After generations of humans strength training will we eventually become naturally stronger?

Question

Since human evolve to be stronger when we require strength from other tough physical work would our bodies know the difference and evolve to become stronger naturally?

This only applies to the people who strength train and their kids strength train and on and on etc.

Answer 1

Your example is not how evolution operates. First of all when someone's muscles become larger due to being subjected to physically demanding circumstances, this is not evolution. This individual already has the traits to build muscle and the influence of weight lifting or intense physical labour is not actually enhancing these traits such that they experience a selective advantage in terms of reproductive success. Even if their children and grandchildren, etc, etc all continue this physical regime that promotes their own musculature development, their is still no selective pressure that is causing a reproductive success and natural selection towards an increased strength in subsequent generations. After many generations of such activities if one generation neglected to continue this physical regime then their muscles and skeletal robustness would only develop to their natural level of activity so all the work of their ancestors would have no "residual" effect towards them being stronger naturally.

Now, how does evolution work to actually achieve what you are asking about? Well within the human population there is already a natural variance where some people are toned with very little activity and others can weight train endlessly but experience only nominal gains. An evolution towards a "natural strength" in our human offspring would not actually require any strength training, but would only require that these naturally toned individuals who are able to build muscle quickly are able to achieve a heightened reproductive success and that those who tend to be physically weaker do not experience as high a reproductive success. There are a few ways that this could happen. The first would be a change in our human selective environment where a natural strength or a denser body type would become preferential to our species reproductive success. Lets say, for instance, that our planet shifted into a lengthy ice age and somehow our cultural structure disintegrated such that we had to deal with this environment in terms of our physiques morphological expression. Dense strong body types are much more successful in colder environments, so if this became our selective environment then weaker skinnier individuals would experience more frostbite and muscle seizures such that they would not look as desirable to potential mates and/or become physically disabled or dead because of this environment so that they were not as reproductively successful in this environment. After even a few generations of such a differential reproductive rate the natural frequency of genes that promoted this dense strong body type would be selected for, and as more distinct genes which promote this body type matched up from separate parents, well their offspring would then stand the chance of acquiring two separate genes which promote this characteristic and be even more prone to a natural strength then their parents.

Another way that this same selective pressure could occur is because of sexual selection. Some might jump on this quickly and say, "of course, many women prefer a well toned man", but to just look at it from this perspective is to miss half of the equation. For a "natural strength" to be selected for over many generations then you would also need sexual selection in the other direction as well. You would need a continued preference not only towards men of a dense strong musculature, but these same men would have to be attracted to women of a dense strong musculature. Then this couple and those like them would have to produce more offspring then the average and their children would also have to be attracted to similar body types to continue this sexual selection over many generations. As it turns out in the majority of people who have the required body type to perpetuate such a sexual selection are not typically choosing mate choices that would cause such a change by either combining genetic traits or in increasing their frequency within the overall gene pool by having more children.

The least frequent type of evolutionary change is that of mutation, but it should also be addressed in the terms of your question. Since "natural strength" is not being overly selected for in either our selective environment, or through mate choice, then if a mutation that caused a greater "natural strength" were to occur, then it would also not be selected for or against and would only maintain a nominal frequency in the population. If this gene which increases "natural strength", however, also had another characteristic that allowed those who carried it to experience a greater reproductive success then depending on how preferential to the reproductive success of it's carriers that this other characteristic was it would permit this gene to increase in frequency either be gradually or quite rapidly. Now, usually the genes expression would be related, so lets say that the gene acted as a pain suppressant such that muscle mass could build more readily because those who carried this gene were able to do more reps more frequently then those who did not carry this gene. Perhaps this natural pain suppression also made the pregnancy process more comfortable in those women who carried this gene and because pregnancy is less physically and psychologically demanding these women are able to have lower IBR's (Inter Birth Ratios) and thus have the ability to have a higher reproductive success in their lifetime. Anyways, the importance of what I'm getting at is that a mutated gene that only promotes "natural strength" is not enough, it would also have to give some other secondary characteristic which would allow a greater reproductive success.

