The evolution of epigenetically mediated adaptive transgenerational plasticity in a subdivided population

Area of Science:

• Evolutionary biology
• Genetics
• Ecology

Background:

• Transgenerational plasticity (TGP) involves offspring inheriting traits influenced by parental environments, representing a nongenetic inheritance mechanism.
• While epigenetic inheritance is of interest, evidence for adaptive and heritable epigenetic modifications is limited.
• Understanding factors promoting epigenetically mediated adaptive TGP is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the conditions under which epigenetically mediated adaptive TGP evolves in a population structured across two distinct habitats.
• To explore the influence of migration rates and differing selection pressures between habitats on the evolution of TGP.

Main Methods:

• Utilized modified population-genetic models incorporating epigenetic induction and inheritance.
• Simulated populations in two connected habitats with varying migration rates and selection directions.

Main Results:

• Differences in selection direction between habitats are shown to drive the evolution of epigenetically mediated adaptive TGP.
• Low migration rates showed increased indirect selection for TGP with higher migration, while higher migration rates showed the opposite trend.
• Moderate migration rates, coupled with differing selection directions, were identified as optimal for TGP evolution.

Conclusions:

• Epigenetically mediated adaptive TGP is most likely to evolve in species with populations subdivided between habitats exhibiting opposing selection pressures.
• Moderate migration rates between these habitats appear to be a critical factor for the evolution of such adaptive TGP.
• The evolution of TGP is favored when the costs associated with these systems are not prohibitively high.