Data from: Developmental arcs of plasticity in whole movement repertoires of a clonal fish

Developmental plasticity at the behavioral repertoire level allows animals
to incrementally adjust their behavioral phenotypes to match their
environments through ontogeny, serving as a lynchpin between ecological
factors that cue phenotypic adjustments and evolutionary forces that
select upon emergent phenotypic variation. Quantifying the continuous arcs
of plasticity throughout animals’ development, however, has often been
prohibitively challenging. Here, we leverage recent advancements in
high-resolution behavioral tracking and analysis to (i) track the behavior
of 45 genetically identical fish clones (Poecilia formosa) reared in
near-identical environments during their first four weeks of life at 0.2 s
resolution and (ii) quantify the continuous arcs of plasticity across
entire behavioral repertoires through development. Doing so, we
empirically address one of the most fundamental theoretical predictions
from Bayesian models of development that, in stable (but initially
unknown) environments, behavioral plasticity should gradually decrease as
individuals age. Using two approaches to measure plasticity across
ontogeny, we first quantify plasticity in individual behavioral metrics
before also developing a novel whole-repertoire approach that calculates
plasticity as the degree of ‘behavioral entropy’ across a
multi-dimensional behavioral phenotype space. We robustly find – despite
experimentally matching as best as possible the assumptions of models that
predict decreasing plasticity – a ~two-week initial increase in plasticity
in movement behaviors before plasticity subsequently decreased. Our
results help address one of the most widespread intuitions about the
optimal developmental course of plasticity through early ontogeny, thereby
also demonstrating the value of long-term behavioral tracking approaches
for testing fundamental predictions on phenotypic development.