Evolutionary biology and healthy ageing
Ageing results in increased likelihood of death and loss of fecundity, and is hence an individually maladaptive trait. Ageing is not inevitable, since some organisms seem not to age at all, yet it is routinely seen in nature and occurs at very different rates in different kinds of organisms. This evolutonary paradox is largely explained by the decreasing power of natural selection to determine the fate of mutations that exert phenotypic effects at later stages in the survival schedule determined by external hazards. As far as we know, no genetic variants have been selected to cause somatic damage, infertility, pathology and death, and ageing evolves as a side-effect of mutations with deleterious effects at late ages (mutation accumulation) or that are advantageous in youth (pleiotropy). Captive animals and humans are largely protected from the external hazards encountered in nature, and hence show marked effects of ageing, although whether these are attributable to mutation accumulation or pleiotropy remains unclear. Ageing nonetheless shows some evolutionarily conserved hallmarks, and both genetic and environmental interventions have proved capable of slowing the process in laboratory animals, raising the prospect of of a broad-spectrum, preventative medicine for the diseases of ageing. The mechanisms leading to natural diversity in rate of ageing remain largely unknown and unexploited to improve human health.
A Neandertal Perspective on the Human Genome
Over 30 years, we have worked on the development of methods to study the tiny amounts of DNA that can sometimes be found in ancient remains of extinct organisms. In particular, we have focused on reconstructing the genome of Neandertals, the closest extinct relatives of present-day humans.
Analyses of these genomes show that Neandertals contributed about 2.0% of the genomes of people today living outside Africa while Denisovans, a hitherto unknown group of Asian hominins distantly related to Neandertals, contributed about 4.8% of the genomes of people living in Oceania as well as small amounts to people elsewhere in Asia. Together, these finding suggest a ‘leaky replacement’ scenario of human origins in which anatomically modern humans emerged out of Africa and received some degree of gene flow from archaic human populations. Work from several laboratories has shown that these genetic contributions have consequences today for the immune system, for lipid metabolism, for adaptation to life at high altitudes in the Himalayas, and for susceptibility for diseases such as diabetes.
The Neandertal and Denisova genomes also allow the identification of novel genomic features that appeared in modern humans since their divergence from a common ancestor shared with Neandertals. A future challenge is to identify the subset of these features that contributed to that modern humans developed complex culture, technology and art.
The relations between evolution and medicine, journals and societies
Evolutionary biology and evolutionary medicine share ideas but emphasize them differently. Ideas very important in evolutionary medicine – such as mismatch, clonal evolution, and evolution-proof interventions – are either given other names, play lesser roles, or are mostly ignored in evolutionary biology. There is opportunity for bright young evolutionary biologists to make foundational contributions to evolutionary medicine. The timing is right, and the need is great. Examples will be discussed.
Societies and journals also have complex relations. Founding a society with a journal is easier when there is pent-up demand: initial growth is rapid, and financial security is more easily attained. When the idea for a society with a journal resides with a small number of visionaries, growth is slower, no matter how solid the long-range vision. Moreover, the direction taken by a journal is determined in important part by a process of self-assembly. Paleontologists did not get involved with JEB; mainstream immunobiologists, oncologists, and infectious disease specialists have not yet contributed heavily to EMPH. The reasons for that will be analyzed.
Scientists also have diverse talents: some for research, some for teaching, and some for building the infrastructure that supports the entire community. The rewards – and costs – of those activities differ in how rapidly they are delivered and how intimately they are felt. Since all are important, the key for an individual choosing among them is to find the happy intersection of what one is good at, what one enjoys, and what one will get paid for – not always easy.
Diversity matters: Horizontal gene transfer and symbiont strain heterogeneity provide multiple benefits to deep-sea mussels from hydrothermal vents
Symbioses between chemosynthetic bacteria and marine invertebrates were first discovered at hydrothermal vents in the deep sea but are now known to occur in a wide range of habitats including coral reef sediments, seagrass beds, cold seeps and sunken whale carcasses. In these nutritional associations, the bacterial symbionts use chemical energy sources such as hydrogen sulfide to fix CO2 into organic compounds and feed their hosts. Chemosynthetic symbioses have evolved multiple times in convergent evolution from numerous bacterial lineages, and occur in at least nince protist and animal groups such as ciliates, flatworms, mussels, clams, snails, annelids, and nematodes.
