Transgenerational Plasticity Is Adaptive in the Wild

Abstract

Plants exhibit adaptive responses to light, but it is not known whether parental plants transmit environmental cues that elicit adaptive responses in offspring. We show that offspring life history (annual versus biennial) is influenced by the maternal light environment (understory versus light gap). This transgenerational plasticity is adaptive when offspring are grown in their maternal light environment, where seeds typically disperse. Projections of population growth show that plants that are appropriately cued for their light environment through maternal effects have 3.4 times greater fitness than otherwise. Transgenerational plasticity has evolved in response to natural variation in light and provides a flexible mechanism by which sedentary organisms cope with heterogeneous environments.

Rapid adaptive responses to climate change in corals

“…For example, adaptive TGP might be expected when the parental environment is a reliable predictor of environmental conditions that their offspring will experience 53,54 . Because short-range offspring dispersal typically enhances environmental predictability among generations 55 , the benefits of TGP are expected to be inversely proportional to the dispersal capacity of the organism. The three main reproductive strategies that characterize coral-reef species -broadcast or pelagic spawning, benthic or demersal spawning, and brooding -represent a spectrum of dispersal potential, and hence differences between parental and offspring environmental conditions.…”

“…TGP occurs when the phenotype of a new generation is influenced by the environment experienced by the previous generation(s). TGP is adaptive when the exposure of parents to a particular environment leads to improved performance of offspring in the same environment 20 , with classic examples of adaptive TGP including morphological defences in animals 19 and the shortening of lifecycles in plants 55 . Parents can influence the phenotype of their offspring through a range of mechanisms, including the transmission of nutrients or other cytoplasmic factors, such as hormones and proteins, or, in some cases, through epigenetic processes, such as CpG methylation, histone modifications and variants, or non-coding RNAs.…”

Transgenerational acclimatization in an herbivore–host plant relationship

“…This theoretically postulated process is termed transgenerational conditioning or acclimatization, the most obvious way that parental effects based on environmental conditions could influence progeny in an adaptive way [5,6]. But although several studies found adaptive maternal effects in plants [8][9][10], insects [2,11] and also in other animals [12 -14], transgenerational acclimatization of progeny to host plants have not be documented so far, in spite of many experimental attempts [4][5][6][7][15][16][17][18]. This is surprising, because host plants provide a wealth of cues about the resource quality and quantity encountered by the next insect generation [6].…”

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

“…The consequence of incomplete epigenetic resetting in germ cells is that environmental conditions encountered in one generation can have effects on the development of the next generation or even many generations later. It is generally accepted that effects which span a single generation (parental effects) may increase fitness by adjusting offspring phenotype to local conditions [27][28][29][30][31]. More stable forms of epigenetic inheritance have been suggested to serve a similar function (e.g.…”