speciation

Question 1

What is a species?

Answer 1

A species is a group of individuals that share a common gene pool and are reproductively isolated from other species.

Question 2

How does speciation occur?

Answer 2

when there is no gene flow, this causes populations to become reproductively isolated from other and ancestral populations.

Question 3

Deme

Answer 3

a local population that has limited gene flow with members of the larger population

Question 4

cline

Answer 4

a pattern of variation between individuals of a species; there is a continuous increase or decease in some phenotypes between adjacent populations.

Question 5

How are deme and cline different?

Answer 5

while a deme is a population with a certain circumstance, a cline is a pattern/trend of varying phenotypes seen in populations.

Question 6

What is a gene pool?

Answer 6

the total number of alleles in a population. (or species)

Question 7

What is an indication of evolution in a gene pool?

Answer 7

any changes in the allel frequency of the gene pool.

Question 8

What are all the processes that contribute to changes in allele frequency in the gene pool and evolution?

Answer 8

mutations, natural selection, and gene flow.

Question 9

What is speciation?

Answer 9

the formation of new species as a result of reproductive isolation

Question 10

What is homologous structure?

Answer 10

similar organs or skeletal elements that suggest a common ancestor; evidence for divergent evolution.

Question 11

What is analogous structure?

Answer 11

individuals/populations with similar biological structures that don’t come from a common ancestor; evidence of convergent evolution.

Question 12

What is all the evidence used for scientific evolution?

Answer 12

fossil evidence, comparative anatomy (homologous or analogous), molecular biology (DNA and proteins), and biogeography.

Question 13

Explain fossils

Answer 13

Fossils are preserved remains or impressions by organisms that lived in the past and are found in sedimentary rocks. It provides evidence for speciation, extinction, gradualism, punctuated equalibrium, divergence and adaptive radiation.

Question 14

What is punctuated equilibrium?

Answer 14

sudden, rapid bursts of a change of form/structure over time

Question 15

What is looked at in comparative anatomy?

Answer 15

the comparison of body structures between different species, looking at fossil records and living individuals.

Question 16

What part of molecular biology is used in evolutionary studies?

Answer 16

Molecular biology refers to the large organic molecules all organisms are made up of; the most important molecules for evolutionary studies is DNA and proteins.

Question 17

What part of an organism is able to provide significant evidence for evolutionary relationships?

Answer 17

Genome/DNA/protein analysis; genome is the complete set of DNA in an organism, including all genes. this analysis from both fossils and living is able to provide significant evidence for evolutionary relationships!

Question 18

What indicates two species have a recent common ancestor?

Answer 18

the more similar DNA proteins are between different species, the more closely related they are and the more recently they shared a common ancestor.

Question 19

what is the only way mtDNA can change?

Answer 19

mtDNA is mitochondrial DNA that is inherited from the egg only. it is not able to be subject to natrual selection or independent assortment, thus the ONLY way it can change is through random mutations in the DNA.

Question 20

What is a molecular clock?

Answer 20

The rate at which mutations occur in the mtDNA, and used to determine the approximate time of divergence between species.

Question 21

What is a phylogenetic tree?

Answer 21

diagrams that show the evolutionary relationships between groups; shows divergent evolution from a common ancestor.

Question 22

Explain how a phylogenetic tree is constructed.

Answer 22

Taxa are classification groups. From left to right is the flow of time (continual timeline). Each point at which two new species occur called a Node. These nodes indicate a common ancestor for the taxa evolved from that point.

Question 23

What is biogeography?

Answer 23

refers to the evidence from geographical distributions of species. Origins and dispersal of modern life is explained through drifting tectonic plates.

Question 24

What is Gondwana?

Answer 24

Gondwana was the southern supercontinent that, from 180-150 mya, began splitting.

Question 25

How does Gondwana relate to gene flow?

Answer 25

Once the supercontinent split apart into separate land masses, seas and oceans became a physicals barrier stopping gene flow. these populations became isolated from the ancestral species and started to evolve in isolation.

Question 26

What is Gondwana distribution?

Answer 26

the indication that organisms evolved in isolation when populations were separated by the drifting apart of three continents.

Question 27

Why do Gondwana distribution species an example of vicariance?

Answer 27

Gondwana distribution species show vicariance as they are geographically split by a physical barrier over a geographical range.

Question 28

What is natural selection and what does it work on?

Answer 28

natural selection is the process in which inheritable traits that make an individual more likely to survive longer and reproduce, become more common in the gene pool over successive generations. Natural selection works on phenotypes.

Question 29

what is fitness

Answer 29

a measure of reproductive success