scholarly journals Heritable spouse effects increase evolutionary potential of human reproductive timing

2018 ◽  
Vol 285 (1876) ◽  
pp. 20172763
Author(s):  
Simon R. Evans ◽  
Dominique Waldvogel ◽  
Nina Vasiljevic ◽  
Erik Postma
Keyword(s):  
Life Histories ◽  
Genetic Effect ◽  
Age At First Birth ◽  
Reproductive Timing ◽  
Evolutionary Potential ◽  
Heritable Variation ◽  
Indirect Genetic Effect ◽  
Component Traits ◽  
Human Reproductive ◽  
Female Specific

Sexual reproduction is inherently interactive, especially in animal species such as humans that exhibit extended pair bonding. Yet we have little knowledge of the role of male characteristics and their evolutionary impact on reproductive behavioural phenotypes, to the extent that biologists typically consider component traits (e.g. reproductive timing) as female-specific. Based on extensive genealogical data detailing the life histories of 6435 human mothers born across four centuries of modern history, we use an animal modelling approach to estimate the indirect genetic effect of men on the reproductive phenotype of their partners. These analyses show that a woman's reproductive timing (age at first birth) is influenced by her partner's genotype. This indirect genetic effect is positively correlated with the direct genetic effect expressed in women, such that total heritable variance in this trait is doubled when heritable partner effects are considered. Our study thus suggests that much of the heritable variation in women's reproductive timing is mediated via partner effects, and that the evolutionary potential of this trait is far greater than previously appreciated.

scholarly journals The Price equation as a bridge between animal breeding and evolutionary biology

2020 ◽  
Vol 375 (1797) ◽  
pp. 20190360 ◽  
Author(s):  
P. Bijma
Keyword(s):  
Evolutionary Biology ◽  
Genetic Effect ◽  
Price Equation ◽  
Response To Selection ◽  
Theme Issue ◽  
Heritable Variation ◽  
Indirect Genetic Effect ◽  
Trait Distribution ◽  
The Social ◽  
Genetic Standard Deviation

The genetic response to selection is central to both evolutionary biology and animal and plant breeding. While Price's theorem (PT) is well-known in evolutionary biology, most breeders are unaware of it. Rather than using PT, breeders express response to selection as the product of the intensity of selection ( i ), the accuracy of selection ( ρ ) and the additive genetic standard deviation ( σ A ); R = iρσ A . In contrast to the univariate ‘breeder's equation’, this expression holds for multivariate selection on Gaussian traits. Here, I relate R = iρσ A to PT, and present a generalized version, R = i w ρ A , w σ A , valid irrespective of the trait distribution. Next, I consider genotype–environment covariance in relation to the breeder's equation and PT, showing that the breeder's equation may remain valid depending on whether the genotype–environment covariance works across generations. Finally, I consider the response to selection in the prevalence of an endemic infectious disease, as an example of an emergent trait. The result shows that disease prevalence has much greater heritable variation than currently believed. The example also illustrates that the indirect genetic effect approach moves elements of response to selection from the second to the first term of PT, so that changes acting via the social environment come within the reach of quantitative genetics. This article is part of the theme issue ‘Fifty years of the Price equation’.

Hybridization in leopard frogs (Rana pipiens complex): terrestrial performance of newly metamorphosed hybrid and parental genotypes in field enclosures

2001 ◽  
Vol 79 (9) ◽  
pp. 1552-1558 ◽  
Author(s):  
Matthew J Parris
Keyword(s):  
Growth Rates ◽  
Life Histories ◽  
Parental Species ◽  
Natural Populations ◽  
Life Cycles ◽  
Natural Hybridization ◽  
Evolutionary Potential ◽  
Leopard Frogs ◽  
Rana Blairi ◽  
Advanced Generation

