This timeline of the evolution of life outlines the major events in the development of life on the planet Earth. Dates given are estimates based on scientific evidence.
In biology, evolution is the ... > more
A moth is an insect closely related to the butterfly. Moths, and more particularly their caterpillars, are a major agricultural pest in many parts of the world. Moths are apparently attracted to ... > more
The anatomy of dogs varies tremendously from breed to breed, more than in any other animal species, wild or domesticated. And yet there are basic physical characteristics that are identical among all ... > more
Spaying and neutering are the respective surgical processes of female and male animal sterilization, to keep them from producing offspring. Neutering is sometimes used to refer to the surgery in ... > more
The Grizzly Bear, sometimes called the Silvertip Bear, has traditionally been treated as a subspecies, Ursus arctos horribilis, of the brown bear living in North America. Bears can run much faster ... > more
In ecology, the trophic level is the position that an organism occupies in a food chain - what it eats, and what eats it. Wildlife biologists look at a natural "economy of energy" that ultimately ... > more
The Komodo dragon (Varanus komodoensis) is the largest lizard in the world, growing to an average length of 2-3 meters (10 feet). It is a member of the monitor lizard family, Varanidae, and inhabits ... > more