Bio - Chapter 21 - evidence for evolution (a), Bio - Chapter 21 - evidence for evolution (b), Bio - Chapter 21 - evidence for evolution (c), Bio - Chapter 21 - evidence for evolution (d), Bio - Chapter 21 - evidence for evolution (e), Bio - Chapter 2...
different traits evolve at different rates and different times
Archaeopteryx fossils exhibit some traits that are characteristic of birds and other traits that are indistinguishable from those of carnivorous dinosaurs. This indicates that
seeds
Galapagos finches with powerful beaks typically eat (pg 418)
1.greatest similarity is present 2.different characteristics are lost or formed 3.final form is attained
developmental patterns seen in a group of organisms often reveal evolutionary relationships. Place the developmental description in the order that they would occur in a group of related organisms
1. greatest similarity is present 2. different characteristic are lost or formed 3. final form is obtained
developmental patterns seen in a groupof organisms often reveal evolutionary relationships. Place the developmental description in the order that they would occur in a group of related organisms, beginning with the earliest description at the top
unintentional
domestication is a form of artificial selection that has lead to _______ selection for some traits in the silver fox
1.atmospheric composition 2.climate
dramatic shifts in which of the following have led to the mass extinctions and influenced the course of evolution
modern horses have a single toe enclosed in a bony hoof
early horses had four toes on the front foot and three toes on the hind feet, all enclosed in a fleshy pads. What is true for modern horses
broad , short
early horses inhabited woody areas ...... this explains why those animals had ______ feet and _______ legs
pharyngeal pouches
early human embryos have _____ pouches which indicates that one of our earliest ancestors was an aquatic species
1.organic 2.inorganic
early organisms were thought to be autotrophs because of their ability to sythesize complex __________ compounds from simple ________ compounds and later use them as energy sources
1.pigs 2.corn 3.cattle
economically important organisms that have been modified significantly through artificial selection include
teeth , tail
even though it has feathers similar to modern birds, Archaeopteryx also has many features of carnivours dinosaurs for example______ in its mouth and a bony _______ (pg 425)
the evolutionary change in a series of related organisms
even though the fossil record is still incomplete there are many examples where fossils provide information on (pg 425)
intermediate
even though there are gaps in the fossil records some of the most direct evidence for evolution comes from fossils called _______ fossils that illustrate how the major transition in life occurs
the widespread appearance of grasslands
evolutionary changes in the horse in North America is related to
35- 40 generation
experiments with fruit flies have shown that significant evolutionary change can be observed within
Darwin initially identified some of the finches incorrectly
explain Darwins observations on his Galapagos finches using the correct choice
1.similar 2. resistance
fast swimming marine predators such as dolphins ,sharks and tuna have _____ body shape that ________ in the water
1.variation 2.food
finches on the Galapagos islands exhibit remarkable _______ in the shape of their beaks that can be related to their specific ____ gathering habits
1. specimen preserved in permafrost 2. in dry caves 3.in amber 4. remains preserved in rocks
fossils include 4 examples (pg 424)
speed
gradualism and punctuated equilibrium differ in their views concerning the ______ of evolutionary change
55 (MYO)
horses are a member of an animal family that produced many extinct species and originated approx _______ million yrs ago (pg 425)
traits produced by convergent evolution have not evolved from a common ancestral trait while homologies have
how are traits produced by convergence evolution different from homologies? (pg 428)
traits produced by convergent evolution have not evolved from a common ancestral trait while homologies have
how are traits produced by convergent evolution different from homologies
differences between breeds can be larger than differences between different genera of animals or plants
how does artificial selection contradict the claim that selection can only produce minor evolutionary change
the climate impacts on the size of seeds which is a selective force for beck size
how does climate drive evolution in the medium ground finch
the parent species do not come into contact with one another
how does ecological isolation prevent successful interspecies hybridization
individuals of different species breed at different times of the year preventing the exchange of gametes
how does temporal isolation prevent successful interbreeding among members of different species
relative dating was used in the past now we use absolute dating
how has rock and fossil dating changed since Darwin's time
will experience gene flow,which will homogenize them, causing them to integrate into one species
if two distinct populations that have not evolved independently for a long enough time to be completely reproductively isolated come into physical contact with one another, they ......
