Locomotion - evolution

Question 1

How to you track the patterns of evolution?

Answer 1

Phylogeny is used to track the evolution history of species and related species.

The level of relation is based on timing of divergence and historical sharing of novel traits.

Question 2

What are the two types of speciation?

Answer 2

Anagenesis - the gradual transformation of one species into another. Involving the rapid extinction of the previous.

Cladogenesis - the rapid splitting of a species into another.

Question 3

What are the sources of variation that can lead to evolution?

Answer 3

• mutation
• constraints can reduce/channel variation
• phenotypic plasticity/environmental influences
• recombination

Question 4

What are the modifiers of variation that can lead to evolution?

Answer 4

• Non-random mating/sexual selection
• Genetic flow/genetic drift/population constraints
• Natural selection

Question 5

What are adaptations?

Answer 5

Traits that enhance the fitness of an animal that arise due to historical natural selection for its current biological role.

Must occur in conjuction with feature being present, more offspring and being advantageous.

Question 6

What is adaptive radiation?

Answer 6

An explosion of speciation in a lineage, linked to a key innovator trait providing an advantage.

Question 7

What are explanations of adaptation?

Answer 7

Phylogenetic baggage
Design constraints
Sexual selection
Neutral features
Exaptation
Random genetic drift