bio ch 20-24
For a gene with two alleles whose frequencies are p and q, the Hardy-Weinberg equation states that the genotypes that are possible for the population are p2 + 2pq + q2, which is equal to
(p + q)2.
Why is evolution considered a theory?
- because it helps explain a very wide range of observations -because it is supported by a large body of evidence
If the frequency of heterozygotes in a population of mice is 0.48 for a particular gene, what would be the frequency of heterozygotes in future generations if the population is in Hardy-Weinberg equilibrium?
0.48
In a population of seahorses, red seahorses on average produce 125 offspring and brown seahorses produce 75 offspring. What is the fitness of the brown phenotype?
0.6- Remember that the most fit phenotype is assigned a fitness value of 1. In this case the red seahorses will have a fitness of 1 and the brown seahorses will have a fitness of 75/125, or 0.6.
Consider a gene in a population of fruit bats. There are two alleles for this gene, A and a, that occur in a population with the frequencies 0.8 and 0.2, respectively. If the population is in Hardy-Weinberg equilibrium, what genotype frequencies will be observed?
0.64 AA, 0.32 Aa, and 0.04 aa
Consider a population with 100 cats. If 72 cats are black and 28 are white, what is the phenotypic frequency of black cats?
0.72
You are examining allele frequencies of a gene in a population of frogs. This gene has two alleles, T and t. If the frequency of the dominant allele (T) is 0.25, then the frequency of the recessive allele (t) is
0.75, .75, or 75%
The most fit phenotype is assigned a fitness value of ______.
1
The genomes of humans and chimps are different due to a number of insertions and deletions found in them. What is the percent of indels that are different between those two species?
1.5
Malaria is responsible for
1.7-2.5 million deaths each year
the feet of modern horses have ___ toe(s), early horses had _____ toes on their front feet and _____ toes on their hind feet.
1; 4; 3
Humans have a haploid chromosome number of _____ while all living great apes have a haploid chromosome number of _____. (Fill the blanks with numbers, do not spell them out.)
23; 24
In this example, six populations are currently under study. Four out of the six populations can interbreed with one another and produce fertile, viable offspring. Two of the populations can only form fertile, viable offspring with members of their own population. According to the biological species concept, how many species are present in this example? 2
3
The FOXP2 protein in mice and humans differs by only _____ amino acids, but the FOXP2 protein in chimps and humans differs by only _____ amino acids.
3; 2
In artificial selection experiments with corn plants that began in the 19th century, scientists have managed to increase oil content of corn kernels by
450%
The fossil record indicates that how many mass extinctions have occurred in the past?
5
The genome of P. falciparum appears to have about
5500 genes with those of related function clustered together
What proportion of insect species are beetles?
80%
Select all of the following that increase the chances of genetic drift in a population.
A few individuals of a population become isolated. A population becomes very small. Only a few individuals contribute gametes to the next generation.
What does a cladogram depict?
A hypothesis of evolutionary relationships
What are reproductive isolating mechanisms?
Barriers that prevent successful interbreeding among members of different species.
Why is it that some organisms do not appear to be perfectly adapted to their environment?
Because natural selection can only work on the variation present in a population.
Why does selection occur?
Because some individuals in a population possess more favorable phenotypes than others.
True or false: According to the fossil record, only two major mass extinctions have occurred in the past: one at the end of the Permian period and the other at the end of the Cretaceous period.
False- Five mass extinctions have occurred in the past. The one at the end of the Permian was the most severe and the one at the end of the Cretaceous is the most well-studied.
Which of the following processes are involved in making synthetic polyploids?
Crossing closely related plant species in the lab. Chemically inducting chromosome duplication in hybrids.
After a branch on a cladogram, each species will share a set of these characters that are not found in species below the branch point.
Derived
When populations are only partially reproductively isolated, which of the following may occur?
Despite prezygotic and postzygotic isolating mechanisms, some individuals may survive and reproduce.
How does artificial selection contradict the claim that selection can only produce minor evolutionary change?
Differences between breeds can be larger than differences between different genera of animals or plants.
