WASHINGTON (AP) — Newly discovered fossils have given scientists their first real glimpse of when Earth made a crucial transition from plants and unrecognizably simple animals to the complex creatures ...

A series of whole genome and gene duplication events that go back hundreds of millions of years have laid the foundations for tissue-specific gene expression, according to a new study. The 'copy-paste ...

A microorganism whose evolutionary roots can be traced to the era of the first multicellular animals may provide a glimpse of how single-celled organisms made a critical evolutionary leap. In ...

A huge and beautifully preserved suite of fossils discovered in China has cast doubt on the idea that complex life flourished dramatically during a rapid burst of evolution known as the Cambrian ...

Embryonic germ layers are the fundamental organizing principle in animal development. They provide the structural basis from which tissues and organs arise. During early embryogenesis, cells divide to ...