The Evolution of Multivariate Maternal Effects

Abstract

There is a growing interest in predicting the social and ecological contexts that favor the evolution of maternal effects. Most predictions focus, however, on maternal effects that affect only a single character, whereas the evolution of maternal effects is poorly understood in the presence of suites of interacting traits. To overcome this, we simulate the evolution of multivariate maternal effects (captured by the matrix M) in a fluctuating environment. We find that the rate of environmental fluctuations has a substantial effect on the properties of M: in slowly changing environments, offspring are selected to have a multivariate phenotype roughly similar to the maternal phenotype, so that M is characterized by positive dominant eigenvalues; by contrast, rapidly changing environments favor Ms with dominant eigenvalues that are negative, as offspring favor a phenotype which substantially differs from the maternal phenotype. Moreover, when fluctuating selection on one maternal character is temporally delayed relative to selection on other traits, we find a striking pattern of cross-trait maternal effects in which maternal characters influence not only the same character in offspring, but also other offspring characters. Additionally, when selection on one character contains more stochastic noise relative to selection on other traits, large cross-trait maternal effects evolve from those maternal traits that experience the smallest amounts of noise. The presence of these cross-trait maternal effects shows that individual maternal effects cannot be studied in isolation, and that their study in a multivariate context may provide important insights about the nature of past selection. Our results call for more studies that measure multivariate maternal effects in wild populations.

Local adaptation in transgenerational responses to predators

“…For these populations, exposure to a predator cue essentially forecasts the presence of a predator for the immediate future. The observed within-generation response in this population aligns then with theoretical expectations for organisms inhabiting seasonal environments [22][23][24][25][26][27]. Given that the presence of a predator varies in these lakes, parental Daphnia are not expected to adaptively alter the phenotypes of future generations.…”

Predator-induced phenotypic plasticity within- and across-generations: a challenge for theory?

“…[2,3,15,16,[20][21][22]). However, only one extant framework considers both within-and across-generation plasticities and makes specific predictions regarding the connections between the two [23,24].…”

“…[17][18][19]). Transgenerational responses are expected to be favoured when there is environmental heterogeneity across generations and when offspring environmental conditions are predictable from parental environmental conditions [2,3,[20][21][22]. Current theory that explicitly incorporates phenotypic plasticity and 'maternal effects' [23,24] indicates that predictable environmental variation will simultaneously select for increased plasticity within-and across-generations.…”

When is incomplete epigenetic resetting in germ cells favoured by natural selection?

“…Our approach is different because we explicitly modelled the joint evolution of plasticity and inheritance, which can result in partial inheritance of acquired states. As with maternal effects [39,40,[51][52][53], the adaptive value of this environmentdependent heredity depends on the statistical relationship between environmental fluctuations and generation time [38].…”