Genetic diversity and long periods of time are things that are crucial for evolutionary adaptation. This made scientists wonder why invasive species, lacking genetic diversity, succeed quickly. And some ecologists are beginning to think that epigenetic factors might be modifying genes while leaving the genome intact.
The scientists presented their findings at a meeting of the Society of Integrative and Comparative Biology (SICB) in San Francisco. Biomedical researchers have been investigating the links between epigenetics and human health for a while, but evolutionary biologists are just starting to tackle it. Ecological epigenetics face a lot of challenges because the genomes of wild animals and plants have not been sequenced, meaning that scientists can’t pinpoint which genes have been modified. They also have trouble linking gene modifications to behavioral changes.
House sparrows (Passer domesticus) in Kenya are all descendants from a single group, so they have little genetic diversity. When scientists compared the genomes of the birds, looking for parts which had methyl groups attached to them, a key epigenetic marker, they found a high level of variability across populations. Similarly, two genetically identical plants of the invasive Japanese knotweed (Fallopia japonica) species had differently shaped leaves and grow to different heights depending on where they live. Like P. domesticus, F. japonica exhibited high epigenetic diversity.
Some scientists think that mapping the level of epigenetic modification might reveal whether a population will prosper or be extinguished. However, some critics aren’t ready to accept the links between epigenetics and invasive species.