Take the 2-minute tour ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

We can cure many diseases nowadays, and thus the natural selection is very limited. Plus, mankind spent the whole beginning of its existence in almost the same hostile environment, and that's where he evolved the most, whereas our environment is changing very quickly. So, can we say that mankind froze, if not stopped, its own evolution ?

share|improve this question
    
As long as some individuals reproduce more often than others then there will be evolution. –  Kevin May 24 '13 at 4:28
add comment

3 Answers 3

up vote 2 down vote accepted

Not at all.

  • Mutations accumulate independent of medical progress. In fact harmful mutations which would otherwise cause an individual to die can now be "cured" thus if anything increasing the gene pool.
  • Typically medical progress extends our lives when we are much older, thus we have already passed mutations on to our children before a bottleneck in evolution could occur
  • We are getting taller, less hairy and women are getting more attractive which is another form of evolution
  • As new diseases develop the selective pressures on humans are ever changing. HIV which was never as widespread is now pushing certain immunogenetic traits to be favourable, the same is true for malaria (HLA 5701) and many others

In conclusion, whilst there are fewer and fewer strong selective pressures forcing extreme evolution, our bodies are designed to evolve slowly unlike viruses like HIV. Our mutation rates are around 1 in 10^9, allowing us to always slowly evolve as there will always be traits which are slightly more advantageous.

share|improve this answer
1  
Women are getting more attractive?! Could you please elaborate? –  daniel May 18 '13 at 17:38
    
Women that are going to have children pass their traits on. Some people believe that the women who are more likely to get married and have multiple children are those that are most attractive. Other theories suggest that the most attractive women do not have children. Either way a certain trait, whatever it is, is the one more prevalent in women bearing children and thus this is the one that is passed on. –  AndroidPenguin May 18 '13 at 21:47
    
It doesn't sound like there is a testable hypothesis in any of this. Do you have a cite or two? –  daniel May 18 '13 at 23:46
    
here's a post if not the primary reference. This sounds reasonable to me, though i'm sure its not completely proven. abc.net.au/news/2009-07-29/… –  shigeta May 20 '13 at 23:32
    
Evolution is not entirely progressive - look up the 'red queen' on wikpedia. Competition changes traits by selection, but there is constant competition from the outside that reinforces change only for change's sake - it doesn't necessarily make the traits stronger. If you get the most masculine man and the most feminine woman, will the children have both extreme traits when and where you want them? Many exceptional trait combinations are not reproduced in offspring - they are as much coincidence as they are the product of selection. Look at pictures of Schwarzenegger Sons - not that big. –  shigeta May 23 '13 at 16:55
show 2 more comments

Keep in mind that most people live in environments where antibiotics are of limited availability and hygiene is not as rigorous as in the "western" world. Combine this with high population densities and you get, if anything, more natural selection due to the spread/proliferation of pathogens and the subsequent mortality of the patient. Also, don't confuse natural selection for evolution. Natural selection is one of only five causes of (micro-) evolution. Mutations will continue to occur. Sexual selection continues unabated, and migration is more important now than ever. The only evolutionary factor I'd argue is being diminished is genetic drift since there are so many people today.

share|improve this answer
add comment

In certain cases, yes medical intervention has delayed NATURAL SELECTION, but not evolution. We are adapting in the process of developing new drugs, which is one of the evolutionary strategies. However, genomic evolution is retarded by retardation of natural selection. But again, Genomic changes can be triggered by medicine (both in the context of side effects of chemical drugs and because of gene therapy)

share|improve this answer
add comment

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.