scholarly journals The Loss of Phenotypic Plasticity Via Natural Selection: Genetic Assimilation

2021 ◽  
pp. 161-181
Author(s):  
Samuel M. Scheiner ◽  
Nicholas A. Levis
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Genetic Assimilation

MEASURING NATURAL SELECTION ON PHENOTYPIC PLASTICITY

Evolution ◽  
1999 ◽  
Vol 53 (6) ◽  
pp. 1704-1713 ◽  
Author(s):  
Samuel M. Scheiner ◽  
Hilary S. Callahan
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity

3. How behaviour develops

2017 ◽  
Author(s):  
Tristram D. Wyatt
Keyword(s):  
Gene Expression ◽  
Gene Regulation ◽  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Mate Choice ◽  
Social Influences ◽  
Future Generations ◽  
Gene Frequencies ◽  
Brain Gene Expression ◽  
Genes And Environment

Behaviours evolve by natural selection. As genes influence how behaviours develop, selection on behaviour will alter gene frequencies in subsequent generations: genes that lead to successful behaviours in foraging, parental care, or mate choice, for example, will be represented in more individuals in future generations. If conditions change, then mutations of the genes that give rise to advantageous behaviours will be favoured by selection. ‘How behaviour develops’ explains that the environment is equally important: both genes and environment are intimately and interactively involved in behaviour development. Behavioural imprinting is also discussed along with co-opting genes, gene regulation, social influences on brain gene expression, phenotypic plasticity, and play.

Adaptation to heterogeneous environments. II.* Phenotypic plasticity in response to spacing in Linum

1976 ◽  
Vol 27 (4) ◽  
pp. 519 ◽  
Author(s):  
MA Khan ◽  
AD Bradshaw
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Genetic Control ◽  
Linum Usitatissimum ◽  
Field Conditions ◽  
Heterogeneous Environments ◽  
Varietal Differences ◽  
Individual Character ◽  
Abundant Evidence ◽  
Epigenetic Processes

Six varieties of Linum usitatissimum, three of flax and three of linseed, were grown under field conditions at six different spacings, from 1 to 32 in. (2.5–81.3 cm) apart. There was abundant evidence of varietal differences in phenotypic plasticity in response to variation in spacing. This indicates that response to spacing is a genetically controlled and not an automatic phenomenon. The major differences were between the flax and linseed groups; linseed varieties were more responsive in branching. However, there were considerable differences between varieties within each group. Different characters showed very different patterns and degrees of response, which indicated that control of response operates on an individual character rather than on a whole organisms basis. Plausible explanations in terms of natural selection can be given for the origin of many of the differences in the response of varieties and in characters. Taken as a whole, the results suggest that there is precise genetic control of the epigenetic processes involved in the response of plants to spacing, and that evolution of different patterns of response can easily occur. _______________ *Part 1, Evolution, 22: 496-516 (1968).

Genetic Assimilation and the Paradox of Blind Variation

2017 ◽  
Author(s):  
Arnaud Pocheville ◽  
Étienne Danchin
Keyword(s):  
Genetic Variation ◽  
Natural Selection ◽  
Genetic Assimilation ◽  
Random Mutation ◽  
Empirical Claim ◽  
Hypothetical Mechanism

This chapter confronts the neo-Darwinian core tenet of blind variation, or random mutation, with classical and recent models of genetic assimilation. We first argue that all the mechanisms proposed so far rely on blind genetic variation fueling natural selection. Then, we examine a new hypothetical mechanism of genetic assimilation, relying on nonblind genetic variation. Yet, we show that such a model still relies on blind variation of some sort to explain adaptation. Last, we discuss the very meaning of the tenet of blind variation. We propose a formal characterization of the tenet and argue that it should not be understood solely as an empirical claim, but also as a core explanatory principle.

scholarly journals Plasticity-led evolution: evaluating the key prediction of frequency-dependent adaptation

2019 ◽  
Vol 286 (1897) ◽  
pp. 20182754 ◽  
Author(s):  
Nicholas A. Levis ◽  
David W. Pfennig
Keyword(s):  
Natural Selection ◽  
Phenotypic Plasticity ◽  
Adaptive Evolution ◽  
Natural Populations ◽  
Evolutionary Change ◽  
Adaptive Refinement ◽  
Fairy Shrimp ◽  
Extreme Form ◽  
Spadefoot Toad ◽  
Evolution By Natural Selection

Plasticity-led evolution occurs when a change in the environment triggers a change in phenotype via phenotypic plasticity, and this pre-existing plasticity is subsequently refined by selection into an adaptive phenotype. A critical, but largely untested prediction of plasticity-led evolution (and evolution by natural selection generally) is that the rate and magnitude of evolutionary change should be positively associated with a phenotype's frequency of expression in a population. Essentially, the more often a phenotype is expressed and exposed to selection, the greater its opportunity for adaptive refinement. We tested this prediction by competing against each other spadefoot toad tadpoles from different natural populations that vary in how frequently they express a novel, environmentally induced carnivore ecomorph. As expected, laboratory-reared tadpoles whose parents were derived from populations that express the carnivore ecomorph more frequently were superior competitors for the resource for which this ecomorph is specialized—fairy shrimp. These tadpoles were better at using this resource both because they were more efficient at capturing and consuming shrimp and because they produced more exaggerated carnivore traits. Moreover, they exhibited these more carnivore-like features even without experiencing the inducing cue, suggesting that this ecomorph has undergone an extreme form of plasticity-led evolution—genetic assimilation. Thus, our findings provide evidence that the frequency of trait expression drives the magnitude of adaptive refinement, thereby validating a key prediction of plasticity-led evolution specifically and adaptive evolution generally.

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