Developmental bias, macroevolution, and the fossil record

Abstract

A fuller understanding of the role of developmental bias in shaping large-scale evolutionary patterns requires integrating bias (the probability distribution of variation accessible to an ancestral phenotype) with clade dynamics (the differential survival and production of species and evolutionary lineages). This synthesis could proceed as a two-way exchange between the developmental data available to neontologists and the strictly phenotypic but richly historical and dynamic data available to paleontologists. Analyses starting in extant populations could aim to predict macroevolution in the fossil record from observed developmental bias, while analyses starting in the fossil record, particularly the record of extant species and lineages, could aim to predict developmental bias from macroevolutionary patterns, including the broad range of extinct phenotypes. Analyses in multivariate morphospaces are especially effective when coupled with phylogeny, theoretical and developmental models, and diversity-disparity plots. This research program will also require assessing the "heritability" of an ancestral bias across phylogeny, and the tendency for bias change in strength and orientation over evolutionary time. Such analyses will help find a set of general rules for the macroevolutionary effects of developmental bias, including its impact on and interactions with the other intrinsic and extrinsic factors governing the movement, expansion, and contraction of clades in morphospace.

Phenotype bias determines how natural RNA structures occupy the morphospace of all possible shapes

“…Much of evolutionary theory has focussed on this second step. By contrast, the study of variation has been relatively underdeveloped [1][2][3][4][5][6][7][8][9][10][11][12]. If variation is unstructured, or isotropic, then this lacuna would be unproblematic.…”

“…[8,10,13] for some contrasting perspectives). While the discussion has moved on significantly from the days of Gould's critique, primarily due to the growth of the field of evo-devo [7], these issues are far from being settled [5][6][7][8][9][10][11][12] Unravelling whether a long-term evolutionary trend in the past was primarily caused by the pressures of natural selection, or instead by biased variation is not straightforward. It often means answering counterfactual questions [14] such as: What kind of variation could have occurred but didn't due to bias?…”

The evolution of red blood cell shape in a continental radiation of fishes

“…This clustering of distantly related species suggests that convergence, apparently not caused by water column position, could be a mechanism influencing RBS shape evolution (Adams and Collyer 2019). Clustering in morphospace can also suggest a developmental constraint (Jablonski 2020) that impedes species to change their traits after speciation (Pie and Weitz 2005). Also, a few species were in extreme positions.…”

Historical and philosophical perspectives on the study of developmental bias

“…In a similar vein, the contributions to this special issue illustrate that the study of developmental bias spans different biological domains (and thus implicates different fields): gene regulation (e.g., Hu et al, ), parthenogenesis (Galis & van Alphen, ), phenotypic plasticity (Draghi, ; Levis & Pfennig, ; Parsons et al, ; Uller et al, ), the morphology of extant and fossil species (Jablonski, ; Jackson, ), brain development (Finlay & Huang, ), symbiosis and interactions involving microbial species (Gilbert, ), development of the vertebrate skeleton (Kavanagh, ), and behavior, learning, and niche construction (Hu et al, ; Laland et al, ), among others. Some of the studies are experimental, some include field work, and others make primarily use of theory and computational simulation (Draghi, ; Hordijk & Altenberg, ).…”