Biology test 1

what happened in 1859?

Darwin publishes Origin of the Species

Darwin say the orgin and diversity of life explainable by

gradual , heritable changes over time through Evolution by Natural selection

\______ biological disciplines today are only fully understood through a lens of \____ \____ \_____

all; evolution by natural selection

at 16 yrs old Charles Darwin was renowned for

beetle collection

Darwin first studied \______ (unsuccessfully )and \_______ at \____ \_____

medicine ; theology ; Cambridge university

what did Darwin do after graduating ?

unpaid naturalist ; 5 year voyage on the HMS Beagle

What was the mission of the HMS Beagle ?

chart coastlines for safe harbors , gather geological and biological specimens

What did 2 things did Darwin encounter on the voyage?

geological processes and unfamiliar juxtaposition of fossils

What are examples of geological processes that can lead to great change?

* an earthquake that raised the seabed
* -volcanoes and glaciers

What are examples of unfamiliar juxtaposition of fossils ?

-sea shell fossils in high mountain cliffs

What animals did Darwin see ?

\-finches with different beaks and diets

\-different mockingbirds on each island

\-giant tortoises with different shells

Darwin perceived \_____ to the environment and the origin of new species as closely related processes

adaptation

t or f darwin in 1844 introduced his theory of natural selection to the general public

f; he didn't submit his essay at first

Who sent Darwin an essay that supported Darwin's thought?

Alfred Russel Wallace

What did Darwin do when he received that essay?

quickly finished his first public text the Origin of Species and published it

What are the two main ideas of Darwin's theory ?

1. Descent with modification
2. Natural selection

What is the Darwinian view?

the history of life is like a tree with branches representing life's diversity

What are Darwin's first observation?

1. For any given trait there is variation within a population

What is Darwin's 2nd observation?

All species are capable of producing more offspring than the environment can support and many of these offspring do not survive

What is Darwins first inference?

Individuals whose inherited traits give them a higher probability of surviving and reproducing in a given environment tend to leave more offspring than other individuals

What is Darwin's 2nd inference?

this unequal ability of individuals to survive and reproduce will lead to the accumulation of favorable traits in the population over generations

\__________ do not evolve;\___________ evolve over time

individuals; populations

natural selection acts through

individual reproduction

Natural selection can only \________, \________ or \________ heritable traits that are \_________ \______ in a population

increase, decrease, modify ; already present

T or F; adaptation will vary with different environments

t

What is the first evidence to support natural selection ?

fossils ( trilobite)

what's the 2nd evidence to support natural selection ?

homologies -(similaries in common ancestors) tetrapod limbs

what is the 3rd piece of evidence to support natural selection ?

direct observation ; dogs (artificial selection)

What is the naming and classification of species and groups of species

taxonomy

The scientific discipline of classifying organisms based on their evolutionary relationships . . . .

systematics

Who came up with the naming system?

Carl Von Linnaeus

What is the nested hierarchy order?

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

(dear king Philip calls out for good soup)

What are the 3 domains?

Bacteria, Archaea, Eukarya

What is modern systematics?

using DNA to determine relatedness and establish a family tree

what is another name for modern systematics?

phylogeny (shared evolutionary traits)

\__________- is a change in the allele frequencies of a population over time

microevolution

\______________- changes higher than the population level

macroevolution

\____________ is something different although micro evolution may lead to it

speciation

what must there be in a population for it to evolve?

variation among individuals

Where does variation within a population come from?

changes in phenotype come from change in genotypes

What is the first cause for changes in genotypes?

mutation (a change in DNA)

what is the second reason for changes in genotypes ?

sexual reproduction's (crossing over and independent assortment )

What do asexual organisms depend on?

mutation for variation

Sexual reproduction can \______ existing alleles into \_____ \____________

shuffle; new combinations

T or F for organisms that reproduce sexually mutation is more important that the recombination of alleles

F; recombination is more important

T or F new combinations are important in a changing environment

T

What is the first agent of evolutionary change?

mutation

what is the second agent of evolutionary change?

natural selection

what is the 3rd agent of evolutionary change

genetic drift

what is the 4th agent of evolution change ?

gene flow

Mutation is considered to be an

evolutionary force

Mutations are changes in

the nucleotide sequence of DNA

Mutations cause

new genes and alleles to arise

To be passed off to the offspring . . .

only mutations in cells that produce gametes

T or F traits that increase the likelihood of survival become less common in the population over time

F; more common

What is the only adaptive agent of evolutionary change?

natural selection

What is the first mode of natural selection ?

directional

what is the second mode of natural selection ?

stabilizing

what is the 3rd mode of natural selection ?

disruptive

what is the most influential mechanism of evolution

natural selection

What is directional selection?

favors individuals at one end of the phenotypic range ( goes in one direction)

What is stabilizing selection?

favors intermediate variants and acts against extreme phenotypes(to be in the middle)

what is disruptive selection?

favors individuals at both extremes of the phenotypic range(one side or the other NO MIDDLE)

\___________ \____________ acts on existing variation to change frequency of different phentypes

selective pressure

Intermediate forms are favored in

stabilizing selection

ex of directional selection

peppered moths

ex of stabilizing selection

human birth weights

When extremes are favored over intermediate forms that is

disruptive selection

ex of disruptive selection

Galapagos finches

What is a special form of natural selection ?

sexual selection

T or F selective pressure is the ability to survive and reproduce not attract mates

FALSE; ability to attract mates

What can explain costly& showy structure and behaviors?

sexual selection

What is are the 2 subcategories of sexual selection ?

Intrasexual and intersexual

What is intrasexual selection?

competition among individuals of one sex (often males) for mates of the opposite sex

ex. of intrasexual selection

stag beetles

what is intersexual selection ?

mate choice

ex of intersexual selection?

bower bird

What is balancing selection?

when natural selection maintains two or more forms in a population

What are two types of balancing selection?

1. Heterozygote advantage
2. Frequency-dependent selection

What is heterozygote advantage?

neither allele becomes predominant when the heterozygotes are favored

example of an autosomal recessive disorder

sickle cell anemia

What is genetic drift?

random changes in allele frequency over time

T or F genetic drift is not driven by any selective pressure

T

Genetic drift can be . . . .

beneficial , neutral or detrimental but tends to reduce genetic variation through losses of alleles

Genetic drift has a \________ effect in \________ populations

greater; small

What are the two types of genetic drift?

bottleneck effect and founder effect

What is the bottle neck effect?

a drastic reduction in population size brought about by severe pressure

What happens after a bottleneck?

genetic drift is pronounced when a few individuals rebuild a population

ex of bottlenecked species

cheetah

what is the founder effect?

genetic drift is pronounced when a few individuals start a new population

Breeding or mating between close relatives who share a large number of alleles is called

inbreeding

ex of inbreeding

ellis-can creveld syndrome (amish ?)

Gene flow consists of the

movements of alleles among populations

How can alleles be transferred?

through the movement of fertile individuals or gametes (pollen)

gene flow tends to \_________ difference between populations over time

reduce

ex of founder effect

when individuals leave to start their own colony

what is the biological species concept

\-reproductive compatibility

\-a group of population whose members have the potential to interbreed in nature and produce viable fertile offspring

problems with the biological species concept

asexual organisms and fossils

What does speciation need to have ?

reproductive isolation

what are to causes of reproductive isolation?

pre-zygotic barriers and post-zygotic barriers