Which of the following can be found when comparing genomes?
Differences in genes Differences in noncoding DNA Differences in the rate of genetic change DIfferences in whole DNA sequences
What type of evidence for evolution is provided by fossils?
Direct
Selection against intermediate-sized beaks in African black-bellied seedcracker finches is an example of which of the following?
Disruptive selection
Which type of selection acts to eliminate individuals which are intermediate on a phenotypic range?
Disruptive selection
Mechanisms that prevent formation of a zygote include ecological or environmental isolation, behavioral isolation, temporal isolation, mechanical isolation, and prevention of gamete fusion.
Ecological Behavioral
Archaea are most closely related to
Eukarya
Which of the following are common misconceptions about evolution?
Evolution has not been demonstrated. Complex organs cannot be explained by evolution, but can be explained by intelligent design. A common misconception about evolution is that it violates the second law of thermodynamics.
Which of the following are common misconceptions about evolution that were traditionally thought to be revealed by the fossil records of horses.
Evolutionary change is constant through time. Natural selection is a progressive guiding force pushing evolution in a single direction.
What conclusion can be drawn from the observation that a population is not in Hardy-Weinberg equilibrium?
Evolutionary forces are affecting the population.
Which of the following is true of evolutionary forces in natural populations?
Evolutionary forces can alter allele frequencies in natural populations
Populations of a single species that are quite distinct from one another phenotypically may be connected by populations that have which characteristics?
Exhibit intermediate phenotypes
True or false: Recent findings suggest that there is no correlation between the prevalence of dark forms of moths and the pollution levels in an area.
False
True or false: The pace of speciation in most species is slow and gradual.
False
True or false: Even though humans have used artificial selection for centuries, only animals have been significantly modified by our efforts.
False- No, there are many types of organisms that have been modified by artificial selection, including many plants such as corn, strawberries, etc.
True or false: Genetic sequences are the only points of interest in the comparison of different genomes.
False- Other information, such as rate of change, is important as well.
What is synthesized in the apicoplast (and nowhere else in the cell) of the parasite P. falciparum?
Fatty acids
Which of the following is a driving force of intersexual selection?
Female choice of males based on certain characteristics
What term quantifies reproductive success of a phenotype?
Fitness
Which of the following statements about marsupials in Australia is true?
For many types of placental mammals found throughout the world, there is a strikingly similar marsupial mammal in Australia.
As the horse family fossil record became more complete, scientists realized that the evolution of horses was not linear, constant, and unidirectional. Why?
In some lineages completely opposite trends are observed The rates of evolution varied through time with long periods of little or no change Change often occurred simultaneously across the different lineages of the horse family
What type of sequences do scientists search for in the genome of distant human relatives such as pufferfish when trying to find clues about the causes of human diseases?
Highly conserved sequences
Which are true of antibiotic resistance?
Increased resistance is due to selection. Resistance initially was due to a random mutation.
Why is the use of a molecular clock controversial?
It assumes that DNA divergence rates are constant over time.
Which of the following best distinguishes vestigial from homologous structures?
Homologous structures are functional, while vestigial structures have no function.
How are homologous and homoplastic traits different?
Homologous traits are inherited from a common ancestor; homoplastic traits are not.
Some stretches of an organism's genome do not appear to have any function. How does this affect the construction of phylogenies?
Homoplasy can be more common in these regions.
Which of the following statements are true of an outgroup?
It can be used to polarize characters. It it closely related to the group under study, but is not a member of the group.
What is the cause of the sixth mass extinction?
Human activity
What is one of the reasons for the much higher genome size of humans when compared to pufferfish?
Humans have many more introns which are also substantially larger.
Identify the feeding behavior and habitat of lions.
Hunt in groups in open grassland areas
Although the biological species concept can be useful when distinguishing among species, it is not as effective when pertaining to organisms that commonly undergo _____ with other species and produce viable offspring.
Hybridization
Why are giraffe necks not perfectly suited for their function?
Like all mammals, giraffes only have 7 vertebrae in their necks which limits their flexibility.
Which of the following statements about the reproductive strategies of males and females is true?
