Lecture 1-3

Question 1

tree of life

Answer 1

family tree of organisms that describes the genealogical relationships among species with a single ancestral species at its base

Question 2

theory of evolution by natural selection

Answer 2

all species come from preexisting species and all species, past and present, trace their ancestry back to a single common ancestor

Question 3

Phylogeny

Answer 3

actual genealogical relationships among all organisms

Question 4

speciation

Answer 4

a divergence process in which natural selection has caused populations of one species to diverge to form new species

Question 5

Taxonomy

phylum

Answer 5

the effor to name and classify organisms
major lineage within a domain
phylum > class > order > family > genus > species

Question 6

genus

species

Answer 6

made up of a closely related group of species

made up of individuals that regularly breed together or have characteristics that are distinct from those of other species

*(genus names are capitalized, but species names are not)

Question 7

fossils

Answer 7

traces of organisms that lived in the past

Question 8

fossils/sedimentary rocks/ geologic time

Answer 8

most fossils are found in sedimentary rocks, which form from layers of sand or mud, and each layer is associated with a different interval in geologic time

Question 9

Homology

Answer 9

a similarity that exists in species descended from a common ancestor
recognized at three interacting levels: genetic, developmental, structural

Question 10

evidence for evolution by natural selection

Answer 10

fossil record
homologies
fossil series- transitional forms
vestigial traits
bacteria/insects/plants

Question 11

Law of succession

Answer 11

animals living in certain areas looked a lot like the fossils found in the same areas

if traits observed in more recent species evolved from traits in more ancient species, then intermediate forms are expected to occur

Question 12

vestigial traits

Answer 12

reduced or incompletely developed structure in an organism that has no function or reduced function, but it clearly similar to functioning organs or structures in closely related species

Question 13

resistance to antibiotics: M. tuberculosis

Answer 13

the bacterium M. tuberculosis causes tuberculosis (TB), in late 1980s TB surges to to evolution of drug–resistant strains. DNA from rifampin-resistant bacteria was found to have a single point mutation in a gene called rpoB. Rifampin works by interfering with transcription, but the mutation prevents rifampin from binding. During antibiotic therapy, “normal” cells grow more slowly or die, while those with the mutation proliferate

Question 14

Testing Darwin’s Postulates (TB)

Answer 14

variation existed in the population
the variation was heritable
there was variation in reproductive success
selection occurred

Question 15

polygenic (characteristics)

Answer 15

many genes each exert a relatively small effect

Question 16

gene
locus
allele

Answer 16

a section of DNA that encodes information for a protein

the physical placement of that gene on a chromosome

one of the forms of that gene

Question 17

dominant allele

recessive allele

co-dominant

heterozygote

homozygote

Answer 17

determines phenotype of heterozygote

phenotypic effect only seen in homozygote

heterozygotes exhibit both traits seen in either homozygote

having two different alleles of a certain gene

having two identical alleles of a certain gene

Question 18

Natural selection

Answer 18

increase in traits that enhance reproduction from one generation to the next.
if a phenotype is successful, all alleles in the individual will be selected
differential reproduction of different genotypes in a population
it does not deal principally with survival but rather with reproduction

Question 19

adaptation

Answer 19

trait that increases the fitness of an individual in a particular environment. As a result of natural selection, populations adapt over time as an adaptation (the trait) becomes more and more common
it is not progressive/goal directed
it is not a random process

Question 20

importance of genetic variation

Answer 20

without heritable genetic variation there is no natural selection
neutral genetic variation: majority of genetic material is non-coding and also heritable. Natural selection does not act on non-coding DNA!

Question 21

microevolution

macroevolution

Answer 21

evolution on a small scall- within a single population or species

evolution of groups larger than an individual species

Question 22

monomorphic

polymorphic

Answer 22

both copies of the allele are the same in all individuals in the population –no variation at that locus

two or more different alleles are present at that locus within the population

Question 23

Gene frequencies within a population change over time due to (4)

Answer 23

mutation: a change in the genetic material of an organism

genetic drift: a change in allele frequencies due to random events

gene flow: the movement of alleles between populations

natural selection : process by which individuals with certain heritable traits produce more offspring, leading to a change in genetic makeup of a population

Question 24

Hardy-Weinberg Principle

Answer 24

p^2 + 2pq + q^2 = 1

Question 25

Four mechanisms that shift allele frequencies in populations

Answer 25

Natural Selection: increases the frequency of those alleles that contribute to reproductive success in a particular environment Gene flow: occurs when individuals leave one population, join another, and breed Mutation: modifies allele frequencies by continually introducing new alleles Genetic drift: causes allele frequencies to change randomly

Question 26

Each of the four evolutionary mechanisms has different consequences

Answer 26

Natural selection: produces adaptation Genetic drift: causes random fluctuations in allele frequencies Gene flow: equalizes allele frequencies between populations Mutation: introduces new alleles

Question 27

Info on Hardy-Weinberg Principle

Answer 27

acts as a null hypothesis when researchers want to test whether evolution is occurring at a particular gene for a population to conform to the principle, none of the four mechanisms of evolution can be acting on the population and mating must be random

Question 28

Are there only 2 alleles in every system? (Hardy weinberg pq)

Answer 28

any diploid individual can only have a combination of two of the alleles most genes have more than two alleles in the population

Question 29

Natural selection occurs in a wide variety of patterns

Answer 29

1. directional selection 2. stabilizing selection 3. Disruptive selection *populations are usually not at HW equilibrium