Where next for human evolution?

Humans are pushing constantly at the boundaries of what is possible. Running faster, flying further and discovering more. It is part of the reason we have become the dominant species on earth.

But through such discoveries as genetics, penicillin and atomic energy, technology has offset or removed many of the forces we fought with to survive, and which helped us to evolve.

Does that mean human evolution as Charles Darwin envisioned it 150 years ago has now stopped or is it being overtaken by a rapidly accelerating technological evolution?

Biological evolution

Darwin’s theory of evolution was simple. Animals and plants with the characteristics best suited to their environment survived and reproduced. The ones that did not died out.

This concept - the ‘survival of the fittest’ - explained the gradual evolution of species to their natural environment. One consequence for humans was a preponderance of fair skinned inhabitants in cold northern climates and darker skinned populations in the hotter territories.

Recently, however, scientists have begun to believe that natural evolution is being altered by a world population that is becoming less and less isolated.

"We’re seeing a homogenisation of the differences that exist now," says Professor Andrew Pomiankowski, a geneticist at University College London.

"Perhaps the best example of that today is Barack Obama who has African and European ancestry. This mixing of humans is going to be the biggest evolutionary change over the next 100 to 200 years," said Pomiankowski.

Other scientists disagree. Professor Julian Savulescu from Oxford University believes this type of biological evolution will be overtaken by more profound human-controlled genetic changes.

Human enhancement

"The problem with evolution is that it does not care about our personal happiness. But we can now fix that through genetic engineering."

Professor Savulescu predicts that as well as making changes to their own bodies, humans will also become more selective about their offspring.

"Within 200 years humans will probably have a large number of embryos and pick the best ones based on factors such as disease resistance and quality of life," he says.

We might also be able to mix human characteristics with those of other species, such as a cat’s physique or turtles' longetivity.

However, genetic engineering is just one of the technologies increasingly available to humans.

Transhumanism

Dr Susan Blackmore, a psychologist at the University of Plymouth, predicts growing competition between different technologies. She foresees a new kind of evolutionary battle in which only those applications most useful to humans will survive and be further developed.

She calls it the "battle of the memes" and characterises it as a choice between mobile phones in our ears, language chips in our brains and other technologies we might want to incorporate into our bodies.

"We could end up replacing all our organs," Blackmore concludes. "But is it still our body when all the organs are new?"

Rise of the machines

In a potent illustration of science fiction becoming science fact, the technology we create could unleash a faster pace of change in humans.

"Biological evolution is already being overtaken by technological change but that may in turn be overtaken by the development of machine intelligence," says Professor Nick Bostrom, director of the Future of Humanity Institute at Oxford University.

"A computer is an extension of us. We already use it to remember simple tasks but the development of super intelligent machines could see them [the machines themselves] invent new technologies far faster than us," he said.

Such a powerful capacity to change is a condition some fear humans could misuse.

"We’re at a tipping point.  We’re getting enormous powers but we haven’t evolved from the hunter gatherer as fast as our technology," believes Professor Savulescu.

"It’s like giving a three-year-old an automatic gun and expecting them to use it in the right way.

"In a single generation we could bring about more changes than in the entire human history or we could destroy ourselves."

Encarta: human evolution Encarta: transhumanism Centre for Practical Ethics Lecture series: Darwin's legacy