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90 Cards in this Set

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How old is the earth?
Around 4.6billion years old
What was the primitive atmosphere made of?
Carbon dioxide, nitrogen, ammonia, and methane
-no ozone layer
-lots of UV light hitting the ground
-lots of lightening
What is the current atmosphere made of?
78% nitrogen
21% Oxygen
.03% carbon dioxide
Who was the Oparin hypothesis propopsed by?
Alexander Oparin (1920s)
-independently described by Haldane around the same time
What is the Oparin Hypothesis?
-Life evolved from nonliving substances by interacting with the natural environment
-lighting and UV radiation provided the energy for the chemical reactions that produced the major organic macromolecules
What is the heterotroph hypothesis?
Heterotrophs (anaerobic prokaryotic cells that used organic compounds for food)--> Photosynthetic bacteria (gave off oxygen) --> eukaryotic cells (possibly came from cells which engulfed other cells which became organelles...)
What did Miller and Urey do in 1950?
Test Oparins ideas about the origin of life
How did they test Oparins ideas?
Laboratory experiments verified that these ideas were in fact possibly and probably under the conditions believed to exist on the primitive earth
-they mixed gases that were in primitive atmosphere with a spark from an electrode
-found amino acids and other organic compoundsw necessary for life as result
What was a popular hypothesis of where cells came from?
Monomers --> polymers --> membranes --> Cells
why were monomers important in milley and ureys experiment
They were found in the "organic soup"
What were Miller and Ureys 2 hypothesis' with polymers?
-small puddles evaporated and concentrated amino acid pools were left
-monomers were in clay crystals and joined with other monomers
What were miller and ureys hypothesis about membranes?
-formed around vcery primitive "pre-cells" called protocells, which contained only random nutrients
What were miller and ureys hypothesis about cells?
THey were likely developed from proto-cells
What was the pinching in hypothesis?
Organelles were formed by folding in and pinching off of portions of the cell membrane
What is the Endpsymbiont hypothesis?
Organelles such as the mitochondria and chloroplase were formed by larger prokaryotic cells engulfing smaller cells
what are the 2 hypothesis' of how we arised as we know today?
spontaneous generation
-biogenesis
spontaneous generation
The idea that life could come from nonliving matter- proposed by aristotle
biogenesis
the principle that life only comes from life
How did Redi try to disprove spontaneous generation
did an experiment with meat jars
open jars --> maggots
sealed jars --> no maggots
jars covered w/ cloth--> no maggots
(Strong evidenec that things only arise from living things)
How did Needham try to prove spontaneous generation?
-broiled broth, then sealed loosely with cork stoppers--> bacteria appeared
(concluded bacteria came from broth by spontaneous generation)
How did Spallazani try to disprove spontaneous generation?
repeater Needhams experiement with more tightly sealed flasks-->no bacteria
How did Pasteur disprove spontaneous generation?
Experimented with broiled broth and curved neck flasks:
-boiled broth in regular flasks-->bacteria
-boiled broth in curved neck flasks--> no bacteria
definition of evolution
A gradual change over time
types of evolution
geologic evolution
organic evolution
Geologic evolution
the slow change of the eaarth itself since its formation about 4.6 billion years ago
organic evolution
the change of a species since its appearance on earth
definition of a fossil
any trace or remains of an organism that has been preserved
-the fossil record provides the greatest evidence for evolution
-by comparing the remains of ancient organisms to current organisms we can determine whether or not organic evolution has occured
Homologous structures
are similar in structure and development, but have different functions
analogous structures
are similar in appearance and function, but have different structures
vestigial structures
are remnant structures with no current usage (over 100 in humans)
what are the 2 hypothesis' of how we arised as we know today?
spontaneous generation
-biogenesis
spontaneous generation
The idea that life could come from nonliving matter- proposed by aristotle
biogenesis
the principle that life only comes from life
How did Redi try to disprove spontaneous generation
did an experiment with meat jars
open jars --> maggots
sealed jars --> no maggots
jars covered w/ cloth--> no maggots
(Strong evidenec that things only arise from living things)
How did Needham try to prove spontaneous generation?
-broiled broth, then sealed loosely with cork stoppers--> bacteria appeared
(concluded bacteria came from broth by spontaneous generation)
How did Spallazani try to disprove spontaneous generation?
repeater Needhams experiement with more tightly sealed flasks-->no bacteria
How did Pasteur disprove spontaneous generation?
