Scientists discover the evolutionary secret behind different animal life cycles

For over 100 years, biologists have wondered why animals display different types of life cycles. Some species, like us humans and most vertebrates, develop directly into a fully formed—yet smaller—version of an adult. In contrast, many other animals give rise to beautifully diverse intermediate forms we call larvae, which then metamorphose into the adult.

In a study led by a team at Queen Mary University of London (QMUL), published in the prestigious journal Nature, researchers uncover for the first time the mechanism that likely explains how embryos form either a larva or a miniature version of the adult.

 Nature paper 'Annelid functional genomics reveal the origins of bilaterian life cycles'