Mankinds altered genes

Not wanting to post an idea on a far more serious post, I decided to post my thought here.

"A single generation of domestication heritably alters the expression of hundreds of genes".

That is a serious topic regarding the potential loss of wild fish and one that I am concerned about.

But it did make me wonder.......How long has mankind been domesticated? How many of our genes have been altered?

But then, the thought of running around buck naked in the forests, eating raw meat and twigs does not thrill me at all so I will accept my domestication and alteration of my genes.

Larry ---sagefisher---

I had to look up "heritably"; it means ability to pass genes from one generation to the next.

I had a similar thought regarding a recent post on the Orvis blog about Greenback Cutthroat trout. Apparently, the only true genetic strain was confined to a single stream containing about 700 individuals. Now that population is being used to repopulate parts of the original range. Talk about lack of genetic diversity! Especially when you realize Greenbacks are just an isolated strain of the broader cutthroat group, which is probably just an offshoot of the Rainbow group.

Regarding people, the best way to preserve gene pool diversity is for different races to intermarry. The worst thing would be to marry someone who looks like you and comes from a similar region of the world. But that's exactly what people tend to do.

Anyway, interesting thoughts, Larry.

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Originally Posted by waskeyc

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Regarding people, the best way to preserve gene pool diversity is for different races to intermarry. The worst thing would be to marry someone who looks like you and comes from a similar region of the world. But that's exactly what people tend to do.

Anyway, interesting thoughts, Larry.

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Larry,
I suspect that your comment about preserving various gene pools is exactly opposite of the actual method used. Strains are maintained in as much isolation as possible to allow breeders to create new strains. The best way to preserve the diversity of strains is to maintain populations of them which are not crossbred, regardless of the species being discussed. Organizations like Seed Savers and the Rare Breeds Trust seem to think so, too. Line breeding, breeding the male to three continuous generations of females, has been used by cattle breeders to purify certain strains and bring out desired qualities. It is only considered "safe" to do through 3 generations. Purebred varieties are raised for breeding and then crossbred to create F1 hybrid vigor in production herds. Back to cattle, the F1 heifers are often bred to purebred bulls to produce the animals used for dairy or beef. The same was done with swine. At least things were like that back when I was an agriculture major.

As far as genetic stability goes, some species are more stable than others. Scientist have determined that under conditions pure natural selection, feral cats need only three, widely diverse individuals to create a stable populations. Cheetahs are quite different in that regard.

Regards,
Ed

I don't get my jeans altered. if they don't fit right, back to the store they go.

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Originally Posted by sagefisher

Not wanting to post an idea on a far more serious post, I decided to post my thought here.

"A single generation of domestication heritably alters the expression of hundreds of genes".

....How long has mankind been domesticated? How many of our genes have been altered?
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This article really piqued my interest. I thought genetic changes took thousands of years to affect a population.

Can anyone explain what is meant by "expression of genes"? Is that different from changing the genes themselves?

Curious

Bruce,

Good question so I looked it up on Wikipedia. The explanation is almost as clear as mud but gives hints as to what the meaning of gene expression is, sort of, almost.

I vaguely remember biology when I was in high school and naturally all that knowledge (what little there is) is so outdated as to be unusable. :)

Here is a link to Wikipedia.

https://en.wikipedia.org/wiki/Gene_expression

Larry ---sagefisher---

Looks like gene expression is the result of the gene - e.g. blue eyes. I thought this was interesting - tiger genetics give them stripes, but the stripes change depending on environment.

Genotype is the genetic composition. Phenotype is visible expression of genes. A person with heterozygous genes will show the dominant gene, the phenotype. That person may still pass along recessive genes to their offspring. This is why redheads and blonds can pop up in an otherwise brunette family. Note that recessive phenotypes require both genes involved to be recessive. So while a brunette might carry genes for blond or red hair, people who are very blond won't pass along brunette genes. To make matters more interesting, hair color and a lot of other things have multiple alleles. That is to say that more than one gene is involved. Another factor is gene activation. Some genes are dormant and don't make the proteins which cause whatever they do. These genes can become active and start making impacts on their body. Some cancer patients have had their gray hair return to its original color, for example.