Terrestrial ecology has been largely neglected in the study of amphibian life histories because it is difficult to manipulate most species during the terrestrial stage. I examined the terrestrial performance of Rana blairi, Rana sphenocephala, and four hybrid (two F1 and two advanced generation) genotypes in replicated experimental enclosures to test for differences in traits related to juvenile terrestrial fitness. I produced all genotypes by means of artificial fertilizations using frogs collected from natural populations in central Missouri, and juvenile frogs were obtained from larvae reared in experimental ponds. Following metamorphosis, froglets were raised in single-genotype groups in terrestrial enclosures through the first overwintering. The proportion surviving did not vary among genotypes, but the power to detect significant differences was low. F1 hybrid genotypes BS and SB demonstrated significantly higher growth rates than either parental species or advanced-generation hybrid genotypes. Observation of growth rates of advanced-generation hybrids equal to those of the parental species, and heterosis in F1 hybrids for growth rate, suggests that natural hybridization between R. blairi and R. sphenocephala can produce novel and relatively fit hybrid genotypes. Direct measurement of multiple fitness components for hybrid and parental genotypes is critical for assessing the evolutionary potential of natural hybridization in organisms with complex life cycles.

Reproductive-timing-dependent alternation of offspring life histories in female threespine sticklebacks

1999 ◽  
Vol 77 (8) ◽  
pp. 1314-1321 ◽  
Author(s):  
Toshihiko Saito ◽  
Shigeru Nakano
Keyword(s):  
Life Histories ◽  
Gasterosteus Aculeatus ◽  
Reproductive Timing ◽  
Equivalent Age ◽  
Structured Population ◽  
Otolith Increments ◽  
Threespine Sticklebacks ◽  
Young Of The Year ◽  
Age Structured ◽  
Breeding Seasons

Relationships between reproductive timing of spawners and timing of hatch and age at maturity of their offspring were examined in fluvial threespine sticklebacks, Gasterosteus aculeatus. Some age 2 and all age 3 females matured in this age-structured population, with only a few females reproducing over two successive breeding seasons. Age 2 females spawned over the relatively long breeding season (March-August), whereas age 3 females spawned mainly early in the season (March-June). Although the standard length of mature age 3 females was greater than that of age 2 females, the back-calculated standard lengths of the former were always shorter than those of the latter at an equivalent age, the most distinct differences being apparent in young of the year. Analysis of daily otolith increments showed that the earlier the young of the year were born, the larger they were at the end of the growing season. As a result of these findings, age 3 females can be expected to produce offspring that will mature at age 2, whereas the offspring of late-spawning age 2 females are more likely to mature at age 3. Therefore, a partial alternation of life histories between generations is thought to occur.

scholarly journals Natural selection and the advantage of recombination

2020 ◽  
Author(s):  
Philip J Gerrish ◽  
Benjamin Galeota-Sprung ◽  
Fernando Cordero ◽  
Paul Sniegowski ◽  
Alexandre Colato ◽  
...  
Keyword(s):  
Natural Selection ◽  
Great Difficulty ◽  
Founder Effects ◽  
Evolutionary Potential ◽  
Heritable Variation ◽  
Number Of Factors ◽  
Population Recombination

The ubiquity of recombination (and sex) in nature has defied explanation since the time of Darwin1–4. Conditions that promote the evolution of recombination, however, are well-understood and arise when genomes contain more selectively mismatched combinations of alleles across loci than can be explained by chance alone. Recombination remedies this across-loci imbalance by shuffling alleles across individuals. The great difficulty in explaining the ubiquity of recombination in nature lies in identifying a source of this imbalance that is comparably ubiquitous. Here, we look to natural selection itself as a possible source of pervasive imbalance, with the rationale that the ubiquity of natural selection approximates the ubiquity of sex and recombination in nature. Natural selection is fed by heritable variation which may be produced by any number of factors, such as drift, founder effects, migration and mutation. We ask how natural selection, acting on this variation, affects the across-loci imbalance and hence the evolutionary potential of recombination. Remarkably, we find that the effect of natural selection is to always promote the evolution of recombination, on average, independently of the source of the variation that feeds it. We show this is true for both across- and within-population recombination. Our findings suggest that recombination evolved and is maintained more as an unavoidable byproduct of natural selection than as a catalyst.

scholarly journals Individual selection leads to collective efficiency through coordination

2018 ◽  
Author(s):  
Arthur Bernard ◽  
Nicolas Bredeche ◽  
Jean-Baptiste André
Keyword(s):  
Social Interactions ◽  
Genetic Effect ◽  
Evolutionary Robotics ◽  
Genetic Mutation ◽  
Single Mutation ◽  
Individual Selection ◽  
Alternative Strategies ◽  
Evolutionary Trap ◽  
Evolutionary Consequence ◽  
Indirect Genetic Effect

