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general biology 2 > unit 3 evolution > Flashcards

unit 3 evolution Flashcards

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1
Q

sympatric speciaton

A

occurs in populations living in the same geographic area

Can occur if gene flow is reduced

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2
Q

types of sympatric speciation

A

Habitat differentiation – genetic factors in a subpopulation allow for differential interaction with a habitat or resource not used by the parent population.

Polyploidy- Polyploidy is the heritable condition of possessing more than two complete sets of chromosomes. Polyploids are common among plants, as well as among certain groups of fish and amphibians.

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3
Q

Types of polyploidy

A

An allopolyploid is a fertile individual that has more than two chromosome sets as a result of two different species interbreeding and combining their chromosomes.

An autopolyploid is an individual that has more than two chromosome sets that are all derived from a single species

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4
Q

allopatric vs sympatric speciation

A

Allopatric Speciation

Gene flow restricted by geographic isolation

Genetic changes occur in isolated population(s)

Natural selection

Genetic drift

Sexual selection

Reproductive barriers may arise as byproduct

Prevention of interbreeding with parent/sibling population

Sympatric:

Subset of population isolated by reproductive barrier

Gene flow between subpopulation and parent population blocked

Polyploidy

Natural selection – habitat/food source

Sexual selection

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5
Q

hybrid zone

A

A hybrid zone is a region in which members of different species meet and mate, producing some offspring of mixed ancestry

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6
Q

reinforcement

A

Reinforcement: A process in which natural selection strengthens prezygotic barriers to reproduction, reducing the chances of hybrid formation

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7
Q

what is fusion

A

When two species contact for reproduction are not strong, gene flow occurs and two may fuse into a single gene pool

Reverses speciation process

May favor one species as larger contributor of alleles coupled with extinction of the other species

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8
Q

what is stability

A

The hybrid zone may remain stable (continually produced) over time

Hybrids may survive or reproduce better than members of either parent species

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9
Q

types of postzygotic barriers

A

Reduced hybrid viability is fertilization occurs but the genes of different species may interact in ways that impair completion of development or survival in its environment.

Reduced hybrid fertility is the result when hybrids complete development and are vigorous but are sterile, parents may have differing number or structure of chromosomes leading to failure of normal gametes

Hybrids don’t produce normal offspring only half of gene flow

Hybrid breakdown is first generation hybrids are fertile and viable but subsequent mating with other hybrids or either parent species leads to sterile offspring in the following generation.

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10
Q

types of prezygotic barriers

A

Habitat isolation is two species different habitats within the same area rarely encounter with each other.

Temporal summation species breed at different times ( day, season, years).

Behavioral isolation are behaviors unique to a species help with mate recognition a way to identify potential mates of the same species

Mechanical isolation is morphological differences physically prevent successful mating

Gametic isolation sperm of one species are not able to fertilize the eggs of another species

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11
Q

difference between prezygotic and postzygotic barriers

A

Prezygotic barriers block fertilization from occurring.

Postzygotic barriers is a barrier that contributes to reproductive isolation after fertilization occurs between individuals of two different species.

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12
Q

what is speciation

A

Speciation is the process by which one species split into two or more species

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13
Q

the difference between macroevolution and microevolution

A

Microevolution are changes in allele frequencies in a population

Macroevolution broad pattern of change above the species level

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14
Q

species definition

A

A species is a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring.

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15
Q

what are the modes of selection

A

Modes of selection

Directional: conditions favor ins exhibiting 1 extreme of phenotype range

Disruptive selection occurs when conditions favor individuals at both extreme phenotypic ranges.

Stabilizing selection acts against both extreme phenotypes and favors intermediate favors.

Directional and stabilizing selection does cause shifts that tend to reduce variation.

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16
Q

what is reproductive isolation

A

Reproductive isolation refers to the existence of biological factors of barriers that keep members of 2 species from interbreeding and producing viable, fertile offspring.

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17
Q

what is a population

A

a population is a group of indivisuals that are the same that interbreeds and produce fertile offspring and live in the same place.

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18
Q

three main mechanisms that cause a change in allele frequency

A

natural selection
genetic drift
gene pool

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19
Q

genetic variation

A

genetic variation is differences in genotype or other DNA segments.

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20
Q

gene pool

A

genetic make up of a population and copies of all alleles at every locus

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21
Q

factors that affect hardy weinberg equation

A

no mutations
non random mating
no natural selection
no gene flow
population size is large

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22
Q

what is the hardy weinberg principle

A

frequencies of all genotypes in a population will remain constant from generation to generation only if there is segregation and recombination of alleles.

