Ancestral plasticity paves the way for evolutionary novelty in spadefoot toads

by Nicholas A Levis, August 9, 2018

The question, “Where do new traits come from?” has long puzzled evolutionary biologists. New traits are often assumed to arise exclusively from genetic changes – including, but not limited to, mutations in regulatory sequences or gene bodies, inversions, and gene (or genome) duplications. Mary Jane West-Eberhard formalized a hypothesis in which the evolution of novelty can begin with new mutations or with environmental perturbation in her 2003 book Developmental Plasticity and Evolution. Indeed, the interchangeability of mutation and environment on phenotype production has a long history (e.g. Drosophila phenocopies). Despite West-Eberhard’s emphasis on adaptive evolution starting with mutation or environment, the aspect of her hypothesis that has really taken off is the latter – when trait origin occurs because of environmental perturbation of development. Indeed, a growing number of researchers have begun asking if environmentally initiated phenotypic change (i.e., phenotypic plasticity) might initiate novelty.

The unlikely but fruitful waltz of a curious couple: Phenotypic plasticity and learning theory

by Miguel Brun-Usan, August 6, 2018

When the Modern Synthesis was put together in the early decades of the twentieth century, natural selection became the obvious focus of evolutionary thought. Although this focus has increased our understanding of biological evolution by orders of magnitude, it tells us little about how phenotypic variation is produced. Variation – the third evolutionary pillar envisioned by Darwin (the other two being selection and heredity) – is typically taken for granted, and assumed to follow from the random, isotropic, and unbiased genetic changes that arise by mutation.1

Extended Heredity: An interview with Russell Bonduriansky and Troy Day

by Russell Bonduriansky, Troy Day, Kevin N Laland & Katrina J Falkenberg, July 31, 2018

Extended Heredity: A New Understanding of Inheritance and Evolution is a fantastic new book by Russell Bonduriansky and Troy Day about the role of nongenetic inheritance in evolution. There are many similarities between the views presented in the book and the extended evolutionary synthesis but there are also differences. Kevin Laland identified some of these in his book review for Science and we wanted to take a deeper dive into some of the key issues. Katrina Falkenberg asked Russell and Troy some questions about the evolutionary significance of nongenetic inheritance, and asked Kevin to elaborate on some points he makes in his review.

Developmental bias and evolution

by Tobias Uller, July 27, 2018

David Houle and his colleagues must have been tired of flies. By the time they finished, they had been photographing and measuring over 50,000 fly wings. The results revealed that mutations commonly produced particular wing shapes, whereas others were rare. Equally painstaking work has quantified variability of the nematode vulva, butterfly eyespots, and mammalian teeth. In each case, some phenotypes pop up more frequently than others. Some that seem perfectly plausible never show up at all.

Structural inheritance: The parent as a developmental template

by Katrina J Falkenberg & Russell Bonduriansky, July 23, 2018

Structural inheritance is an often-neglected form of nongenetic inheritance. In their new book, Extended Heredity: A New Understanding of Inheritance and Evolution, authors Russell Bonduriansky and Troy Day describe numerous examples of structural inheritance, where structural features – and their mutilations – are inherited in subsequent generations through self-templating and related processes.

Developmental bias: An interview with Wallace Arthur

by Wallace Arthur & Katrina J Falkenberg, July 10, 2018

Wallace Arthur is an Emeritus Professor of Zoology at the National University of Ireland in Galway. He is a renowned evolutionary developmental biologist, working across disciplinary boundaries to understand the evolution of animal body plans and segmentation, a subject on which he has published numerous scientific papers and books, as well as popular science pieces. Wallace is one of the leading advocates of an important role for developmental bias in evolution, a view that he brought to prominence through his academic monograph Biased Embryos and Evolution and textbook Evolution: A Developmental Approach. Katrina Falkenberg is the science communication and outreach officer for the EES research program. She interviewed Wallace about developmental bias and its role in evolution.

D’Arcy Thompson and the Extended Evolutionary Synthesis

by Kevin N Laland, June 29, 2018

Last week I had the privilege of attending the workshop The Conceptual Legacy of “On Growth and Form” held in St Andrews UK, a (late) celebration of the centenary of publication of D’Arcy Thompson’s classic book (1917/1942).1 The meeting, organized by philosophers of biology Alan Love and Sahotra Sarkar, comprised an interesting mix of developmental biologists and philosophers.  Like most evolutionary biologists, I had been vaguely aware that Thompson was an early pioneer of the use of mathematical approaches in biology. I also knew that his views were regarded as heretical by the establishment. However, prior to the workshop I had not read “On Growth and Form”, which was something of an embarrassment as D’Arcy is a famous alumnus of my university, St Andrews.