Exam #3 - Speciation Vocab

Question 1

Speciation

Answer 1

A splitting event that results from a two-step process:
1. Genetic Isolation: occurs when some sort of barrier to gene flow isolates two populations within a species
2. Genetic divergence: occurs when mutation, natural selection, and genetic drift occur in each of the isolated population - meaning populations begin to evolve independently of each other

Question 2

Species

Answer 2

An evolutionary independent population or group of populations

Question 3

Identifying Species

Answer 3

1.Biological Species Concept
2. Morphospecies Concept
3. Phylogenetic Species Concept

Question 4

Biological Species Concept

Answer 4

Populations that interbreed and produce fertile offspring
-Testable
- Intuitive
- Does not apply to asexual species
- Does not apply to fossils

Question 5

Morphological Species Concept

Answer 5

Groups of morphologically similar individuals (look the same)
- We can look at fossils & asexual organisms
- Quick & easy
- Homoplasy
- It is subjective
- How different is different enough?

Question 6

Phylogenetic Species Concept

Answer 6

(Monophyletic) Smallest group that forms a phylogenetic tip
- Can use a lot of date
- More inclusive of data
- Objective
- Lots of data needed

Question 7

Prezygotic Isolation

Answer 7

“Before-zygote”; prevents individuals of different species from mating successfully

Question 8

Postzygotic Isolation

Answer 8

In which the hybrid offspring of matings between members of different species either do not survive or do not reproduce

Question 9

Cryptic Species

Answer 9

Differ in traits other than morphology

Question 10

Monophyletic Groups

Answer 10

Consists of an ancestral population, all of its descendants, and only those descendants

Question 11

Synapomorphy

Answer 11

A trait that is found in certain groups of organisms and their common ancestor but is missing in more distant ancestors

Question 12

Systematics

Answer 12

The discipline of biology that characterizes and classifies the relationships among all organisms on Earth

Question 13

Taxonomy

Answer 13

Practice of describing, naming, and classifying individual species

Question 14

Allopatry

Answer 14

The term used to describe populations that are geographically seperated

Question 15

Allopatric Speciation

Answer 15

Speciation that begins with geographic isolation
1. Dispersal: the movement of individuals from one place to another
2. Vicariance: the study of how species and populations are distributed geographically

Question 16

Biogeography

Answer 16

The study of how species and populations are distributed geographically

Question 17

Sympatry

Answer 17

When populations of how species and populations are distributed geographically

Question 18

Sympatric Speciation

Answer 18

Speciation that occurs even though populations live within the same geographical area
1. Extrinsic (external) factors, ex: disruptive selection for extreme phenotypes based on different ecological niches and/or mate preferences
2. Intrinsic (internal) factors, such as chromosomal mutations

Question 18

Niche

Answer 18

Used to describe the range of ecological resources that a species can use and the range of conditions that it can tolerate

Question 19

Polyploidy

Answer 19

The condition of possessing more than two complete sets of chromosomes

Question 19

Autopolyploid

Answer 19

Individuals produced when a mutation results in a dividing of chromosome number and the chromosomes all come from the same species

Question 20

Allopolyploid

Answer 20

When individuals are created when parents of different species mate and then an error in mitosis occurs, resulting in viable, non sterile offspring with two full sets of chromosomes