chapter 2- evolution of populations

Question 1

what is evidence for evolution

Answer 1

Direct observation
fossil record- gives us some evidence that species must have evolved
homologous structures- give us some aspect of unity of life
convergent evolution

Question 2

What is convergent evolution

Answer 2

similar characteristics that evolved independently in two lineages, can be homologous or analgous

Question 3

How does convergent evolution happen

Answer 3

in response to similar environmental pressures

Question 4

How can homologous or analogous characteristics be visualized

Answer 4

on a phylogeny

Question 5

How do you know what species share ancestors on a phylogeny

Answer 5

by seeing how close to the root it is

Question 6

What is microevolution

Answer 6

ind. posses heritable genetic differences on which natural selection acts resulting in evolution. changing allele frequencies in a population

Question 7

What are the 4 mechanisms of evolution

Answer 7

natural selection
genetic drift
gene flow
mutation

Question 8

what is gene flow

Answer 8

means the movement of genes. In some cases, small fragments of DNA may pass from one individual directly into the germline of another, migration

Question 9

what is genetic drift

Answer 9

Any random change to the allele frequency of a population due to a chance event.

Question 10

What does the hardy weinberg model describe

Answer 10

a non evolving population

Question 11

HWE equation

Answer 11

p2+ 2pq+ q2= 1

Question 12

What does the HWE examine

Answer 12

what happens to allele frequencies when these evolutionary mechanisms are not working,

Question 13

_ acts on inds, _ acts on a population

Answer 13

natural selection, evolution

Question 14

_ is the unifying theory of all of biology

Answer 14

Evolution

Question 15

What are patterns of natural selection on phenotypes

Answer 15

Directional selection, disruptive selection, stabilizing selection.

Question 16

what does directional selection show

Answer 16

selection for a rare phenotype that differs from mean of population

Question 17

what does disruptive selection show

Answer 17

selection against the common intermediate phenotype and favouring extreme phenotypes. there is no mean or middle section, favouring 2 extreme phenotypes.

Question 18

Stabilizing selection

Answer 18

favouring a common intermediate phenotype

Question 19

Biological Species Concept

Answer 19

1. Produce viable, fertile offspring (at least potentially)
2. Breeding with other species is prevented (reproductive isolation)

Question 20

Morphological species concept

Answer 20

(look different), = unique combination
of traits

Question 21

Ecological species concept

Answer 21

(unique environmental niche)

Question 22

Phylogenetic species concept

Answer 22

(monophyletic groups only identified), traits that are unique to descendants of a common ancestor

Question 23

Speciation:

Answer 23

evolutionary process of divergence of one species into
two species

Question 24

Allopatric speciation

Answer 24

geographical isolation through the formation of a physical
barrier, Uplift of mountain range splits a population

Question 25

Sympatric speciation

Answer 25

– NO geographical isolation,Requires special conditions
happens more in plants

Question 26

Sexual Selection

Answer 26

: Females mate only with males of the same species, based on
coloration