Posting in Cities
British researchers discover genes that might explain disease resistance around the world. This shows a perfect case of evolution.
City living is no day in the park for hypochondriacs. Between coughs in the subway and close contact with people, germs are ubiquitous and unavoidable. As a New Yorker, I like most Americans have become accustomed to the urban lifestyle.
If trends continue, much of the world will, too: About 60 percent of people will live in cities by 2030.
Hello, mega cities and their problems.
People who live in cities are more likely to be exposed to infectious diseases. While individually this is bad, as a whole everyone is better off because over time the population builds up resistance to bugs (even if you need to sacrifice your life).
The gene defect that causes the lung disease cystic fibrosis might be seen as a bad thing. However, cystic fibrosis might have helped them fight the cholera toxin. So evolutionarily speaking, cystic fibrosis might be been a good thing back then.
Researchers at University College London and the University of London looked specifically at gene variants known to give a person resistance to deadly diseases like tuberculosis and leprosy.
British researchers checked the DNA of people from 17 countries. The researchers also checked historical records of the cities.
The gene variants for TB and leprosy were found in Middle Eastern and Europe cities, but weren't present in regions like Africa.
Urban living helps people build resistance. This selective pressure might explain some of the other types of disease resistance observed, like in the case of cystic fibrosis.
An Imperial College London professor told the BBC:
Individuals who are more resistant to a pathogen that causes a disease with substantial mortality, such as malaria or TB, will survive better and will contribute more offspring to the next generation.
Oct 1, 2010
In 1959, the median age of survival of children with cystic fibrosis was six months. That's not even long enough for a pregnancy, much less old enough to get pregnant; unless you're a cockroach. Even as recently as 2008, the life expectancy for infants born with CF is 37.4 years; which is old enough to have children and a small family. But that never would have occurred without modern medicine and antibiotics. No, the people who cite CF as a human mutation of benefit against disease as 100% WRONG.
I like most Americans as well, however, I think a few well-placed commas would make your article more readable!
Evolution moves in spurts. When there is little or no environmental pressure then nothing changes. When something changes that kills a lot of animals then only the fittest (those with the genes that let them survive) live to produce offspring. The last few million years have been a rather dynamic period in earth's history so animals a changing more rapidly.
It's a bit misleading. Individual people do not develop a gene for disease immunity during their lives, but the community does. How? Well, those that are not born with the favorable genetic mutation that makes them immune die before procreation. If all the sick people die the community is left only with those that are immune. Thus the community has developed a gene for disease resistance/immunity. The problem is that this is the 21st Century. We don't let people die of diseases that we can treat. People with some fairly common and once deadly conditions can lead normal, productive, and procreative lives. So the process of natural selection is stunted in affluent communities. Populations that have no access to health care will probably see Darwinian evolution happening much quicker than the Upper Manhattan Penthouse Crew. But the process is still slow, hundreds to thousands of years slow.
unless a gene is already around in high numbers and a disease decimates the population, it's going to be slow.
I'm a firm believer in evolution, but isn't it taking an awfully long time for the human species to develop these faulty genetically-induced disease coping mechanisms? Do animals in the wild (as opposed to the domesticated human animal) both develop these resistant genetic strains, and suffer from the faulty strains dying out? Well, actually, "suffer from" on an individual basis, and "benefit from" on a species-basis? Still--seems awfully slow when one considers all the work that had to have been done to progress from slime mold to hominid. I would love to (and fully expect to) be proven wrong, or short- sighted on this.