Social interactions involving coordination between individuals are subject to an “evolutionary trap.” Once a suboptimal strategy has evolved, mutants playing an alternative strategy are counterselected because they fail to coordinate with the majority. This creates a detrimental situation from which evolution cannot escape, preventing the evolution of efficient collective behaviours. Here, we study this problem using the framework of evolutionary robotics. We first confirm the existence of an evolutionary trap in a simple setting. We then, however, reveal that evolution can solve this problem in a more realistic setting where individuals need to coordinate with one another. In this setting, robots evolve an ability to adapt plastically their behaviour to one another, as this improves the efficiency of their interaction. This ability has an unintended evolutionary consequence: a genetic mutation affecting one individual’s behaviour also indirectly alters their partner’s behaviour because the two individuals influence one another. As a consequence of this indirect genetic effect, pairs of partners can virtually change strategy together with a single mutation, and the evolutionary barrier between alternative strategies disappears. This finding reveals a general principle that could play a role in nature to smoothen the transition to efficient collective behaviours in all games with multiple equilibriums.

scholarly journals Indirect genetic effects underlie oxygen-limited thermal tolerance within a coastal population of chinook salmon

2014 ◽  
Vol 281 (1789) ◽  
pp. 20141082 ◽  
Author(s):  
Nicolas J. Muñoz ◽  
Katja Anttila ◽  
Zhongqi Chen ◽  
John W. Heath ◽  
Anthony P. Farrell ◽  
...  
Keyword(s):  
Maternal Effects ◽  
Chinook Salmon ◽  
Thermal Tolerance ◽  
Egg Size ◽  
Oncorhynchus Tshawytscha ◽  
Genetic Effects ◽  
Adaptation To Climate Change ◽  
Evolutionary Potential ◽  
Heritable Variation ◽  
Indirect Genetic Effects

With global temperatures projected to surpass the limits of thermal tolerance for many species, evaluating the heritable variation underlying thermal tolerance is critical for understanding the potential for adaptation to climate change. We examined the evolutionary potential of thermal tolerance within a population of chinook salmon ( Oncorhynchus tshawytscha ) by conducting a full-factorial breeding design and measuring the thermal performance of cardiac function and the critical thermal maximum (CT max ) of offspring from each family. Additive genetic variation in offspring phenotype was mostly negligible, although these direct genetic effects explained 53% of the variation in resting heart rate ( f H ). Conversely, maternal effects had a significant influence on resting f H , scope for f H , cardiac arrhythmia temperature and CT max . These maternal effects were associated with egg size, as indicated by strong relationships between the mean egg diameter of mothers and offspring thermal tolerance. Because egg size can be highly heritable in chinook salmon, our finding indicates that the maternal effects of egg size constitute an indirect genetic effect contributing to thermal tolerance. Such indirect genetic effects could accelerate evolutionary responses to the selection imposed by rising temperatures and could contribute to the population-specific thermal tolerance that has recently been uncovered among Pacific salmon populations.

scholarly journals Flexibility in reproductive timing in human females: integrating ultimate and proximate explanations

2011 ◽  
Vol 366 (1563) ◽  
pp. 357-365 ◽  
Author(s):  
Daniel Nettle
Keyword(s):  
Age Of Onset ◽  
Mortality Rates ◽  
Age At First Birth ◽  
Reproductive Decisions ◽  
Reproductive Timing ◽  
Female Reproduction ◽  
Healthy Life ◽  
Proximate Mechanisms ◽  
Reproductive Activities ◽  
Cross National

From an ultimate perspective, the age of onset of female reproduction should be sensitive to variation in mortality rates, and variation in the productivity of non-reproductive activities. In accordance with this prediction, most of the cross-national variation in women's age at first birth can be explained by differences in female life expectancies and incomes. The within-country variation in England shows a similar pattern: women have children younger in neighbourhoods where the expectation of healthy life is shorter and incomes are lower. I consider the proximate mechanisms likely to be involved in producing locally appropriate reproductive decisions. There is evidence suggesting that developmental induction, social learning and contextual evocation may all play a role.

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