Males and females often have different reproductive strategies.
Review the following list of processes that can alter the genetic make up of a population. Which one is considered by scientists to be primarily responsible for evolution?
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?
Natural selection
Which evolutionary mechanism causes beneficial traits that are heritable to become more common in a population?
Natural selection
Why is the rate of evolution more rapid in segments of DNA that have no function?
Natural selection does not affect these DNA sequences.
Why are genome size and gene number not correlated?
Not all DNA is coding
If we find evidence that a population is experiencing changes in allele frequencies from one generation to the next, we say that this population is which of the following?
Not in Hardy-Weinberg equilibrium
What is meant by the term allopatric?
Occurring in geographically separated areas
What is a character state?
One of two or more variations of a character
We know that evolution is not a random process, but imagine for a moment that evolution is random. If so, which of the following would be true?
Organisms that are least adapted to their environment could have the highest fitness.
What is the difference between paleo and synthetic polyploids?
Paleopolyploids are ancient, while synthetic polyploids are generated by scientists in the lab.
Which of the following statements reflect similarities and differences between paralogues and orthologues?
Paralogues arise through duplication, while orthologues arise through speciation. Both orthologues and paralogues reflect homology.
Which species could be used as an outgroup for the trait of having lungs in this cladogram?
Shark
After generations of selective breeding, this animal has been made exceptionally tame.
Silver fox
What kind of data were first used to create phylogenetic trees?
Similarities in morphology
Which of the following most accurately describes the evolution of different characters?
Some characters evolve more rapidly than others.
which of the following most accurately describes the evolution of different characters?
Some characters evolve more rapidly than others.
How much genome size variation can be accounted for by polyploidy?
Some genome size variation
What is a potential problem with the PSC (phylogenetic species concept)?
Some species may be paraphyletic.
What types of species are most likely to be able to disperse to an island (choose all that apply)?
Species that fly Species that float Species that drift
Which type of selection favors individuals with intermediate phenotypes and selects against individuals with extreme phenotypes?
Stabilizing selection
When little or no evolutionary change in a species occurs for a long time, that time period is known as which of the following?
Stasis
Which of the following are findings of the 1000 Genomes Project?
Substantial differences in the amount of variation in different parts of the genome An average of about 24 to 30 alleles associated with known inherited disorders per individual A large number of SNPs among the different individuals (about 14 million)
Which of the following (choose all that apply) have been suggested as hypotheses that may explain industrial melanism?
Surfaces in polluted areas get darker due to soot deposition. Pollution has toxic effects on light-colored moths. Lichens decline due to pollution.
A phylogeny is a hypothesis about the evolutionary history of a species or a group of species. Classification does not necessarily refer to evolutionary history.
Systematics refers to the reconstruction and study of evolutionary relationships. Classifications do not always reflect evolutionary relationships (although biologists are always improving them in that respect).
If we consider all frogs and toads together, we are including numerous genera and families at once. Which would be the appropriate term to use for this group of beings?
Taxon
Which of the following statements best describes the evolution of HIV?
The AIDS virus evolves very rapidly, changing significantly even within a single host.
Which of the following is the habitat of the scrub oak in California?
The chaparral
If reproductive isolation is the criterion used to define species, then the process of speciation is equivalent to which of the following?
The evolution of reproductive isolating mechanisms
Which organism has been extensively used in the laboratory to show that selection can produce evolutionary change?
The fruit fly
The phenomenon that causes a single ancestral species to evolve into a wide array of descendant species with diverse habitats, forms, or behaviors that occurs often as a result of colonization of a new area is known as which of the following?
Adaptive radiation
What evolutionary process leads to the existence of groups of closely related species that have recently evolved from a common ancestor by adapting to different parts of the environment?
Adaptive radiation
electroreception
African and South Asian electric fish independently have evolved specialized organs in their tails that produce electrical discharges and electroreceptors on their skins to detect them. These discharges are used to communicate in social interactions
How do postzygotic isolating mechanisms prevent successful interspecies hybridization?
Although fertilization is successful, the resulting hybrid is unable to develop or reproduce.
