Natural Selection


Terms

Artificial selection  -  Selection by humans for desired traits. Also called domestication or breeding.
Choice  -  In sexual selection, the competition for attention from the opposite sex.
Contest  -  In sexual selection, fights or aggressive displays between same-sex individuals of the same species; contests usually determine possession of territory or mates.
Directional Selection  -  When selection pressures favor one extreme of the trait distribution.
Disruptive Selection  -  When the average form of the trait is selected against while either extreme is unaffected.
Fitness  -  The probability that an individual will contribute its genes to the next generation.
Morphs  -  The different physical forms a trait may have. Long necks and short necks are examples of morphs.
Natural Selection  -  The theory holding that competition exists within species, determining which species live to have offspring, and pass their traits on to those offspring.
Polymorphic  -  A trait that exists in several different morphs is polymorphic.
Stabilizing Selection  -  When selection pressures favor the average form of the trait.
Sexual Selection  -  The selection of traits based on their role in courtship and mating.
Trait  -  A particular characteristic of an individual plant or animal.

Take a Study Break

SparkLife

Star Trek gets SEXY

Chris Pine and Zoe Saldana heat up the red carpet!

SparkLife

Are you afraid of relationships?

Auntie SparkNotes can help!

SparkLife

Wanna get JLaw's gorgeous glow?

Click here for simple, sexy makeup tricks!

SparkLife

Sexy starlet style

See every single look from the Met Gala!

SparkLife

Who'd be on your zombie-apocalypse crew?

We already dib'sed Genghis Khan.

Geek out!

The MindHut

Geeky Actors: Then and Now

Travel back in time!

The MindHut

Villains We Want These Actresses to Play

From super cute to super bad!

The MindHut

10 Movies Better Than Their Books

What do you think?

The MindHut

How To Look Like J-Law...

When you don't look like J-Law.

The MindHut

12 Scientific Inaccuracies in Into Darkness

What did Star Trek get wrong?

The Book

Cover image

Read What You Love, Anywhere You Like

Get Our FREE NOOK Reading Apps