Intro to Evolution Quiz

The logic behind evolution is based on 4 postulates

-Individuals in a population vary

-Traits are passed from parent to offspring

-Some individuals fail to survive and reproduce

-Organisms can produce far more offspring than are required

-Survival and reproduction are not determined by chance

Important things to remember!

-An individual cannot evolve (They are already born)

-All traits begin with a mutation

-Mutations are random/ evolution is not random

-Evolution acts on populations

-An adaptation is a trait that is beneficial

-To adapt is to change your behavior due to your environment (has nothing to do with evolution)

Comparative anatomy (Comparing the anatomy of different species) gives us evidence of descent with modification

Homologous Structures

-A homologous structure is one that has the same evolutionary origin despite any functional or appearance differences

-For example all mammals have the same bones in their arms.

-A bat uses its arms as wings and a human uses them to hold things but the bone structure is the same. These are homologous structures.

Analogous Structures

-An analogous structure has the same function but does not have the same evolutionary origin

-For example a fly has wings and a bird has wings. Both structures have the same function but they have completely different anatomy.

-A bird's wings did not share the same evolutionary path as a fly's wings

-These are analogous structures

Vestigial Structures

-A vestigial structure is an anatomical part that has lost its function

-If a trait no longer provides an advantage it might stay the same or become selected against

-If a trait is selected against those with smaller versions of the trait will be more successful in reproducing causing the evolution of that trait to become smaller or be removed from the population

-Sometimes an organism is left with the remnants of a structure that no longer functions

-These structures are inherited from their ancestors

Micro-Evolution

-The change of allele frequency over time

-A population's traits changing towards a specific direction

-For example getting taller or shorter

-Making a pet dog out of a wolf

Macro-Evolution

-Speciation- When one species branches into two species due to reproductive isolation

-All life on earth shares common ancestors

-All life started from a single cell (The single cell hypothesis)