Macroevolution

Question 1

Biological species concept

Answer 1

organisms that are/are potentially interbreeding and are reproductively isolated from other groups

Question 2

ecological species concept

Answer 2

emphasizes roles of natural selection in maintaining species boundaries
- gene flow can occur but natural selection acts against hybrids

Question 3

modes of speciation (3)

Answer 3

allopatric - physical boundary
parapatric - reduced gene flow
sympatric - no barriers

Question 4

Cladogenesis

Answer 4

speciation by splitting lineages (A to B+C)

Question 5

adaptive radiation

Answer 5

rapid series of multiple cladogenic events (A to B+C+D+E)

to fill niches when colonize new landmass

Question 6

anagenesis

Answer 6

gradual transition from one species to the next (A to B)

Question 7

Exaptation (+example)

Answer 7

adaptations emerge for one function, then are useful in another context (feathers = originally adaptation for keeping warm then exaptation for flight

Question 8

Primitive

Answer 8

in LCA, plesiomorphy

Question 9

Derived

Answer 9

new trait, apomorphy

Question 10

Rules to construct phylogeny (2)

Answer 10

must use synapomorphies

homoplasy is everywhere

Question 11

homoplasy

Answer 11

independent evolution in two or more lineages

Question 12

3 types of homoplasy

Answer 12

convergence - different structures as starting point = analogus

parallelism - same structure as starting point = homologus

evolutionary reversal - re-evolve a plesiomorphic feature

Question 13

Principle of Parsimony

Answer 13

features will evolve the fewest number of times as possible -> minimizes homoplasy

Question 14

to reconstruct phylogenies: (3)

Answer 14

use synapomorphies
employ principle of parsimony
called cladistic methodology

Question 15

genetic synapomorphies
component?
specific + time scale?

Answer 15

retrotranspoons - DNA sequences that replicate and insert into the genome at random

Alu elements - in primates and close relatives (inserted into genome 65 mya)