they will remain distinct species
if two species that have evolved over time to be completely reproductively isolated suddenly come into contact with one another
relative dating , absolute dating
in Darwin's day rocks were dated using _______ dating, while today we can determine the ________ age of rocks using carbon dating (pg 424)
1. marsupials 2.placental
in _______ mammals the young are born in pouches while the offspring of _______ mammals are not born until they can safely survive
postzygotic
in _________ isolating mechanisms a hybrid zygote is formed, but it is unable to survive or reproduce due to developmental or genetic problems
the cytosol
in eurkaryotes, RNA transcripts from nuclear DNA are processed, transported and translated in
higher
in his experiments with peppered moths, Kettlewell recaptured a _______ proportion of dark moths in a polluted wood than in an unpolluted wood
has lead to strong, predicable evolutionary response
in the laboratory setting selection for a trait in fruit flies
reinforcement
incomplete reproductive isolation may become completely effective over time when natural selection acts upon less fit hybrid individuals, a process termed what?
very
island species are usually _______ closely related to the species on nearby continents
prezygotic
isolating mechanisms that prevent the formation of a zygote are called ______ isolating mechanisms
postzygotic
isolation mechanisms that block the development of a variable and fertile individual after fertilization has taken place are called
different species
laboratory selection experiments have produced forms that cannot reproduce and thus would in nature be considered
intermediate
many _____ fossils have been found that illustrate how major transitions in life have occurred in the past
intermediate fossils
many _______ fossils have been found that illustrate how major transition in life have occurred (pg 425)
related
many fossils that have been discovered provide information regarding the evolutionary change of a series of ________ organisms
fruit fly
many of the laboratory experiments that test the hypothesis that selection can produce evolutionary change have been performed with drosophila melanogaster, known by its common name (pg 422)
wolf = thylacine lesser anteater = numbat flying squirrel = flying phalanger
match marsupial mammals to placental mammals that look similar and occupy the same niche (431)
1.whales = pelvic bones 2.boa constrictors = hip bones 3.manatees = finger nails on fins 4.cave fish = rudimentary eyes 5.humans = ear wiggling muscles
match organisms to their vestigial structures
ground finches= crushing beaks vampire finches = sharp beaks warbler finches = small narrow beaks
match the beaks with feeding habits
homology = vertebrate limb embryonic development = lanugo vestigal structure = coccyx
match the different types of anatomical evidence for evolution to an example
artificial selection
most of the species that humans use as foods have been modified through (pg 422)
isotopic dating
much of what we know about history of life on earth comes from the fossil record. Which of the following methods can determine the absolute age of fossils
light
on trees without lichens Tutt proposed that _____ coloured peppered moths were more visible to predators
light
on trees without lichens Tutt, proposed that _____ coloured peppered moths were more visible to predators
equidae family
one of the best studied examples of evolutionary change is the _______ family
inaccessible
one reason why fossils records is incomplete is that many fossils occur in rocks that are ______ to scientists (pg 424)
1.invertebrates 2.first land animals 3.amphibians 4.reptiles 5.flowering plants
order the different types of organisms according to their appearance in fossil records
1.5 BYA
organisms belonging to the domain eukarya appear in the fossil record about
increased
over the last 55 million years, the limbs of animals in most lineages of the horse family have ______ in length
the evolution of photosynthesis
oxygen that provides an environment for cellular respiration was added to the ocean and atmosphere during which of the following
1.hybrid offspring have lower fitness than non-hybrid offspring, but some hybrid survive and reproduce 2.
partial reproductive isolation examples are
light gray , black
peppered moths come in a variety of shades from _____ grey with speckles to completely ____ (melanic)
1.organism becomes buried in sediments 2.hard tissues (such as bones) mineralise 3.surrounding sediments harden into rock
place the series of events that must occur to produce a rock fossil
zygotes
prezygotes isolating mechanisms prevent the formation of which of the following
very rare
prior to 1850, the melanic form of the peppered moth in Europe was ______
dark, light
regarding the peppered moth, many studies have shown that in polluted areas, the ______ form of the moth is favoured, and in unpolluted the ______ form of the moth is favoured (pg 420)
polluted
scientist have observed that light coloured moths decrease in abundance in areas that are _____
dehydration
some species, for example frogs are very vulnerable to _______ in saltwater and therefore have almost no chance of island colonization (pg 432)
compartments
specialised functions occur in distinct _______ within eukaryotic cells
the populations undergoing speciation do or do not live in he same geographic area
speciation is defined as allopatric or sympatric based on whether which of the following occur
gene flow
speciation is more likely in allopatric populations than in sympatric populations because _______ does not homogenize genetic differences between allopatric populations
mechanical isolation
species are unable to mate due to structural differences such as size or incompatibility
ecological isolation
species live in the same area but occupy different habitats
behavioural isolation
species may live in the same area but do not select each other as mates due to differences in courtship communication
niches
species on islands often show great diverification as islands may have many unexploited ecological _______
the absence of many plants and animals means there are many unexploited niches
species on islands often show great diversification why?