Similar to Darwin's finches, whose beaks have evolved different shapes and forms as an adaptation to different food sources, the symbionts of hosts from chemosynthetic environments have acquired a wide and flexible repertoire of assimilation pathways in adaptation to the energy and carbon sources available in their environment. Intriguingly, this flexibility appears to have been gained through horizontal gene transfer. In my talk, I will describe how our meta'omic' analyses of symbionts from deep-sea, hydrothermal vent mussels have revealed that horizontal gene transfer and symbiont diversity play a key role in the ecology and evolution of these host-microbe associations.
The power of recombination to create new adaptations and innovations (tentative)
From biology to technology, a powerful mechanism to create innovation is recombination – the formation of new systems by combining old parts in new ways. However, we poorly understand the causes of this power. Part of the reason is that most success stories of innovation by recombination – especially in the history of technology – are historical narratives that do not allow a quantitative analysis. I discuss a biological system that can provide a systematic and principled understanding of recombination’s power to create new evolutionary adaptations and innovations. The system is metabolism, a complex network of chemical reactions that has been the source of countless innovations in life’s evolution. It is responsible for the ability of organisms to survive on a bewildering diversity of energy sources, for the adaptation of life to chemically hostile environments, and for the ability of organisms – especially plants – to manufacture myriad useful molecules. I discuss both experiments and computational analyses from my laboratory that help us understand the power of recombination.
Individual variation, ecological dynamics and evolutionary feedbacks
A major problem in ecology and evolution is linking proximate mechanisms of phenotypic variation to larger scale processes. I will present a conceptual framework that illustrates why the recognition of the active role of organisms in responding to their environment is crucial to understanding the mechanisms underlying evolutionary processes. This perspective makes explicit the feedbacks between behavioral change, ecological dynamics and evolutionary change. I will illustrate these dynamic feedbacks between ecology and evolution with an empirical example of two passerine birds whose populations are characterized by repeated cycles of colonization and species replacement. In this system, population level changes in competitive and social environment influence expression of dispersal behavior in the next generation. Thus, the colonizing generation creates the environment that induces rapid changes in offspring behavior and population growth. The interdependence of dispersal, competitive behavior, social environment and density produce a feedback loop in which changes in population density are simultaneously a causal selective agent in shaping behavior and an ecological consequence of resulting changes in behavior. I will show how lessons learned from this system have important implications for understanding community formation, evolution of species’ ranges, and the dynamics of hybridization.
From jungles to genomes: Insights into adaptation and speciation from brightly coloured Heliconius butterflies.
A major undertaking in evolutionary biology is to link genotype to phenotype and understand the evolutionary changes that lead to adaptation and speciation. Here I will give an overview of our work on the brightly coloured Heliconius butterflies. Among these butterflies, a great diversity of wing patterns are controlled by just a few genes of major effect, each with a remarkable diversity of regulatory alleles. Furthermore there is a modularity in the genetic control of patterns both within and between these loci, which allows new combinations of alleles to form new phenotypes through hybridisation and recombination, without the need for novel mutations. We can now further test the function of these wing patterning genes using CRISPR gene knockouts. Changes in colour pattern contribute to speciation, but need to be associated with corresponding mate preferences to generate assortative mating. The genetic basis for these mate preferences has a remarkably similar genetic basis to wing pattern, with just three major QTL controlling mate preference between H. melpomene and H. cydno, and some evidence for a similar functional modularity as seen in wing pattern. Despite these loci of large effect that differ between species, across the genome there is evidence for pervasive polygenic selection maintaining species differences in the face of ongoing gene flow, and little evidence for ‘islands’ of differentiation around loci of large effect.
Nina Wedell Presidential address
Evolution in the 21st Century
Evolutionary biology has been a tremendously successful discipline. It has provided us with many fundamental insights, revolutionized how we treat disease and furthering our understanding of cooperation and sociality for example. Despite this success, evolution remains unexpectedly controversial, being denied by some states, politicians and religious leaders. Yet, evolutionary biologists have the potential to provide sustainable solutions to many major problems. Major societal issues related to health, energy, food and clean water can be confronted using evolutionary principles, yet remarkably this approach is rarely explored. I will discuss the opportunities and importance of applying evolutionary thinking to these ‘big problems’, and outline some examples of how nature’s solutions can and have been successfully applied. I will also argue the need for evolutionary biologists to better inform the general public and influence decision makers more generally. Evolutionary biologists have a lot to offer – but we need to be better at getting our message out there.
