Caenorhabditis elegans
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Ninety-year-old theory now tested
New versions of genes, called alleles, can appear by
mutation in populations. Even when these new alleles turn the individuals
carrying them more fit to survive and reproduce, the most likely outcome is
that they will get lost from the populations. The theory that explains these
probabilities has been postulated by the scientist J.B.S. Haldane almost 90
years ago. This theory has become the cornerstone of modern population
genetics, with studies on adaptation to novel environments and conservation of
species, for example, being based on it. However, until now there were no
explicit experimental tests of this theory.
The research team led by Henrique Teotónio, at the Instituto
Gulbenkian de Ciência (IGC, Portugal), in collaboration with Isabel Gordo, also
from the IGC, has now experimentally tested Haldane's theory. By performing
competition tests in roundworms, they have confirmed this theory for the
introduction of a new beneficial allele in a population. However, the
researchers found that this theory cannot predict the ultimate fate of the
allele. This study, published in the latest issue of the scientific journal
Nature Communications*, contributes to a better comprehension of how a
population can evolve, with implications for studies on how species adapt to
changing environments or species conservation.