Which of the following best describes the general trend in global species diversity over time?
An overall increase, but with some some sharp declines occurring at certain times
How can natural selection play a role in speciation?
As species adapt to different environments, they can accumulate differences that lead to speciation.
Which evolutionary mechanism changes genotype frequencies but does not change allele frequencies?
Assortative mating
Match the different types of anatomical evidence for evolution to an example.
homology- vertebrate forelimbs embryonic development- lanugo vestigial structures- human coccyx
Because there are only four character states possible for any nucleotide base in DNA, the probability of _____ between two species is higher than if more character states were possible.
homoplasy
Survival is significantly lower in individuals who are _____ for the sickle cell allele because of the lethal effect of the alleles, but individuals that are _____ for the sickle cell allele are more resistant to malaria because only the blood cells containing the malaria parasite sickle and are filtered out by the spleen. Listen to the complete question
homozygous; heterozygous
When genes are transferred from one species to another, we say that _____ gene transfer has occurred, but in _____ gene transfer, genes are passed from generation to generation.
horizontal; vertical
Phylogenies provide information about
how evolution occurred. evolutionary relationships among species.
The primary difference between natural and artificial selection is
how the parents are chosen (by humans or because of their reproductive success)
Modern tobacco arose from the _____ of two Nicotiana species and subsequent genome _____. Listen to the complete question
hybridization or cross; duplication
Starting in 1850 when Europe become industrialized, the frequency of melanic forms of the peppered moth in populations ______ until they made up ______ of some population.
increased; almost 100%
There is about a 1.5% difference in the number of _____ and _____ between humans and chimps.
insertions; deletions
A common misconception among the general public is that the features of species can be scientifically explained by _____ design.
intelligent
According to the theory of blending Inheritance, offspring were expected to be phenotypically _____ relative to their parents, which would dilute any new genetic variants.
intermediate
Even though there are gaps in the fossil record, some of the most direct evidence for evolution comes from fossils called ______ fossils that illustrate how certain major transformations in life forms occurred. Select all that apply.
intermediate transitional
The phenotype frequency is calculated by dividing the total number of individuals with a particular phenotype by which of the following?
The total number of individuals in that population
What is the predicted response of transposons to genome shock caused by polyploidization?
They jump to a new position in the genome.
In a laboratory experiment, researchers placed guppies in three different types of pools: no predation, low predation, and high predation. Researchers hypothesized that predation is a selective force and that large, brightly colored guppies are more conspicuous to predators. Based on that, what would you predict the guppies will look like in the pool with high predation after 10 generations?
They should be smaller and not very brightly colored
Segmental duplication occurs when:
a block of genes is duplicated
What are some fossil findings in recent years that have bridged major gaps in our understanding of vertebrate evolution?
a four-legged aquatic mammal was discovered only recently that provides important insights concerning the evolution of whales and dolphins from land-dwelling, hoofed ancestors a fossil snake with legs has shed light on the evolution of snakes, which are descended from lizards that gradually became more and more elongated with the simultaneous reduction and eventual disappearance of the limbs. Tiktaalik, a species that bridged the gap between fish and the first land-living vertebrates
A population bottleneck could be caused by
a natural disaster.
HIV obviously descended from SIV. All strains of HIV are phylogenetically nested within clades of SIV strains, indicating that HIV is derived from SIV humans have acquired HIV from different host species.
a number of different strains of HIV exist, and they appear to represent independent transfers from different primate species. Each of the human strains is more closely related to a strain of SIV than it is to other HIV strains, indicating separate origins of the HIV strains.
