Ch. 5 Continued

Question 1

Macroevolution

Answer 1

evolution on a large scale (evolution above the species level)

Question 2

“Why are there more beetle species on the planet than any other insect lineage?” is a macro/microevolution perspective?

Answer 2

Macroevolutionary perspective

Question 3

“How has natural selection shaped an individual beetle species?” is an example of macro/microevolutionary perspective?

Answer 3

microevolutionary

Question 4

Specitation

Answer 4

the splitting of one species into two or more

Question 5

Microevolution and macroevolution are the result of the same processes, it is the _____ that differs.

Answer 5

scale

Question 6

The same microevolutionary principles that work on a population work to promote/restrict speciation. These include:

Answer 6

• genetic drift
• mutation
• migration
• natural selection

Question 7

What is the “species problem?”

Answer 7

it is difficult to define the word “species” in a way that applies to all organims

Question 8

What are the different types of species definitions used?

Answer 8

• Typological species concept
• Ecological species concept
• Phylogenetic species concept
• Biological species concept
• Evolutionary species concept

Question 9

Typological species concept

Answer 9

a species is a group of organisms conforming to a common morphological plan with fixed properties, emphasizing that species are essentially static

Question 10

Problems with the typological species concept

Answer 10

• a species may not have many measurable traits (bacteria)
• species are not fixed!
• different phenotypes do not necessarily denote different species

Question 11

Ecological species concept

Answer 11

a species is a set of organisms adapted to a particular set of resources, called a niche

Question 12

Niche

Answer 12

the space that an organism occupies

Question 13

Phylogenetic species concept

Answer 13

a species is the smallest diagnosable cluster of individual organisms, distinct from other clusters, and where there is a parental pattern of ancestry and descent

Question 14

Biological species concept

Answer 14

groups of actually or potentially interbreeding populations, which are reproductively isolated from other groups

Question 15

Biological species concept has nothing to do with external appearance, but everything to do with ______ _______.

Answer 15

reproductive isolation

Question 16

Problems with biological species concept

Answer 16

• What about asexual species?
• fossils?
• hybridization
• reproductive isolation is usually assumed

Question 17

Evolutionary species concept

Answer 17

a species is a lineage (ancestral-descendant sequence) evolving separately from others and with its own evolutionary roles and tendencies.

Question 18

Reproductive Isolating Mechanisms

Answer 18

• barriers that prevent successful reproduction
• can be prezygotic
• can be postzygotic
• make it unlikely for hybridization to occur

Question 19

prezygotic

Answer 19

before mating

Question 20

postzygotic

Answer 20

occurring after mating

ex. mule exists but can’t reproduce

Question 21

Prezygotic barriers

Answer 21

prevent reproductive attempts between two individuals

Question 22

Examples of prezygotic barriers

Answer 22

• habitat isolation
• temporal isolation
• behavioral isolation
• mechanical isolation
• gamete isolation

Question 23

Habitat isolation

Answer 23

when two species occupy different habitats within the same geographic range; leads to resource partitioning

Question 24

Resource partitioning

Answer 24

a process where similar species exploit limited resources without overlap

Question 25

Temporal isolation

Answer 25

reproduction occurs in the same space but at a different time

Question 26

Behavioral isolation

Answer 26

mate-recognition behaviors that are accepted or ignored between species

Question 27

Gamete isolation

Answer 27

when sperm and egg are not able to fuse, a zygote cannot form

Question 28

Mechanical isolation

Answer 28

incompatible genitalia or plant strucutres

Question 29

Postzygotic barriers

Answer 29

operate after the formation of a zygote and prevent hybrid offspring form developing/reproducing - hybrid inviability - hybrid sterility

Question 30

Hybrid inviability

Answer 30

zygote is not viable and dies

Question 31

Hybrid sterility

Answer 31

hybrid zygote develops into a sterile adult

Question 32

Prezygotic isolating mechanisms

Answer 32

- habitat isolation - temporal isolation - behavioral isolation - mechanical isolation - gamte isolation

Question 33

Post zygotic isolating mechanisms

Answer 33

- zygote mortality - hybrid sterility - F2 fitness

Question 34

Speciation

Answer 34

the splitting of one species into two or more species

Question 35

There are multiple modes of speciation but ______ of some sort is a must.

Answer 35

isolation

Question 36

Isolation can be ______ or _______.

Answer 36

geographic; behavioral

Question 37

What are the modes of speciation?

Answer 37

- allopatric | - sympatric

Question 38

Allopatric speciation

Answer 38

speciation when a population becomes separated by a geographic boundary or other physical barrier; once separated, microevolutionary processes can change one population enough so that it becomes reproductively isolated form the other population

Question 39

Sympatric speciation

Answer 39

speciation in the absence of a geographic barrier | -typically a result of a divergence in diet, microhabitat, or both

Question 40

Which mode of speciation is less common?

Answer 40

sympatric because there is no physical barrier to observe

Question 41

In plants, sympatric speciation often involves _______

Answer 41

polyploidy

Question 42

Polyploid plants can reproduce with themselves but produces _____ offspring when mated to diploid individuals.

Answer 42

sterile

Question 43

What are the two types of polyploidy?

Answer 43

- autoploidy | - alloploidy

Question 44

Autoploidy

Answer 44

- occurs when a diploid plant produces diploid gametes during meiosis - diploid gamete then fuses with haploid gamete - a triploid plant is the result (sterile) - ex. banana

Question 45

Alloploidy

Answer 45

- occurs when two different plant species are able to hybridize - followed by spontaneous doubling of chromosomes - produces new hybrid species

Question 46

Adaptive radiation

Answer 46

-a type of speciation that occurs when a single ancestral species rapidly gives rise to a variety of new species, each of which is adapted to a specific environment

Question 47

Adaptive radiation is seen in what two scenarios?

Answer 47

- unoccupied ecological space | - the evolution of a novel trait confers a major/new advantage

Question 48

Ecological release

Answer 48

- landscape-level extinction leaves large areas vacant | - movement into new/unoccupied area

Question 49

How fast do new species evolve? 2 proposed mechanisms

Answer 49

- gradualism | - punctuated equilibrium

Question 50

Gradualism

Answer 50

species change gradually from an ancestral species into new species

Question 51

Punctuated Equilibrium

Answer 51

periods of stasis are punctuated by speciation