Thursday, August 18, 2011

Evolution and G6PD Deficiency

Evolution takes place over thousands of years, when I asked about evolution, I was looking for an answer that had the same scope. I wasn't not talking about the past few decades, but the past few thousand years. So while some made very valid comments on botox and the nebulous cultural standards of beauty, the answer I liked best looked at the bigger picture and had some specific examples to support his thoughts.

M Fawlful made a good point about many genetic diseases becoming apparent later in life. These inherited diseases have no effect on the mating fitness of an individual. M Fawlful also stated that individuals heterozygous for the disease can actually be more fit and produce more affected progeny versus unaffected homozygotes. It's why some populations in Africa have sickle cell anemia; G6PD deficiency confers resistance to falciparum malaria (one of the biggest infectious killers in Africa).

The thing is, in developed countries, our environment is no longer selecting for any physical trait in particular. It is no longer putting a selective pressure against the unfit, because humankind has changed the environment to fit its needs.

We have made homes with air conditioning, built supermarkets and awesome hospitals, developed vaccines against polio and tetanus, for example. These allow everyone to live and thrive, regardless of their physical fitness or their potential skills as a hunter/provider.

A lot of you mentioned ugliness or perceived physical beauty was irrelevant when we're talking about sexual fitness, but I'm still not convinced. An individual's preference, influenced by upbringing or whatever, doesn't have as much influence on the evolutionary progress of a species. People are instinctively drawn to people who look a certain way. Having a symmetrical face is a sign of physical fitness. Having wide hips and large breasts is a good indication of a female's fertility, for example. That's what I mean by good-looks, but I digress.

Another good point made by many of you is that mutations are always popping up in our genomes, and these mutations lead to birth defects and weird traits like a long neck or whatever. Given that these mutations are the substrate on which evolution can take its course and new ones constantly pop up in every generation, ugliness and new genetic diseases can never be completely eradicated.

Ultimately, M Fawlful, I picked your comment out of the many great comments by Bellingham, Ghevrix, GMSoccerPicks, Inverse, Procras, Gareth Thomas, DS, Bersercules, Mekkor, Clueless Dolphin, Equalz, Electric Addict, Lars, Twist of Events, H., Maxe's Maze, Natural One, ason31, neversettleforsecond, Michael Westside, Randall A., Shaw, Timothy Bowen, Kid Shuffle, convictus, and last but not least, Bulletproof Zombie. To everyone who contributed to this very interesting discussion, thank you. To the people who have followed this website since July, thank you for your continued support. TheTruthAboutGenetics.com has 200 followers now.

Sources linked directly above.

17 scientific replies:

Hento the loony repairman :D said...

perhaps with our "advanced" societies becoming more fat, there has to be some kind of genetic thing that might happen with it, probably natural selection will be about who is less fat and lives longer D:? but yeah.. i feel we are kinda reaching a point of phisical evolutionary stagnation the more "technological" we get

Gareth Thomas said...

Think of the potential for human evolution had the Toba Catastrophe (possibly) happened when the earth's population was divided by ten. Amazing to think what could've happened.

Sketchar said...

Aww I didn't comment in time :P. But one thing I didn't mention which I believe is also the problem is indeed DNA mutations. As radiation in forms or radioactive radiation, EMR, x-rays, gamma-rays can affect human cells such as gametes (sexual cells), DNA, cells. And as these chromosomes and cells mutliple differently due to such radiation, chromosome die or new chromosomes. So there are always new problems being made in our environment.

Pieter said...

200 Followers, that's great :) And I'm glad to be one of them, this is an interesting conversation.
I agree with you on the evolution btw. Humans don't adapt to the environment anymore, they adapt the environment to themselves.

Timothy Bowen said...

congrats to M Fawlful! and congrats to you for getting 200 followers!

Kyran said...

Kind of like how the internet organism has evolved to favour blogs with cleavage in their display picture.

Inverse said...

A very interesting topic. I hope to see more posts like this one in the future.

ChazWellington said...

people who are not fit should not be able to thrive. it takes a certain mindset to get somewhere and if they have that mindset they should be able to get fit

Azurikai said...

i absolutely agree with the survival of the fittest mindset.

FabFawk said...

This is what I call brain candy. Awesome!

H. said...

Congratulations on 200 followers!

Bersercules said...

Survival of the ones who adatp the best.

Bulletproof Zombie said...

1) First things first: that is, in fact, a new banner. Also, I love deviantART too, I've been part of the community for about eight years now.

2) Congrats on passing the 200-count threshold.

3) I've come to admire this blog for its inclination towards higher thinking and excellent topic choices. I feel privileged to be a part of it now.

Natural One said...

Congrats on the 200!

Publius said...

Evolution is awesome and VERY REAL! Never ceases to amaze me, especially me being a big fan of evolutionary psychology! +follow

That Bastard From Bellingham said...

I normally have a much more creative and intelligent comment, especially on a blog that I respect as much as I do here...

...but man, I had a tough day.

Congratumalations MFawful, and congratumalations on yer 200 followers, Genetics!

M Fawful said...

Yay! Do I get a prize or something? ;D

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