Evolution is not some physical construct. It’s not something that organisms “undergo”. It’s not something that humans choose to enact or not enact. Evolution is, fundamentally, a mathematical construct. Traits that lend themselves to the increased survival of an organism NECESSARILY will be passed on more BECAUSE organisms that survive longer, reproduce more. Traits that DECREASE one’s ability to survive NECESSARILY will not be passed on as often, because organisms with those traits will survive shorter periods, and reproduce less. So what do you suppose MUST happen as a result? Well, gradually the frequency of the negative trait diminishes, and the frequency of the positive trait increases. As I said - it is a mathematical construct.
It’s a very common misconception, and has been for over a century now, that humans are exempt from evolution because of our ability to think conceptually and use tools. That’s simply not true. There’s nothing that we can do, categorically, that another organism cannot do in order to deal with changing circumstances. Other organisms migrate, other organisms use tools and shelter (to an extent, depending on the organism), other organisms do as much as they can to adapt to their changing environment, just like humans do. But that doesn’t change the mathematical certainty that negative traits will necessarily reduce in frequency over time as a result of diminished lifespans and reproductive viability. The effect may be smaller in humans due to the existence of medical science, but it does still exist.
I trust Ayn Rand’s ability to interpret and explain philosophy and literature. But she is not an evolutionary biologist, or a biologist in any sense. Just because she thinks that humans are not subject to the effects of the environment does not mean that she’s right.
I don’t know much about biology but isn’t the frontal lobe involved in “inhibiting” reflexes, not causing them?
See! This is what happens when a biologist comments on neurology, entirely outside of his area of expertise!
I looked into it more, and you are indeed correct. The frontal lobe inhibits primitive reflexes, which originate in the brain stem as automatic responses to stimuli. Which again leads us back to the definition of instinct - does an automatic response count as an instinct?
Instincts may improve the survival advantage of animals but it works against human survival: which requires a mind free from endless streams of “evil” thoughts and “compulsions”. Existence of human instinct (again, assuming you are all conscious of it) is the assertion that there are “metaphysical” components to human consciousness. Natural selection does not apply to humans because human deaths are not metaphysical facts. They didn’t have to happen. Development of the human genome is not a metaphysical fact. It didn’t have to develop in a certain way.
Natural selection certainly applies to human beings for the exact reasons I listed above. No organisms’ death is a “metaphysical fact”. Deaths do not have to happen to any organism. Which is why organisms with traits that aid their survival, including humans, are more likely to survive longer and reproduce more, and therefore, from a purely mathematical standpoint, those traits have an increasing frequency within a population, including human populations.
I’d like to repeat a point that you did not address earlier: human attraction. Instinctually, humans are attracted to the opposite sex. There are some humans that are different in this respect, but most humans are attracted to the opposite sex. This befits the definition of an instinct that I laid out earlier:
-
Universality - the trait in question can be found in all members of the species
-
Tendency - the action or set of actions is a tendency that can be overridden by conscious thought or present in a different form in different members of the species
-
Not learned - evidence currently points to sexual attraction being genetic, not a conscious choice.
This is an example of an “instinct” in my mind, and the mind of the professor that I mentioned earlier. It’s beneficial for the species overall to pursue a specific course of action - the pursuit of the opposite gender - and so traits that cause humans to inherently tend towards the opposite sex have been bred for. We can consciously choose to not pursue a member of the opposite sex, but it’s fairly clear that our sexual orientation is not a learned behavior. This is a very, very, abundantly clear example of an “instinct”.
Reproduction itself is an example of an “instinct.” If it were simply that we chose to reproduce as part of our value system, we’d see much greater variance in the choice to reproduce than we do - as it is, most humans want to reproduce, pretty much starting from the age that they’re capable of doing so. The fact that some don’t - just as the fact that some people are not attracted to the opposite gender - is actually proof that it is an instinct: there’s a clear MINORITY in both examples, which makes it fulfill the criterion for being an instinct by making it a “tendency” and not a “reflex”: it can be overridden.