RESEARCH

“To develop is to interact with the envionment.
To evolve is to alter these interactions in a heritable manner.”

Organisms and their form and function are the products of developmental processes operating in specific ecological conditions over evolutionary time. The nature of interactions between development (devo) and ecology (eco), and how these are shaped by, and are in turn shaping, evolutionary processes (evo), are the foci of Ecological and Evolutionary Developmental Biology (eco evo devo) and the objectives of our research. In particular, our group is focused on understanding how novel complex traits originate and diversify in development and evolution, and how this process is channeled by ecological conditions. But we also study the reverse – once in existence we ask how novel complex traits feed back on ecological and evolutionary processes, such as range expansions or adaptive radiations. Specifically, we structure our exploration around what we consider eight interdependent dimensions of innovation of diversification:

Below find brief summaries of each research program alongside corresponding recent publications that have emerged from our work.

The developmental genetic basis of morphological innovation

Understanding how novel complex traits like the vertebrate eye, the insect wing, the light producing organ of fireflies, or the turtle shell originate is a fundamental objective of evolutionary biology. Evo devo has provided critical insights into how developmental processes evolve to facilitate such innovation. For example, developmental evolution has emerged as highly modular process, whereby phenotypic diversity is facilitated through the select re-use and re-assembly of an otherwise rather limited pool of genes, developmental pathways, cell types, and morphogenetic processes. Much like the same Lego bricks can be re-arranged and recombined in a variety of ways, complex innovation in development is facilitated by often relatively simple changes in the timing, location, amount, and regulation of components of a given developmental process.

Our work seeks to identify the mechanisms that facilitate and bias innovation in developmental evolution. In particular we seek to understand how novel complex traits may emerge from within the confines of ancestral variation, and how organismal diversity – rather than being constrained by ancestral variation and developmental conservation – may instead be enabled by it.

Suggested readings

Hu Y, Linz D, Moczek AP 2019. Beetle horns evolved from wing serial homologs. Science 366, Issue 6468, pp. 1004-1007.

Linz D, Hu Y, Moczek AP. The origins of novelty from within the confines of homology: the developmental evolution of the digging tibia of dung beetles. Proceedings of the Royal Society of London, Series B: rspb.2018.2427.

Moczek AP 2008. On the origin of novelty in development and evolution. Bioessays 5: 432-447.

The developmental evolution of size, shape, and position

Multicellular organisms can be viewed as mosaics of discrete traits that originated at different time points along a species’ evolutionary history. Every complex trait was once a novelty, but to persist, evolutionary innovations had to overcome multiple, interrelated challenges. For example, to enable functional fine tuning by selection independent of other traits, novel traits needed to evolve developmental regulatory mechanisms with limited pleiotropic effects. Similarly, to diversify, novel traits had to acquire sufficient modularity such that specific trait components could be modified independent of other components. Yet perhaps most significantly, novel traits had to find ways to integrate developmentally, physiologically, and morphologically, within and alongside pre-existing structures without compromising their ancestral functions. However, how novel traits achieve such integration within preexisting contexts during ontogeny, and how such mechanisms themselves evolve, remains poorly understood. Our work seeks to identify the mechanisms that integrate, position, and properly size and sculpt morphological novelties, from the thoracic and cephalic horns of scarab beetles to the bioluminescent lantern of fireflies.

Suggested readings

Linz D, Moczek AP 2020. Integrating evolutionarily novel horns within the deeply conserved insect head. BMC Biology, in press.

Zattara EE, Busey H, Linz D, Tomoyasu Y, Moczek AP 2016. Neofunctionalization of embryonic head patterning genes facilitates the positioning of novel traits on the dorsal head of adult beetles. Proceedings of the Royal Society of London, Series B 283: 20160824.

Stansbury M, Moczek AP 2014. The function of Hox and appendage patterning genes in the development of a novel organ, the Photuris firefly lantern. Proceedings of the Royal Society of London, Series B 281: 1471-2954.

The developmental evolution of sex differences AND The origin and diversification of environment-sensitive development

Sexual dimorphism and environment-sensitive development generate an enormous fraction of intraspecific variation. Both dimensions interact in development and evolution. For example, sexual dimorphism often depends on nutritional conditions or parasite load. At the same time, not all parts of an organism are equally influenced by sex and the environment, instead organisms are mosaics of tissues and organs that differ in their sensitiviy to environmental conditions or sex. Our work seeks to understand the genetic, developmental, endocrine, and symbiotic mechanisms that facilitate these and other forms of conditional development, their similarities and differences, their interactions in development and evolution, and their contribution to diversification and innovation.

