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.

长期以来，生物学家一直就个体发生（ontogeny）是否重演系统发育（phylogeny），以及若成立其背后缘由展开争论。目前存在两种较为合理的解释：其一，早期发育阶段的变异往往会干扰后续发育过程，因此这类变异易被自然选择所淘汰；其二，若某类结构可作为更复杂结构的构建基础，那么在个体发生与系统发育进程中，这类简单结构通常会先于复杂结构出现。在自然系统中通过实验验证这些假说难度颇高，因此本研究采用了具备演化动力学特征的计算系统开展相关实验。我们观察到，个体发生确实会重演系统发育：在谱系演化历史中较早出现的性状，往往也会在个体发育的更早阶段得以表达。性状的相对复杂度对这一相关性有着显著贡献，但即便在控制性状复杂度这一变量后，重演现象的显著趋势依然存在。这一额外效应证明，针对发育干扰的自然选择同样有助于维持发育早期阶段的保守性。