Finding an animal that looks unfamiliar is only the beginning of discovering a new species. Scientists must document where it was found, compare it with known animals, test whether the differences are consistent, decide whether the evidence supports a separate species, and publish a formal description that follows zoological naming rules. The process can begin … Read more
The difference between a species and a subspecies is mainly about evolutionary independence. A species is treated as a distinct evolutionary lineage, while a subspecies is a named, consistently different population within a species. Subspecies usually occupy part of a species’ geographic range and remain more closely connected to other populations of that species than … Read more
An animal species is usually understood as a distinct evolutionary lineage: a population, or connected set of populations, that is evolving separately from other such lineages. Scientists test that idea with evidence from reproduction, genes, anatomy, behavior, ecology, and geographic history. No single test works for every animal. That is why the familiar rule that … Read more
Species, genus, family, and order are taxonomic ranks used to organize animals into nested groups. A species is usually the most specific standard rank, a genus contains one or more closely related species, a family contains related genera, and an order contains related families. Moving upward through the hierarchy creates broader groups that include more … Read more
Warm-blooded animals produce and retain much of the heat needed to keep their bodies within a useful temperature range. Cold-blooded animals depend more heavily on heat moving between their bodies and the environment. Biologists usually call these strategies endothermy and ectothermy, because the familiar labels can be misleading. An ectothermic lizard basking on a rock … Read more