Keith Bowers John Maynard Smith Prize winner 2016
Silver spoons, sexy sons, and constraints on sex allocation
One component of sex-allocation theory posits that sons and daughters are differentially affected by early rearing conditions, whereby the amount of parental care received has differing effects on the fitness of males and females. When this occurs, selection is expected to favor offspring sex-ratio adjustment according to anticipated fitness returns. Here, I describe a series of questions related to sex-by-environment effects on the development, survival, and future reproduction of offspring and associated variation in primary offspring sex ratios. What emerges is a pattern of consistent, and persistent, sex-specific effects of natal environmental conditions on offspring, thus favoring the adjustment of offspring sex ratios by mothers. However, increased sensitivity of males to environmental conditions should also contribute to shaping an optimal offspring sex ratio, with implications for the evolution of sex-ratio adjustment.
Amanda Kyle Gibson John Maynard Smith Prize winner 2017
What use is sex?
Over forty years ago, John Maynard Smith inspired one of the outstanding problems in evolutionary biology: the maintenance of sexual reproduction. First, I’ll show that Maynard Smith’s simple model, the two-fold cost of males, holds in a natural system. I combined theory and experimental data to directly quantify the cost of sex in the freshwater snail Potamopyrgus antipodarum. Consistent with Maynard Smith’s prediction, the per-capita birth rate of asexual lineages is at least twice that of sexual lineages. So, in Maynard Smith's terms: what use is sex? Second, I’ll present tests of the Red Queen hypothesis, which proposes that host-parasite coevolution maintains sex. Observations of a natural population, paired with experimental manipulations, show that coevolution can explain fine-scale spatial and temporal variation in the frequency of sexual snails. Field data spanning a fifteen-year period reveal a dynamic coevolutionary process, with parasites switching to select against sexual reproduction as asexual lineages become rare. Taken together, these results support coevolving parasites in maintaining coexistence of reproductive modes.
|[S1] Parasite evolution in response to treatment||Pleuni Pennings||Why study drug resistance evolution in HIV and what have we learned?|
|Sebastian Bonhoeffer||Combination therapy and the evolution of drug resistance|
|[S2] The spread and evolution of ancient infectious diseases||Helene Donoghue||The spread and evolution of ancient tuberculosis and leprosy|
|Dong Hoon Shin||The Scientific Studies on Ancient Parasite Infection of East Asia by Microscopic and Genetic Researches|
|[S3] Network-based approaches in evolutionary biology and medicine||Danielle Bassett||The Network Architecture of Human Thought|
|Laura Hindersin||The effect of spatial population structure on evolutionary outcomes|
|[S4] Evolution of immune diversity||Mary Carrington||...|
|[S5] Evolutionary biology of ageing: integrating function and mechanism||Russell Bonduriansky||Incorporating epigenetics into the evolutionary theory of ageing|
|Thomas Flatt||Evolutionary and Functional Links Between Longevity and Immunity|
|[S6] Evolutionary significance of biological clocks||Steven Reppert||Circadian clocks and monarch butterfly migration|
|Takashi Yoshimura||Molecular basis of vertebrate seasonal adaptation|
|[S7] Sociality and disease||Rebecca Kilner||Social immune function and the management of a bacterial community: experiments with burying beetles|
|Charles Nunn||Infectious Disease and Group Size: The Social Bottleneck Hypothesis|
|[S8] Major transitions in evolution||Richard Michod||A Darwinian approach to the major transitions: Evolution of individuality in the volvocine green algae|
|Silvia de Monte||Coupled evolution of collective function and structure|
|[S9] Fitness and evolution in a social environment: from theory to reality||Piter Bijma||Social evolution of fitness: quantitative genetic connections of theory and reality|
|Florence Debarre||Fidelity of parent-offspring transmission and the evolution of social behaviour in structured populations|
|[S10] Cognitive evolution||Judith Burkhart||...|
|Reuven Dukas||Evolutionary biology of social cognition: fruit flies as a model system|
|[S11] Evolution of communication signals||Candy Rowe||...|
|Astrid Groot||New insights in the evolution of sexual communication signals|
|[S12] Environmental effects on sexual selection||Ulrika Candolin||Sexual selection in changing environments: effects on populations and communities|
|Erik Svensson||The importance of an environmental perspective: Integrating sexual selection with population biology, macroecology and biogeography|