temporal isolation
species reproduce in different seasons or at different times of day
1.fly 2.swim 3.float
species that _____, _______ or _________ are more likely to be able to disperse to an island than others
sympatric
species that are ________ species can occur in the same location and are pheonotypicallly different
niches
species that make it to islands will often times diverge into many new species that copy ecological ______ typically used by unrelated species on the continent (pg 432)
islands , water
species usually arrive on _______ by dispersal across the ________ from a nearby continent (pg 432)
increased almost 100%
starting in the 1850 when europe become industrialised the frequency of melanic forms of the peppered moth in populations _______ until they made up ____ of some populations
homologous , vestigial
structures that were derived from a common ancestor but with different appearance and functions are called ______ structures, while ______ structures refers to structures that have little or no function
homologous
structures with different appearances and functions that are all derived from the same body part in a common ancestor are called ______ structures
1.vestigal structures 2.imperfect adaptions
supporters of intelligent design cannot explain the presence of
1.disruptive selection 2.allopolyploidy 3.autopolyploidy
sympatric speciation may occur as a result of which of the following
larger , increased
the Grants were able to show that after dry years when _______ seeds are produced, the average beck depth of medium ground finches ______ (pg 419)
regardless of environmental conditions
the Grants were able to show that the depth of beak in finches was similar between parents and offspring (pg 419)
biological
the _______ species concept defines a species as a group of individuals that is able to interbreed, producing viable and fertile offspring
oil , artificial selection
the amount of _____ in corn kernels has been increased dramatically by over 90 generations of ________ selection (pg 422)
convergent
the ant eaters of South America and echidna have similar features. This is an example of _____ evolution (pg 431)
melanic
the black jet form of the peppered moth is also known as the ____ form
gradualism
the concept of _________ suggests that each new species evolve continuously over long spans of time
CO2
the early atmosphere of earth likely had water that slowly vaporised from the molten rock and high levels of
infolding of the plasma membrane
the endomembrane system of eukaryotes is thought to have evolved through
well documented by the fossil records
the evolution of members of the horse family is
one four three
the feet of modern horses have _______ toes in contrast early horses had ________ toes on their front feet and _______ toes on their hind feet
1.genus 2.species
the first words in the scientific name of an organism is the _______ to which it belongs, and the second is its __________
1.parents with large beaks tend to have offspring with large beaks 2.beak depth seems to be genetically inherited trait 3.parents with small beaks tend to have offspring with small beaks
the following graph plots the relationship between beak depth of medium ground finches and their offspring. What can you conclude from the graph
evolved from the same body part in a common ancestor
the forelimbs of modern vertebrates are homologous structures meaning that they may have changed evolutionary to perform functions but the
homologous structures
the forelimbs of modern vertebrates exemplify
homologous , vestigial
the forelimbs of vertebrates are an example of _______ structures, while the human coccyx is an example of a _______ structure (pg 428)
prezygotic , postzygotic
the formation of an interspecies hybrid zygote is prevented by ______ isolating mechanisms, whereas ________ isolating mechanisms prevent the successful development of hybrid zygotes once they are formed
false
the formation of proteins, nucleic acids, carbohydrates and lipids were essential and sufficient for life
increase
the fossil record reveals that during the last 25 million years horses have exhibited rapid and substantial _______ in their size (pg 426)
skull
the fossil records indicate that the ______ of horses has evolved, growing stronger in order to withstand stress imposed by continued chewing
offspring
the grants were able to show that the beak depth they observed ............ similar to the beak size of their _________
adaptive radiation
the great diversity of Hawaiian Drosophila, Finches , NZ alpine buttercup and cichlids may be attributed to the process of
eye
the human ______ is an example of imperfect adaption: this becomes very evident when compared with that of mollusks (pg 429)
gradualism
the idea that evolution occurs over time through the accumulation of small changes at a realatively slow pace is known as ______
