I've been thinking about genetics recently. I have red hair and fair skin (if I were any more pale I would be transparent). As well as giving me a fiery temper, the red hair gene reduces production of the skin pigment melanin, which provides protection from the sun. Consequently I burn easily, and the closest I ever come to a tan is when freckles join up. This may make you wonder why such a trait would ever exist in the population.
It turns out that the red hair gene is advantageous because red heads can produce more vitamin D from sunlight. Which is why red hair is common in north western Europe. If the gene had occurred in Africa, then it is unlikely to be passed on since carriers of the gene would have succumbed to skin cancer before adulthood. I find this interesting because it is a recent addition to the human genome. For the creationists in the audience, it is a gene in human beings that has come about through natural selection (go Darwin, it's your birthday)! I suspect that if human beings didn't move about so much my descendants would evolve in to the lesser-spotted red human, common in northern areas.
My girlfriend has a very different complexion to me. She is Brazilian, with ancestors from Italy and Portugal. Her skin is darker than mine and tans very easily. She also has other adaptions to a sunny climate; her skin always seems hotter than mine, as if her body favours getting rid of heat rather than conserving it. And she will shiver and get goose-bumps at temperatures that I find comfortable. I can see us fighting over the thermostat!
The red-hair gene is recessive, so a child must get it from both parents to have red-hair. Which means that if Maria and I have children (patience sweetheart), they are unlikely to have red hair since she probably doesn't have the gene (our kids will probably look like this). I'm actually quite relieved that my kids will look more like her. Hopefully they also won't also inherit my unmanageable hair and allergy to house dust mites.
This makes me wonder if evolution in human beings has effectively been halted? We are no longer constrained by geography in the way the rest of the animal world is, and most people will get the opportunity to pass on their genes. Will human beings evolve in any significant way in the distant future? I suspect not. There are plenty of species that seem to have stopped evolving, because they occupy an evolutionary niche. Disappointing really, I wouldn't mind a philips screw-driver for a pinky finger.
24 Responses to "I am the next stage in human evolution"
oh I know I'll write a masturbatory blog about a topic even the most elementary of children have thought about and then post it on reddit so everyone else can look at my navel too
You do that, my friend. And I will go write poorly-punctated comments in peoples blogs, that completely miss the point.
Actually natural selection only serves to reduce the gene pool - by eliminating inefficient genes.
The phrase 'a gene in human beings that has come about through natural selection' doesn't actually make sense.
The proposed mechanism for new genes is random mutation.
> And she will shiver and get goose-bumps at temperatures that I
> find comfortable. I can see us fighting over the thermostat!
Actually, that's because she's a girl. Girls are cold.
and why didn't you delete that first comment? It seems to serve no useful purpose beyond an illustration of the need for further evolution...
Good point, I have got that the wrong way around. It is more accurate to say that the gene survived due to natural selection.
I never pass on an opportunity for a pithy comeback. :-)
I was taking the pith...
Speaking as a creationist, I'll throw my 2 cents in: I don't have a problem with natural selection (gasp!) My problem with evolution is the whole 'one species making the jump to become another species' thing, not with people in one part of the world being more prone to having recessive red-headed genes. :-)
BTW, I really enjoy your pygame stuff . . .
But if you are ok with natural selection making small changes, can't you extend that to the point where the the changes have accumulated enough to make a different species?
Glad you like the PyGame stuff. :-)
Considering that on average for every new adquired positive mutation to a gene during that time there are 10 000 negative mutations, and that natural selection only removes individuals with excessive amount of negative mutations, it is more likely for the human race to become extinct in the next few thousand years than to evolve significantly.
Redheads also have a higher tolerance for pain than people with other hair colors, according to an NPR blurb I heard last week.
And to answer your question, no. Humans no longer participate in natural selection in traditional terms.
(Good for you to leave that first comment up, BTW. No need to censor morons.)
I personally have a problem with it. Look at people - I have no problem with the idea that people who live in a different climate have 'evolved' traits that make them better suited for their environment. On the other hand, we're all still humans.
Natural selection favors the best traits in a given species, but like you said - your red hair may be recessive, but it isn't a 'new trait', just a recessive one that is very well suited to your climate. Natural selection helps promote the best given traits that a species already has. It doesn't 'evolve' new ones.
Put some humans in a watery environment for a long period of time (minus the trappings of civilization and society) and see where natural selection leads - people better suited to the water would be healthier, stronger, more likely to pass those traits on to their children. I have no problem with that. On the other hand, would those people eventually evolve to have gills and webbed hands/feet? That would be better suited to their environment, but those are not human genetic traits. I don't think it would happen.
