In Darwin's theory of evolution, natural selection was based on random genetic mutations. For Francesca Merlin, a postdoctoral student from the Université de Montréal Department of Philosophy, such notions of chance and determinism are themes she explores in the November issue of the journal Pour la Science.
At each of these levels, it is important to properly define the concepts of chance, probability, determinism and indeterminism. “We often define chance as a phenomenon for which the cause is unknown. In biology, the Darwinian notion of chance refers to the fact that a mutation isn't the response to an environmental change. In other words, a favorable mutation is as likely as an unfavorable or neutral one.”
The debate between chance and determinism was a staple of evolutionary biology research until the 1950s. However, recent discoveries on genetic mutations based on environmental stress and eating habits have brought the debate back into the limelight. This is known as epigenetics. “Epigenetics is compatible with the Darwinian model,” says Merlin. “It is not questioning the theory of natural selection but simply limiting the role of chance.”
Certain genes within a population remain unpredictable and therefore indeterministic in nature. However, this perception could be based on our ignorance of certain details, such as imperceptible differences in the genetics or the environment, which could be the source of differences that we attribute to chance.
Merlin says all mutations aren't equally probable: “Certain biases exist in the mutation process. There is such contingency in all these processes that if we reset the history of evolution to zero, the result could be very different today.”
It is impossible to resolve the debate between determinism and chance, says Merlin. “Certain aspects can be indeterministic or random, but that doesn't imply that all evolution is indeterministic. The real question isn't choosing between these two possibilities but to determine the portion of determinism and chance in each biological process.”
Partners in research:
Francesca Merlin, who is supported by the Fonds de recherche sur la nature et les technologies du Québec, is a working under the supervision of Frédéric Bouchard.
On the Web:
- About the Université de Montréal
- French version of the news story
Media contact:
Sylvain-Jacques Desjardins
International press attaché
Université de Montréal
Telephone: 514-343-7593
Email: sylvain-jacques.desjardins@umontreal.ca
