Mechanisms of Evolution

Artificial and Sexual Selection

Christian Bien Portrait_edited.jpg

Ben Whitten


What are these types of selection?

Artificial selection refers to how plants and animals can be deliberately bred in order to produce the most desirable traits. For example, certain pigs are chosen to breed with eachother which results in some really buff pigs with a high yield of meat!

Sexual selection is a selection process that occurs between males or between females in a population for an inherited trait that assists in the copulation or winning of a mate.

How does artificial selection work?

As mentioned before, artificial selection (sometimes referred to as selective breeding) is the breeding of plants and animals to produce desirable traits. Organisms with the desired traits, including things such as but not limited to size, taste or appearance are mated or cross-pollinated with organisms with similar desired traits.

There are three mechanisms/proccesses in artificial selection.

  1. In-breeding: Breeding organisms that are more closely related than the average members of a given breed or strain; such as sire to daughter, mother to son or full-brothers to full-sisters

  2. Line-breeding: Breeding closely related organisms, using multiple pedigree crosses from a single exceptional animal/plant; a systematic use of in-breeding

  3. Out-crossing: Breeding together unrelated plants or animals that are less related than the average members of a given breed or strain

Artificial selection results in changes in allele frequencies in gene pools over time. The breeding for particular traits results in changes in allele frequencies over generations, and therefore this is a mechanism for evolution. Specific allele frequencies will decrease, and variation will also decrease, as humans breed for specific desirable traits. Artificial breeding is also often applied to sheep and cattle, as well as fruits and vegetables.

Topic Menu
Gene Pool Change
Mutation and Variation in Evolution
Natural Selection
Artificial and Sexual Selection
Genetic Drift
Gene Flow
Principles of Evolution
Students Walking Up Stairs_edited.jpg

Want your ATAR notes to empower over 77,000 students per year?


Join the Team.
Empower Education.


Sign Up for Free to Read More 

Get instant access to all content and subscribe to our weekly email list on study tips, opportunities and other free resources. 

It only takes a minute...

How does sexual selection work?

Sexual selection is a process linked to mating behaviours in animals, where some individuals with certain characteristics are more able to attract a mate and pass on their genes to their offspring.

Sexual selection can produce a phenomen called sexual dimorphism where males and females have different appearances or sizes such as the peacock. There is a theory that sexual selections helps females choose mates who have a higher level of fitness.