Speciation

Question 1

What is the problem with ‘species’?

Answer 1

Different biologists have different definitions
Taxo - info retrieval
Phylogenetisists - relationships

Question 2

What did Linnaeus believe?

Answer 2

Special creation - not evolutionary came up with the hierarchical classification system and binomial naming system

Question 3

What is the phenetic method?

Answer 3

Groups species according to what we can see
Fossils - shape of bones
Birds - shape of beak or colour pattern in feather

Question 4

Problems with the phenetic method?

Answer 4

Phenotypic polymorphism- banded or striped Cali king snake

Cryptic species - morphologically all look the same but behaviours different so different species

Question 5

What must a new species have acquired?

Answer 5

Reproductive isolation
Specie-specific niche
New stabilised and well integrated genotype

Question 6

What’s important about ring species?

Answer 6

Dramatic example of importance of reproductive isolation

Question 7

Advantages of biological species concept

Answer 7

Measurable and testable

Speciation can be studied through reproductive isolation

Question 8

What other factors do we need to take into consideration with biological species concept?

Answer 8

Asexual
Fossil species
Of complete reproductive isolation is necessary
Plants - hybridise more

Question 9

Types of speciation?

Answer 9

Allopatric - no gene flow between geographically isolated pops

Parapatric- limited gene flow between geographically adjacent pops

Sympatric - free gene flow in a pop in which divergence occurs

Question 10

Where are new forms of species usually found?

Answer 10

Across geographic barriers or on islands

Question 11

What does the allopatric model show?

Answer 11

Speciation occurs when a species is split into two or more geographic sub populations - gene exchange stops between the two species

Question 12

What is phylogeography?

Answer 12

The evolution of incompatibility
Sterility must be a by-product of evolution
How can genes causing unfitness spread throughout a species

Question 13

What did Guy Bush do?

Answer 13

Looked at evolution in fruit maggots - there were two types that adapted to different host plants

Question 14

what did guy bush suggest?

Answer 14

that strong selection may be able to drive speciation to get two different species in the one distinct geographic location