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23
Q

types of genetic drift

A

founder effect is when a few indivisuals from a big population become isolated from the big population and make a new populaion with a different gene pool that doesn’t resemble the original population.

bottleneck effect occurs when the size of population is reduced and that new population doesn’t genetically represent the original population.

24
Q

what is gene flow

A

the transfer of a population to a new population due to their gametes.

25
Q

natural selection

A

survival of the fittest and indivisuals with traits are more likely to survive because they are suited for the enviroment.

26
Q

relative fitness

A

relative fitness is the contribution and individual makes to the gene pool of the next generation when compared to individual contributions and type of natural selection.

27
Q

how can the degree of genetic variability be measured

A
  1. gene variability
    average heterozygosity which is the percentage of loci that s heterozygous in a population.

nucleotide variability is when dna sequences are compared in indivisuals of that population.

28
Q

what is genetic drift

A

a process in which events cause unpredictable fluctations in allele frequencies going from several generations

29
Q

what is vestigal structure and give example of vestigal structures ?

A

vestigal structures are structures that are present in modern animals no longer in use.

example wings in ostriches because even though all birds have wings ostriches use wings different from birds .
birds use wings to fly but ostriches flap their wings.

30
Q

what is an analagous structure
and give an example of an analagous structure ?

A

Analogous structures share similar function but are not the result of common ancestry.

Analogous structure examples are wings of birds and butterflies because both species have wings but come different ancestors.

31
Q

what is homologous structures and give example of it ?

A

Homologous structures are structures in different species that are similar because of common ancestry.
The arm of a human, the wing of a bird or a bat, the leg of a dog and the flipper of a dolphin or whale are homologous structures.

32
Q

what was jean baptist de lemarck theories on evolution ?

A

Jean Baptist de Lexmark – Principle#1 use and disuse

Parts of the body used regularly become larger and stronger those not used detoriate.

Principle #2: Inheritance of acquired traits

An organism can pass modifications acquired by use along to offspring.

33
Q

what is convergent evolution and give an example of convergent evolution ?

A

Convergent evolution is the independent evolution of similar features in different lineages.

Flippers of dolphins and penguins are examples of convergent evolution. In both animals; flippers have different origins but serve a similar purpose

34
Q

the difference between natural selection and adaption ?

A

Natural Selection- Process which individuals that have certain inherited traits tend to survive and reproduce at higher rates.

Adaptions is the characteristic that changes in an organism that will increase its chance of survival in specific environments.

The idea of natural selection is that traits that can be passed down allow organisms to adapt to the environment better than other organisms of the same species. This enables better survival and reproduction compared with other members of the species, leading to evolution.

35
Q

what were 3 observations made by darwin

A

Darwin’s observations

  • Unity of life – organisms share many characteristics; all organisms are descendants of a common ancestral organism.

-Diversity of life – Descendants of common ancestors accumulated diverse modifications over millions of years.

  • Match between organisms and their environment’s accumulated modifications are reflective of their environment influence.
36
Q

what is descent with modification ?

A

Descent with modification broadly describes that organisms are not unchanging meaning we can have species that change over time and sometimes new species may emerge.

37
Q

what is artificial selection and give example of artificial selection ?

A

Artificial selection is the selective breeding of domestic plants and animals to make the occurrence of desirable traits.

example by allowing only like indivisuals to breed, breeders have variety of dogs breeds and crop plants.

38
Q

what were hunton, linneaus, and george curvier, and lyell, and hunton contributions, and theories of evolution ?

A

Carlous Linnaeus- Developed binomial (two parts) format naming species

Nested classification system which is similar species grouped into increasingly general categories.

George Curvier – Opposed the idea of evolution and each boundary between of evolution and each boundary between strata represents catastrophe.

Observed older the stratum, more dissimilar fossils to different life forms.

Charles Lyell- Same processes operating across areas. Same processes occur at the same rate.

Hunton- Profound changes happen over time.

39
Q

what is embryology ?

A

Embryology compares early stages of developmental and can reveal anatomical homologies not visible in adult.

the study of embryos, can help us find plenty of evidence to support the theory of evolution. For example, vestigial structures such as tails or gills in humans can be found in embryos early during their development

40
Q

what is relative fitness ?

A

Relative fitness is defined as the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals.

41
Q

what is adaptive evolution ?

A

Natural Selection is the only mechanism that consistently causes adaptive evolution.

Natural Selection is the only mechanism that consistently causes adaptive evolution.

adaptive evolution occurs over time as natural selection increases frequencies over of alleles that can enchance survival and reproduction ?

