Unit 9 - Evolution Flashcards
spontaneous generation
living things come from nonliving things
francesco redi experiment
meat in jars, one open one corked and one with gauze over the top
louis pasteur experiment
s-shaped flasks with boiled water
what two things had to occur before life
simple organic molecules form, simple molecules come together to form carbs, proteins, nucleic acids
all living organisms come only from other living organisms
biogenesis
earth’s early atmosphere
no O2, atmosphere had water vapor, CO2, nitrogen, maybe methane and ammonia
who hypothesized life began in the ocean
alexander oparin
when did Alexander oparin hypothesize life began in the ocean
1930s
what happened to create primordial soup
energy from the sun, lightning, and earth’s heat triggered chemical reactions that made small molecules from substances present in the atmosphere, small molecules get washed into the ocean
who recreated primordial soup in a lab and when
miller and urey, 1953
how did miller and urey recreate primordial soup
put gases from early atmo in flask, sent electric current through it, cooled mixture for a week and found amino acids, sugars, and other small molecules (experiment is still being observed today)
evolution of cells
protocell –> prokaryote –> eukaryote
structure surrounded by membrane
protocell
what did amino acids come together to form in primordial soup
protocell
what were the first prokaryotic cells in the ocean like
anaerobic and heterotrophic, eventually used up all the food and evolved into archaebacteria
prokaryotes that live in harsh environments (deep sea vents, hot springs)
archaebacteria
what do archaebacteria use for food
chemosynthesis
to use chemicals in the environment to make food
chemosynthesis
one organism lives inside another
endosymbiosis
why did the amount of O2 in the atmosphere increase
photosynthesizing prokaryotes used energy from the sun to make food and gave off oxygen
prokaryotic cells ingested bacteria that became mitochondria and photosynthesizing bacteria that became chloroplast to form animal and plant cells
endosymbiotic theory
a group of similar organisms that can breed and produce fertile offspring
species
a group of individuals of the same species living in the same area
population
change in the frequency of alleles in a population of organisms over time
evolution
British naturalist, took a job on HMS Beagle and went on a five year journey, wrote “On the Origin of Species”, famous for theory of evolution by natural selection, conducted studies in Galapagos Islands
Charles Darwin
organism used to gather info and perform research
specimen
French scientist who believed organisms could change during their lifetimes by choosing to use or not use parts of their bodies, believed organisms have a desire to be more complex and perfect and would then pass those “perfect” traits to their offspring
Jean-Baptist Lamarck
structure or behavior that helps an organism survive in its environment
adaptation
adaptation where one species looks like another
mimicry
adaptation that allows an organisms to blend in with its surroundings
camouflage
organism with favorable variation survives and passes on that variation, brings about change in a population of organisms
natural selection
breeding organisms with specific traits to get offspring with that trait
artificial selection
how well an organism can survive and reproduce in its environment
fitness
steps of natural selection
1)population has variations
2) some variations are favorable
3) more offspring born than survive
4) those that survive have favorable traits and pass them on
5) population will change over time
type of natural selection that favors average individuals, reduces variation
stabilizing selection
type of natural selection where one extreme is favored
directional selection
type of natural selection that favors both extremes, two new species evolve
disruptive selection
evolution of a new species
speciation
two populations seperated by geographic barriers and eventually become seperate species
geographic isolation
one species evolves into many because of different environments
adaptive radiation
one species evolves into different species with similar traits, share a common ancestor
divergent evolution
type of evolution that has homologous structures (same background, different function)
divergent evolution
structures that are similar internally but different externally
homologous structures
unrelated organisms evolve into forms that resemble each other, do not share common ancestor, similar traits due to similar environments
convergent evolution
type of evolution that has analogous structures (different background, same function)
convergent evolution
structures that are different internally but similar externally
analogous structures
species evolve through a slow, steady change in adaptations
gradualism
species evolve quickly, in rapid bursts, then long periods with no change
punctuated equilibrium
change in allele frequencies due to chance, random
genetic drift
preserved remains or an important of an ancient organism
fossil
imprint of an ancient organism
mold
mold of an ancient organism filled with minerals
cast
oldest fossil at the bottom, most recent at the top
relative dating
uses carbon -14 dating to give exact age of fossil
radioactive dating
fossils can show:
anatomy, where the organism lived, what it ate
bone and organ structure of an organism
anatomy
structure in a present day organism that no longer has a purpose but was probably useful to an ancestor
vestigial structure
earliest stage of growth and development in an animal
embryo
fossils, anatomy, vestigial structures, embryology, and biochemistry are all evidence of…
evolution
using biological molecules to see evolutionary relationships
biochemistry
______ trees show evolutionary relationships based on DNA similarities
phylogenetic
______ organize living things by how closely related they are based off of shared traits, picture that shows evolutionary relationship between groups of organisms
cladograms
species currently living
extant
