Meeting: Evolutionary Developmental Biology: Current Debates

This satellite meeting, to be held one day before the EHBEA (http://www.ehbea2015.org) Helsinki conference, has been generously sponsored by the Galton Institute, EHBEA, and the Journal of Evolutionary Psychology.

Time: Saturday the 28th of March 2015 (from 9:00-16:00)

Location: University of Helsinki (Fabianinkatu 33, 2nd floor)

Topic:  In recent years there has been much discussion about how to conceptualize the relationship between development and evolution: are developmental trajectories selected for, and how much does development influence evolutionary process?  In this event we will excoriate the fundamental assumptions at work in several influential existing arguments, to look at the view of development within the modern synthesis, and to look at criticisms of this synthesis.  

Registration: There is a separate registration fee for this meeting: 50 € for full EHBEA members, 25 € for student EHBEA members and 80 € for everyone else. This includes teas/coffees, buffet lunch, and wine reception. You can sign up for the event by registering and paying the participation fee here. Up to 70 participants can register. Registration is on a first come, first served basis. Refunds are not possible. Please note that the registration does not include hotel accommodation.

Speakers and titles:

Open reaction norms and human flexibility
H. Clark Barrett, University of California, Los Angeles

(Epi)mutational dynamics and bet hedging
Ben Dickins, Nottingham Trent University

Information as a loom to weave development and evolution
Sinead English, University of Oxford

Developmental changes in aggression and body size: an evolutionary perspective
Tim W. Fawcett, University of Bristol

Developmental niche construction
Emma Flynn, Durham University

Developmental plasticity in the European starling: Empirical observations and evolutionary interpretations
Daniel Nettle, Newcastle University

Organisers:
Clark Barrett – UCLA
Tom Dickins – Middlesex University
Willem Frankenhuis - Radboud University Nijmegen

Questions: Contact Tom Dickins at T.Dickins AT mdx.ac.uk

Abstracts:

Open reaction norms and human flexibility
H. Clark Barrett
Department of Anthropology and Center for Behavior, Evolution, and Culture
University of California, Los Angeles

In biology, the concept of a reaction norm typically implies a closed mapping function: a curve that maps between a range of environmental conditions and a range of phenotypic outcomes, both of which are in some sense pre-specified. However, many of the things humans learn and the environments they face are evolutionarily novel in many ways, never having been encountered by prior generations. Empirically, humans and other animals often (though not always) deal with such novelty adaptively. Generally, adaptive responses shaped by selection must be due to the fitness success of phenotypes produced in the past, which poses something of a puzzle: closed reaction norms generally involve mapping functions from environments to phenotypes that occurred over stretches of past evolutionary time. As a possible resolution to this puzzle I present the concept of an open reaction norm, which can include both open (i.e. unspecified) and closed (specified) parameters. I discuss how such reaction norms might evolve and how to conceptualize them theoretically, using as an example recent work on children’s cultural learning about danger, and explore the potential of the open reaction norm concept to solve the puzzle of adaptive responses to evolutionarily unprecedented circumstances.

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(Epi)mutational dynamics and bet hedging
Ben Dickins 
Nottingham Trent University

New phenotypes can arise through changes in sequence context maintained by epigenetic marks such as histone modifications. Epigenetic changes underlie cell differentiation, but their contribution to inter-individual variation in multicellular organisms has attracted attention because this connects gene regulation, which is responsive to environmental variation, to changes in populations. In microbes, mutations are a significant source of adaptive and non-adaptive variation, yet this variation is not simply random and can also be responsive to the environment. More generally DNA replication and repair vary in efficiency between lineages and mutation rates and biases cause evolution directly and through interaction with selection or drift. Examining these dynamics can guide our understanding of the interaction between variation-generating mechanisms and evolution.

Mutation accumulation. In small genomes many mutations are deleterious. The accumulation of deleterious mutations in a population reduces its mean fitness. If the mutation rate is sufficiently high, this can lead to extinction (“lethal mutagenesis”). I will describe approaches taken in my laboratory at Nottingham Trent University to understand the influence of elevated mutation rates in a model organism, the bacteriophage ΦX174.

Mutation and drift. The persistence of mutant alleles, whether deleterious or not, is also affected by the severity of population “bottlenecks” in which only a small number of individual genomes give rise to subsequent generations. I will describe recent work with colleagues at Penn State University on human mitochondrial DNA. Using samples from apparently healthy family members we applied Illumina sequencing to estimate both the mutation rate and the bottleneck size.