42
Q

hardy weinberg rules

A

P +q =1

P^2+ 2pq+q^2=1

2pq is the frequency of heterozygote

Q^2 is frequency of homozygote recessive

P^2 is frequency of homozygote dominant

p= homozygote dominant allele/ total number of alleles in each population

43
Q

how did life begin and explain it in order ?

A

we first started off with aneorobic prokaryotes because there wasn’t enough oxygen —-> then we got cyanobacteria which are photosynthetic prokaryotes that use photosynthesis to release oxygen—> then we got aerobic prokaryotes becayse the oxygen levels in the atmosphere was gradually rising . aerobic prokaryotes utilize celluar respiration which is the process by animals and plants break down food and sugar to make energy —–> leading to unicelluar eukaryotes meaning complex celluar organization such as nuclear envelope, endoplasmic recticulum, and cytoskeleton for the eukaryotic cell structure to perform different functions and jobs —–> which led to endosymbiosis states that a host cell (prokaryote) engulfed a small cell eukaryote that evolved into one organism. ( type of symbiosis in which one organism lives inside the other, the two typically behaving as a single organism ) ——> giving rise to multicelluar eukaryotes suggesting we came from a common ancestor -> cambrian explosion we see a shift in diversity meaning predators have selective advantages and prey has to make defensive adaptions —-> colonization of land ( plants then fungi co colonize with plants and take organic nutrients from plants —-> lastly it led to insects inveterebrates then to tetrapods 4 limbs .

44
Q

speciation vs extinction

A

rise and fall of organisms . when rise of organisms and new species arise and are lost to extinction.

45
Q

changes in groups of organsims are due to

A

plate tectonics and continential drift
mass extinctions
adaptive readiations

46
Q

what is plate tectonics and continental drift

A

Plate tectonics is a scientific theory that explains how major landforms are created as a result of Earth’s subterranean movements

continental drift the gradual movement of the continents across the earth’s surface through geological time.

continental drift led to animals being distributed outside to certain areas.

47
Q

what is mass extinction

A

occurs when global enviroment changes leads to the large numbers of species throughout earth.

48
Q

what is adaptive radiations

A

Adaptive radiation refers to the adaptation of an organism which enables it to successfully spread, or radiate, into other environments.

Adaptive radiation leads to speciation and is only used to describe living organisms.

49
Q

genes that control development influence

A

rate and timing
spatial patterning
changes in genes

50
Q

changes in rate timing define

A

heterochrony is an evolutionary change the rate or timing of developmental events.
humans ; mutations slow the growth of the jaw and relative to other parts of the skull.

51
Q

define changes in spatial pattern

A

homeotic genes determine gross patterning of gross anatomy.

example play a role in limb patterning it mutes the information in the genome because its not appropiate or needed anymore.

52
Q

define changes in genes

A

morphological forms may be linked to new developmental genes arising after duplication events.
promotes a new leg growth because of genetic variation.

53
Q

examples of prezygotic barriers

A

mechanical isolation when parts don’t fit together to reproduce and is prezygotic barrier. the way a shell fits is built may have a curve and don’t fit together.

habitat isolation two different species could interbreed but do not because they live in different areas. example in india lion and tigers can interbreed but since tigers live in the forest and lions live in the desert can’t mate.

behavioral isolation occurs when mismatches in mating traits prevent mating within two species because they have preferences. blue guppies don’t want to mate with red guppies because blue guppies have a type liking pink guppies.

temporal isolation species breed at different times. example 3 species live in the forest birds breed in the night, tigers in the morning, and lions in the afternoon.

gametic isolation prevents fertilization as the sperm cells of cannot unite with eggs of a different species.

54
Q

examples of postzygotic barriers

A

reduced hybrid viability a lower potential to survive for organisms whose parents have incompatible genetics.

Reduced Hybrid Fertility
Hybrids between the two species/subspecies are sterile or are completely sexually unattractive to members of either species/subspecies.

When a male horse and female donkey mate and reproduce, they produce a hybrid cross called a mule that cannot reproduce for itself due to having an uneven amount of chromosomes (63) which disrupts meiosis.

Hybrid breakdown is a type of reproductive failure that appears after the F2 generation of crosses between different species or subspecies. It is caused by incompatibility between interacting genes.

Hybrid breakdown is a type of reproductive failure that appears after the F2 generation of crosses between different species or subspecies. It is caused by incompatibility between interacting genes.

55
Q

factors that influence gene pool

A

are: mutation, non-random mating, gene flow, finite population size (genetic drift), and natural selection.

general biology 2 (1 decks)

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