Genetic variance in fitness indicates rapid contemporary adaptive evolution in wild animals

Funding: Hoge Veluwe great tits: the NIOO-KNAW, ERC, and numerous funding agencies; Wytham great tits: Biotechnology and Biological Sciences Research Council, ERC, and the UK Natural Environment Research Council (NERC).The rate of adaptive evolution, the contribution of selection to genetic changes that increase mean fitness, is determined by the additive genetic variance in individual relative fitness. To date, there are few robust estimates of this parameter for natural populations, and it is therefore unclear whether adaptive evolution can play a meaningful role in short-term population dynamics. We developed and applied quantitative genetic methods to long-term datasets from 19 wild bird and mammal populations and found that, while estimates vary between populations, additive genetic variance in relative fitness is often substantial and, on average, twice that of previous estimates. We show that these rates of contemporary adaptive evolution can affect population dynamics and hence that natural selection has the potential to partly mitigate effects of current environmental change.PostprintPeer reviewe

Warmer temperatures attenuate the classic offspring number and reproductive investment trade-off in the common lizard, Zootoca vivipara

International audienceLife-history traits involved in trade-offs are known to vary with environmental conditions. Here, we evaluate the response of the trade-off between ‘offspring number’ versus ‘energy invested per offspring’ to ambient temperature in 11 natural populations of the common lizard, Zootoca vivipara. We provide evidence at both the intra- and interpopulation levels that the trade-off is reduced with an increase in air temperature. If this effect enhances current individual fitness, it may lead to an accelerated pace of life in warmer environments and could ultimately increase adult mortality. In the context of global warming, our results advocate the need for more studies in natural populations to explore interactions between life-history traits' trade-offs and environmental conditions

Sex- and state-dependent covariation of risk-averse and escape behavior in a widespread lizard

<p>Mounting evidence has show<span>n</span> that personality and behavioral syndromes have a substantial influence on <span>interspecific interactions</span> and <span>individual </span>fitness. However, the stability of <span>covariation among multiple behavioral traits involved in antipredator responses</span> <span>has seldom been tested</span>. Here, we <span>investigate whether </span>sex, <span>gravidity</span>, and parasit<span>e infestations influence</span> <span>the covariation</span> <span>between</span> <span>risk-aversion</span> <span>(hiding time within a refuge) </span>and <span>escape</span> <span>response (immobility, escape distance)</span> using a viviparous lizard<span>,</span> <em>Zootoca vivipara</em><span> as a model system. Our results</span> <span>demonstrated a correlation between risk-averse and escape behavior at the among-individual level, but </span>only <span>in</span> <span>gravid</span> females<span>. We found no significant correlations in either males or neonates</span>. <span>A striking result was the loss of the association in post-parturition females. </span>Th<span>is</span> <span>suggests</span> that the <span>'risk-averse</span> – <span>e</span>scape<span>'</span> syndrome <span>is ephemeral and only emerges in response to constraints on locomotion driven by reproductive burden.</span> <span>Moreover</span>, parasites have the potential to disassociate the<span> correlations between</span> <span>risk-aversion and </span>escape <span>response</span> in <span>gravid</span> females, <span>yet the causal chain requires further examination</span>. <span>Overall, o</span>ur findings provide evidence of differences in the association <span>between</span> <span>behaviors within the life-time of an individual</span> and <span>indicate</span> that <span>individual states, sex and life stages can together</span> influence the stability of behavioral syndromes.</p><p>Funding provided by: National Natural Science Foundation of China<br>Crossref Funder Registry ID: https://ror.org/01h0zpd94<br>Award Number: 32001124</p><p>Funding provided by: Zhejiang Provincial Natural Science Foundation<br>Crossref Funder Registry ID: https://ror.org/04aqat463<br>Award Number: LY22C030002</p><p>Funding provided by: National Science Foundation<br>Crossref Funder Registry ID: https://ror.org/021nxhr62<br>Award Number: EF128428</p><p>Funding provided by: National Science Foundation of Sri Lanka<br>Crossref Funder Registry ID: https://ror.org/010xaa060<br>Award Number: DEB 1959606</p><p>Funding provided by: Agence Nationale de la Recherche<br>Crossref Funder Registry ID: https://ror.org/00rbzpz17<br>Award Number: ANR MOBIGEN</p><p>Funding provided by: Laboratoire d'Excellence TULIP<br>Crossref Funder Registry ID: https://ror.org/03j65n394<br>Award Number: ANR-10-LABX-41</p><p>Funding provided by: China Postdoctoral Science Foundation<br>Crossref Funder Registry ID: http://dx.doi.org/10.13039/501100002858<br>Award Number: 2022M722783</p&gt

Sex‐ and state‐dependent covariation of risk‐averse and escape behavior in a widespread lizard