|[S13] Modern quantitative genetics and the study of adaptation||Mark Blows||The distribution of genetic variance across phenotypic space|
|Anne Charmantier||Testing for local adaptation in tits: from phenotypic to genetic approaches|
|[S14] Fitness landscapes, big data and the predictability of evolution||Michael Lässig||The antigenicity-stability seascape: a minimal fitness model for evolutionary predictions|
|[S15] Experimental evolution in complex environments||Michael Brockhurst||Evolution of microbial interactions in complex environments|
|Ivana Gudelj||Harbouring public good cheats within a pathogen population can increase both fitness and virulence|
|[S16] Genomics of adaptation||Susan Johnston||The evolution of individual recombination rates in natural populations.|
|Peter Tiffin||Genomics of variation and adaptation in a model mutualism|
|[S17] Evolutionary causes and consequences of variation in recombination rate||Abraham Korol||Evolvability of recombination features|
|Irene Tiemann-Boege||Determinants of recombination activity—the alternative hotspot view|
|[S18] The evolutionary significance of chromosomal inversions||Mathieu Joron||The evolution and consequences of adaptive inversion polymorphism in butterflies|
|Michael Fontaine||Evolution of salt-water tolerant species in the Anopheles gambiae complex from a comparative genomic perspective|
|[S19] Evolution of gene expression regulation||Leonid Kruglyak||...|
|[S20] Evolutionary implications of transposable elements, epigenetics, and non-genetic inheritance||Severine Chambeyron||Genome integrity maintenance through transgenerationally inherited piRNAs|
|Tobias Uller||Non-genetic inheritance and evolution|
|[S21] Genetic exchange in microbial adaptation and infectious disease||Didier Mazel||Integrons: adaptation on demand.|
|Alvaro San Millan||Evolution of plasmid-mediated carbapenem resistance in a hospital setting|
|[S22] Coevolution of hosts and their microbiome||Seth Bordenstein||...|
|[S23] Rapid evolution revisited||Loeske Kruuk||Little evidence for rapid evolution in wild populations?|
|Kimberly Hughes||Predictability of evolution in fish and flies|
|[S24] Eco-evolutionary dynamics||Jonathan Pruitt||Selection on colony foraging aggressiveness favors social susceptibility in social spiders|
|Jen Schweitzer||Plant-soil-nutrient feedback contributes to genetic divergence across a species range|
|[S25] Spatial evolution||Stéphane Joost||Current challenge in landscape genomics: what about the environmental counterpart of high-throughput genomic data?|
|Hanna Kokko||A sex-specific guide to using spatially varying resources|
|[S26] Adaptation to global climate change||Michael Angilletta||How biologists model ecological and evolutionary impacts of climate change|
|Yngvild Vindenes||Eco-evolutionary responses to changing climate variability|
|[S27] Evolutionary implications of hybridization||Nicola Nadeau||Genome-wide patterns of divergence and gene flow across a butterfly radiation|
|Mario Vallejo-Marin||Hybridisation and genome duplication under global change: Rapid speciation in an invasive plant|
|[S28] Intragenomic conflicts and cytonuclear incompatibilities as engines of speciation||Dan Mishmar||Mito-nuclear interactions underlie insipient speciation – the role of mtDNA transcription|
|Daven Presgraves||Sex chromosomes, genetic conflict, and complex speciation in Drosophila|
|[S29] Integration of micro- and macroevolution||Christen Bossu||Phylogenomic and demographic inferences of Pieris butterflies|
|Thomas Ezard||Inferring incipient speciation through changes in trait covariation|
|[S30] Phylogenetics in the genomic era||Scott Edwards||Comparative genomics, the anomaly zone, and the phylogeny of palaeognathous birds|
|Ziheng Yang||Bayesian species tree inference under the multispecies coalescent using genomic sequence data|
|[S31] Evolution across the mutualist-parasite continuum||Ellen Decaestecker||The role of the Daphnia microbiome along the parasitism–mutualist continuum|
|Hinrich Schulenburg||The nematode C. elegans as a powerful model for experimental analysis of symbiont adaptation|
|[S32] Coevolution in antagonistic ecological interactions||Candace Low||Optimal Control Dynamics and Cold War Dynamics between Plant and Herbivore|
|Minus van Baalen||Information use and misuse in interacting populations|
|[S33] Urban evolution||Caroline Isaksson||...|
|Jason Munshi-South||A Tale of Two Rodents: evolution of deer mice and rats in New York City|
|[S34] Applications of evolutionary biology in agriculture and industry||Piter Bijma||Breeding social animals: the use of kin and group-selection to improve traits affected by IGE | Social evolution of fitness: quantitative genetic connections of theory and reality|
|Ford Denison||Domestication versus "taming” (manipulation) of crop plants and their symbionts|
|[S35] Open symposium||x|