Evolution test

violent, very hot

early Earth’s atmosphere

H, CO, N

what gases made up early Earth’s atmosphere?

rain got zapped by lightning, forming organic compounds

how did life form?

they passed water vapor and an electric current through a closed system with a mixture of gases, which produced 21 different amino acids

What happened in the Miller-Urey experiments?

protocells

membrane-like vesicles assembled from fatty acids

RNA; self-replicating

first genetic material and why

anaerobic

the first prokaryotes were __________

cyanobacteria

photosynthetic bacteria

photosynthetic bacteria increased the amount of O2 in the atmosphere, which allowed aerobic prokaryotes to evolve

how did aerobic prokaryotes evolve?

1.5 BYA

when did eukaryotes evolve?

endosymbiosis

a relationship in which one organism lives inside the body of another, and both benefit

aerobic, single-celled

first eukaryotes were __________ (aerobic/anaerobic) and ____________ (single-celled/multicellular)

mitochondria and chloroplasts

2 organelles that support the endosymbiotic theory

energy; a stable environment

what did the smaller prokaryote provide for the larger one in endosymbiosis, and vice versa?

• own DNA/ribosomes

• self-copying

• same size as prokaryotes

• similarly structured DNA to prokaryotes

Evidence of mitochondria and chloroplasts supporting the endosymbiotic theory

genetic variation

major advantage of sexual reproduction

increased rate of evolution because of genetic variation

What did sexual reproduction do for the rate of evolution and why?

Paleozolic Era

Age of fishes

Mesozoic Era

age of reptiles

Cenozoic Era

age of mammals

evolution

the process of biological change by which descendants came to differ from their ancestors

Carolus Linnaeus

Who was the “father of taxonomy” who proposed a new classification system for organisms based on structural similarities?

Georges Louis Leclerc Buffon

Who proposed that species share ancestors instead of arising separately?

Erasmus Darwin (Darwin’s grandpa)

Who proposed that all living things descended from one common ancestor?

Jean-Baptiste Lamarck

Who suggested that individual living things evolve to suit their environment and that those acquired traits are passed on to offspring? (Ex. if I work out a lot my child will be buff from birth)

catastrophism (Georges Cuvier)

theory that organisms go extinct after disasters such as volcanic eruptions and earthquakes (and the scientist that proposed it)

gradualism (James Hutton)

theory that changes on Earth occurred as a series of small steps (ex. canyons carved by rivers), (and the scientist that proposed it)

uniformitarianism (Charles Lyell)

theory that processes that shape Earth are uniform through time (and the scientist that proposed it)

he knew why it happened the way it did

Why did Darwin’s ideas about evolution persist when others’ didn’t?

HMS Beagle

Darwin’s ship

adaptation

a physical characteristic that makes an animal more suited for survival

type of food they ate

Galapagos finches diversified based on….

macroevolution

type of evolution that involves extinction and speciation

microevolution

type of evolution that involves adaptation (measured by the change in allele frequency)

species

2 similar organisms who can produce fertile offspring

artificial selection

humans determine which traits are favorable and breed individuals with those traits

heritability

the ability of a trait to be passed on from 1 generation to another

natural selection

organisms with better adaptations can survive better and reproduce (survival of the fittest)

descent with modification

favorable traits are passed on (principle of natural selection)

phenotype

is selection based on phenotype or genotype?

variation

traits vary within a population (principle of natural selection)

overproduction

more offspring are produced than will survive (principle of natural selection)

adaptation principle

some traits are better than others and increase fitness (principle of natural selection)

fossils, geography, embryology, DNA sequences, comparative anatomy

main evidences of evolution

homologous structures

structures with similar structure and different functions

a common ancestor

homologous structures indicate…

analogous structures

structures with similar function but separate structure/origin

similar environmental pressures

Analogous structures indicate…

vestigial structures

remnants of structures that had a function in a common ancestor but no longer serve a purpose

changing

Genetic variation helps a species survive a(n) ___________ environment.