punctuated equilibrium
the idea that evoution proceeds with long periods of stasis alternating with relatively rapid periods of evolutionary change is known as
biological species concept
the idea that species are defined based on the ability to interbred with each other and exchange genes is the basis of which species concept (437)
wet
the medium ground finch of the galapagos islands feeds on small seeds,produced in abundance during ______ years
industrial melanism
the phenomenon where dark forms of moths become more prevalent than light forms is knowns as? (pg 421)
corn
the plant teosinte has been modified to become ________
how the parents are chosen (by humans)
the primary difference between natural and artificial selection is
rarely
the process of fossilization occurs only ______ (pg 424)
in both Europe and north America
the reversal of melanism after the introduction of pollution control laws has been observed
wooded areas
the short legs and broad feet of early horses made them well adapted to
natural
the significant changes illustrated by artificial selection provide strong support for the power of _______ selection
natural
the significant changes illustrated by artificial selection provide strong support for the power of ________ selection
convergent evolution
the similar shapes of fast swimming marine predators are an example of
small and relatively simple
the teeth of early members of the horse family were
large with complex pattern of ridges
the teeth of modern members of the horse family are
all major groups of vertebrates
today, fossils have been found that link (pg 425)
1. illustrate how major transitions in life occurred 2. fill in gaps in fossils records between two groups
transitional fossils help _____ (pg 424)
true
true or false: Darwins theory of evolution is not accepted by everyone, especially in the general public (pg 432)
false
true or false: Even though humans have used artificial selection for centuries, only animals have been significantly modified by our efforts (pg 422)
false
true or false: current diversity in the horse family is much greater than it was in the Myocene
true
true or false: evidence indicates that the first cells were probably prokaryotic
true
true or false; gene flow decreases differences between populations
false
true or false; industrial melanism has only been observed in a few countries in Europe
true
true or false; intermediate fossils are not usually intermediate in every single trait (pg 424)
true
true or false; reinforcement increases differences between populations
behavioral
two species of frog live in the same pond, but do not interbreed because they have different mating calls. This is called ________ isolation
homologous and vestigial structure
two types of structures in adult organisms that provide anatomical evidence for evolution are ______ and ________ structures (pg 427)
more closely
typically how are species on islands related to species on nearby continents
1. ancestors 2. descendant
typically not all the traits of an intermediate fossil are intermediate some traits resemble those of its ________ and some, those of its ______
1.corn 2.dogs 3.cats 4.pigeons
varieties of which of the following organisms are the result of artificial selection
barriers that prevent successful interbreeding among members of different species
what are reproductive isolating mechanisms
1.tree seeds rarely make it to isolated islands 2.the tree niche is empty and so a flower can evolve through natural selection to be tree like
which of the following are reasons why island trees belong to plant families that typically do not have trees members
1.the tree niche is empty and so a flower can evolve through natural selection to be tree like 2. tree seeds rarely make it to isolated islands
which of the following are reasons why island tress belong to plant families that typically do not have tree members eg. the sunflower family
1.many fossil occur in rocks that are inaccessible 2.fossils can be destroyed before they are collected 3.organisms decay or are scavenged before forming fossils
which of the following are reasons why the fossil record is incomplete
sediment , mineralize , hardens
Rock fossils occur when three events occur: dead organisms are buried in _______; hard tissues ________; the material that surrounds the remain ________to form rock (pg 424
developmental
______ homologies are temporary similarities in species that occur during the early embryonic stages (pg 428)
developmental
_______ homologies are temporary similarities in the species that occur during the early embryonic stages
mitochondria
_________ are organelles, which originated through endosymbiosis, and are present in all modern eukaryote cells
vestigial
