Ch 3 - Patterns of evolution

Question 2

Cladogenesis

Answer 2

Starting a new branch (Gould)

Question 3

Anagenesis

Answer 3

Slow gradual change of one particular feature within a certain lineage (Darwin)

Question 4

Punctuated equilibrium

Answer 4

SJ Gould: majority of change occurs at a speciation event, little change otherwise

Question 5

Protostome and deuterstome

Answer 5

the first opening (the blastopore) becomes the anus, while in protostomes it becomes the mouth.

Question 6

Rise of HIV from phylogenetic tree

Answer 6

HIV-1 developed from chimpanzee SIV, HIV-2 from mangabey; multiple independent origins and transfers to humans;

Question 7

Monophyletic, para- and poly-

Answer 7

Mono- group including all descendants of a certain ancestor; para- only a few of them (ie the reptiles, excludes birds); poly- includes descendants of two of more ancestors but not all of their descendants

Question 8

Determining homology

Answer 8

Many features are modified from pre-existing ones from common ancestor; same genetic and developmental basis but CAN differ!

Question 9

Compare differences in humerus, radius and ulna, and metacarpals

Answer 9

Very different! Porpoise has really small, horse metacarpals are massive, bats have extended fingers

Question 10

Convergence

Answer 10

Independent evolution of similar states usually in widely separated taxa

Question 11

Parallelism

Answer 11

Independent evolution of similar states but similar genes/development (usually in more closely related species)

Question 12

Reversals

Answer 12

Independent evolution of similar states but change back to ancestral condition

Question 13

Mimicry

Answer 13

Aposematic: warning colouration; Batesian (“safe” animal resembling a dangerous species) and Mullerian (two dangerous species are alike); example of convergence.

Question 14

Rates of character change

Answer 14

Organisms are mosaics - gradualism (Darwin) and saltations (Gould)

Question 15

Individualization

Answer 15

A feature becomes more specialized (ie teeth - once were all similar shape, now many are diverse)

Question 16

Heterochrony

Answer 16

Evolutionary change in timing of developmental processes (ie stop of brain growth in chimps is sooner than humans)

Question 17

Neotony

Answer 17

Type of heterochrony where sexual maturation is complete before other characters have reached the mature state.

Question 18

Allometry

Answer 18

Differing growth rates from different parts of body (y=bx^a, a describes relative growth rate, x and y are the measurements in question), ex. head vs legs

Question 19

Heterotopy

Answer 19

Different place of expression for a certain tissue; eg Lianas - really long roots exposed from canopy to floor, or development of sesamoid bones

Question 20

Paedomorphosis

Answer 20

Organism takes on some maturity characteristics early while retaining many juvenile ones into adulthood

Question 21

Paralogy

Answer 21

Genes that are related through duplications in a common ancestor (ie A into A and B)

Question 22

Orthology

Answer 22

homologous gene found in two different lineages, related via speciation