populations

who evolves, individuals or populations?

mutations, sexual reproduction, gene flow

sources of genetic variation

gene pool

the combined alleles of all of the individuals in a population

allele frequency

how common an allele is in a population

to determine whether a population is evolving

What are allele frequencies used for?

the number of a particular allele / the total number of alleles

how to calculate allele frequency

normal distribution curve

all organisms have an equal chance of survival (NO natural selection); phenotypes in the middle are more common

directional selection

favors individuals on one end of the phenotypic range (ex. super dark mice over super light or medium mice)

stabilizing selection

favors intermediate variants and acts against extreme phenotypes (ex. bird clutch size)

disruptive selection

favors individuals at both extremes of the phenotypic range (ex. black-bellied seed crackers)

natural selection, gene flow, genetic drift, non-random mating

4 mechanisms of evolution

gene flow

the movement of alleles from one population to another

gene flow

a bull moose leaves his herd to mate with a cow of another herd — this is an example of which mechanism of evolution?

increases; decreases

Gene flow _________ genetic variation in the population the organism(s) join(s) and ___________ genetic variation in the population the organism(s) leave(s).

genetic drift

the changes in allele frequencies due to chance

low

Genetic drift results in _______ genetic diversity

small

Is genetic drift more obvious in small or large populations?

bottleneck effect

genetic drift mechanism in which the original population is greatly reduced in size very quickly

founder effect

a few individuals leave and colonize a new area

bottleneck effect, founder effect

2 common processes that cause populations to become small enough for genetic drift to occur

Florida panthers are now genetically similar enough to be siblings because poaching has decreased their numbers

example of the bottleneck effect (override if you provided a different example but it was still correct)

finches on Galapagos Islands developed different traits based on the founders that colonized their islands

example of the founder effect (override if you provided a different example but it was still correct)

allele frequencies

__________ in the small founder population can be different from those in the larger parent population

it is less likely to survive in a changing environment

What happens to a species’ chance of survival when genetic drift causes genetic variation to decrease?

sexual selection (non-random mating)

natural selection for mating success

sexual dimorphism

marked differences between the sexes in secondary sexual characteristics

intrasexual selection

competition among males for females

intersexual selection

occurs when males display certain traits that attract the female

speciation

the rise of 2 species from one existing species

genetic flow

Speciation is caused by a decrease in _________ between 2 isolated populations.

reproductive isolation

when members of 2 populations can no longer mate successfully

behavioral isolation

when species are reproductively isolated due to differences in behavior

bird songs being different from species to species

example of behavioral isolation (override if you provided a different example but it was still correct)

geographic isolation

physical barriers divide a population into 2 groups

Galapagos finches’ speciation because they were all on different islands

example of geographic isolation (override if you provided a different example but it was still correct)

temporal isolation

timing prevents mating between 2 species (different mating seasons)

convergent evolution

different species adapt to a similar environment

analogous

Convergent evolution results in _________ traits/structure

homologous

Divergent evolution results in ____________ traits/structures

divergent evolution

closely related species evolve in different directions

coevolution

process in which 2+ species evolve in response to changes in each other

predator-prey, parasite-host

2 types of relationships that usually involve coevolution

punctuated equilibrium

theory stating that episodes of speciation occur suddenly and are followed by long periods of evolutionary change

radiation of mammals after the extinction of dinosaurs

example of punctuated equilibrium (override if you provided a different example but it was still correct)

primates

mammalian order including lemurs, lorises, tarsiers, monkeys, apes, and humans

large brain; good depth perception; complex social behavior; flexible hands, feet, and shoulders

characteristics of primates

fully opposable thumbs

characteristic of primates unique to monkeys, apes, and humans

prosimians, tarsiers, anthropoids

3 main groups of living primates

prosimians

the oldest living primate subgroup which includes lemurs, lorises, and bush babies

tarsiers

the only organisms in the family Tarsiidae