When ecology meets genetics: Towards an integrated understanding of mating system transitions and diversity

International audienceA recommendation of:Yang X, Lascoux M, and Glémin S. Variation in competitive ability with mating system, ploidy and range expansion in four Capsella species. bioRxiv 214866, ver 5 peer-reviewed and recommended by PCI Evol Biol (2018). DOI: 10.1101/21486

Hermaphrodite life history and the maintenance of partial selfing in experimental populations of Caenorhabditis elegans

Classic population genetics theory predicts that mixed reproductive systems, where self reproduction (selfing) and outcrossing co-exist, should not be as common as they are in nature. One means of reconciling theory with observations is to recognize that sexual conflict between males and hermaphrodites and/or constraints in the allocation of resources towards sex functions in hermaphrodites can balance the fitness components of selfing and outcrossing.PhD fellowship from Fundação para a Ciência e a Tecnologia (FCT; SFRH/BD/36726/2007); National Science Foundation - Funding (DEB-1120417

Reproductive assurance drives transitions to self-fertilization in experimental Caenorhabditis elegans

Evolutionary transitions from outcrossing between individuals to selfing are partly responsible for the great diversity of animal and plant reproduction systems. The hypothesis of 'reproductive assurance' suggests that transitions to selfing occur because selfers that are able to reproduce on their own ensure the persistence of populations in environments where mates or pollination agents are unavailable. Here we test this hypothesis by performing experimental evolution in Caenorhabditis elegans

The role of hermaphrodites in the experimental evolution of increased outcrossing rates in Caenorhabditis elegans

Why most organisms reproduce via outcrossing rather than selfing is a central question in evolutionary biology. It has long ago been suggested that outcrossing is favoured when it facilitates adaptation to novel environments. We have previously shown that the experimental evolution of increased outcrossing rates in populations of the male-hermaphrodite nematode Caenorhabditis elegans were correlated with the experimental evolution of increased male fitness. However, it is unknown whether outcrossing led to adaptation, and if so, which fitness components can explain the observed increase in outcrossing rates.PhD fellowship from Fundação para a Ciência e a Tecnologia (SFRH/BD/ 36726/2007)

An experimental test on the probability of extinction of new genetic variants

In 1927, J.B.S. Haldane reasoned that the probability of fixation of new beneficial alleles is twice their fitness effect. This result, later generalized by M. Kimura, has since become the cornerstone of modern population genetics. There is no experimental test of Haldane's insight that new beneficial alleles are lost with high probability. Here we demonstrate that extinction rates decrease with increasing initial numbers of beneficial alleles, as expected, by performing invasion experiments with inbred lines of the nematode Caenorhabditis elegans. We further show that the extinction rates of deleterious alleles are higher than those of beneficial alleles, also as expected. Interestingly, we also find that for these inbred lines, when at intermediate frequencies, the fate of invaders might not result in their ultimate fixation or loss but on their maintenance. Our study confirms the key results from classical population genetics and highlights that the nature of adaptation can be complex.Human Frontiers Science Program grant: (RGP0045/2010)

Sustainable Urbanizing Landscape Development (SULD) decision support tool: report on frontrunner Aqua Cases

"This report has been developed in the context of the international co-operation projectAqua-Add (Deploying the added value of water in local and regional development), aiming atthe sharing of knowledge and experience between project partners as to better deploy thepotential of 'water' (economically, socially and environmentally) in urbanised landscapes andto improve the implementation of water measures in local and regional spatialdevelopment. Aqua-Add not only collects, analyses, disseminates and promotes the specificfunctions, services and values of green/blue spaces, but also develops and applies a DecisionSupport Tool (DST) that: i) demonstrates the (potential) social, environmental and economicimpacts of different water management scenarios, and ii) facilitates the planning processand better informed decision making across stakeholders.The objective of this report is to present, not only, the theory and methodologyunderpinning, but also, the application of the Sustainable Urbanizing LandscapeDevelopment decision support tool (SULD; Roebeling et al., 2007). Case studies arepresented for the two frontrunner Aqua Cases (Aveiro PT; Eindhoven NL), to assess theimpact of location-specific green/blue space and socio-economic scenarios on the location ofresidential development, housing quantity, residential development density, populationdensity, population composition, household living space and real estate values. (...)

An Evolutionary No Man’s Land and Reply from L. G. Harshman and A. A. Hoffmann

The gap between evolutionary studies in laboratory versus natural populations is a persistent problem

Sustainable Urbanizing Landscape Development (SULD) decision support tool: report on other Aqua Cases. Aqua-Add project

"This report has been developed in the context of the international co-operation projectAqua-Add (Deploying the added value of water in local and regional development), aiming atthe sharing of knowledge and experience between project partners as to better deploy thepotential of 'water' (economically, socially and environmentally) in urbanised landscapes andto improve the implementation of water measures in local and regional spatialdevelopment. Aqua-Add not only collects, analyses, disseminates and promotes the specificfunctions, services and values of green/blue spaces, but also develops and applies a DecisionSupport Tool (DST) that: i) demonstrates the (potential) social, environmental and economicimpacts of different water management scenarios, and ii) facilitates the planning processand better informed decision making across stakeholders.The objective of this report is twofold. First, the importance of stakeholder meetings in thedevelopment and application of the Sustainable Urbanizing Landscape Development (SULD;Roebeling et al., 2007, 2014) decision support tool is assessed. In particular, the extent towhich these meetings facilitated the identification, assessment and communication ofdifferent views and interests and, in turn, encouraged the effective engagement ofstakeholders in the participative design of (peri-) urban development plans. Second, theapplication of SULD to the other Aqua Cases (Bremerhaven DE; Copenhagen DK; DebrecenHU; Imperia IT; Lyon FR; Sofia BU) is presented and discussed, to assess the impact oflocation-specific green/blue space and infrastructure projects on the location of residentialdevelopment, housing quantity, residential development density, population density,population composition, household living space and real estate values. (,,,)