a _______ structure has no apparent function in a species but is fully functional in the species ancestors (pg 429)
minor , species
a common criticism of evolution is that selection only produces ______ changes and cannot produce the variety of _______ documented in the fossil record (pg 423)
mechanical
a prezygotic isolating mechanism that physically prevents mating due to structures differences of reproductive organs is _______ isolation
can produce significant evolutionary change
artificial selection clearly shows that selection ____ evolutionary changes such that over millions of years selection can produce the diversity of life on earth
1.unintended 2.intended 3.undesirable 4.desirable
artificial selection may result in traits that are
to migrate between the once disconnected continents
cold periods that led to glaciation and a drop in sea levels during the last 2 million years created an opportunity for humans and other animals
a widespread phenomenon
convergent evolution is (pg 431)
radioactive decay
currently the age of fossils is estimated by the rate of ______ _________ (absolute dating)
20 times
Co2 levels prior to the cooling that began in the Ordovician are thought to have been about ______ higher than present day concentrations
Birmingham
Kettlewell released peppered moths in Birmingham a highly industrialised area, and Dorset then an unpolluted wood. In which area did he recapture a higher proportion of dark moths
equal , recaptured
Kettlwell tested Tutt's hypothesis on peppered moths by releasing ______ numbers of dark and light individuals and counting those that were ______ (pg 420)
1.hydrogen cyanide 2.formaldehyde
Miller and Ureys experiment revealed that carbon in the form of methane gas could be converted to which of the following simple carbon compound before being converted to more complex molecules
silver fox
after generations of selective breeding this animal has been made exceptionally tame
long legged, fast running, open grasslands
all modern members of the horse family are large, _____ legged, _______ running animals adapted to living in open _______ (pg 426)
populations are geographically isolated and diverge because of natural selection and random processes
allotropic speciation is thought to occer when
allopolyploidy
an increases in chromosome number due to the hyberization of two species followed by doubling of the chromosomes number in the hybrid offspring is a type of polyploidy called
pheromones
chemical signals that are used in communication between different individuals are known as
1.the rates of evolution varied through time with long periods of little or no change 2.change often occurred simultaneously across the different lineages of the horse family 3.in some linages completely opposite trends are observed
as the horse family fossil record became more complete scientists realised that the evolution of horses was not linear constant and unidirectional. Why?
3 billion years
at the beginning of the cambrian, life had been unicellular (with the exception of a few algae) for
is a non-random process
because it favour those variations that lead to the highest reproductive fitness, natural selection
is a nonrandom process
because it favoured those variations that lead to the highest reproductive fitness natural selection (pg 432)
the geographic distribution of modern and extinct species
biogeography studies
1.tiktaalik, a species that is transitional between fish and amphibians 2.a four legged aquatic mammal that links marine mammals to their terrestrial ancestors 3.a fossil snake with legs that link modern snakes to the lizards from which they descended
what are some fossils findings in recent years that have bridged major gaps in our understanding of vertebrate evolution
1. evolution has not been demonstrated 2. complex organs can be explained by intelligent design
what are two of the common misconception of evolution (pg 432)
their skulls
what feature of horses strengthened over tome to cope with continuous chewing (pg 426)
1.gene linkage 2.pleiotropy
what genetic phenomena may be responsible for unintentional selection
substantial
what is the magnitude of change produced by artificial selection
natural selection
what is the primarily responsible for evolution (pg 418)
genetic drift
what process can promote speciation through random changes between isolated populations
natural selection
what process may lead to speciation when a population adapts to its environment in such a way that it becomes reproductively isolated from other populations
reversal of industrial melanism is not correlated with the re-appearance of lichens
what recent obsevation has prompted scientists to challenge Tutt's hypothesis about the cause of industrial melanism
some organisms do not appear to be perfectly adapted to their environments
what statement is true about natural selection?
