Lecture 4

Question 1

Evolution

Answer 1

splitting of linages

Question 2

Biological evoltion

Answer 2

genetic and potentially phenotypic changes in groups of organisms.

Question 3

Anagenesis

Answer 3

evolution taking place in a single linage

Question 4

cladogenesis

Answer 4

splitting of one linage into two

Question 5

3 species concepts

Answer 5

1- Phenology species concept
2- Phenetic species concept
3- biological species concept

Question 6

Phenetic species form?

Answer 6

Clusters within a phenotypic space

Question 7

How does biological species concept classify species

Answer 7

looking at gene flow within species

Question 8

Phenology classification

Answer 8

smallest set of organisms which share an common ancestor

Question 9

Phenology tree

Answer 9

shows the relationship between organisms (how closely related they are common ancestors etc)

Question 10

Phenology based on

Answer 10

Molecular Data from extinct species

Question 11

Genetic similarity of two organisms is based on?

Answer 11

Phenology

Question 12

Rooted vs unrooted

Answer 12

Have a common ancestor vs do not

Question 13

Terminal nodes

Answer 13

• at the end of a phenology tree

- in which have been phylogeny constructed

Question 14

Scaled vs unscaled

Answer 14

Length of branch is proportional to the amount of evolutionary change

Question 15

Rooted phenology trees contain an

Answer 15

outgroup/common ancestor

Question 16

Horse x donkey

Answer 16

mule

Question 17

Donkey horse

Answer 17

hinny

Question 18

tiger x lion

Answer 18

liger

Question 19

Lion x tiger

Answer 19

tigon

Question 20

Allopatric

Answer 20

Geographical isolation

Question 21

Parapatric

Answer 21

speciation when populations are not isolated, but adjoining – individuals mate locally

Question 22

Peripatric

Answer 22

population is peripheral to a main population

Question 23

Sympatric

Answer 23

linages are not isolated from eachother, populations overlap

Question 24

Example of allopatric speciation

Answer 24

Caribbean pacific split during Panamar, shrimp Alpheus

formed six pairs of species all with a common ancestor (one Caribbean and one Pacific

Question 25

New niche =

Answer 25

new species

Question 26

Example of peripatirc

Answer 26

Mountain ranges between peripheral and main population

Question 27

Parametric speciation hybrid zone?

Answer 27

small hybrid zone (in which linages overlap)

Question 28

Gene flow in parapatric?

Answer 28

limited

Question 29

What does parapactric speciation usually assume?

Answer 29

Environmental gradient and therefore different selection pressures

Question 30

Example of parapartric speciation

Answer 30

Salamanders in california

Question 31

Examples of sympatric speciation?

Answer 31

Apple maggots in North America
eggs laid first on hawthorn berries
then when apples introduced, laid eggs there
lead to sympatric speciation? Controversial

fish in a lake (cichlids)

Question 32

dobzhanskys Reproductive isolation types

Answer 32

1- post zygotic

2- Prezygotic

Question 33

In prezygotic isolation do the potential mates live in the same environment?

Answer 33

YES, but don’t encounter one and other

Question 34

2 types of isolation prezygotic isolation

Answer 34

• habitat isolation

- temporal isolation (time of day)

Question 35

Behavioural isolation

Answer 35

interact (potential mates) but do not mate

Question 36

Individuals copulate ?.. prezygotic isolation

Answer 36

But male gametes is not transferred to the egg

or sperm does transfer to egg but no fertilisation occurs (gametes incompatibility)

Question 37

Postzygotic isolation ?

Answer 37

1- Embryo dies early on in embryogenesis
2- F1 survive but inviable
3- F2 are inviable or sterile

Question 38

Secondary contact

Answer 38

When two linages split but can be reintroduced to each other (by loss of barriers)

Question 39

After secondary contact are linages able to reproduce, factors?

Answer 39

1- Behavioural- do they want to reproduce?

2- Are the hybrids viable?

Question 40

Euhadra snails?

Answer 40

Rare case in which reproductive isolation linked to one gene

left and right coiling

numerous cases in which speciation is down to chirality of snail shell