20.6 Speciation + Artificial Selection

Question 1

Define a SPECIES

Answer 1

A group of individuals that are able to breed together to produce FERTILE OFFSPRING

Question 2

Define SPECIATION

Answer 2

the formation of a new species

Question 3

What is the process of speciation?

Answer 3

• a population becomes split into isolated groups, so no breeding between groups, no gene flow
• alleles within groups continue to mutate randomly
• different groups have different selection pressures
• change in allele frequencies
• accumulation of mutations and changes in allele frequencies over generations lead to large changes in phenotype
• the groups have become so genetically different that they can no longer produce fertile offspring together

Question 4

What is ALLOPATRIC SELECTION?

Answer 4

the more common form of selection, it occurs as a result of a group becoming isolated as a result of a physical barrier (GEOGRAPHIC ISOLATION)

Question 5

What is an example of ALLOPATRIC SELECTION?

Answer 5

Darwin’s Finches as an original species was blown onto the Galapagos Islands and were stranded on the islands that they landed on, unable to travel from island to island

Question 6

Define ADAPTIVE RADIATION

Answer 6

where rapid organism diversification occurs

Question 7

What is SYMPATRIC SELECTION?

Answer 7

speciation that occurs when population within the same habitat breed, less common than ALLOPATRIC SELECTION and more common in plants than animals

Question 8

What is an example of SYMPATRIC SELECTION?

Answer 8

this can occur as a result of two different species breeding to produce fertile offspring, mostly occurring in plants, producing a hybrid species
can also occur in animals, for example, fungus-farming ants often have parasitic ants that feed on the fungus as well, these parasitic ants are a descendant species of the farming ants but have speciated due to a behavioral change