Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Ecology and Evolution Unit 1 & 2 > Unit 2: Species and Speciation > Flashcards

Unit 2: Species and Speciation Flashcards

1
Q

What is Species?

A

group of populations that interbreed and produce fertile offspring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Speciation?

A

a splitting event that creates 2 or more distinct species from a single ancestral species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is Species Concept?

A

a set of criteria used to define and differentiate species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Morphological Species Concept?

A

species defined based on differences in size, shape, or other morphological features

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the Pros & Cons of morphological species concept?

A

Pros:
- typically easy to measure traits
- can be applied to asexual and extinct species (fossils)
Cons:
- which traits, and how different do they need to be?
- species with different morphs (order of colors of birds)
- cryptic species ( 2 different species which look alike)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Gene Flow?

A

transfer of alleles from one population to another; makes populations similar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is Reproductive Isolation?

A

behaviors or processes that prevent gene flow between populations; creates opportunity for divergence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Biological Species Concept?

A

species defined based on reproductive isolation:
- species do not interbreed in nature, or if they do, the offspring is not viable/stable

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the Pros & Cons of biological species concept?

A

Pros:
- based on mechanism (reproductive isolation) low to lead to evolutionary divergence
Cons:
- can not be applied to asexual and extinct species
- what if populations are not sympatric?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is Phylogenetic Species Concept?

A

species defined based on analysis of a phylogeny

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is Phylogeny (Phylogeny Tree)?

A

(evolutionary tree) representation of the evolutionary relationship among organisms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is criteria of the phylogeny tree?

A

species are the smallest possible sets of monophyletic groups on a phylogeny tree

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is Monophyletic Group/Clade?

A

a group that consists of one ancestor and all its descendants

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Phylogenies are nest hierarchy of clades. True of False?

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the steps of prating Phylogenies?

A
  1. gather data from multiple population and samples
  2. use data to construct phylogeny
  3. analyze for monophyletic groups
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the Pros & Cons of phylogenic species concept?

A

Pros:
- can be applied to asexual and extinct species
- can be used to analyze allopatric populations
Cons:
- production of phylogenies limited by samples
- different data sets may produce different phylogenies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Allopatry?

A

(occurring in different geographically areas) is an effective way to hinder gene flow between populations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Without gene flow, there is opportunity for populations to _____ and become reproductively isolated.

A

diverge

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is Allopatric Speciation?

A

speciation that occurs via geographically separation; most common mode of speciation

20
Q

What are 2 routes to allopatry?

A
  1. dispersal to a new habitat
  2. vicariance
21
Q

With dispersal, the likelihood of speciation is ______ correlated with connectively between patches

A

negatively, high connectivity = low chance of speciation

22
Q

What is Vicariance?

A

the physical splitting of a population into smaller, isolated populations by a physical barrier

23
Q

With vicariance, the likelihood of speciation is _____ correlated with the strength of the barrier.

A

positively

24
Q

What is Reproductive Isolation?

A

situation that occurs when a species is reproductively independent from other species

25
Q

What causes reproductive isolation?

A
  • behavior
  • location
  • reproductive barriers
26
Q

Isolating mechanisms can be _______ (before zygote formation) or ________ (after zygote formation)

A

prezygotic, postzygotic

27
Q

What are the types of mechanism that prevent the formation of a zygote?

A
  1. temporal
  2. habitat
  3. behavioral
  4. mechanical
  5. gametic
28
Q

What is Temporal Isolation?

A

differences in breeding schedules that can act as a form of pre zygotic barrier leading to reproductive isolation

29
Q

What is Habitat Isolation?

A

reproductive isolation resulting when species’ populations move or are moved to a new habitat, taking up residence in a place that no longer overlaps with the same species’ other populations; may never come into contact during mating periods = no hybridization

30
Q

What is Behavioral Isolation?

A

type of reproductive isolation that occurs when a specific behavior or lack of one prevents reproduction from taking place (e.g. sound frequencies in mating calls are unattractive)

31
Q

Does behavioral isolation extend to plants?

A

Yes, pollinators may favor different floral shapes or food (nectar)

32
Q

What is Mechanical Isolation?

A

differences in size and shape of reproductive organs, making mating impossible (e.g. genital lock & key)

33
Q

What is Gametic Isolation?

A

prezygotic barrier occurring when closely related individuals of different species mate, but differences in their gamete cells (eggs & sperm) prevent fertilization from happening

34
Q

What are types of mechanisms that prevent zygotes from passing on alleles?

A
  1. Hybrid Inviability
  2. Hybrid Biological Sterility
  3. Hybrid Ecological Sterility
35
Q

What is Hybrid Inviability?

A

hybrids do not survive to sexual maturity, instead they die during development or soon after birth

36
Q

What is Hybrid Biological Sterility?

A

hybrids survive to maturity but do not produce gametes or are not fertile

37
Q

What is Hybrid Ecological Sterility?

A

hybrids survive to maturity are are fertile, but have an intermediate phenotype that keeps them from reproducing (e.g. don’t attract mates or are not adapted to environment)

38
Q

How do these reproductive isolation mechanisms evolve?

A

allopatry (e.g. natural selection, genetic drift, and mutation)

39
Q

What are the 3 types of changes in hybrid zones?

A
  1. reinforcement
  2. fusion
  3. stability
40
Q

What is Reinforcement?

A

continued speciation divergence between 2 species due to low fitness of hybrids between them

41
Q

What is Fusion?

A

reproductive barriers weaken until the 2 species become 1

42
Q

What is Stability?

A

fit hybrids continue to be produced

43
Q

What is a Hybrid Zone?

A

area where 2 closely related species continue to interact and reproduce, forming hybrids; relatively stable over long periods of time

44
Q

In a Hybrid Zone, exchange of alleles is limited and parental species remain distinct. True or False?

A

True

45
Q

Since producing hybrids decreased fitness, natural selection results in _____

A

reinforcement

Ecology and Evolution Unit 1 & 2 (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions