Studied by 1 personwhat 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 ?
Descent with modification
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?
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?
Heterozygote advantage
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
Note
Flashcard