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Evolution continues down to the present day


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2016 Oct 30, 7:05pm   13,281 views  77 comments

by Patrick   ➕follow (59)   💰tip   ignore  

http://www.economist.com/news/science-and-technology/21698645-researchers-can-now-watch-human-evolution-unfold-not-what-they-were

The effects of two thousand years of evolution, covering a hundred or so generations, are such that if ancient Britons were given all the benefits of a modern diet and modern medicine, they would still end up shorter than their modern counterparts, have narrower hips, and give birth to babies with slightly smaller heads.

#science #dna #evolution

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66   RealEstateIsBetterThanStocks   2016 Oct 31, 10:55pm  

men screwing men is "normal?" what's next?

sex with animals is normal?

sex with parents is also normal?

these are really sick that people need medical attention.

67   Dan8267   2016 Oct 31, 11:04pm  

rando says

technically correct is the best kind of correct!

It's the only kind of correct. But to address the issue you brought up...

rando says

There's a fun Ted talk where the speaker points out that men actually share a greater percentage of their genes with male chimpanzees than they share with human women. This is because of the difference in the sex chromosomes: X chromosomes have a lot of genes on them, and men have just one copy.

I haven't seen that tech talk, but I think your counting wrong.

First, the statistic I quoted, 99.9%, is an accepted figure. However, I haven't read anything regarding there being a difference comparing males and females.

Second, and more importantly, I believe you are counting copies of genes rather than counting unique genes, i.e. identical base pair sequences. The figure I quoted deals with genes, not how many copies you have.

So it's true that men have a tiny bit of genetic material that women don't have because it's on the Y chromosome. It's also true that women have two X chromosomes and men usually only have one. It's further true that having two X chromosomes can make a difference for two reasons. First, the two X chromosomes aren't identical. You can have a mutated gene on one of them that malfunctions, but still have a good copy of the gene on the other. This is why men are more susceptible to some genetic diseases like color blindness. Second, having two copies of a gene can cause the gene to be more strongly expressed.

However, regardless of those points, the actual set of base pairs does not vary that much just by having a second X chromosome with pretty much all the same genes, maybe slightly different variations. So I would measure the differences by counting up base pair sequences that exist in only one of two individuals and dividing by the total number of base pairs in each individual. I believe that's where the 99.9% figure comes from. Having two copies of a gene is not the same thing as having two genes.

68   Dan8267   2016 Oct 31, 11:14pm  

Another thought occurs. Genes can indirectly influence things. Let's say that subsequent sons are increasing likely to become gay due to testosterone increases in the womb. In that case, any gene that influences either men or women to want to have more children would tend to cause more sons to be born, and thus would trigger the situation in which a greater percentage of men would be gay. In contrast, any gene that makes men or women want to have a single child, would decrease second, third, and fourth sons and thus decrease the percentage of men who are gay.

So in this case, do you call that a genetic component? Certainly a gene is indirectly affecting the outcome, but it's not directly causing the sexual orientation. It's not a "gay gene" as much as a "have more babies gene" that has a side effect on orientation due to increasing the number of subsequent sons. In fact, it's the genetic code of the parent, not the child, that affects the child's orientation.

69   NDrLoR   2016 Nov 1, 8:54am  

rando says

Actually okra is still rather repulsive

The boiled kind, okra in spit.

70   NDrLoR   2016 Nov 1, 9:05am  

It seems like comments have numbers some days, but today they don't.

71   FNWGMOBDVZXDNW   2016 Nov 1, 9:17am  

There are plenty of things that caused by a combination of genes and environment. Heart disease and cancer are examples. You can look at someones family health history and see if they are prone to heart disease or certain cancers. But, people can influence whether or not they get those diseases by their habits. Some diet doctors use the phrase, genes load the gun, but diet pulls the trigger.

A person might be genetically coded to get wood around people of the same sex. Their environment obviously affects whether or not the suppress that desire or act on it, and whether or not to do it in the open. Environment might also impact expression of genes in some way and help determine who the guy gets wood for in the first place. Homosexual behavior is all over the animal kingdom, so there is really no arguing that it goes against evolution. Evolution created homosexuality over and over again in many types of animals. The only question is understanding the mechanism for it.

72   Patrick   2016 Nov 1, 9:36am  

P N Dr Lo R says

It seems like comments have numbers some days, but today they don't.

Are numbers important? I could put them back.

YesYNot says

A person might be genetically coded to get wood around people of the same sex.

Actually, that does not seem to be true in humans. If a man were "genetically coded" to be gay, then his identical twin would also be gay. But 93% of the time, the identical twin is not gay.

YesYNot says

Homosexual behavior is all over the animal kingdom, so there is really no arguing that it goes against evolution.

No, exclusive homosexuality is exceptionally rare in the animal kingdom. Lots of animals, especially males, will fuck basically anything they can. Your dog will hump your leg. You just get the impression gayness is common among animals because the exceptions are promoted so strongly in the press as the highly-desired "evidence" that gayness is in absolutely no way a choice.

73   Strategist   2016 Nov 1, 9:39am  

rando says

P N Dr Lo R says

It seems like comments have numbers some days, but today they don't.

Are numbers important? I could put them back.

Helps when searching for a previous post.

74   Patrick   2016 Nov 1, 10:05am  

OK, I'll put them back.

75   NDrLoR   2016 Nov 1, 12:30pm  

Strategist says

Helps when searching for a previous post.

rando says

OK, I'll put them back.

Thanks!

76   FNWGMOBDVZXDNW   2016 Nov 1, 12:51pm  

rando says

But 93% of the time, the identical twin is not gay.

There's a difference between being excited by someone of the same sex and admitting it. There's also a difference between what your genes make likely and what gets expressed. So your test whereby you expect 100% match is the wrong test. I'll ask you this. Is cancer caused by genes? Do some people get large muscles because of genes? The answer to both questions is mixed. Genes certainly help some people develop big muscles, but two identical twins separated at birth will not have the exact same size muscles. One might get cancer at 40 and the other might not develop it in his lifetime. If you your test for something being caused by genes is 100% equal results, then you will find that nothing is caused by genes.

If people find that the chance of being gay is affected by genes, then it is partially out of their control and not determined completely by nurture. Same goes for disease.

77   Patrick   2016 Nov 1, 10:11pm  

P N Dr Lo R says

Strategist says

Helps when searching for a previous post.

rando says

OK, I'll put them back.

Thanks!

@"P N Dr Lo R" The comment numbers are back now.

I guess they do add some useful info.

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