Lec 11 Species and Speciation

Question 1

What is the definition of multiple species?

Answer 1

involvement of two or more species

Question 2

What are pre-zygotic barriers to reproduction?

Answer 2

prevents mating or fertilization if mating occurrs

Question 3

What are post-zygotic barriers to reproduction?

Answer 3

prevents hybrid offspring of 2 species from developing into fertile adults

Question 4

How is speciation related to evolutionary isolation?

Answer 4

Species can emerge from evolutionary isolation due to reproductive barriers or genetic interbreeding

Question 5

Define allopatric speciation

Answer 5

Prevented reproduction from geographic isolation of a previously breeding population; the populations are isolated and can no longer mate

Question 6

Define parapatric speciation

Answer 6

Geographically continuous populations occur over EXTREMELY vast distances experience divergence

Question 7

Define sympatric speciation

Answer 7

Speciation occurs among populations that live in the same geographic area

Question 8

Name the challenges of defining clearly delineated species (ex: ring species)

Answer 8

It’s a classification challenge. Continuous populations can interbreed over large geographic areas except where the populations rejoin.

Where is that point at?

Question 9

Define allopatric speciation using vicarience

Answer 9

The population is split by a geographic barrier that gradually occurs over time

Question 10

Define allopatric speciation using dispersal

Answer 10

Random movement to new areas result in such a long distance that the populations no longer mate and are no longer continuous/are fundamentally different.

Question 11

Differentiate allopatric speciation using vicarience and dispersal

Answer 11

Vicarience separates the populations gradually over time

Dispersal events happen suddenly

Question 12

Define morphological species concept:

Answer 12

organisms from the same species share the longest possible evolutionary history and are on the same path.

share similar phenotypic characteristics

Question 13

Define genetic species concept:

Answer 13

organisms from the same species share similar DNA than those of different species due to a long shared evolutionary history

share similar molecular characteristics (share DNA in reproduction)

Question 14

Define biological species concept:

Answer 14

species from groups of organisms interbreed and produce offspring that are reproductively isolated from other species

test of genetic information and same evolutionary path

Question 15

What similarity is found between the biological, morphological, and genetic species concept?

Answer 15

members of the same species are linked by shared ancestral history by exchanging genetic information

Question 16

How are phylogenies related to the hypothesis of species divergence?

Answer 16

We can construct a phylogeny to observe how close or related species are from their ancestors dependent on the amount of time that has passed

Question 17

define adaptive radiation

Answer 17

Periods of evolutionary change where organisms form a variety of new species with adaptations accustomed to certain niches

Question 18

define competitive exclusion

Answer 18

Two species can never be perfectly and equally successful at utilizing a resource so the more successful competitor excludes the second from its niche

Question 19

define niches

Answer 19

Specific biotic and abiotic resources used by a species

Question 20

How does speciation conclude species concept testing?

Answer 20

Theoretical predictions based on evolution and biodiversity are concluded when phylogenetic trees, mtDNA testing or (biological) species concept(s) provide needed evidence

Question 21

What limitations are present in the biological species concept?

Answer 21

hybrids (2 species mate), extinct organisms, and asexually reproducing organisms

Question 22

What limitations are present in the morphological species concept?

Answer 22

tremendous variation within species and don’t understand what variation could be relevant

Question 23

What limitations are present in the genetic species concept?

Answer 23

tremendous variation within species and don’t understand what variation could be relevant

Question 24

define speciation

Answer 24

process where populations attain reproductive isolation

Question 25

define reproduction isolation

Answer 25

biological barriers that impede members or different species from interbreeding to produce viable offspring

Question 26

What is mechanical isolation?

Answer 26

morphological differences (often genital) causes mating incompatibility

Question 27

What is an example of mechanical isolation?

Answer 27

variation in duck penis and vaginal tract morphology complicated genitals decrease likelihood of mating

Question 28

Is mechanical isolation a pre-zygotic or post-zygotic barrier?

