AP Bio Natural Selection (Unit 7)

Evolution is .. … … over time

change in population

The driving force of evolution is called … …. – which operates on the level of the individual

natural selection

Darwin developed his history-changing work by observing animals especially in the … …

Galapagos Islands

Darwin noted that animals probably .. … … across generations to adjust to environment

change their

Since certain traits are better qualified for reproducing, more organisms with the beneficial traits make offspring – making them reproduce more and more until it becomes .. …

the norm

Survival of the fittest – only the organisms most … .. .. will survive and reproduce

fit to survive

Nature “…” which living things survive and reproduce

selects

Evidence supports the theory that all living organisms … a … …

share a common ancestor

Paleontology is the study of …..

fossils

Paleontology revealed to us the … … of organisms

great variety

Paleontology also revealed the major … of ….

lines of evolution

Biogeography is the study of ….. of .. and …

distribution of plants and animals

Scientists found relates species in … … regions of the world

widely separated

Embryology is the study of the … of an ….

development of an organism

Embryology shows that all embryos … …

look alike

Morphological homologies is the study of …. of … ….

anatomy of various animals

Through morphological homologies, scientists have discovered that some animal have … … that serve different functions

similar structures

Similar structures with different functions are called … …

homologous structures

Homologous structures point toward a … …

common ancestor

Structures that look different but with the same function are called .. ….

analogous structures

Through molecular biology, we can find …. in … … between organisms

similarities in genetic code

Some scientists use charts called …. to study relationships between organisms

clado

Cladograms are built using data from …. … or … ….

molecular records or fossil records

Cladograms always begin with the .. … and branch out

common ancestor

Forks in the road indicate a … …. …

At a common ancestor nodes, this is when evolution went in … … …

Comparing the similarities between a organism and another one farther down cladogram or closer, …. one shares more traits with it

farther

The species closest to the common ancestor is the …. – because it is the least related to the other species

out-group

Shared traits indicate … …

common ancestry

Differences in each person are known as … … – NO TWO INDIVIDUALS IN POPULATION have identical … … …. …

genetic variability, two sets of alleles

If all of a population was genetically the same, they would have the same … and same …

weaknesses and strengths

Natural selection only occurs when some individuals have more … and can be ….

fitness, selected

Mutations create new …. and …

variations and alleles

Genetic variation is also caused by …. …

sexual production

Genetic variation is the very foundation of …..

evolution

Natural selection functions … and …

internally and externally

Internally, natural selection works through … …

random mutations

EXTERNALLY, natural selection works through … ….

environmental pressures

Natural selection requires genetic variation and an … …. that gives some individuals an advantage

environmental pressure

When mutations occur out of chance and not due to environmental pressures: … …

random mutation

An adaptation is a … …… by natural selection

variation favored

Any traits that help the individual REPRODUCE and SURVIVE better is something that gives the individual … ….

evolutionary fitness

Traits that don’t help an individual survive specifically, but does help them sexually reproduce

Two popilations in different popula

If populations grow apart to the point they can’t reproduce with each other anymore, we would say these are … … …

two different species

Catastrophic events can … … natural selection and adaptation

speed up

Something causing a change in … of …. (NOT NATURAL SELECTION)

genetics of population

When (usually a catastrophic event( happens, only a FEW INDIVIDUALS are left in a population to mate and regrow – known as …. …

bottleneck effect

When different populations of same species interact, …. … will change

genetic diversity

Change in genetic diversity after different populations of same species interacting is known as … …..

gene flow

When one phenotype is favored at one of the extremes of the normal distribution – this is called …. … (black moths in coal polluted area)

directional selection

Directional selection “… …” one of phenotypes

weeds out

…. …. means that organisms with EXTREME traits are eliminated (favors average, medium traits)

Stabilizing selection

… …. means organisms with extreme traits (on both ends)

Disruptive selection

… … is when humans directly affect variation in other species

artificial selection

Different ….. and different …. … could cause things of the same species to change in different ways and not be able to …

variation and environmental pressures, mate

Two populations of animals once in the same species being changed and no longer able to mate is called…..

divergent evolution

Divergent evolution occurring quickly after only a little evolution is called … …. (often due to a major event)

Punctuated equilibrium

A change in evolution occurring after many small changes is called…

gradualism

Evolution form when species rapidly DIVERSIFIES due to an abundance of ecological niches – this is called …. …

adaptive radiation

…-…. … prevent fertilization (ex. when two species reproduce at different times of the year)

pre-zygotic barrier

….-… …. is related to an inability for hybrid organism to produce offspring, they are STERILE (horse+donkey=mule, but mule is sterile)

post-zygotic barrier

Convergent evolution is the process when two UNRELATED species come together to have similar (ANALOGOUS) traits – because they face …. …. ….

face similar pressures

Speciation is the … of … … following evolution

formation of new species

Allopatric speciation is when there is a …. … so two populations of same species cannot interbreed anymore (ex. mountain)

geographic barrier

When new species is formed without any geographic barrier – … …

sympatric speciation

Plants often undergo speciation due to …, when they get DOUBLES of chromosomes

polypoidy

Hardy-Weinberg is a model for predicting … …. in a nonevolving population

allele frequencies

… … of … will always stay the same in a population

Relative frequencies of genotypes

The rate of extinction usually accelerates during … …

ecological stress

A population with high … …. is more protected from extinction events

genetic diversity

This theory says original-life forms were simply molecules of RNA

RNA-world hypothesis