What is the Human Fitness Function? written 10 years ago

The Selfish Gene

In the Genetic Algorithm, different solutions to a problem are compared using something known as a “Fitness Function”. Solutions which show a higher level of fitness than others are then allowed to have more mating opportunities than those with a low fitness. This, in theory should lead to a second generation with a higher overall fitness function than the first. This is a somewhat mechanical representation of Natural Selection, first introduced by Darwin.

Comparing Modern Men

What might the fitness function for today’s modern man be? What decides, fundamentally, if person A is “better” than person B?

What is the human Fitness Function?
What makes one person “fitter” than another?

It is easy if we use the animal kingdom as our population; Leopard A might be better than Leopard B because it is faster, therefore any offspring A may have will be better fed than the offspring of B (and so more likely to survive into adulthood, and produce offspring of their own1)

But upon comparing our population of humans we see no easily identifiable quality which might make one human better than another. Attractiveness? — no, Ugly people still have sex2. Physical Dexterity? — no, Unfit people still have sex, and although “healthier” people may live longer, most people already live much longer than is necessary to successfully raise children. Financial status? — no, poor people still have babies.3

Technological Advances

A further interesting point on a similar thread to this is that in today’s society, people that wouldn’t have produced offspring 50 (500?, 5000?) years ago now have the chance to do so, either because of advancements in medicine, or social changes (People choose “mates” based on love, rather than them being a good provider).

So in the apparent absence of any selection going on, is the human race evolving?. Children that otherwise would have died, now live, owing to either medical advances, or adoption / state childcare in the case of parents failing to live long enough to raise their young.

Might our technological & medical advances promote the stagnation of the human race? A recent study on prostitutes in Kenya has revealed that sex workers there may carry a gene that prevents them from HIV. This shows a clear case of Natural Selection, those with the immunity gene survive, and those without will contract the virus. This shows a clear (binary) fitness function. It is difficult to suggest something of a similar nature occurring in the western world. Are we to rely on third world countries to evolve our medicines?

If the (Western) human race has stopped evolving, what then does the future hold for the human race?

Is Genetic Modification the Answer?

— One Suggestion is that the technology of Genetic Modification will lose much of it’s taboo, and hence one means of “evolving” the human race would be to pick and choose bits of DNA from surrounding nature and splice it in with our own DNA, much like we can make tomatoes resistant to frost by copying and pasting a bit of Arctic Flounder DNA in.

Arctic Flounder, source: Natural Resources Canada
Will human DNA soon start to contain bits of DNA from other animals, like the DNA of the Arctic Flounder, used to make tomatoes frost resistant?
Image source:Natural Resources Canada

Amongst the many technical problems involved in this, the ethical experts will also create many problems for the process; For example, might this enforce a rich/poor divide? The rich becoming immune to the common cold, or having superhuman powers, and the poor being left behind to suffer? The real question for this being good/bad for the human race as a whole may never even get asked. Let us not even get started on the numerous religious objections which will be raised.

Questioning the Questions

There is also a consideration to be made that I am simply looking at this from a very narrow viewpoint. My 21 years of life contributes nothing to the scope of millions of years of evolution. Genetic Evolution takes many, many thousands of years to produce even small changes, so perhaps even with the subtlest of fitness functions, the human race will continue to evolve, maybe at the same rate, maybe at a slower rate.

This in itself raises another interesting question, if we are indeed evolving at a slower rate than our animal friends, might they one day in the none too distant future (in evolutionary time), “overtake” us? Becoming competitors for our status as “superior beings”? Might there be a war of the mutants? It is very hard to see it (especially in today’s mechanised warfare world), but might it happen?

Many questions produced, and not even the notion of an answer. I lack the necessary understanding to even know whether these are relevant questions to be asking (or even if they have any serious merit!). These questions, however, keep me awake at night, wondering what might become of the human race.


  1. Producing offspring is, the ultimate goal for any replicator.
  2. Although it may be seen that prettier people have more sex, our monogamous society dictates they will largely have children with only one partner.
  3. Possibly even more so than rich people.

← previous entry | next entry → Mon 27th Nov 2006 - 19:00 | 2 comments | tagged with Real World, Evolution, Essays

 Comments 2 comments made

Nina’s GravatarNina 3 weeks later

HA! I absolutely love this, if only this could be explained to those idiots in society without them bleeding from the ears…..

originally posted by Nina

HA! I absolutely love this, if only this could be explained to those idiots in society without them bleeding from the ears…..

Perhaps it is our duty to do so, speeding up natural selection perhaps?

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