The closest relative to HIV is
a virus that infects monkeys
Natural selection results in ______ in a population.
adaptations
The formation of small islands by volcanic activity and subsequent colonization may lead to _____ _____, evolution of a closely related group of species adapted to different parts of the environment.
adaptive radiation
The genome of P. falciparum proved very difficult to sequence because of its high proportions of _____ and _____ which made it difficult to distinguish one region of it one from another.
adenine; thymine
The term heterozygote _____ refers to situations in which heterozygotes are more fit then either homozygotes.
advantage
Today, fossils have been found that link
all major groups of vertebrates
gene pools
all of the alleles present in a species
The founder effect results in a new population which differs in _____ frequencies from its source population.
allele
Genetic variation in a population results from evolutionary forces that cause changes in
allele frequencies
geographically separated, or allopatric, populations appear much more likely to have evolved substantial differences leading to speciation
allopatric speciation as the primary means of speciation
The toads, Bufo woodhousei and Bufo americanus have overlapping ranges. They usually do not interbreed because B.______ breeds in rainwater puddles and B. _____ breeds in stream.
americanus; woodhousei
In genes that are epistatic in nature,
an allele's selective advantage may vary from one individual to another based on their genotype.
Suppose that a population of finches migrates to a small island where most of the seeds are large. On the island, birds with large beaks are more likely to survive, and over time, the mean beak size of the population increases. This is an example of a type of natural selection known as _____ selection.
directional
Examples from artificial selection clearly show that natural selection
can produce large differences between populations
Artificial selection clearly shows that selection ______ evolutionary changes, such that over millions of years, selection can produce the diversity of life on earth.
can produce significant
A variant of a trait used in cladistic analyses is known as a _____ state.
character
In cladistics, a(n) _____ is any aspect of the phenotype, including morphology, physiology, behavior, and DNA.
character
The process by which natural selection produces a divergence in traits and resource use among sympatric species is called _____ displacement.
character
When examining species, we can look at multiple aspects of the makeup of those organisms, from DNA to behavior. Any such feature that we examine is called a(n) ______.
character
The apicoplast is a _____-like structure found in the cells of P. falciparum.
chloroplast
In the chromosomes of humans, the rate of duplication is related to the number of genes such that
chromosomes with fewer genes have also had fewer duplications
A _____ is constructed by nesting clades characterized by shared derived characters.
cladogram
The type of diagram that represents hypothesized evolutionary relationships among taxa is called a ______.
cladogram
The process of categorizing species and determining where they belong in the taxonomic hierarchy is known as ______.
classification
Overall, the evolutionary changes observed in the fossil record of the horse family can be understood as adaptations to changes in global
climates
Many genes in plants and animals are found across many species and show high degree of similarity, i.e. they are highly
conserved
Sequences that are ______ between humans and distant relatives such as the pufferfish provide valuable information regarding how genes cause human diseases.
conserved
The ant-eaters in South America and the Australian echidna have similar snouts and tongues that they use to capture ants. This is an example of _____ evolution.
convergent
The similar shapes of fast swimming marine predators are an example of _____ evolution.
convergent
_____ evolution happens when two species from different lineages independently evolve similar characteristics because they occupy similar environments.
convergent
_____ selection favors individuals at one extreme of a phenotypic range. Those individuals usually have greater reproductive success in a particular environment
directional
The genomes of threatened species can be mined to find genes that will lead to _____ reduction in those species.
disease
Beaks in African black-bellied seedcracker finches are small or large, but not intermediate in size. This is an example of _____ selection.
disruptive
Pseudogenes are genes that
do not produce a functional product
Genetic _____ leads to random changes between populations that may result in reproductive isolation.
drift
Genome sequence for pathogens can help researchers find suitable _____ targets used to eliminate the pathogens without harming the human host.
drug
Both the genomes of closely and distantly related organisms are useful in medical research; the former because they can be used in designed _____ to identify gene function, the latter because _____ sequences provide clues about the causes of disease.
experiments; conserved
Because genes can be _____ differently, species with nearly identical genomes (such as humans and chimps), can look and behave very differently.
expressed or regulated
As a result of polyploidization, the _____ of genes can be changed.
expression
Species with nearly identical genomes can look and behave very differently due to differences in the
expression of their genes
True or false: Within the same species, females and males usually employ the same reproductive strategy.
false
True or false: Polyploidy accounts for all genome size variation.
false- Other factors, such as ncDNA, are incorporated also.
In general, _____ are more likely to exhibit mate choice than _____.
females; males
Which of the following are reasons why island trees belong to plant families that typically do not have tree members (for example the sunflower family)?
