Evolution

Question 1

Adaptive Radiation

Answer 1

a process in which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes ew resources available, creates new challenges, and opens environmental niches

Question 2

Allele

Answer 2

A variant form of a gene (diploid organisms have 2 alleles per genetic locus)

Question 3

Allopatric Speciation

Answer 3

A population forms a new species because of geographic isolation from parent population

Question 4

Analogous Structures

Answer 4

Structures in different animals that appear similar yet are anatomically different, with different functions

Question 5

Antibiotic Resistance

Answer 5

Occurs when bacteria change in some way that reduces or eliminates the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections

Question 6

Artificial Selection

Answer 6

The process by which species are modified by humans (i.e. selective breeding of dogs)

Question 7

Bottleneck Effect

Answer 7

a sudden change in environment drastically reduces the size of a population (gene pool of survivors may not reflect the old population)

Question 8

Adaptation

Answer 8

A change in an organism in response to its environment which increases its chance of survival (inherited and passed along generations; do not occur quickly)

Question 9

Cladogram

Answer 9

A diagram to show relations among organisms

Question 10

Clade

Answer 10

A life-form group consisting of an ancestor and all its descendants—representing a single “branch” on the “tree of life”. The ancestor may be an individual, a population or even a species (extinct or extant).

Question 11

Convergent Evolution

Answer 11

explains why distantly related species can resemble one another; two organisms develop similarities as they adapt to similar environmental challenges, NOT due to common ancestry. (resulting likeness is analogous)

Question 12

Directional Selection

Answer 12

shifts overall makeup of population (phenotype); favors one extreme

Question 13

Disruptive Selection

Answer 13

spreads out population; favors both extremes

Question 14

Divergent Evolution

Answer 14

The accumulation of differences between groups which can lead to the formation of new (different) species; often result of diffusion of same species which blocks gene flow and allows differentiation of characteristics

Question 15

Evolution

Answer 15

Change in species over time

Question 16

Founder Effect

Answer 16

A few individuals become isolated from a larger population and establish a new population whose gene pool is not reflective of the source population

Question 17

Gene Flow

Answer 17

occurs when a population gains or loses alleles by genetic additions or subtractions; reduces genetic difference/population becomes more similar

Question 18

Genetic Drift

Answer 18

unpredictable fluctuation in allele frequencies from one generation to the next; smaller populations are more likely to be affected

Question 19

Homologous Structures

Answer 19

Anatomical signs of evolution; suggest common ancestor

Question 20

Prezygotic Barriers

Answer 20

prevent mating or hinder fertilization; isolation- habitat, behavioral, temporal (timing), mechanical (anatomical), gametic (gametes won’t fuse)

Question 21

Postzygotic Barriers

Answer 21

Prevent fertilized egg from developing into fertile adult; reduced hybrid viability (incompatibility ceases development), fertility (offspring is sterile), hybrid breakdown (offspring can reproduce but their offspring are sterile)

Question 22

Natural Selection

Answer 22

heritable traits become more or less in a population as a function of the effect of inherited traits on the differential reproductive success of organisms interacting with their environment

Question 23

Outgroup

Answer 23

a group of organisms that serve as a reference group when determining the evolutionary relationship among three or more groups of organisms

Question 24

Phylogenetic Tree

Answer 24

a branched diagram showing the inferred evolutionary relationships among various biological species or beings

Question 25

Protobiont

Answer 25

abiotic produced molecules which spontaneously self-assemble into droplets (spheres) that enclose a watery solution and maintain a chemical environment different from their surroundings.

Question 26

Reproductive Isolation

Answer 26

the existence of biological barriers (prezygotic or postzygotic) that impede members of two species from producing viable, fertile hybrids

Question 27

Serial Endosymbiosis

Answer 27

endosymbiont: an organism that lives within the body or cells of another organism; theory claims- mitochondria and plastids (chloroplasts) were formerly small prokaryotes that began living within larger cells

Question 28

Sexual Selection

Answer 28

natural selection arising through preference by one sex for certain characteristics in individuals of the other sex

Question 29

Speciation

Answer 29

the formation of new and distinct species in the course of evolution

Question 30

Stabilizing Selection

Answer 30

narrows population curve; removes extremes

Question 31

Sympatric Speciation

Answer 31

A small part of a population becomes a new population (evolves) without geographic isolation

Question 32

Vestigial Organs

Answer 32

Structures of marginal, if any, importance to the individual, yet served important functions in organism’s ancestors (i.e. remnants of the pelvis and leg bones found in snakes)