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59 Cards in this Set

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What is evolution?
Evolution is heritable changes in organisms over time
What is the first part of evolutionary theory?
The idea that species change over time
What is Natural Selection?
Natural Selection is the differential reproductive succedd of individuals due to genetically inhereited traits
Name the four theories that Darwin's Theory are based on
1) The world is ever changing and very old
2) Species change
3) species are composed of populations of individuals
4) every species and group of specied are descended from a common ancestral species
Who is best known for his theory of inheritance of acquired traits, which states that acquired traits are passed on to offspring?
Lamarck (1800's)
True or False: In modern times only traits with no genetic basis can be inherited
False: Only traits with a genetic basis can be inherited
True or False: In modern times only traits with no genetic basis can be inherited
False: Only traits with a genetic basis can be inherited
Who independently hit upon natural selection as a mechanism for evolution?
Alfred Wallace (1858)
Who was the scientist that Darwin communicated closely with and may have taken some of his ideas for his book?
Alfred Wallace
What is comparative anatomy?
Species that descend from a common ancestor may evolve in very different directions yet retain many of the same basic structural characteristics
What are homologous structures?
Similar structures seen in two or more species
True or false: Evolution is opportunistic
True
What is a vestigal structure?
One that has little or no function; an evolutionary remnant, i.e. appendix
What is a vestigal structure?
One that has little or no function; an evolutionary remnant, i.e. appendix
What is Comparative Embryology?
Early embryos of all vertebrates are alike
What is selection?
The differential survival and reproduction of genetic variants
What does it mean if inheritance is blended?
Offspring have a blend of both parents traits
Who published results showing the particulate nature of inheritance?
Gregor Mendel (1866)
Who was one of the first biologists to completely reject the inheritance of acquired characteristics?
August Weismann
What is the "continuity of life" theory?
1) Germ plasm is separate from the rest of the body from the beginning
2) Only the germ plasm is passed on to the offspring
3) Acquired traits cannot be inherited
According to Weismann's theory, did he conclude that natural selection brings together old traits into new combinations, thus producing variation upon which evolution may work?
No, SEXUAL REPRODUCTION brings together old traits and produces variation upon which NATURAL SELECTION may work
What were the scientists called who rediscovered Mendel's laws?
Mendelains
What were the scientists called that insisted that Mendelian genetics did NOT cause evolution?
Naturalists
What was the "marriage" of genetics and evolutionary theory called, and when did it occur?
"Population Genetics" and 1930's
What are population genetics?
Explains in mathematical terms the processes by which variation is generated and passed on within populations of organisims.
What is microevolution?
The changes in the frequency of alleles of genes in a population
What is macroevolution?
The orgin and multiplication of species
True or false: Prior to the mid-1800's most people believed that new life developed spontaneously from living material
False: from NON-LIVING materials
What is spontaneous generation?
Development of life from non-living materials
Who performed one of the 1st controlled experiments, challenging the idea of spontaneous generation?
Francesco Redi
Who used his powerful microscope to see microorganisims everywhere?
Anton Van Leeuwenhoek
Who designed a simple experiment disproving spontaneous generation for microorganisms?
Louis Pasteur
True or false: Pasteur concluded that all life comes from existing life?
True
Name the two general explanations of where life comes from
1) arrived from somewhere in the universe
2) developed spontaneously from non-living organisms
What is pre-biotic evolution?
Life must have developed from non-living matter on the early Earth's surface
True or false: Earth formed about 7.5 million years ago
False: 4.6 billion
What kept earth from solidifying for another billion years?
Gravity compaction and meteor bombardment
When did the 1st sediments and 1st life appear on Earth?
about 3.8 billion years ago
True or false: early atmosphere had twice the oxygen content than today
False: no oxygen
What are three possible sources of energy necessary for prebiotic evolution?
1) UV radiation
2) Heat from earth's interior
3) lightening
What is the modern atmosphere composed of?
78% nitrogen, 21% oxygen, 1% inert gasses, water vapor
What two important steps would have to come 1st?
1) evolution of reproduction
2) evolution of metabolism
What do the balloon-like droplets of polypeptides, nucleic acids and polysaccharides that spontaneously form called?
Coacervates
Why are coacervates important?
Because the inside and outside are separated by a membrane-like boundary
What properties would the 1st true cells have needed?
1. A boundary
2. enzymes to get energy from chemicals in the environment
3. store the energy (ATP molecule)
4. RNA that specifies the structure of an enzyme
5. DNA/RNA replication/synthesis using the Watson-Crick rules for base pairing
6. specific amino acid for a triplet codon
7. primitive tRNA to connect amino acids to nucleotides
True or false: The earliest organisms are thought to have obtained both energy and building blocks from preexisting organic molecules present in primordial soup?
True
Name three ways to get energy from molecules
1. photosynthesis
2. cellular respiration
3. fermentation
Of those three ways to get energy from molecules, which is considered to be the oldest and used in both bacteria and eukaryotes?
Fermentation
What allowed oxygen exploitation to occur?
Cellular respiration
Define endosymbiosis
A close association of two organisms which one lives inside the other
True or false: Most modern-day biologists reject the view that both the chlorplasts and mitchondria are the endosymbiotic descendents of free-living prokaryotes?
False: they FAVOR that view
What is the Definition of Species?
"Species are groups of actually or potentially interbreeding populations, which are reproductively isolated from other such groups"
Name the two groups that the biological species concept does not apply to
1. asexual organisms
2. easy to extinct species
Why must a species become reproductively isolated?
In order to become separate species, the gene flow must permanently stop
What two mechanisms are involved in creating reproductive isolation?
Prezygote barriers
Postzygote barriers
What is a prezygote barrier?
They prevent the fusion of the sperm and the egg preventing the formation of a zygote
Name the five prezygote barriers:
1. Ecological isolation: how species live
2. temporal isolation: when they reproduce
3. behavioral isolation: mating behaviors
4. mechanical isolation: do not have complementary male and female reproductive organs
5. gamete isolation-gametes aren't compatable
What is a post-zygotic barrier?
Occur when fertilization leads to zygote that either dies or fails to reproduce
Name an important aspect of homologous structures
Structures may perform the same or different functions