Mutation and selection. Adaptation can take the form of “bet hedging” to accommodate variable environments encountered over time and space. I will explore the consequences of mutation and other variation-generating mechanisms in this context. 

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Information as a loom to weave development and evolution
Sinead English
Edward Grey Institute, Department of Zoology
University of Oxford, OX1 3PS

Natural selection shapes the developmental processes that construct the phenotypes, which, in turn, are under selection. Here, I present a framework in which this interplay between development and evolution can be conceptualized by considering information transmission within and across generations. This perspective sheds light on major questions in evolutionary biology such as how individuals integrate different inputs for development (genes, parents, the environment) and the conditions under which non-genetic versus genetic mechanisms of inheritance evolve. A key component determining the reliability of information is the autocorrelation of the environment across generations. I describe a meta-analysis on the empirical support for adaptive maternal transmission of information which illustrates how rarely studies have considered this autocorrelation. Thus, to move the field forward we need more theory-driven studies and data-driven theory.

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Developmental changes in aggression and body size: an evolutionary perspective
Tim W. Fawcett
Modelling Animal Decisions (MAD) Group
University of Bristol

During development, humans and other social animals must learn how to navigate a dynamic, interactive environment in which the consequences of behaviour depend critically on how others perceive and respond to them. Given the uncertainty inherent in such situations, natural selection will tend to favour rules for adjusting behaviour flexibly in response to social feedback from previous interactions. These rules should generate ontogenetic changes in behaviour as individuals gain experience and gradually adapt to their personal social circumstances. Here I examine whether this evolutionary perspective can help us to understand observed patterns of behavioural development, using childhood aggression as an example. I first present a state-dependent evolutionary model that predicts developmental trajectories of aggression as a function of physical strength and information state, as individuals interact and learn about the consequences of their behaviour. I then analyse the developmental relationship between body size and physical aggression in humans, using a longitudinal cohort study of boys growing up in the Canadian province of Québec. Both the model and the data show a strengthening association between relative size and aggressive behaviour across ontogeny, consistent with the hypothesis that individuals gradually learn about their physical capabilities through interacting with their peers. In the human data, after controlling for age-related changes, weight was the strongest predictor of aggressive behaviour: boys who were heavier than average for their age and height were more likely to get into fights or physically attack other children. Further refinements of the model are needed, but these findings hint at the potential of evolutionary theory to shed light on the interplay between physical and behavioural development.

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Developmental niche construction
Emma Flynn
Centre for the Coevolution of Biology and Culture (CCBC)
School of Education, Durham University

Niche construction is the modification of components of the environment through an organism’s activities. Humans modify their environments mainly through ontogenetic and cultural processes, and it is this reliance on learning, plasticity and culture that lends human niche construction a special potency. In this talk I aim to facilitate discussion between researchers interested in niche construction and those interested in human cognitive development by highlighting some of the related processes. I discuss the transmission of culturally relevant information, how the human mind is a symbol-generating and artefact-devising system, and how these processes are bi-directional, with infants and children both being directed, and directing, their own development. I reflect on these in the light of four approaches: natural pedagogy, activity theory, distributed cognition and situated learning. Throughout, I highlight pertinent examples in non-humans that parallel or further explicate the processes discussed. Finally I offer three future directions; two involving the use of new techniques in the realms of neuroscience and modelling, and the third suggesting exploration of changes in the effects of niche construction across the lifespan.

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Developmental plasticity in the European starling: Empirical observations and evolutionary interpretations
Daniel Nettle
Centre for Behaviour and Evolution & Institute of Neuroscience
Newcastle University

In altricial birds, experience during the first few days of life can affect whole many different behavioural traits in adulthood. We study such effects using cross-fostering in the European starling, and I will review our recent findings with respect to boldness, food motivation, impulsivity, expectation of reward, and flight performance. It is widely suggested that responsiveness to early developmental inputs is adaptive. I will discuss the prevailing adaptive explanations for such responsiveness (the ‘weather forecast’ model, in which a stressful ontogeny is suggested to carry information about the adult environment, and the ‘making the best of a bad job’ model, in which adult behaviour represents a compensation for phenotypic limitations resulting from development). I will also suggest non-adaptive alternative interpretations of some of the empirical findings. I will conclude by considering what needs to be demonstrated to show that a developmental response is adaptive, and how we discriminate between competing adaptive interpretations of the same phenomenon.