Bio Midterm Module 1

Front 1

Evoulution

Back 1

Change through time

Front 2

Biological evoulution

Back 2

Change in allele frequencies in populations, genetic changes in populations

Front 3

Microevoulution

Back 3

Changes within species

Front 4

Marcoevolutiom

Back 4

Change between species

Front 5

Penicillin

Back 5

First antibiotic based on a naturally occurring substance

Front 6

Population

Back 6

Individuals of species at the same time and place

Front 7

Phenotypic variation

Back 7

Heritable variation in apperance and/or function

Front 8

Quantitative variation

Back 8

Characteristics with a range of variation (controlled by multiple genes)

Front 9

Qualitative variation

Back 9

Characteristics with distinct sets

Front 10

Homozygote

Back 10

An individual having two identical alleles of a particular gene

Front 11

Heterozygote

Back 11

And individual having having two different alleles (one dominant one recessive)

Front 12

Gene pool

Back 12

Set of all genes or genetic information in any population

Front 13

Genotype frequency

Back 13

The number of individuals with a a given genotype divided by the total number of indivuals in that population

Front 14

Alleles frequency

Back 14

The relitative frequency of an allele (variant of a gene) at a particular locus in a population

Front 15

Null model

Back 15

What the genetic makeup of a population would be if it were not evolving at that locus

Front 16

Hardy - Weinburg Equilbrium

Back 16

The frequencies of alleles and genotypes in a population will remain constant from generation to generation, provided that only medialian segregation and recombination of alleles are at work

Front 17

Recombination

Back 17

Chromosomal crossover, this leads to offspring having different combinations of genes from those of their parents

Front 18

Hardy-Weinburg Conditions

Back 18

1. No Mutations

2. No gene flow

3. Popluayion is infinite in size

4. No natural selection

5. Individuals mate randomly

Front 19

Mutation

Back 19

DNA is changed in a way to alter genetic message carried by the gene

Front 20

Neutral mutation

Back 20

Change in DNA that are neither helpful or harmful

Front 21

Advantageous mutation

Back 21

Mutation that benifits an organism

Front 22

Gene flow

Back 22

Movement of alleles across different populations

Front 23

Genetic drift

Back 23

Variation in the relative frequency of different genotypes in a small population, owing to the change dissaperance of a particular genes as individuals die or do not reproduce

Front 24

Population bottleneck

Back 24

An event that drastically reduces the size of a population, caused by enviormental disaster etc.

Front 25

Founder effect

Back 25

Loss of genetic variation that occurs that occurs when a new population is established by a very small number of individuals from a larger population

Front 26

Natural selection

Back 26

Organisms that are better adapted to the environment tend to survive longer and transmit more of their genetic characteristics ti succeeding generations than those who are less adapted

Front 27

Fitness

Back 27

The genetic contribution of an individual to the next generations gene pool relative to the average for the population

Front 28

Directional selection

Back 28

Favours individuals near one end of the phenotypic spectrum

Front 29

Stabilizing selection

Back 29

Favours individuals with intermediate phenotypes

Front 30

Distributive selection

Back 30

Favours individuals with extreme phenotypes

Front 31

Sexual selection

Back 31

Natural selection arising through preference by one sex for certain characteristics in indivuals of the other sex

Front 32

Balanced polymorphism

Back 32

A situation in which two different versions of a gene are mantained in a population of organisms because individuals carrying both versions are better able to survive than those that have two copies of either version alone

Front 33

Heterozygote advantage

Back 33

Describes the case in which the heterozygote genotype has a higher relative fitness than either the the homozygote dominant or the homozygote recessive genotype

Front 34

Negative frequency dependant selection

Back 34

The fitness of a phenotype decreases as it becomes more common

Front 35

Adaptive traits

Back 35

A trait with a current functional role in the life of an organism that is mantained and evolves by the means of natural selection

Front 36

Adaptation

Back 36

Accumulation of adaptive traits over time

Front 37

Natural history

Back 37

The research and study of organisms leaning more towards observational than experimental methods of study

Front 38

Taxonomy

Back 38

The science of defining groups of biological organisms on the basis of shared characteristic and giving names to those groups

Front 39

Biogeography

Back 39

The study of the distribution of species and ecosystems in a geographic space and and through (geological) time

Front 40

Morphology

Back 40

The study of form and structure of organisms and their specific sructural features

Front 41

Vestigial structures

Back 41

Currently useless structures

Front 42

Stratification

Back 42

Formation of layers (strata) in which objects are found

Front 43

Paleobiology

Back 43

Study of ancient organisms

Front 44

Catastrophism

Back 44

Theory of fossil formation by catastrophe

Front 45

Radiometric dating

Back 45

A method of dating geological or archeological specimens by determining the relative proportions of particular radioactive isotope present in the sample

