As it happens: current directions in experimental evolution

Abstract

Recent decades have seen a significant rise in studies in which evolution is observed and analysed directly-as it happens-under replicated, controlled conditions. Such 'experimental evolution' approaches offer a degree of resolution of evolutionary processes and their underlying genetics that is difficult or even impossible to achieve in more traditional comparative and retrospective analyses. In principle, experimental populations can be monitored for phenotypic and genetic changes with any desired level of replication and measurement precision, facilitating progress on fundamental and previously unresolved questions in evolutionary biology. Here, we summarize 10 invited papers in which experimental evolution is making significant progress on a variety of fundamental questions. We conclude by briefly considering future directions in this very active field of research, emphasizing the importance of quantitative tests of theories and the emerging role of genome-wide re-sequencing.

Evolution in eggs and phases: experimental evolution of fecundity and reproductive timing inCaenorhabditis elegans

“…Experimental evolution methods provide us with the opportunity to look beyond the classical genetic methods [1], and provide us with a means to study the effects of natural selection in a way not possible with comparative or inferential techniques [2]. In particular, experimental evolution allows control and temporal resolution over the evolutionary process, which enables novel functional assessments of existing mutant genotypes [3]. Using a dataset of a single wild-type genotype and 13 mutant genotypes, we will address:

— What effect does natural selection and mutational diversity have on fecundity (as measured by population size over a finite interval)?

— Are the observed differences in population size informative with respect to genotypic identity?

— Do we observe changes in reproductive timing (as measured by reproductive carry-over (RCO)) that result from positive selection for fecundity?

…”

Copying error, evolution, and phylogenetic signal in artifactual traditions: An experimental approach using “model artifacts”

“…Within evolutionary biology, profound progress over several decades has been made in the understanding of fundamental microevolutionary processes, such as mutation, via laboratory experiments involving so-called "model organisms" (Elena and Lenski, 2003;Futuyma and Bennett, 2009;Garland and Rose, 2009;Mueller, 2009;Bataillon et al, 2013). Model organisms are valuable in this respect because they enable a more secure understanding of phenomena of wide interest, from seemingly discrete, but highly controlled, laboratory experiments.…”

Differences in Manufacturing Traditions and Assemblage-Level Patterns: the Origins of Cultural Differences in Archaeological Data

“…The most suitable model organisms thus display some of the complexities of the phenomenon of general interest, yet are not so complex that they are unwieldy in experimental settings and facilitate a more precise study of discrete factors and processes. For paleobiologists interested in understanding the evolution of animals such as Tyrannosaurus rex, experiments looking at subtle differences in fruit flies generated under highly controlled laboratory conditions may seem far removed from the phenomena of interest; and yet, biologists have long recognized the immense value of this body of work in respect to increasing an understanding of specific microevolutionary factors, which are particularly important for building a robust evolutionary theory that can be applied in broader contexts (Bataillon et al 2013). Elsewhere, we have argued that in regard to the study of cultural evolutionary processes, simple experiments that replicate certain aspects of artifactual form (e.g., their size and/or shape) make a particularly useful subject of study for similar reasons Schillinger et al 2014a).…”

“…Over many decades of study in evolutionary biology, profound progress has been made in the understanding of fundamental biological microevolutionary processes (e.g., the basis of heredity, inheritance of specific characteristics, the proximate causes of phenotypic variation, influences on mutation rates, and so forth) via the use of so-called "model organisms" (Bataillon et al 2013;Futuyma and Bennett 2009;Garland and Rose 2009;Mueller 2009). Model organisms are valuable because they enable a more secure understanding of phenomena of wide interest, from seemingly discrete, even trivial, laboratory experiments.…”