Data from: Ontogeny tends to recapitulate phylogeny in digital organisms

Biologists have long debated whether ontogeny recapitulates phylogeny and,
if so, why. Two plausible explanations are that (i) changes to early
developmental stages are selected against because they tend to disrupt
later development and (ii) simpler structures often precede more complex
ones in both ontogeny and phylogeny if the former serve as building blocks
for the latter. It is difficult to test these hypotheses experimentally in
natural systems, so we used a computational system that exhibits
evolutionary dynamics. We observed that ontogeny does indeed recapitulate
phylogeny; traits that arose earlier in a lineage’s history also tended to
be expressed earlier in the development of individuals. The relative
complexity of traits contributed substantially to this correlation, but a
significant tendency toward recapitulation remained even after accounting
for trait complexity. This additional effect provides evidence that
selection against developmental disruption also contributed to the
conservation of early stages in development.