Front 46

Half life

Back 46

The time it takes for a substance to lose half of its mass

Front 47

Convergent evolution

Back 47

The process where by organisms not closely related independently evolve similar traits as a result of having to adapt to certain environments or ecological niches

Front 48

Phylogeny

Back 48

The evolutionary history of a species or a group of species

Front 49

Systematics

Back 49

Classifying organisms and determining their evolutionary relationships

Front 50

Classification of Organisms

Back 50

Domain, kingdom, phylum, class, order, family, genus , species

Front 51

Phylogenetic tree

Back 51

Diagram showing evolutionary history of a group of organisms

Front 52

Pleiotropy

Back 52

Multiple characters controlled by the same gene

Front 53

Homologies

Back 53

Homologous characters result from common ancestry

Front 54

Homoplasy

Back 54

A character shared by a set of species but not present in their common ancestor

Front 55

Derived trait

Back 55

Differs from ancestral trait

Front 56

Ancestral trait

Back 56

Present in the ancestor

Front 57

Synamorphies

Back 57

Derived traits that are shared among a group and are viewed as evidence of the common ancestry

Front 58

Evolutionary reversal

Back 58

A character reverts from a derived state back to the ancestreal state

Front 59

Multiregional hypothesis

Back 59

proposes that populations of H.erectus and archaic humans had spread through much of Europe and Asia by 0.5mya

Front 60

African emergence hypothesis

Back 60

suggests that all modern humans are descended from a fairly recent African ancestor

Front 61

Hominids

Back 61

includes modern humans and our bipedal ancestors

Front 62

Reinforcement

Back 62

Selection for traits that isolate populations reproductively

Front 63

Hybrid zone

Back 63

A geographic area where interbreeding between two populations occurs and hybrid offspring are common.

Front 64

Autopolyploidy

Back 64

an individual has more than the two sets of chromosomes (4n) all derived from an original species (2n).

Front 65

Sympatric speciation

Back 65

When natural selection overcomes geneflow

Front 66

Sympatry

Back 66

Populations or species that live in the same geographic region (close enough to mate) live in sympatry

Front 67

Continental drift

Back 67

the movement of continental plates explained by the theory of plate tectonics— separated species physically.

Front 68

Allopatry

Back 68

Populations that live in different areas

Front 69

Allopatric speciation

Back 69

Speciation that begins with physical isolation via either dispersal or vicariance

Front 70

Postzygotic isolation

Back 70

occurs when individuals from different populations do mate, but the hybrid offspring produced have low fitness and do not survive or produce offspring.

Front 71

Prezygotic isolation

Back 71

Prevents a species from mating

Front 72

Speciation

Back 72

the creation of new species.

Front 73

Phylogenic species concept

Back 73

A species is a group of organisms bound by a unique ancestry

Front 74

Biological species concept

Back 74

A species is a group of organisms that can interbreed and produce fertile offspring

Front 75

Morphological species concept

Back 75

Members of species look alike because they share many alleles.

Front 76

Molecular clock

Back 76

Rate of DNA mutation in different genome regions

Front 77

paleontology

Back 77

the branch of science concerned with fossil animals and plants

Front 78

Development

Back 78

Similarities in development patterns may reveal evolutionary relationships.

Front 79

Cladograms

Back 79

tree made of clades

Front 80

Clades

Back 80

Monophyletic group

Front 81

Cladistics

Back 81

Uses only evolutionary relationships

Front 82

Traditional evolutionary systematics

Back 82

uses phenotypic similarites and differences

Front 83

Principle of parisomy

Back 83

Simplest explanation most likely to be correct

Front 84

Paraphyletic taxa

Back 84

Contains an ancestor and some but not all descendants

Front 85

Polyphectic taxa

Back 85

Includes species from separate lineages

Front 86

Monophyletic taxa

Back 86

include one ancestral species and all its descendants

Front 87

Phenotypic plasticity

Back 87

An organism has the ability to change its phenotype due to enviormental factors

Front 88

Analogous character

Back 88

Performing a similar function but having different evolutionary origin, such as the wings in insects and birds

Front 89

Phenetic Approach

Back 89

Based on computing a statistic that summarizes the overall similarity among poplations

Front 90

Vicariance

Back 90

Occurs when a physical barrier splits a widespread population into subgroups that are physically isolated from one another

Front 91

Dispersal

Back 91

Occurs when a population moves to a new habitat colonizes it and forms a new population