Definitions

Question 1

Evolution

Answer 1

change in allele frequencies in a population over time

Question 2

Natural Selection

Answer 2

the unequal REPRODUCTION of individuals in a population of organisms

Question 3

Adaptation

Answer 3

Within a population, adaptation occurs when some individuals over generational time (not within generation), increase in their ability to leave offspring, on average

Question 4

Pleiotropy

Answer 4

one gene has many effects; ex: sickle cell

Question 5

Epistasis

Answer 5

one trait is affected by several genes; ex: huntingtons disease

Question 6

Allometry

Answer 6

Unequal rates of growth of the parts of an organism
Can be within a species or between species

Question 7

Heterochrony

Answer 7

The different or changing time bases for ontogenetic events

Question 8

Ontogeny

Answer 8

continual development of an individual organism from fertilization to death

Question 9

Acceleration

Answer 9

an earlier expression of a trait (timing) or the increase in the allometric constant for a trait within a lineage over time.

Question 10

Retardation

Answer 10

a later expression of a trait (timing) or the decrease in the allometric constant for a trait within a lineage over time

Question 11

Recapitulation

Answer 11

An organism attains the ancestor’s adult characteristics during its juvenile stage of development

Question 12

Paedomorphosis

Answer 12

The retention of the ancestor’s juvenile characteristics into the adult stage of life

Question 13

Macroevolution

Answer 13

The origins of new species (and higher taxonomic groups)

Question 14

Biological Species Concept

Answer 14

A biological species is composed of groups of actually or potentially interbreeding natural populations that can produce fertile offspring and are reproductively isolated from other such groups - Focus on natural population

Question 15

Habitat Isolation

Answer 15

do not encounter each other because live in different habitats

Question 16

Ethological Isolation

Answer 16

Behavioral differences between individuals that prevent the from considering the other an appropriate mate

Question 17

Mechanical Isolation

Answer 17

Incompatibility between genital systems of potential mates

Question 18

Gamete incompatibility

Answer 18

Gametes meet but they are incompatible, no zygote formed

Question 19

Zygote mortality

Answer 19

Zygote forms but ceases to develop very early

Question 20

Hybrid inviability

Answer 20

Zygote forms, goes to term, does not live long

Question 21

Hybrid sterility

Answer 21

Zygote goes to term, hybrid often (not always) quite vigorous physically but sterile

Question 22

Allopatric Speciation

Answer 22

Speciation that occurs because of extrinsic barriers between populations that allow intrinsic barriers to evolve

Question 23

Vicariance model of allopatric speciation

Answer 23

a large population is divided more or less equally by a barrier to gene exchange

Question 24

Peripatric model of allopatric speciation

Answer 24

Small number of individuals from parent population found a new population at a biologically significant difference away from the parent population

Question 25

Parapatric speciation

Answer 25

Evolution of reproductive isolation (i.e., speciation) between two populations with overlapping borders but distributed geographically with conditions changing dramatically from one region to the other Requires low fitness of intergrade individuals and adaptations to highly contrasting regions

Question 26

Sympatric speciation

Answer 26

Evolution of reproductive isolation in a potentially randomly mating population. No geographic variation is involved

Question 27

Cladistics

Answer 27

Wherever an organism is on the tree of life, it is related to everything else

Question 28

Hennigian Species Concept

Answer 28

Species are separate branches of a phylogenetic tree. Each species, or branch, is bounded by a splitting, or cladogenic, event at its origin and, in most cases (i.e., those species no longer extant), by a splitting, or cladogenic event at its demise.

Question 29

Apomorphies

Answer 29

A unique character or state of a character that is derived from what the presumed ancestor had

Question 30

Plesiomorphies

Answer 30

The original state of a character

Question 31

Cladogram

Answer 31

Visual representation of relationships as we hypothesize them to be at the moment

Question 32

Homoplasy

Answer 32

The independent evolution of solutions to an environmental demand in 2 separate clades.

Question 33

Principle of Parsimony

Answer 33

The best explanation is the simplest one that accounts for all the data because it is the most likely one

Question 34

Polytomy

Answer 34

When evolutionary relationships unclear, sometimes see cladogram with polytomy

Question 35

Cladogenesis

Answer 35

the breaking of a lineage into 2 daughter lineages

Question 36

Anagenesis

Answer 36

change in a character state within a lineage over time

Question 37

Punctuated equilibrium

Answer 37

stasis punctuated by rapid change