It's hard to say what traits would develop, but webbed feet is entirely possible. Don't know about humans growing gills - but there are fish that have lungs, and can walk on land.
Disgusting fish people seem quite plausible to me!
I doubt that human evolution has halted, just that because genes aren't eliminated and lack of geographic boundaries we will all tend to evolve together. Possibly expanding what it means to be human?
Also, Horizontal Gene Transfer is another mechanism for "new" genes.
You reasoning is incorrect. Quoting: "In Africa - from where we presumably all came - the intense equatorial sun acting through the forces of natural selection produced a race of dark skinned people. The dark skin allowed enough absorption of UVB to produce plenty of vitamin D, but prevented the absorption of enough to destroy the folate. [Folate is necessary for development.] As people migrated out of Africa into cooler, less sun-exposure intense areas, skin color got lighter allowing more absorption of UVB to produce vitamin D."
So your light skin is an adaptation to the environment of your ancestors and is as "evolved" as any other skin color.
But consider this: "According to research at Oxford University red hair, fair skin and freckles stem from Neanderthal ancestors." Of course, this is disputed research, but, hey, maybe you're a step back. ;-)
Well I have often wondered why my knuckles drag on the ground as I walk!
Regarding the suggestion that humans may have stopped evolving:
I think, as an intelligent species, most of our evolution is memetic, not genetic. memes can evolve *MUCH* faster than genes.
It can even be argued that the whole point of "intelligence" as an evolutionary trait is that intelligent organisms gain the ability to adapt on the scale of a individual's life-span, whereas non-intelligent organisms must be satisfied to evolve over geological timescales.
on the creationist side of the discussion, most creationists acknowledge microevolution (e.g. corn being bread to yield bigger ears with more kernals, juicier tomatoes, etc) but don't acknowledge macroevolution(e.g. breeding tomatoes until they become radishes). i've read articles that include reasearch from renowned mathematicians that say given the estimated time of human presence on earth, the statistical probability of having enough positive mutations for human beings to evolve as they are today is unlikely. also, during the cambrian geological period, so many new forms of life sprung up that evolution could not possibly account for all of them. not something the powers that be emphasize in your school book, but not really disputed hotly in the scientific community either. those who want to cling to the THEORY of evolution generally treat it as a situation that they just haven't found the evolutionary answer for yet.
I love you blog, I have a red head boy with sun sensitivity and I found your story. I hope thet people live long enough to become one race, more than likely they would look like Tiger Woods. I totally believe in evololution and know no matter how above animal instincts we think we are, we still follow our noses and eyes. Smell is a sense we greatly underestimate but still somewhere deep inside our bodies know when others around us are ready for courtship. A mans eyes travel in a triangle when speaking to a woman first from both eyes to breast then later both eyes to mouth... ladies keep an eye out it is true! No matter how far we try to escape from or cave man roots we are still just Mammals. Never think you are greater than beasts. They only kill for food or protection, if only we were that advanced.
I'm all for mingling of genes, but genetic diversity is probably a good thing. If only for the fact that it keeps things interesting!
The fact that humans are no longer constrained by geological boundaries doesn't mean that human evolution is going to halt. On the contrary, we are the only beings that have the ability to influence the evolution of our own species. For centuries, we have been choosing our species destiny as we advance into new and new technologies; now the physical being isn't as important as the mental. Brawn as pretty much lost out to the brain as we start to use machines more and more and need to think out problems and process more information faster and with a higher degree of accuracy to become successful in life and thus produce more children, some of us have genetic traits that are helpful for that are being passed, while the genes that promote the ability to lift heavy objects or increase our stamina are becoming less needed. We are the only creature on the face of this planet that has the ability to augment our genetic structure and thus promote our own ideals for what we need to continue our civilization. The human mind will prevent evolutionary stagnation.
“red hair is common in north western Europe. ”
Why dosn't it get more common in a gradient towords the north then? Finns are further north than Scots. And blonde hair dosn't lighten the skin much.
The amount of Vitamin D made in the skin over a couple of hours is the same for everyone and it's limited to the same amount for everyone. Readheads take only 20 minutes to make what Africans make in 2 hours, but redheads don't make any more in a day at the beach for example. <a href="http://ww.jsecjournal.com/NEEPSfrost.pdf [ww.jsecjournal.com]">SEXUAL SELECTION AND HUMAN GEOGRAPHIC VARIATION</a>
<a href="http://evoandproud.blogspot.com/2009/06/pseudo-epidemic.html [evoandproud.blogspot.com]">A pseudo-epidemic?</a>
you have a nice decision.
yeah! red hair looks good!! thanks 4 your help in our project in science under maam b.