Haeckel’s most influential idea was his now-infamous biogenetic law, summarized by the phrase “ontogeny recapitulates phylogeny”—in other words, an organism’s embryo progresses through stages of ...

Some species within the genus retain fully developed eyes, while others have reduced ... comprehensive description of ...

The team used the funnel-web spider Tegenaria pagana and studied its entire embryonic development from fertilization to ...