Tree seeds rarely make it to isolated islands The tree niche is empty and so a flower can evolve through natural selection to be tree-like
Darwin's _____ likely evolved after an ancestral species colonized the Galapagos Islands and underwent character displacement as they adapted to the vacant ecological _____ available.
finches; niches
In _____ - _____ selection, the fitness of a phenotype depends on the proportion of individuals in the population that have that phenotype.
frequency dependent
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 the
fruit fly
Due to mutation without negative consequences, new character states may form more rapidly in regions of DNA that don't appear to have any
function
On occasion, the shuffling of parts of a gene due to a meiosis mistake can "land" the gene in a spot where it acquires a new
function or role
Promoting or constraining evolutionary change via the movement of beneficial or detrimental alleles into or out of a population is an effect of
gene flow.
In many cases, polyploidy induces the elimination of duplicated _____ or even whole _____
genes; chromosomes
A genome is the entire _____ sequence of an organism.
genetic
Evolution can result from any process that changes the ______ composition of a population.
genetic
Evolutionary change cannot occur in populations with no _____ variation.
genetic
the processes that lead to evolutionary change are mutations, natural selection, _______ drift, gene flow, and _____ mating.
genetic drift; nonrandom mating
The entire DNA sequence of an organism is called its
genome
Assortative mating changes ______ frequencies but does not change ______ frequencies.
genotype; allele
The accumulation of small changes at a relatively steady pace is known as
gradualism
The concept of _____ suggests that each new species evolves continuously over long spans of time.
gradualism
The idea that evolution occurs over time through the accumulation of small changes at a relatively steady pace is known as
gradualism
Many fishes that inhabit the sub-freezing Arctic and Antarctic waters posses antifreeze proteins; we now know that there are at least five different kinds of antifreeze protein genes that have evolved independently in different species to perform the same function. This is an example of:
convergent evolution
Structures that have evolved separately but look very similar exhibit _____ evolution; in contrast, structures that evolved through modification from a common ancestral trait are _____ structures.
convergent; homologous
Synthetic polyploids are created in the lab by _____ closely related plant species and then chemically inducing chromosome
crossing; doubling
Regarding the peppered moth, many studies have shown that in polluted areas, the ______ form of the moth is favored by natural selection, and in unpolluted areas, the ______ form of the moth is favored.
dark (melanic); light (peppered)
In the early 1850s, scientists noticed that the frequency of light colored peppered moths in polluted areas
decreased
biological species concept
defines species as " ... groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups."
Laboratory selection experiments have produced forms that cannot reproduce and thus would in nature be considered
different species
Evolutionary changes in the horse family can be related to changes in their habitat in North America (where most of the horse evolution has occurred); in particular, horse evolution was related to the widespread appearance of
grasslands
A type of sexual selection in which members of one sex, usually females, choose mates based on particular characteristics such as courtship songs is called
intersexual selection
_____ selection is a form of sexual selection based on same-sex competition usually involving males, in which the winner "gains" a mating partner.
intrasexual
One of the reasons for the large human genome is the presence of many relatively large _____ in our gene sequences.
introns
Because it favors those variations that lead to the highest reproductive fitness, natural selection:
is a non-random process
Darwin noted that _____ communities are often missing plants and animals typically found on continents.
island
Mechanisms that prevent genetic exchange between members of different species are termed reproductive _____ mechanisms and often play a role in plant and animal speciation. Listen to the complete question
isolating
Reproductive _____ is the key to the process of
isolation
Sometimes evolution can occur very rapidly and the number of derived shared characters can be small. In such cases, how is parsimonious analysis affected?
it can be inaccurate and misleading. similarity of species in this situation would more likely result from homoplasy than from inheritance from a common ancestor
A potential problem with the phylogenetic species concept is that
it may recognize even slightly differentiated populations as separate species.
