Earth’s earliest animals may have held evolution back because they reproduced asexually, creating low-competition communities ...

Life was pretty nice during the Ediacaran, so the need for sex was rather limited,” Emily Mitchell, a paleozoologist at the ...

A study has found that the reason why the evolution of the first animals to appear on Earth was delayed for over 10 million ...

Tracks left by some of the earliest complex animals are giving new insights into how they experienced the world. New research reveals how these creatures started to understand their surroundings, ...

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 ...

When the environment changes dramatically, animals from mollusks to crows can make big changes in their behavior that enable them to survive. For example, marmots and ground squirrels in California ...

When people build cities and introduce invasive creatures, resident critter populations sometimes adapt Brian Handwerk | Science Correspondent Several species have evolved in response to human ...

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 ...