Can Organisms Direct their Own Evolution?
For a biologist to suggest that organisms can direct their own evolution is tantamount to heresy. Nevertheless, that’s exactly what Peter Corning, director of ISCS (the Institute for the Study of Complex Systems) is saying -
What they’re talking about is not some small curiosity, noted a few times in a laboratory. They have observed effects significant enough to have guided the development of life on Earth.
They are saying that, over their lifetime, living things make significant adjustments to their physical being as opposed to their genetic makeup. They do this in order to adapt to the environment they live in. They grow differently based on how they use their bodies and, in the process, various genes get turned on or off according to requirements. Mutation is random but development is not.
They say that this doesn’t constitute ‘evolution’ as such because no changes are made to the organism’s genetic make-
A number of studies support the idea of evolutionary genes as followers rather than leaders, says Carl Schlichting of the University of Connecticut in Storrs. In many cases, developmental changes are triggered by behavioural choices – food preferences, hand preferences etc. It can though be more far-
Peter Richerson at the University of California at Davis, says that although natural selection has been active on a wide range of genes since the beginning of human agriculture, many genes have altered in order to create the enzymes necessary for humans to process cereals and cow’s milk. Many other mutations have taken place he says, many of which we have still to identify their purpose. Clearly, culture is goal-
Not all evolutionary biologists agree with the above conclusions. In fact, Richard Dawkins is vehemently against it. He set out his stance on the matter nearly forty years ago in his book The Selfish Gene.
Is it possible that organisms are able to ‘request’ mutations exactly when they need them? It’s not proven yet but not as fanciful as one might think. According to Patrick Bateson of the University of Cambridge in the UK, certain genes possess markers that can be turned on and off. The result of turning one on means results in rapid period of mutation in order to adapt to a situation. What’s more, says James Shapiro of the University of Chicago, different types of stress including starvation, wounding and infection can disrupt the normal functioning of genes. He calls this natural genetic engineering. It provides a way for genes to experiment in times of crisis and perhaps find an adaptation that can stave off disaster.
Richerson adds that flexibility in development and behaviour can help organisms adapt to new environments, even when they lack the genetic raw materials. For example, it’s relatively easy to introduce the larger brained birds, such as crows and parrots, into new environments.
This may underlie the bursts of diversification that happens when a species colonises a new habitat. It could be the tip of a very big iceberg, says Eva Jablonka of Tel Aviv University. Learning has been enormously important in evolution. Once learning evolved, it was the driving force in animal evolution. She thinks associative learning may have been what sparked the Cambrian explosion of species diversification nearly 550 million years ago and produced nearly all of today’s animal life, including humans. If she is right, then we owe almost everything to the ability of organisms to direct evolution towards a useful end.
Peter Corning, director of the ISCS (Institute for the Study of Complex Systems in Friday Harbour, Washington)
Matthew Wund, College of New Jersey at Ewing: http://onlinelibrary.wiley.com/doi/10.1111/evo.12348/abstract
Carl Schlichting of the University of Connecticut in Storrs
Patrick Bateson of the University of Cambridge in the UK
Peter Richerson at the University of California, Davis
James Shapiro of the University of Chicago
Eva Jablonka of Tel Aviv University