reproductive
what type of isolation occurs when members of one species are unable to successfully interbreed with members of another species
1. mass extinction 2. formation of islands through volcanic activity and subsequent colonization 3. a species occurs in an environment with few other species and many resources
what types of conditions may lead to adaptive radiation
1.a species occurs in an environment with few other species and many resources 2.formation of islands through volcanic activity and subsequent colonization 3.mass extinction
what types of conditions may lead to adaptive radiation (pg 446)
70 (MYO)
when did Australia separate from other continents
centuries and millennia ago
when did humans begin to utilize artificial selection (pg 422)
evolutionary change
when fossils are arranged and compared according to their age, from oldest to youngest, successive ________ change becomes apparent
species
when members of two populations are completely reproductively isolated they will remain distinct ________ species when they come into physical contact
throughout eurasia and North America
where has industrial melanism been observed
fossils
which if the following is the most direct evidence for evolution (pg 424)
species in geographically separated areas = allopatric speciation
which is a correct description of geography and speciation
1.they are also known as fossil genes 2. they are the sites where mutations can occur 3. they are made inactive by mutations
which is correct about pseudogenes
climatic variation impacts seed size which is a selective force on beak size
which is the correct statement about the evolutionary changes in the medium ground finch
1.connections between different population of the same species 2.distinctiveness of species that occur together in a single location
which must be accounted for in any species concept
1.early embryonic similarities 2.vestigial structures 3.homologous structures
which of the following anatomical features that provide evidence for evolution
1.evolution has not been demonstrated 2.complex organs can be explained by intelligent design
which of the following are common misconceptions about evolution
1.evolutionary change is constant through time 2.natural selection is a progressive guiding force pushing evolution in one direction
which of the following are common misconceptions about the evolution of horses
1.wings in birds 2.lungs in fish 3.wings in insects
which of the following are considered to be key innovations in the course of animal evolution
1. Reinforcement: increases differences between populations 2. Gene flow: decreases differences between populations
which of the following are correctly matched
1.bony tail 2.pharyngeal pouches 3.a fine fur
which of the following are developmental features observed in humans embryos, but not in adults
1.appearance of hooves 2.increase in size of molars 3.increase in body size
which of the following are predominate adaptive changes that occurred between the first members of the horse family and its modern representatives
1.light moths in some areas increased in frequency long before lichens re-appeared 2.in some areas, evidence suggests that moths rest on leaves in the treetops, not trunks 3.in some areas, lichens never changed even though dark moths become predominant
which of the following are recent observations that have challenged Tutts hypothesis about peppered moths
distinct populations of the same species that inhabit different areas
which of the following best defines subspecies
1.toxic effects of pollution on light coloured moths 2.surfaces in polluted areas get darker due to soot deposition 3.lichens decline due to pollution
which of the following have been suggested as hypothesis that may explain industrial melanism
the hemoglobin gene in the icefish
which of the following is a pseudogene
the human coccyx
which of the following is not an example of an imperfect adaption
lipids and proteins
which of the following macromolecules may have composed a vesicle (or bubble) from which living cells arose?
1.memebers of a species of fish are separated when a lake dries into a series of small ponds 2.a population of big horn sheep are separated by a glacier 3.the emergence of a mountain range prevents 2 populations of Elk from reproducing with one another
which of the following may lead to allotropic speciation
1.mitochondria 2.chloroplasts
which of the following organelles found in eukaryotic cells are involved in producing or providing energy for the cell? (pg 518)
reductive version of the Krebs cycle
which of the following pathways for carbon fixation is used by archaea and some lithotrophic bacteria (pg 514)
1.an oscillating environment 2.an unchanging environment
which of the following promotes stasis within a species?
interbreeding between two populations that are incompletely reproductively isolated
which of the following situation will result in homogenization of two populations
convergent evolution is frequently documented
which of the following statements about convergent evolution is true
1.they are tall and have tough covering 2.they are members of families that typically exist as flowers or shrubs
which of the following statements about island trees are true
it originated 55 million years ago and over that time many of its members have become extinct
which of the following statements about the horse family is true
members of different species maybe able to hybridize under artifical conditions but not in the wild
which of the following statements is true in regard to how scientists define species based on the biological species concept
speciation may occur through random or non random processes
which of the following statements is true regarding speciation
miller -urey
which scientists demonstrated that prebiotic synthesis of organic molecules is possible
for many types of placental mammals found throughout the world, there is a strikingly similar marsupial in Au
which statement is true about Australian marsupials (pg 431)
1.a species occurs in an environment with few other species and many resources 2.mass extinctions 3.formation of islands through volcanic activity and subsequent colonization
which types of conditions may lead to adaptive radiation
like all mammals giraffes only have 7 vertebrae in their necks which limits their flexibility
why are giraffe necks not perfectly suited for their function?
polyploid individuals cannot mate with normal diploid individuals
why does polyploidy lead to sympatric speciation
1. because it is supported by a large body of evidence 2. because it helps explain a very wide range of observations
why is evolution considered a theory
1.these genes are like a database for genetic changes 2.the trait coded for by the gene is no longer present
why is fossil gene an appropriate name for a pseudogene
because natural selection can only work on the variation present in a population
why is it that some organisms do not appear to be perfectly adapted to their environments
probability cannot be used to argue backwards
why is the argument "proteins are to improbable" invalid? (pg 433)
