Bs 162 Exam 1

Front 1

Heterochrony

Back 1

Evolutionary change in timing or rate of an organism's development. Used for comparisons of different species. Organism's shape depends in part on relative growth rates of different body parts during development. Changes in rates can alter adult form substantially, leading to evolution of one or more new species.

Front 2

Paedomorphosis

Back 2

Retention in adult of one or more juvenile features. Eg, Axol-lottle salamander species that grows full size and develops sexual maturity and can reproduce while retaining larval characteristics.

Front 3

Allometry

Back 3

Relation between size of an organism and the size of its parts. Eg, relation between body size and brain size.

Front 4

Homeotic genes

Back 4

Master regulatory genes determine basic features, eg, where a pair of legs/wings will develop. Eg, hox genes: provide positional information of a structure in animal embryo. Change in location correlates with conversion of swimming appendages to feeding appendages.

Front 5

Exadaptation

Back 5

Structures evolve in one context with one function but through time develop another function. Eg, bones that formerly comprised the jaw hinge of early mammals were incorporated into ear region for hearing.

Front 6

Taxonomic hierarchy mnemonic device

Back 6

King Phillip Came Over From Germany Singing

Front 7

Microevolution / Macroevolution

Back 7

Micro: Takes place at species level or below.

Macro: Above the species level.

Front 8

Allele

Back 8

contrasting gene for the same phenotype

Front 9

Phylogeny

Back 9

Study of the evolutionary history of the development of a group of organisms compared to other groups of organisms

Front 10

Homologous / Analogous structures

Back 10

Homologous: structures that are similar in form, shape, structure and function but more importantly share a common embryological ancestor (Eg, wing of bat, flipper of whale)

Analogous: no embryological source (eg, wing of bat and wing of butterfly)

Front 11

Scala Naturae

Back 11

Aristotle's Ladder of Nature--species are fixed

Front 12

Hutton

Back 12

Principle of gradualism (Earth's surface gradually changing)

Front 13

Lyell

Back 13

"Principle of uniformitarianism" - supported Hutton's gradualism

Front 14

Malthus

Back 14

"Essay on the Principle of Populations" - Humans are outstripping food sources

Front 15

Date: Theory of natural selection

Back 15

1838

Front 16

Wallace

Back 16

theory of natural selection similar to Darwin

Front 17

Date: "Origin of Species"

Back 17

1859

Front 18

Mendel

Back 18

Discovered genetics

Front 19

Is NS an all-or-none phenomenon?

Back 19

No.

Front 20

Stabilizing selection

Back 20

Involves elimination of individuals with extreme phenotypes. Eg, clutch size in swiss starling

Front 21

Disruptive selection

Back 21

Increase in the number of individuals with extreme phenotypes, decrease in number of individuals with intermediate phenotypes. Eg, Coho salmon in pacific northwest

Front 22

Directional selection

Back 22

Increase in number of individuals with an extreme phenotype due to replacement of one allele or more by one or more alleles. Eg, peppered moths

Front 23

Intrasexual / Intersexual selection

Back 23

Intra: Individuals of one sex of species compete with each for other sex.

Inter: Individuals of one sex act as selection pressure on other sex (women are picky, selection pressure on men)

Front 24

Balanced polymorphism

Back 24

Phenotypes are maintained in fairly stable proportions from one generation to the next through time. Eg, terrestrial snail and bird predators

Front 25

Cline

Back 25

Graded variation in a trait that follows geographic distribution

Front 26

Ecotype

Back 26

Groups of distinct phenotypes in different habitats that make up a species. Eg, brown bears, bottlenose dolphins

Front 27

Convergent evolution

Back 27

2 species not closely related evolve similar adaptations or structures because of similar selection pressures.

Front 28

Parallelism

Back 28

Same as convergent evolution, except species are closely related.

Front 29

Divergent evolution

Back 29

Populations of organisms isolated from the rest of the species evolve into different species because of selection pressures. Eg, brown bear --> polar bear.

Front 30

Allopatric meaning. 2 types

Back 30

Different land. Vicariance and dispersal

Front 31

Allopatric speciation: vicariance

Back 31

Formation of geographical barrier splitting the species

Front 32

Allopatric speciation: dispersal

Back 32

Group of individuals somehow move to a new habitat and evolve into new species because of selection pressures

Front 33

Sympatric speciation. 2 types

Back 33

Same land. Ecological isolation and polyploidy

Front 34

Sympatric speciation: ecological isolation

Back 34

Different resources. Eg, some species of insects

Front 35

Sympatric speciation: polyploidy

Back 35

Increase in the number of chromosomes beyond the normal diploid number; more common in plants than animals; results from the abnormal movement of chromosomes during meiosis when the gametes are formed. Two types: autopolyploidy and allopolyploidy

Front 36

Autopolyploidy

Back 36

Individuals of same species

Front 37

Allopolyploidy

Back 37

Individuals of different species

Front 38

Anagenesis

Back 38

Species A becomes species B. No increase of number of species.

Front 39

Cladogenesis

Back 39

Species A becomes species B and C. Increase in number of species.

Front 40

Gradualism v. Punctuated Equilibrium

Back 40

Gradualism: Speciation is a gradual process and there are intermediates in the formation of a new species.

Punctuated Equilibrium: Speciation is a very fast process with no intermediates.