Chapter 18: evolution and origin of species Flashcards

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1
Q

artificial selection

A

when human chose phenotypes we want and breed to create more ideal hybrids and breed (also known as selective breeding)

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2
Q

what were darwin’s postulates

A
  • characteristics are heritable (passed to an offspring)
  • the more offspring that are present that can survive creates a competition
  • characteristics of offspring vary and variations are heritable
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3
Q

natural selection

A

idea that organisms that are more adapted to an environment are more likely to survive

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4
Q

how does homologous structures support evolution

A

the similar construction of these appendages that indicates that organisms share a common ancestors

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5
Q

what are the key ideas of evidence of evolution

A
  • divergent and convergent evolution
  • fossil record
  • homologous structures
  • vestigial structures
  • biogeography
  • molecular biology
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6
Q

convergence

A

similarities occur not because of common ancestry but because of similar selection pressures

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7
Q

how does biogeography support evolution

A

development and presence of species based on a location
- groups that develop in certain regions or continents
- when species develop because of isolation by physical land barriers

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8
Q

how does molecular biology support evolution

A
  • DNA analysis shows that closely related organisms have similar DNA
  • evolution of new functions for proteins after mutations occur
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9
Q

What are the misconceptions of evolution

A
  • evolution is just a theory
  • individuals evolve: its populations that evolve not the individual
  • evolution explains the origin of life
  • organisms evolved on purpose
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10
Q

what is a species

A

a group of organisms that can interbreed and produce viable and fertile offspring

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11
Q

what is a hybrid

A

a cross between two species

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12
Q

what is a gene pool

A

a collection of all the variants of genes in a species

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13
Q

what is speciation

A

the movement of species (the movement of genetic information of a species)

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14
Q

what is allopatric speciation

A

speciation that involves geographic isolation (this can include anything that changes the environment at all)

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15
Q

what is the ultimate example of allopatric speciation

A

panagea

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16
Q

what are the three types of allopatric speciation

A
  • dispersal
  • vicarience
  • adaptive radiation
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17
Q

what is dispersal speciation

A

happens is when a few members of a species move to a new geographical areas

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18
Q

what is vicariance speciation

A

happens when a natural situation arises to physically divide organisms (happens in cases of storms and natural disasters)

19
Q

what is adaptive radiation in terms of speciation

A

when a single species exists and through events is dispersed out
- every animal comes from the same species (founder species)

20
Q

what is sympatric speciation

A

speciation that happens within the same physical location and conditions

21
Q

what are the two types of sympatic speciation

A
  • chromsomal errors in cell division
  • reproductive isolation
22
Q

what are the types of chromosomal errors that can happen in sympatric speciation

A
  • aneuploidy
  • autopolyploidy
  • allopolyploidy
23
Q

what are the types of reproductive isolation that can take place in sympatric speciation

A
  • prezygotic barriers
  • postzygotic barriers
24
Q

what is speciation

A

occurs when a group within a species separates from other members of its species and develops its own unique characteristics

25
Q

when does speciation occur

A
  • when groups become isolated geographically for a long period of time
  • mutations/changes in each group over time lead to the groups no longer being reproductively compatible
26
Q

what is aneuploidy speciation

A

happens when there are two few or many chromosomes in an organism (can happen during anaophase and metaphase when chromosomes are not evenly split)

27
Q

what is autopolyploidy speciation

A

happens when two or more set of chromosomes after divison ( results from an error in meiosis 1 when the whole PMAT stages are not followed by cytokinesis)

28
Q

what is allopolyploid speciation

A

when gametes from two different species combine (typically results in an offspring that is sterile)

29
Q

what is prezygotic isolation in sympatric speciation

A

something that physically prevents gametes from meeting

30
Q

what are the types of presygotic barriers

A
  • temporal isolation
  • habitat isolation
  • behaviourial isolation
31
Q

what is temporal isolation

A

when species have different breeding schedules (ie. human ovilation cycle)

32
Q

what is habitat isolation

A

members of species move or are otherwise seperated (anything that migrates)

33
Q

what is behaviourial isolation

A

certain actions or behaivours that impacts reproduction (what attracts two organisms together)

34
Q

what is postzygotic isolation

A

a barrier that blocks the reproduction after fertilization and zygote formation

35
Q

what is hybrid inviability

A

when an embryo is produced but cannot survive its development (chromosomes won’t line up)

36
Q

what is hybrid sterility

A

when different species can produce a viable offspring but that offspring cannot reproduce

37
Q

what is hybrid zones

A

an area in regards to speciation where two closely related species interact and interbreed

38
Q

what is reinforcement

A

a process where hybrids are less fit and thus there is nudge towards further divergence between the two species

39
Q

what are the types of hybrid zones

A
  • reinforcement
  • fusion
    -stability
40
Q

whats is fusion

A

when reproductive barriers weaken until the two species become one (when the dispursal event doesn’t properly work so the two species come back together)

41
Q

what is stability in regards to hybrid zones

A

when a species seperates and the fit hybrids continue to be produced

42
Q

what is rate of speciation

A

a graphically measurement of how a species changes over time to and new species are formed

43
Q

gradual speciation

A

when species diverge gradually through time with small step (species diverge at a slow and steady pace as trait change in small increments)

44
Q

what is punctuated equilibrium in regards to rates of speciation

A

when a species exhibits a large change in relatively short period of time followed by long periods of stasis (species diverge quickly and then remain unchanged for a long period of time)