β-catenin, Bmp4, PtchI, and Lbh are genes that determine the size and shape of the cichlid _____.
jaw
The human genome contains a
large amount of foreign DNA
The teeth of modern members of the horse family are
large with a complex pattern of ridges
Despite the _____ differences in their morphology and behavior, humans and chimps have accumulated _____ genetic differences since they last shared a common ancestor.
large; small
Evidence suggests that the human-specific mutations in FOXP2 gave early humans the ability to better use their brain to coordinate their _____ and _____, thus allowing them to speak.
larynx; mouth
Soon after it was established due to a founder effect, a population is expected to have (choose all that apply)
less genetic variation than the original larger population. different allele frequencies than the original larger population.
Peppered moths come in a variety of shades, from _____ gray with speckles to completely _____ (melanic).
light gray; black
Enzyme allele frequencies within a population may vary based on
location of the population.
What are the most likely fates of the duplicate gene after a gene duplication event?
lose function through mutation assume part of the function of the original gene gain novel function through mutation
Formation of a polyploid from two different species is usually followed by a rapid _____ of genes.
loss
what is a shared derived character for the group containing salamanders, lizards, tigers, gorillas, and humans?
lungs
Sequence analysis indicates that most of the transposon hitchhiking in the human genome seems to have occurred
many millions of years ago
Our genome carries how many transposons relative to the genomes of Drosophila, C. elegans or Arabidopsis.
many more
Aneuploids arise through mistakes in _____
meiosis
The jet black form of the peppered moth (Biston betularia) is also know as the _____ form.
melanic
Increased _____ may cause alteration of gene expression after polyploidzation.
methylation
The genome of a complex eukaryotic species normally evolves over
millions of years
A common criticism of evolution is that selection only produces ______ changes and cannot produce the variety of ______ documented in the fossil record.
minor; species
A _____ group includes its most recent common ancestor and all of its descendants, a _____ group includes its most recent common ancestor but not all of its descendants, and a _____ group does not include the most recent common ancestor of the organisms within the group.
monophyletic; paraphyletic; polyphyletic
The most commonly accepted hypothesis that explains industrial melanism and the reversal of industrial melanism is that
moths with coloration that matches their background are less susceptible to predation by birds
What is the ultimate source of all new alleles?
mutation
Changes in allele frequencies within a population may result from _____ which are changes in the nucleotide sequences of an organism's DNA.
mutations
Changes in allele frequencies within a population may result from _____, which are changes in the nucleotide sequences of an organism's DNA.
mutations
The primary process responsible for evolution is
natural selection
Antibiotic resistance in bacteria is an example of
natural selection.
Much of the human genome is composed of
ncDNA
In _____ frequency-dependent selection, individuals whose resource requirements are rarer have fewer competitors for resources than individuals whose resource requirements are more common.
negative
When a population is in Hardy-Weinberg equilibrium
no natural selection is occurring.
As more genomes are being sequenced, we have realized that much of the genome of organisms is composed of Blank 1 of 1 DNA, also known as ncDNA.
noncoding or intron
Darwin's theory of evolution is
not accepted by everyone in the general public
In nature, mutation rates are usually ______ to maintain alleles that are not favored in a population by natural selection.
not high enough
OR genes is an abbreviation used for _____ _____ genes.
olfactory receptor
Which of the following describes the handicap hypothesis?
only genetically superior mates can survive with such a handicap.
Natural selection results in a population better adapted to its environment because
only individuals who are well adapted to the environment contribute their alleles to the next generation.
When considering that Earth is an _____ system, it is easy to see that evolutionary theory does not violate the second law of thermodynamics.
open
Ground finches with large bills are favored during times of drought, while ground finches with small bills are favored during times when water is abundant. This is an example of
oscillating selection
In cladistics, a(n) _______ is a taxon that is closely related to, but not a member of, the group whose evolutionary relationships are being studied.
outgroup
Which is a correct version of the Hardy-Weinberg equation for genotype frequencies in a population in equilibrium?
p2 + 2pq + q2 = 1
Two genes in the genome of an organism that have arisen through the duplication of a single ancestor gene are called _____, in contrast, _____ are genes in different species that are derived from the same common ancestral gene.
paralogues; orthologues
_____ are chemicals produced by a species that trigger a social response
pheromones
In the Arabidopsis genome, many of the unique "plant" genes are involved in _____ and the anatomy required to perform it.