Abstract Mounting evidence has shown that personality and behavioral syndromes have a substantial influence on interspecific interactions and individual fitness. However, the stability of covariation among multiple behavioral traits involved in antipredator responses has seldom been tested. Here, we investigate whether sex, gravidity, and parasite infestations influence the covariation between risk aversion (hiding time within a refuge) and escape response (immobility, escape distance) using a viviparous lizard, Zootoca vivipara, as a model system. Our results demonstrated a correlation between risk‐averse and escape behavior at the among‐individual level, but only in gravid females. We found no significant correlations in either males or neonates. A striking result was the loss of association in postparturition females. This suggests that the “risk‐averse – escape” syndrome is ephemeral and only emerges in response to constraints on locomotion driven by reproductive burden. Moreover, parasites have the potential to dissociate the correlations between risk aversion and escape response in gravid females, yet the causal chain requires further examination. Overall, our findings provide evidence of differences in the association between behaviors within the lifetime of an individual and indicate that individual states, sex, and life stages can together influence the stability of behavioral syndromes

Power analysis simulations

Simulations to analyse our power to estimate heritability

Environmental Variation Mediates the Prevalence and Co-Occurrence of Parasites in the Common Lizard, Zootoca vivipara

© 2019 The Author(s). Background: Hosts and their parasites are under reciprocal selection, leading to coevolution. However, parasites depend not only on a host, but also on the host\u27s environment. In addition, a single host species is rarely infested by a single species of parasite and often supports multiple species (i.e., multi-infestation). Although the arms race between a parasite and its host has been well studied, few data are available on how environmental conditions may influence the process leading to multiple infestations. In this study, we examine whether: (1) environmental factors including altitude, temperature, vegetation cover, human disturbance, and grazing by livestock affect the prevalence of two types of ectoparasites, mites and ticks, on their host (the common lizard, Zootoca vivipara) and (2) competition is evident between mites and ticks. Results: We found the probability of mite infestation increased with altitude and vegetation cover, but decreased with human disturbance and presence of livestock. In contrast, the probability of tick infestation was inversely associated with the same factors. Individuals with low body condition and males had higher mite loads. However, this pattern was not evident for tick loads. The results from a structural equation model revealed that mites and ticks indirectly and negatively affected each other\u27s infestation probability through an interaction involving the environmental context. We detected a direct negative association between mites and ticks only when considering estimates of parasite load. This suggests that both mites and ticks could attach to the same host, but once they start to accumulate, only one of them takes advantage. Conclusion: The environment of hosts has a strong effect on infestation probabilities and parasite loads of mites and ticks. Autecological differences between mites and ticks, as indicated by their opposing patterns along environmental gradients, may explain the pattern of weak contemporary interspecific competition. Our findings emphasize the importance of including environmental factors and the natural history of each parasite species in studies of host-parasite coevolution

data

Phenotypic and breeding data used in the articl

Hufbauer_etal_bemisia_manip2

These data correspond to the second experiment described in the paper - fully factorial with host plant, genetic background, and founding population size. Column headings are: number (identifier of the experimental unit), size (16 or 4), plant (tobacco or cabbage), breeding (inbred or outbred), success_larvae (were larvae produced, 1 or 0), success_adults (were adults produced, 1 or 0), larvae (number of), growthratelarv (larvae/size), adults (numbers of adults), R (adults/size, the net reproductive rate), devtime (development time in days), larval survival (proportion of larvae that reached adulthood), presence of females (1, 0

Role of propagule pressure in colonization success: disentangling the relative importance of demographic, genetic and habitat effects

International audienceHigh propagule pressure is arguably the only consistent predictor of colonization success. More individuals enhance colonization success because they aid in overcoming demographic consequences of small population size (e.g. stochasticity and Allee effects). The number of founders can also have direct genetic effects: with fewer individuals, more inbreeding and thus inbreeding depression will occur, whereas more individuals typically harbour greater genetic variation. Thus, the demographic and genetic components of propagule pressure are interrelated, making it difficult to understand which mechanisms are most important in determining colonization success. We experimentally disentangled the demographic and genetic components of propagule pressure by manipulating the number of founders (fewer or more), and genetic background (inbred or outbred) of individuals released in a series of three complementary experiments. We used Bemisia whiteflies and released them onto either their natal host (benign) or a novel host (challenging). Our experiments revealed that having more founding individuals and those individuals being outbred both increased the number of adults produced, but that only genetic background consistently shaped net reproductive rate of experimental populations. Environment was also important and interacted with propagule size to determine the number of adults produced. Quality of the environment interacted also with genetic background to determine establishment success, with a more pronounced effect of inbreeding depression in harsh environments. This interaction did not hold for the net reproductive rate. These data show that the positive effect of propagule pressure on founding success can be driven as much by underlying genetic processes as by demographics. Genetic effects can be immediate and have sizable effects on fitness