Suggested readings

Casasa S, Zattara EE, Moczek AP 2020. Nutrition-responsive gene expression and the developmental evolution of insect polyphenism. Nature Ecology & Evolution, in press.

Kijimoto T, Moczek AP, Andrews J 2012. Diversification of doublesex function regulates morph-, sex-, and species-specific expression of beetle horns. Proceedings of the National Academy of Sciences. 10.1073/pnas.1118589109

Moczek AP, Cruickshank, TE, Shelby JA 2006. When ontogeny reveals what phylogeny hides: gain and loss of horns during development and evolution of horned beetles. Evolution 60: 2329-2341.

The developmental evolution of phenotypic integration

Complex traits often require the coordinated and integrated co-development of morphological, behavioral, and physiological phenotypes. This integration is itself an evolved process, changes in which can facilitate diversification and innovation. Yet the mechanisms that coordinate the formation of morphological with behavioral and physiological phenotypes are exceedingly poorly understood. In holometabolous insects such as Onthophagus beetles, adult morphology is specified in late larval development relying primarily on epidermal source tissues, whereas adult behavior emerges much later through the actions of a nervous system that in late larval and pupal development undergoes dramatic reorganization. Our work seeks to understand how females and alternate male morphs coordinate the co-expression of sex and morph specific courtship, fighting, and sneaking behaviors with their corresponding morphologies during ontogeny, and how these mechanisms themselves diversify across species and rapidly diverging populations.

Suggested readings

Newsom KD, Moczek AP, Schwab DB 2019. Serotonin differentially affects morph-specific behavior in divergent populations of a horned beetle. Behavioral Ecology 10.1093/beheco/arz192

Beckers O, Kijimoto T, Moczek AP 2017. doublesex alters aggressiveness as a function of social context and sex in the polyphenic beetle Onthophagus taurus. Animal Behaviour, 132: 261-269.

Macagno ALM, Moczek AP, Pizzo A 2016. Rapid divergence of nesting depth and digging appendages among tunneling dung beetle populations and species. American Naturalist 187: E143-E151.

Innovation through team building

A growing body of work illustrates the significance of symbioses in organismal innovation, diversification, adaptation, and resilience. By forming teams, symbioses can meet ecological challenges, adapt to novel conditions, and diversify in ways not available to single taxa. Our work explores the significance of host microbiome interactions in the development and evolution of Onthophagus beetles, and the consequences of these interactions in the context of ecological radiations and biological invasions.

Suggested readings

Parker E, Moczek AP, Newton, I 2020 (My microbiome) would walk 10,000 miles: Maintenance and turnover of microbial communities in introduced dung beetles. Microbial Ecology in press.

Parker E, Dury G, Moczek AP 2018. Transgenerational developmental effects of species-specific, maternally transmitted microbiota in Onthophagus dung beetles. Ecological Entomology 10.1111/een.12703.

Schwab DB, Riggs HE, Newton ILG, Moczek AP 2016. Developmental and ecological benefits of the maternally transmitted microbiota in a dung beetle. American Naturalist 188: 679-692.

Innovation via environment engineering

Organisms adapt to environmental challenges by modifying their traits either developmentally through developmental plasticity within a life time or through adaptive evolution across generations. Additionally, rather than adjusting their traits to fit their selective environment, many organisms can physiologically or behaviorally modify their environment to better suit their traits through the process of niche construction or environment engineering. Niche construction can influence not just developmental but also evolutionary outcomes, for instance by altering the selective conditions experienced by offspring via the transmission of key resources such as nutrients, shelter, territories, learning, or the inheritance of microbial symbionts. Our research examines how organisms shape their own environment or that of their offspring. Of specific interest are microbial communities transmitted from parents to offspring and the roles they play in facilitating development, disease resistance, population differentiation, biological invasions, and speciation.

Suggested readings

Dury G, Moczek AP, Schwab DB 2020. Maternal and larval niche construction interact to shape development, survival, and population divergence in the dung beetle, Onthophagus taurus. Evolution & Development, in press.

