What's the difference between breed and species?

Question

What's the difference between breed and species?

Answer 1

A breed is a homogeneous group of animals within a species that have been deliberately selected and developed by humans for their similar appearance.

Species is a group of plants or animals having similar appearance.

Answer 2

First thing is the two actually come from two different fields, animal husbandry and taxonomy.  In biology there is a great reluctance to use the term breed, since it is not a naturally occurring event.  So it is important to understand the difference.

Breed: Animals that, through selection and breeding, have come to resemble one another and pass those traits uniformly to their offspring.

http://www.ansi.okstate.edu/breeds/

Specie: groups of actually or potentially interbreeding organisms that are reproductively isolated from other such groups. In other words, organisms are considered to belong to the same species if they can potentially reproduce with each other and have offspring that are healthy and fertile. Otherwise, they are considered to belong to different species.

http://www.utm.edu/departments/cens/biol...

The problem with biology is that the term species was used way to generally in the past.  Now that taxonomist have started to incorporate the genetic information in to their classification the term is being defined more precisely.  You will note the term subspecies is disappearing from taxonomic use.

Answer 3

Breeds are different varieties of domestic animals of the same species. For example, German Shepherd and Rottweiler are different breeds, but the same species - dogs. Shire and Arab are different breeds, but the same species - horses. These animals have been selectively bred by humans to have specific traits for specific purposes.

A species is usually defined as a group of animals that can interbreed and produce fertile offspring. Within a species you have subspecies, which are variations in the animals based on location. For example, a Siberian tiger and a Bengal tiger are the same species - they are both tigers - but there are differences in their populations due to them adapting to their particular environments. These differences denote them as different subspecies, but they are not different enough to be considered different species - they can still breed and produce fertile offspring.

Answer 4

Breeds are different types within a species.  They have different characteristics, but they can all mate and have fertile offspring.  Mutts can have puppies, but a mule - the offspring of a donkey and a horse is infertile, because they are not in the same species.