Experimented with broiled broth and curved neck flasks:
-boiled broth in regular flasks-->bacteria
-boiled broth in curved neck flasks--> no bacteria
definition of evolution
A gradual change over time
types of evolution
geologic evolution
organic evolution
Geologic evolution
the slow change of the eaarth itself since its formation about 4.6 billion years ago
organic evolution
the change of a species since its appearance on earth
definition of a fossil
any trace or remains of an organism that has been preserved
-the fossil record provides the greatest evidence for evolution
-by comparing the remains of ancient organisms to current organisms we can determine whether or not organic evolution has occured
Homologous structures
are similar in structure and development, but have different functions
analogous structures
are similar in appearance and function, but have different structures
vestigial structures
are remnant structures with no current usage (over 100 in humans)
embryology
-similar development is a clue towards evolution
-similarities are greatest in early stages
-later in development organisms resemble adults of their own species
biochemical similarities
-close phylogenetic relationships based on morphology and anatomy indicate in DNA and protein structure
-related organisms have similar hormones and enzymes-->allows humans to recieve pig insulin for treatment for diabetes
-testing for similarity can be done by injecting foreign blood and examining the antibodies produced
Lamarck's theory
(coninced that species evolve from other species)
-the more an organism uses a structure, the stronger and more significant it becomes
-structures not used and developed become smaller and weaker
Theory of acquired characteristics
-characteristics developed through use and disuse could be passed on to offspring
-ie. giraffes constantly stretch their necks making it grow (true) it can be passed on to offspring (false)
How did Weismann disprove the 2nd part of the theory of acquired characteristics
he cut off the tails of mice for 22 generations and saw that no short tailed mice evolved
Who was Darwin?
A naturalist who traveled around the world observing organisms and differences between them
What were Darwin's finches?
several species of finches there (island off of Ecuador) are generally alike, but wioth slight variations
-adapted to fit different nickes
-returned to England in 1836 convinced of evolution but unable to prove it
What were Darwins 6 components of his theory of evolution by means of natural selection?
-overproduction
-competition
-variation
-adaptions
-natural selection
-speciation
Overproduction
-most spsecies produce more offspring than necessary to maintain the population
-remain constant only because not all members live to reproductive age
Competition
-offspring of a population compete for resources
-only a fraction survive to reproduce again
Variation
-individuals in a population are not identical
-certain differences may prove benefecial
Adaptions (of a species NOT of an individual)
-an inherited trait which increases chances fro survival
-individuals with favorable adaptions survive to pass those on to the next generation
NATURAL SELECTION (main idea of Darwin's theory)
-environment selects individuals with the favorable adaptions to be the parents for the next generation
-new generation tends to inherit favorable adaptions
Speciation (a side not of Darwin's theory)
-ocer time favorable adaptions accumulate while unfavorable ones disappear
-eventually accumulated changes are so great that the result is a new species
definition of species
A group of organisms that mate and produce fertile offspring under natural conditions
Two types of rates of evolution
gradualism
punctuated equilibrium
gradualism
Darwin's idea that evolution occurs slowly and continuously over many years
Punctuated Equilibrium
-species remains the same for long periods of time
-sudenly over a short period of time (100-1000s of years) chances occur and new species arise
Does evolutino happen to populatiosn or individuals
POPULATIONS
Definition of population
a group of organisms of the ame species living in the same area at the same time and interbreeding
Definition of population genetics
changes in the genetic makeup of a population
definition of gene pool
total of all the genes in a population
definition of gene frequency
the frequency of a gene within a population
definition of genetic equilibrium
gene frequencies do not change from generation to generation
What are DeVries' Genetic sources of variation
-mutations
-genetic recombination
-migration
-nenetic drife (-change in gene pool of small popultions brought on by change
-if only a few individuals carry a gene and they do not reproduce successfully there will be a change in the gene frequency)
Hardy-Weinberg Law
-sexual reproduction alone does not affect genetic equilibrium
what 4 conditiosn must occur in order to have genetic equilibrium (according to h-w law)
-population must be large
-migration must not occur (neither immigration or emigration)
-mutatiosn must not occur
-mating must be completely random
Why is the law still useful even if the 3rd and 4th conditions are almost never met
-It provides a means for determining whether evolution is occuring in a population
-The fact that frequencies change indicates that evolution is occuring
-the extent of variation from the law indicates the rate of evolution
What does natural selection disrupt?
Natural selection disrupts gene frequencies
What is directional selection?
One extreme phenotype becomes the favorable adaption
-usualy occurs with environmental change or migration
What is stabilizing selection?
The average phenotype becomes favorable while extremes are highly unfavorable
-operates in many populations and often maintains genetic equilibrium
What is Disruptive Selection?
Both extreme phenotypes become favorable while the average is unfavorable
-often results in two subpopulations which eventually become two seperate species
How does a new species emerge?
-Each species inhabits a region of the earth, which its range.
-Members of the same species may shoe minor differences throughout their range
-if evolution favors the variations, two separate species may result
What are some types of variation?
-Isolation
-Polyploidy
-Adaptive radiation
Isolation
-The gene pool becomes isolated in 2 groups and the groups no longer interbreed
Polyploidy
-Abnormal mitosis or meiodid reults in a reproductively isolated group, which is a new species
Adaptive radiation
population spreads into different regions, each adapting to tis new environment and becoming separate species (Darwin's Finches)
How can we identify promates?
-eyes face forward allowing to see in 3-D
-complex brains
-an opposable thumb
-flexible shoulders and rotating forelimbs
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