Schwab DB, Moczek AP 2019. Evo devo and niche construction. In: Evolutionary Developmental Biology – A Reference Guide, edited by Laura Nuño de la Rosa and Gerd B. Müller. Springer, doi.org/10.1007.

Ledon-Rettig CC, Moczek AP, Ragsdale EJ 2018. Diplogastrellus nematodes are sexually transmitted mutualists that alter the bacterial and fungal communities of their beetle host. Proceedings of the National Academy of Sciences, 115: 10696-10

Schwab DB, Casasa A, Moczek AP 2017 . Evidence for developmental niche construction in dung beetles: effects on growth, scaling, and reproductive success. Ecology Letters 20: 1353–1363.

Causes and processes in evolution: Reconceptualizing the evolutionary process in the age of eco evo devo

Our work contributes to a growing call to reassess key concepts in evolutionary biology. For example, our work on the role of developmental basis of evolutionary innovation has shown that even though developmental processes (often considered proximate mechanisms) are themselves products of evolutionary processes (typically considered ultimate mechanisms), once in existence developmental features commonly feed back to influence and bias subsequent evolution, questioning the utility of a strict proximate-ultimate dichotomy.

Similarly, our work on the relationship between homology and innovation has challenged the most commonly used definition of a morphological novelty as a structure that lacks homology or homonomy (serial homology) to other traits. Rather than somehow emerging in the absence of homologous relationships, our work illustrates how novelty is instead enabled by them.

Likewise, our work on environment engineering and host microbiome interactions has forced us to consider environments not just as passive and external to an organism, but also as being at least in part shaped by organisms themselves, and as something parents may pass on to their offspring in addition to their genes. Where organisms end and their environment begins, and what all constitutes inheritance, may therefore be more complex than what current concepts are able to capture.

These and other efforts therefore motivate an ongoing re-analysis of key concepts and dichotomies that structure how we think about and study biological phenomena. While some of these developments have made things more complicated, they also made our understanding of the living world more realistic and able to spur new ways of thinking, and investigating, why and how developmental evolution on this planet unfolds the way it does.

Suggested readings

Moczek AP 2019. The shape of things to come: evo devo perspectives on causes and consequences in evolution. In: Evolutionary Causation; edited by K. Laland and T. Uller. Vienna Series in Theoretical Biology, pp. 63-80.

Uller T, Moczek AP, Watson RA, Brakefield PM, Laland KL 2018. Developmental bias and evolution: a regulatory network perspective. Genetics 209: 949–966.

Laland KN, Uller T, Feldman M, Sterelny K, Müller GB, Moczek AP, Jablonka E, Odling-Smee J 2015. Darwin Review; The extended evolutionary synthesis: its structure, assumptions, and predictions. Proceedings of the Royal Society of London, Series B, 282: 20151019.

Schwab DB, Casasa A, Moczek AP 2017 . Evidence for developmental niche construction in dung beetles: effects on growth, scaling, and reproductive success. Ecology Letters 20: 1353–1363.
Moczek AP 2015. Re-evaluating the environment in developmental evolution. Frontiers in Ecology and Evolution, 3:7.

Laland K, Tobias U, Feldman M, Sterelny K, Müller G, Moczek AP, Jablonka E, Odling-Smee J. 2014. Does evolutionary theory need a rethink? Nature 514: 161-164.

Moczek AP 2012. The nature of nurture and the future of evodevo: toward a comprehensive theory of developmental evolution. Integrative and Comparative Biology 52: 108-119.

Moczek AP, Sultan S, Foster S, Ledon-Rettig C, Dworkin I, Nijhout HF, Abouheif E, Pfennig D (2011). The role of developmental plasticity in evolutionary innovation. Proceedings of the Royal Society of London, Series B. 278: 2705-2713.278: 2705-2713.

Pfennig D, Wund MA, Snell-Rood EC, Cruickshank T, Schlichting CD, Moczek AP 2010. Phenotypic plasticity’s impacts on diversification and speciation. Trends in Ecology and Evolution 25: 459-467.

Moczek AP 2008. On the origin of novelty in development and evolution. Bioessays 5: 432-447.

OUR TEAM

We are a diverse group of scientists interested in understanding the origins of novel, complex traits in development and evolution.

LATEST PUBLICATIONS

Read more about the various projects underway in the lab, and our work towards understanding innovation in the natural world.

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