Answer 2

Not unless they tend to produce more children due to our strength training. We know the least likely to get married & produce children are those having an IQ of over 125 & those most likely to produce children have an IQ below 95. Therefore average or below intelligence is being selected by birth rate. The high IQ is being "de-selected" via birth rate & some suggest it is due to lack of social abilities among the group with the higher IQ. Those at either extreme are the least likely to produce a large number of Children... something like a bell curve of human reproduction.
Now, if those that won the strength training were allowed to breed more often, we see a positive selection for strength. This would also work to increase intelligence if the people scoring the highest on SAT or IQ tests were to produce more children that those scoring lower on those tests. In the final analysis positive selection is dependent on a higher birth rate or a lower infant/mother mortality rate.

Answer 3

Before strength was developed for specific activities yet the only activity that still persists today is that of child bearing. All the rest have evolved into more sophisticated and more effective strengths that are pertinent to our time. Weight lifting concentrates on the muscular strengths which of course respects the mental strength required to do such a thing.

Answer 4

I'm not sure your assumption that humans evolved to be stronger is correct. We evolved to be bigger, but I don't know that we are stronger than earlier hominids, and we are weaker than some other primates (chimpanzees, gorillas, etc.)

The traits that affect human evolution are traits that increase survival, number of offspring and the subsequent survival and reproductive success of that offspring. In the past, when strength was 'required', all of the above would have come into play.

Unless the body builders take all the women for themselves, produce more offspring than the non-body-building guys, and also pass on some genetic trait that make their offspring want to be body builders, it ain't gonna happen :-).

I'll bet body builders actually have fewer children on average. (Just a completely unsubstantiated guess)

Answer 5

Nope. You are using the LeMarcian theory of evolution. This was disproven by a guy who tested the theory by chopping off the tails of many generations of mice. According to LeMarc, eventually the mice would evolve with no tails. But it didn't happen. Like someone else answered on here, unless there was some kind of advantage in breeding it's not an evolutionary factor.

Answer 6

No. By that logic, we should all be a terrible mess of scars from every injury that has happened to an ancestor. If my actions in one way will affect my children's physical appearance, why not in another way?

To evolve a stronger population, you have to prevent the weaker ones from procreating. Easiest way is just to kill them. If we instituted, say, hand to hand combat to the death for every young person before they could bear children, and only the strongest survived, eventually we'd end up with a stronger population. It might also work if only strong people were considered sexy enough to sleep with. If no one will sleep with weaker people, eventually the population will become more inclined to build muscle and more capable of building larger muscles.

Answer 7

No. Unless there is a selective pressure that favour people who are naturally strong, meaning that their strength is genetically determined, then only would the human race evolve to become stronger. training would have no effect whatsoever on evolution.

Answer 8

You are confusing Lamarkism with The Theory of Evolution. In the 19th century scientists were trying to explain the mechanism behind change in organisms. A man named Lamarck hypothesized that changes came about in response to a specific need. For example, giraffes' necks became longer because they needed to eat the leaves off of very tall trees.

Evolution does not have a direct cause and effect relationship. Organisms do not acquire traits because their environments require it. On the contrary, organisms that have traits that will allow them to be more successful in a given environment will live longer and pass on more of their genes. Greater reproductive success ensures that traits are passed on. These traits randomly appear in a population. If the trait is beneficial, it is passed on more often through successive generations.

Good Luck!

Answer 9

After generations and generations of Americans cutting their hair, will it stop growing?
Working out is a way to compensate the lack of real physical activities related to work. That's why farmers don't have to go to the gym. So it should be the other way around. Still, that won't happen because no species inherits acquired traits. Genes are not affected by your activities.

Answer 10

Nope. Not unless naturally strong people have more kids. Evolution requires a breeding advantage for a trait to increase.