Where was I? 2-3.

Evolutionary biology has as its purview the entire history and diversity of life, encompassing an unbroken chain of ancestry and descent involving innumerable organisms and spanning billions of years. In light of the tremendous scope and complexity of its subject matter, it should come as no surprise that details regarding the path and mechanisms of evolution are often subject to heated debate. The fact of evolution, however, remains unsinged. — T. Ryan Gregory, Evolution as fact, theory, and path