chapter 24 Flashcards


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1

Define speciation

Process by which one species splits into 2 or more species

2

ecological species concept

views a species based on its ecological niche

3

biological species concept and its limit

Defines a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring – but do not produce viable, fertile offspring with members of other such groups
limits include the grolar bears species can mate? but are still different

4

morphological species concept

characterization f a species based on bod type

5

phylogenetic species concept

smallest group of individuals that share a common ancestor

6

List the three steps of speciation

Isolation of the gene pools of 2 or more populations of a species
Evolutionary change in the gene pools of 1 or both of the isolated populations
Reproductive isolation of 2 or more populations preventing gene flow

7

Distinguish between prezygotic and postzygotic isolating mechanisms.

Prezygotic (pre-fertilization) Barrier
Preventing an attempted mating
Or, fertilization is prevented if mating is attempted
Postzygotic (post-fertilization) Barrier
Mating does occur but offspring either do not survive or are sterile

8

Describe 5 prezygotic barriers and give an example for each.

Habitat Isolation - garter snakes one in water other on land rarely interact
temporal- mating times eastern and western spotted skunks
behavioral - boobie dance
mechanical- snail spiral cant mate...
gametic - sea urchins varying gametes making diffrent fusion hard

9

Explain and give examples of reduced hybrid viability, fertility, and hybrid breakdown

hybrids are frail slamanders
hybrids are sterile donkeys
hybrids can mate second gen but the third are crap

10

Distinguish between allopatric and sympatric speciation.examples

In allopatric speciation, a population is physically isolated into subpopulations – habitat isolation. mosquito fish for example
Polyploidy
Autopolyploidy
Allopolyploidy
Habitat Differentiation
Sexual Selection

11

Explain how polyploidy can cause reproductive isolation

polyploudy individuals can not produce offspring because of problems in meiosis

12

Distinguish between an autopolyploid and an allopolyploid species and describe examples.

An autopolyploid individual is one that has more than 2 chromosome sets that are all from a single species.
alloploid has the correct number of chromosomes

13

Describe how cichlid fishes may have speciated in sympatry in Lake Victoria.

breeding color was a major barrier that effected breeding patterns so two distinct species evoloved in one lake

14

Explain how North American apple maggot flies exemplify sympatric speciation

they mate with like organsims mostly

15

Explain the gradualism model and the punctuated equilibrium model

Punctuated equilibrium statis followed by rapid change
while gradualism is slow changes

16

Give examples that illustrate the amount of genetic change necessary to give rise to a new species.

japanese land snail only needed one gene to change
or dune sunflower only needed a hybrid change

17

macroevelotion

large scale changes creating new species