Origin of Species

Question 1

taxonomic rank + biological classifcation

Answer 1

most specific unit of taxonomic classification

a way we try to classify individuals based on a set of characteristics

Question 2

Speciation

Answer 2

the creation of new species

limited or absent GENE FLOW between populations
no movement of alleles of a gene from one population to another

Question 3

factors that may cause a population to separate / stop exchanging genes

Answer 3

geographic or physical barriers
different courtship, breeding seasons, periods of activity

Question 4

mechanisms of change (4)

Answer 4

change in gene flow (absent)
mutation
genetic drift
natural selection

change each population differently

Question 5

How does natural selection work

Answer 5

differential survival and reproduction of individuals due to difference in phenotype

already existed when they separated OR newly arose from chance mutations

**but evolution is change in genotype

Question 6

Genetic drift

Answer 6

frequency of different genes in a population can change over time, even when not under selection pressure (RANDOMLY)
likely to occur in small populations, by chance

Question 7

Morphological speciation

Answer 7

sorting species by appearance (phenotype)

oldest, and not the best way to define

Question 8

Biological species concept

Answer 8

members of populations that could interbreed and produce fertile offspring

assumes sexual reproduction, not asexual reproduction

Question 9

phylogenetic species concept

Answer 9

species that share a unique common ancestor, determined by individuals that share traits

practice phylogeny

Question 10

Allopatry

Answer 10

species in geographic isolation – no gene flow
ex: river, mountain, break up of Pangea

most common type of speciation, especially on islands

Question 11

Parapatry

Answer 11

species with ranges directly adjacent to each other, ranges overlap slightly

gene flow is reduced because new niche opens or environmental differences with a hybrid zone and very large range

Question 12

Sympatry

Answer 12

species existing in the same geographic location

ex: mutations cause reproductive isolation (change in mating patterns, chromosome duplications)

Question 13

Hybrid Speciation

Answer 13

some interbreeding can create a viable offspring which can survive and mature

rare in animals, more common in plants (propogation)

Question 14

Despeciation

Answer 14

when two species become one
from hybridization, interbreed