Question about genetics.?

Question

If your family line is not naturally muscular and you started to work out and build muscle, then you had a kid would he inheret bigger muscles from you or would he be the same as your ancestors?how many generations would it take for offspring to develop bigger muscle naturally ?
I am using the muscle example because it is something we can control as opposed to other things like skin color etc.

Answer 1

No. If you bulk up to Mr Universe, your progeny would not benefit. Only germ line mutations are heritable. What you propose is called " Lamarkism " and was refuted by Darwin's theory of evolution by natural selection.
To develop more muscular offspring you would have to marry into that line.

Answer 2

You yourself cannot pass your bulkiness to your children, yet, at the same time conformation and muscle mass is in a way, inherited, but selectively.

Since I know show horses best, and The American Quarter Horse best of all, this has to do with horses....

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There are conformation requirements for, say, an American Quarter Horse. And, breeders breed for the ideal, if, again, IF they are breeding for conformation, and conformation only. For example, let us say that he has a particularly great mare... just the standard of the breed: Drop dead gorgeous, and a mare any judge would just adore. She has a short back, wide chest, well sprung ribs, straight legs, great neck and beautiful head. He could go outside her blood line, and hope to get a foal carrying most of her beauty. But to have the best chance getting a foal that looks most like her, breeders will breed her back to her sire... inbreeding. And of course it carries risks, as you know... (that is why we do not allow sisters and brother, and cousins to marry).

This became a big problem about 20 years ago with the American Quarter Horse Association, with a horse called Impressive. OMG he was just to die for. But he carried some weird gene that produces huge, beautiful muscles, but along with it, an inability to utilize a certain protein. Probably you can google it something like AQHA + Impressive+ defective gene. He was, without a doubt the most beautiful animal I ever saw. And then about 10 years after he retired to stud, this weird disease showed up, and a friend of my had one of his daughters. The mare was in constant pain, and I think she finally had her put down.

There are as well screwy genes with Arabians called CID, Combined Immune Deficiency, where the baby is born, seems fine, develops just wonderfully for about 6 months, then things slip south, and it dies. You can probably find something on that one too... Arabians +CID ought to turn up something. Both parents are carriers of this gene, but neither have the disease....

Answer 3

Evolution doesn't work that way.

New traits certainly do develop and are passed down through successive generations; but in order for this to happen the new trait (which arises via mutation) must supply subsequent generations with an advantage over those individuals without the trait. Most mutations (99.99999%) are lethal or confer no advantage.

There is no evidence that the muscular hypertrophy that results from " working out" results in genetic mutations capable of being passed on to subsequent generations. However if you were to have a child who through a chance mutation had a muscular compliment that responded more favorably to "working out" and that by having this muscular compliment your child would gain some sort of reproductive advantage compared with other individuals (let's say he is able to have more children with this trait) then over time his (and your) progeny would be stronger. However because humans have a particularly long generation time( about 18-22 years) it would take an extremely long time to be able to recognize this difference.

Interestingly there is among African individuals a particularly illuminating example of mutation conferring an advantage.

Sickle cell anemia arises from a single mutation resulting in a solitary substitution in the amino acid sequence of the protein hemoglobin. The inheritance pattern is autosomal recessive meaning that two parents both having Sickle cell trait will on average produce out of 4 children one who is normal, two who have the trait and one with sickle cell disease. It turns out that those individuals with sickle cell trait (not disease) are slightly less susceptible to malaria. In areas where malaria is endemic those individuals with sickle cell trait have a slightly greater chance to survive childhood to go on to reproduce (and thus pass on the sickle cell trait). While individuals with sickle cell disease often do not survive childhood untreated at least 50% of children born to a couple with Sickle cell trait will have a better chance to survive childhood in malarial areas.