Lecture 9: Species, Species Concept, and Speciation

Question 1

Who collected birds in New Guinea?

Answer 1

Ernst Mayr

Question 2

How many species did Ernst Mayr recognize?

Answer 2

137

Question 3

Why are species important?

Answer 3

They are the currency with which we do our studies as biologists

Question 4

What are the two most commonly used species concepts?

Answer 4

Biological Species Concept
Phylogenetic Species Concept

Question 5

Who defined the biological species concept?

Answer 5

Ernst Mayr

Question 6

What is the biological species concept?

Answer 6

species are groups of interbreeding natural populations that are reproductively isolated from other such groups

Question 7

What are 2 cons of of the BSC?

Answer 7

1) doesn’t apply to asexual organisms and fossils

2) testable with sympatric populations, not allopatric ones

Question 8

Why is testing for reproductive isolation in lab not feasible for some species? (2 reasons)

Answer 8

1) Species might mate in lab but not in nature

2) Individuals viable in the lab may not survive in nature

Question 9

Who defined the morphological species concept?

Answer 9

Eldredge and Cracraft

Question 10

What is the morphological species concept?

Answer 10

Species are recognized by similarity in morphological characters. There are consistent differences from other species (morphological gaps), particularly in sympatry

Question 11

Which types of species can’t be told apart by morphology?

Answer 11

Sibling or cryptic species

Question 12

What is the evolutionary species concept?

Answer 12

Distinct lineages

Question 13

Who made the evolutionary species concept?

Answer 13

G. G. Simpson

Question 14

What is the recognition species concept?

Answer 14

A set of organisms that recognize each other as potential mates

Question 15

How do moths display the recognition species concept?

Answer 15

Pheromonal recognition

Question 16

What did Joel Cracraft believe?

Answer 16

Organisms are grouped because of evidence for monophyly

Question 17

What is monophyly?

Answer 17

A group of species that have a common ancestor

Question 18

What are the three steps to delimiting species common to all species concepts?

Answer 18

1) Survey morphological variation within/among populations

2) Group individuals into taxa

3) Rank taxa in taxonomic hierarchy

Question 19

What is the phylogenetic species concept?

Answer 19

A species is the smallest diagnosable cluster of individual organisms within which there is a PARENTAL pattern of ancestry and descent

Question 20

Where do BSC and PSC diverge? How?

Answer 20

When ranking taxa in taxonomic hierarchy

BSC: ranking based on reproductive compatibility

PSC: ranking based on diagnosability

Question 21

What is the taxonomic hierarchy?

Answer 21

Kingdom, Phylum, Class, Order, Family, Genus, Species

Question 22

Which species concept is pattern based?

Answer 22

PSC

Question 23

Which species concept is process based?

Answer 23

BSC

Question 24

How does grouping work for the BSC?

Answer 24

BSC groups individuals based on morphological differences into two taxa, and if they hybridize, rank as subspecies

Question 25

How does grouping work for the PSC?

Answer 25

Morphology reveals two groups with independent evolutionary histories, ranks as species whether hybridizing or not

Question 26

What is hybridization?

Answer 26

When two evolutionary species (distinct lineages) come together and interbreed

Question 27

How do you determine how long it takes for hybridization to "erase" evidence of independent evolution?

Answer 27

Cline theory

Question 28

PSC considers hybridization to be an ____ trait

Answer 28

ancestral

Question 29

What do brown towhees show the problems with?

Answer 29

The problems with BSC in allopatry

Question 30

Hybridization in allopatric populations BSC vs PSC

Answer 30

BSC: guessing if allopatric populations could hybridize led to wrong classification PSC: no guessing if allopatric populations could hybridize

Question 31

Under BSC, hybridizing groups are considered to be the ____ species

Answer 31

same species

Question 32

What is one criticism of PSC?

Answer 32

Results in too many species and every individual might end up being a species

Question 33

What is adaptive radiation?

Answer 33

a single ancestor radiated (speciated) into many current species

Question 34

What is allopatric speciation?

Answer 34

speciation by geographic isolation

Question 35

What are the two kinds of isolation in allopatric speciation?

Answer 35

Vicariance: physical barrier Peripatric (peripheral isolate): migration/dispersal

Question 36

Which of the two kinds of isolation in allopatric speciation occurs quicker?

Answer 36

Peripatric (peripheral isolate)

Question 37

What is parapatric speciation?

Answer 37

when you have a main geographic distribution with nearby habitats/niches that are different...and species go to these new niches and eventually become a distinct species

Question 38

What is sympatric speciation?

Answer 38

polymorphism (such as mutation) occurs in original population...polymorphism spreads within population and new species forms

Question 39

What is assortative mating?

Answer 39

Mating with individuals of similar characteristics

Question 40

What is the effect of assortative mating on gene flow?

Answer 40

Gene flow is reduced

Question 41

Which type of speciation happens most?

Answer 41

Allopatric speciation

Question 42

Which type(s) of speciation doesn't require a barrier?

Answer 42

Parapatric and sympatric

Question 43

What is polyploidy?

Answer 43

Instant speciation...entire genome is doubled

Question 44

What is a hybrid zone, what are the two types of hybrid zones, and when do they occur?

Answer 44

regions where genetically distinct groups of individuals meet and mate Primary hybrid zone: in parapatric speciation Secondary hybrid zone: with allopatric speciation and subsequent secondary contact

Question 45

What can hybrid zones result in? What does that concept mean?

Answer 45

Introgression, when alleles are spread from one species into another

Question 46

What are the two main reasons why monkeyflowers aren't very successful at reproduction?

Answer 46

Elevational separation Pollinator isolation

Question 47

What are the two categories of prezygotic isolating mechanisms?

Answer 47

Pre-mating and post-mating

Question 48

What are two types of pre-mating isolation?

Answer 48

Ecological isolation, meet but don't mate

Question 49

What are the two types of ecological isolation? What do they mean?

Answer 49

Temporal isolation: reproduce at different times Habitat isolation: occupy different habitats

Question 50

What are the two types of "meet but don't mate" isolation?

Answer 50

Sexual isolation: reproductively isolated Pollinator isolation: don't get pollinated by the same species

Question 51

What are the three types of post-mating isolation?

Answer 51

Mechanical isolation: genitals not compatible Copulatory isolation: issues during/after copulation Gametic isolation: gametes incompatible