How will evolution change the human anatomy?
Will people in years to come be born without an appendix? What use do tonsils serve? Leg hair…who needs it? Come on evolution! Sort us out!
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Will people in years to come be born without an appendix? What use do tonsils serve? Leg hair…who needs it? Come on evolution! Sort us out!
Well, I dont think there would be any major changes in human anatomy under the currecnt circumstances.
You need selection pressure for evolution to change a species, but because today’s higher living standards (at least in most parts of the world) the selection pressure on humans is much lower then before, for example many of the humans who would have perished in a young age in earlier times can stay alive and reproduce thanks to advances in medicine.
Probably the most obvious change in appearance would be in the skin color, where mixing of races would wipe out the "white" skin color, blue/green eyes and blond hair, and result in a more hemogenous mix of mostly darker skin tones.
what also might be the case is that the average hight of human race would increase, but mostly as a result of better nutrition and (hopefully) healthier life style.
But one could imagine in places like some parts of Africa where due to long time unrest and instability, the evolutionary pressure is still very high, genes coding for superior physical and mental capabilities would have an evolutionary advantage; this might result in individuals developing stronger and more efficient physique for example as they have a better chance for survival and reproduction.
Evolution occurs through Natural Selection (as its primary motivator). Human society is not being acted on by this process because we have so many ways to combat it. Medicine, soap, air conditioning, surgery etc… We just aren’t being selected by nature, so we are in an evolutionary stasis. It would take a major disaster to get us to start evolving again.
Also getting rid of an organ takes a very long time for evolution, which is why whales still have pelvises and femurs, despite having long since lost their legs (though they still have the genes for making them). Vestigal structures will be with us for a long time, especially because they are not making us less "fit", our population isn’t small enough for selection pressures to be very active, and we reproduce anyway.
The only significant selective pressure on us today is virus resistance. If a particular resistance is linked to an allele that also influences a particular body feature then the frequency of the allele will increase if the virus impacts on reproductive success.
Say an allele exists within the gene pool that increases resistance to the HIV virus and also expresses itself by giving the possessor red eyes. In an environment where the virus is prevalent, say sub saharan africa, then more and more people would end up with the allele, as only the survivors would live to reproduce. Eventually the majority of the population would have red eyes.
A similar effect can be seen with sickle cell anemia where a single copy of the allele gives resistance to malaria, but two copies gives rise to the disease. This is far more prevalent within those of African decent that it is in those with European decent.