Humans Are Evolving To Resist Disease

[♦ nivek ♦]

http://www.telegraph.co.uk/earth/main.jhtm.../scievol105.xml

 

Humans are evolving to resist disease

 

Last Updated: 3:01pm GMT 05/02/2008

 

A major genetic survey shows how we are changing, reports Roger Highfield

 

Evidence that humans will evolve to shrug off diseases such as type 2 diabetes and obesity has emerged.

A survey of the human genetic code has shown that our resistance to malaria, diabetes and other diseases is changing in response to our environment.

 

Dr Lluís Quintana-Murci of the Institut Pasteur, Paris, and colleagues analysed more than 2.8 million single letter spelling mistakes in the human genetic code to distinguish the usual random changes over the last 60,000 years from those that seem to be occurring in response to the environment, when a genetic mutation gives people an advantage over their peers.

 

People are surprisingly similar at the DNA level and the work "abolishes the idea of race" he says.

 

But when it comes to the few differences, those showing the strongest signature of this effect, called positive selection, are involved in skin pigmentation and hair development, as is already obvious from how white people live in darker climates. "You do not need genetics to know this, but it shows our method works."

 

In the journal Nature Genetics the team reports that several traits are sometimes linked to the same gene, so that when people in the Far East evolved a different version of a gene called EDAR to sweat differently, the same gene gave them much denser hair and changed their teeth too, an effect he calls "hitchhiking."

 

Genes that protect against disease are also evolving. For example, one called CR1 helps to cut the severity of malaria attacks and is now present in eight Africans in every ten, yet is absent elsewhere, a novel finding.

 

Several genes, such as ENPP1, are involved in the regulation of the hormone insulin and in metabolic syndrome - a combination of adult diabetes and obesity. These are present in 90 per cent of non-Africans and their relative absence could explain why African Americans are particularly at risk of obesity and high blood pressure.

 

The work suggests they are adapted to an African environment and have not adapted to an American lifestyle. "They have not had the time to readapt," says Dr Quintana-Murci.

 

Prof Steve Jones of University College London comments: "They have shown that man was once more like other animals than we might like to imagine, for Nature imposed her rules on us in the same way as she did on rats or flies.

 

"There are three great eras of history; the age of disaster, when we were killed by cold or sabre-toothed tigers, the age of disease - the epidemics which began with farming - and the age of decay, in which most of the developed world now lives, and dies of old age.

 

"DNA now shows how much we were moulded by the force of natural selection during first two; but my guess is that in future, now that we nearly all survive for long enough to pass on our genes, much less will happen. Perhaps you can ask me again in ten thousand years."

 

An earlier study by a team led by University of Wisconsin-Madison anthropologist Prof John Hawks suggested that humankind has evolved more rapidly in the past 5,000 years, at a rate roughly 100 times higher than any other period of human evolution.

 

This work counters a common theory that human evolution has slowed to a crawl or even stopped in modern humans, since in modern society the survivors no longer have to be the fittest.

[Sexton Blake]

We are living in a fast changing world and there could be some micro-evolution to help us cope with the stress, the pollution, changing foods and so on in the modern world.

 

Diseases are evolving too. It has been found that AIDS is now not always fatal. Basically any disease that kills it's host is a failure because it will die too. We know from Indians and Eskimos that the common cold, now just a nuisance, was a killer originally.

[MesaGman]

Does this mean I'll soon evolve my X hormones, to become a mutant? I do hope I am smart like beast! or compassionate like Nightcrawler (scratch that, he's a die hard Catholic), or bad ass like Wolverine. No Morph. I want to be Morph.

[Fweethawt]

I want to be like a cross between Magneto and Wolverine...

[Eric_PK]

The fact that there are specific adaptations for past conditions does not imply that there are current adaptations in process.

 

For example, I'm pretty skeptical of evolution around type 2 diabetes because it's a middle-age disease. You therefore won't commonly see people die of it before they reproduce. You could argue that the children and their children are more likely to die earlier because of growing up with parents that eat poorly, but I'm not sure it would be a big effect.

[Evan]

I hope this data can be used to develop new vaccines and medicines. Maybe even gene therapy to protect us against certain diseases? Too bad thats always been a disaster in the past