Origin Of Species

Question 1

What is the difference between genotype and phenotype?

Answer 1

Genotype you cannot see, where traits come from. Phenotype looks or appearance of the genotype.

Question 2

What is the definition of Species?

Answer 2

share similar physical traits, free interbreed and produce fertile offspring

Question 3

What is population?

Answer 3

any group of individuals, usually of a single species, occupying a given area at the same time

Question 4

Critics of biological species concept examples?

Answer 4

• Successful reproduction between two different species
• Unknown if populations that are geographically separated (allopatric) in nature can interbreed
• Many organisms are asexual and do not mate

Question 5

What is the biological species concept defines species as?

Answer 5

“groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups.”

Question 6

What is a sub-species?

Answer 6

within a single species, individuals in populations that occur in different areas may be distinct from one another
–ex. orange, grey, black, and calico cats

Question 7

What is considered sympatric in a population?

Answer 7

When two different species exist in the same geographic area and thus encounter one another.

Question 8

What happens if sympatric species commonly exchange genes?

Answer 8

Their gene pools should become homogenized.

Question 9

Distinctiveness of sympatric species are?

Answer 9

–Sympatric species are distinctive entities that are phenotypically different, utilize different parts of the habitat, and behave separately.
–Two species that occur together and appear to be nearly identical are termed sibling species.

Question 10

Individuals that cannot produce fertile offspring are termed?

Answer 10

reproductively isolated, and thus members of different species.

Question 11

What is speciation?

Answer 11

process by which new species arise, by either:
–transformation of one species into another
–splitting of one ancestral species into two descendant species

Question 12

What is Cladogenesis?

Answer 12

one ancestral species divides into two descendant species.

Question 13

What is allopatric speciation?

Answer 13

differentiation of populations separated geographic by area into separate species.

Question 14

What is sympatric speciation?

Answer 14

differentiation of populations within a common geographic area into separate species

Question 15

What is reproduction isolation?

Answer 15

populations whose members do not mate with each other or who cannot produce fertile offspring
•Reproductive isolating mechanisms are barriers to successful reproduction

Question 16

What is the prezygotic isolation?

Answer 16

Prevents zygote formation.

Ex. geographic, ecological, behavioral, temporal, mechanical, gamete fusion prevention

Question 17

What is postzygotic isolation?

Answer 17

Prevents proper function of zygote after formation.

Question 18

What is geographic isolation?

Answer 18

–not in the same location (allopatric); do not encounter each other
–Can occur in populations after a natural disaster or anthropogenic disaster

Question 19

What is ecological isolation?

Answer 19

–two species in the same area, but they utilize different portions of the environment
–do not hybridize because they do not encounter each other.
lions and tigers in India
TIGLON lol

Question 20

What is behavioral isolation?

Answer 20

–Many birds differ in courtship rituals which tends to keep species distinct
sympatric species avoid mating with members of the wrong species in a variety of ways, including differences in:
visual signals
sound production
chemical signals = pheromones
electrical signals = electroreception

Question 21

What is temporal isolation?

Answer 21

species reproduce in different breeding seasons or at different times of day.

Question 22

What is mechanical isolation?

Answer 22

Reproductive structures differences prevent mating.

Question 23

What is gamete fusion prevention?

Answer 23

gametes of one species functions poorly with the gametes of another species or within the reproductive tract of another species.

Question 24

What is the result of postzygotic isolation?

Answer 24

–Hybridization often produces embryos that die during early development.
–hybrid sterility
–abnormal sex organ development
–chromosome alterations

Question 25

Dobzhansky: Genetics and the Origin of a Species is?

Answer 25

–Combination of natural selection and population genetics | Evolution is the alteration in a population’s gene pool over time

Question 26

What is gene pool?

Answer 26

All available genes in a population.

Question 27

Gene or allelic frequency is ?

Answer 27

percent that an allele is represented in a population

Question 28

What is gene flow?

Answer 28

movement of genes into/out of a population: –movement of individuals or gametes between populations Flow between two populations causes loss of genetic distinctiveness decrease speciation (as in incompletely isolated populations)

Question 29

What is genetic drift?

Answer 29

changes in a population’s gene pool and gene frequencies by chance –is a greater force in smaller populations

Question 30

What is the founder effect ?

Answer 30

Rare alleles and combinations become more prominent when population founded by few individuals –population bottlenecks; may increase speciation

Question 31

Who said you could stop evolution? How?

Answer 31

Hardy-Weinberg –Population size needs to be large to buffer any chance alterations in the gene pool –No emigration; no immigration –Reproduction is at random –No genetic mutations –Symbolized by the equation: p2 + 2pq + q2 = 1

Question 32

What is adaptation?

Answer 32

change in genes that increases likelihood of survival and reproduction •Adaptation will increase speciation –Natural selection produces differences in physiological and sensory traits –Promotes ecological and behavioral isolation

Question 33

Example of adaptation?

Answer 33

–Adaptations in dewlap color produced behavioral isolation in Anolis lizards; increasing speciation Ability to see dewlap (to attract mate and defend territory) depends on color and environment Light color reflects light in dark forest conditions Dark color more visible in bright glare of open habitats

Question 34

What is stabilizing selection?

Answer 34

Nature favors "average" phenotype.

Question 35

What is directional selection?

Answer 35

Nature favors one extreme phenotype . | Gradualism. Starts slow then hits extreme.

Question 36

What is oscillating selection?

Answer 36

Nature favors one set of traits over time then reverses to a previous trait. Oscillation.

Question 37

What is disruptive selection?

Answer 37

Nature favors both extreme phenotype, eliminating intermediate. –Increase speciation: become different species over multiple generations, assuming the two phenotypes evolve reproductive isolating mechanisms

Question 38

What is polyploidy?

Answer 38

More then two complete sets of chromosomes. | Tetraloid 4n plants can survive. But not fertilized Diploids. Humans are Diploids.

Question 39

What is autopolyploidy?

Answer 39

All chromosomes arise from a single species.

Question 40

What is allopolyploidy?

Answer 40

Two species hybridize. Two species breed with one another. Have chromosomes from both parents. Hybrids often do not develop into adults and Are infertile.

Question 41

What is reinforcement in speciation?

Answer 41

genes naturally selected to prevent hybridization until complete reproductive isolation –ex. pied flycatcher and collard flycatcher appear similar when isolated, but when close, they evolve different color patterns to avoid hybridization

Question 42

What is adaptive radiation?

Answer 42

process producing a cluster of species, occupying a series of similar habitats, all evolving from a recent ancestor.

Question 43

What is character displacement?

Answer 43

Divergent of adaptions or other characteristics in two similar species in a location where they share habitation. Spurred by competition when there habitat overlap.

Question 44

What is key innovation?

Answer 44

Evolves within a species allowing it to use resources or other aspects of the environment that were previously inaccessible. - Evolution of lungs in fish - wings in birds and insects. Allows diversity in descendant species.

Question 45

What is stasis?

Answer 45

Long periods of little or no evolutionary change. | Caused by stabilizing selection and oscillating isolation.

Question 46

Does speciation have to occur which substantial phenotype change?

Answer 46

No. –Do not need to develop new behaviors or morphology for speciation to occur •Phenotypic change can occur within species in the absence of speciation –Not all phenotypic changes will lead to speciation –May form only subspecies

Question 47

How long after an extinction would speciation need?

Answer 47

10 my. - ecosystems must recover. - speciation and adaptive radiation require time to occur.