Answer 28

Pre-zyogtic barrier. If mating cannot occur, fertilization does not occur

Question 29

What is behavioral isolation?

Answer 29

Behavioral differences prevent mating through incorrect courtship displays or the opposite sex cannot recognize mating signals

Question 30

What is reduced viability?

Answer 30

Hybrids fail to develop or are unlikely to survive Barrier to exchange to genetic material

Question 31

Why is reduced hybrid viability a genetic barrier?

Answer 31

The hybrid is so unhealthy compared to it's non-hybrid peers

Question 32

Is reduced hybrid viability a pre or post-zygotic barrier?

Answer 32

Post-zygotic barrier

Question 33

Why is reduced hybrid viability a post-zygotic barrier?

Answer 33

Fertilization has already occurred.

Question 34

What is hybrid sterility?

Answer 34

Hybrid offspring are perfectly healthy but are fully or partially sterile

Question 35

Is behavioral isolation/mate recognition a pre- or post- zygotic barrier?

Answer 35

Pre-zygotic

Question 36

What is temporal isolation?

Answer 36

When different species are reproductively available at different times (days, seasons, or years)

Question 37

What does allopatric mean?

Answer 37

Allo= other Patric = homeland

Question 38

Is temporal isolation a pre-zygotic barrier or post-zygotic barrier?

Answer 38

Pre-zygotic

Question 39

When does allopatric speciation occur?

Answer 39

The populations accumulate so many genetic differences that they couldn't mate, even if the barrier moved

Question 40

What is an example of allopatric vicarience?

Answer 40

Squirrels and chipmunks split over time by grooves in Grand Canyon, they attain mutation separately. Now we have two different breeds of chipmunks in the North and South.

Question 41

What is an example of allopatric dispersal?

Answer 41

A group of iguanas live in the Galapagos island. A storm blew them from one side of the island to another. Furthermore, they made it there from sheer randomness. Over time, they reproduce with another species and create a totally different species. Populations 1 and 2 are fundamentally different as time has passed between the two.

Question 42

What does parapatric mean?

Answer 42

Para=through Patric=homeland

Question 43

When does parapatric speciation occur?

Answer 43

Individuals at either end of distribution are functionally isolated from one another. Thus, they experience distinct selective pressures based on environment.

Question 44

What does parapatric speciation result in?

Answer 44

The divergence of the species populations range on extreme ends.

Question 45

When does adaptive radiation occur?

Answer 45

after mass extinctions or when new areas become colonized

Question 46

What happens to the inferior species among competitive exclusion?

Answer 46

They go locally extinct or utilize different resources

Question 47

Define crypsis

Answer 47

Camouflage

Question 48

Define mimicry

Answer 48

uniform color similar to another species

Question 49

Define ring species

Answer 49

continuous populations that span over large geographic areas to form a ring where they interbreed except where they rejoin

Question 50

What is the classification challenge for ring species?

Answer 50

There is no clear distinction between where one species starts and another species starts; we can only acknowledge they exist in a continuum of differentiation

Question 51

What is sympatric speciation a combination of?

Answer 51

Sexual selection and environmental pressures

Question 52

Define punctuation equilibrium for speciation:

Answer 52

rapid bursts of speciation followed by little change

Question 53

Define the gradual model for speciation:

Answer 53

species steadily diverge over time which leads to substantial differences in model period

Question 54

Define Adaptive Radiation

Answer 54

common ancestoral population that has massive bursts of diversification to result in new species with specialization to niches

Question 55

Define Niche:

Answer 55

full suite of living or non-living resources required by organism for survival and reproduction

Question 56

When does Adaptive radiations occur?

Answer 56

After mass extinctions or when new areas are colonized

Question 57

Why don't Adaptive Radiations result in multiple species who are identical in resource usage (niche)?

Answer 57

Species compete with one another

Question 58

Define competitive exclusion:

Answer 58

2 species will never be perfectly equally successful at utilizing a resource

Question 59

Define resource partitioning:

Answer 59

Similar species coexist in an area if they use different sets of similar resources or same resource at different times