photosynthesis
3814 gene families are shared by every plant, from the algae to grapes and corn.
photosynthetic anatomy
According to the _____ species concept, a population should be considered a separate species if it has been evolving independently of other groups of populations.
phylogenetic
Scientists can distinguish between competing hypotheses on the patterns of biological diversity through the use of _____ methods.
phylogenetic
When more than one process could have caused a pattern in biological diversity that is observed today, what methods do scientists use to distinguish between those competing hypotheses?
phylogenetic methods
Varieties of which of the following organisms are the result of artificial selection?
pigeons dogs cats corn
Economically important organisms that have been modified significantly through artificial selection include
pigs corn cattle
As a result of convergent evolution, many marsupial mammals of Australia look similar to _____ mammals found elsewhere and occupy a similar ecological niche.
placental
Malaria is caused by parasites in the genus _____; humans are typically infected through the bite of the malaria vector - mosquitoes in the genus _____.
plasmodium; anopheles
Some genes can affect multiple aspects of an organism's phenotype. This phenomenon is known as
pleiotropy
Unintentional selection can be the result of linkage and
pleiotropy
In chickens, the same gene that affects a hen's comb also affects the rate at which the hen lays eggs. Tis is an example of
pleiotropy.
Scientists have observed that light colored moths decrease in abundance in areas that are
polluted
The following diagram shows the average number of gene pairs (Y axis) over time (X axis, about 75 million years are represented). The red dots on the diagram represent
polyploidy events
the study of genetic variation within populations
population genetics
reproductively isolated
populations whose members do not mate with each other or who cannot produce fertile offspring; members of different species
The type of selection demonstrated in the figure showing a fish with a rare phenotype attracting the attention of a predator is called
positive frequency-dependent selection
In _____ isolating mechanisms a hybrid zygote is formed, but it is unable to survive or reproduce due to developmental or genetic problems.
postzygotic
Hybrid inviability and hybrid infertility are two examples of
postzygotic isolating mechanisms.
reproductive isolating mechanisms
prevent genetic exchange between species
Ecological isolation, behavioral isolation, and temporal isolation are examples of _____ isolating mechanisms.
prezygotic
Ecological isolation, behavioral isolation, and temporal isolation are examples of _____ reproductive , Incorrect Unavailable isolating mechanisms.
prezygotic
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.
prezygotic; postzygotic
Molecular analysis of lactase DNA _____ in humans shows that genes for that enzyme have _____ evolved in Africa and Europe to produce the same result.
sequences; independently
Sexual selection favors traits that give males greater ability in mate competition, therefore males and females within the same species may exhibit different traits. This difference between the sexes of the same species is known as
sexual dimorphism
Derived characters are
shared with the most recent common ancestor of a group, but not with prior ancestors.
Barbara McClintock hypothesized that transposons could respond to genome _____ by jumping into a new position in the genome.
shock
Early systematics (before the advent of molecular sequencing) was based on overall _____ between species.
similarities
Single-base differences between individuals in a population are known as
single-nucleotide polymorphisms (SNPs).
Fast swimming marine predators such as dolphins, sharks, and tuna, have a _____ body shape that minimizes _____ in the water.
sleek; friction
The teeth of early members of the horse family (for example, Hyracotherium) were
small and relatively simple
Plasmodium falciparum, the organism that causes malaria, has a relatively
small genome
OR genes are responsible for our sense of
smell
Gene flow occurs only between populations that are in contact, however, and populations can become geographically isolated for a variety of reasons
speciation is much more likely in geographically isolated populations.
What types of conditions may lead to adaptive radiation?
species occurs in an environment with few other species and many available resources creation of new islands through volcanic activity catastrophic event leading to the extinction of most other species, a phenomenon termed mass extinction
_____ selection favors individuals with intermediate phenotypes and selects against individuals with extreme phenotypes.
stabilizing
A long period of little or no evolutionary change in a species is known as
stasis
Organisms that have had their genome sequenced and are closely related to humans can be used in _____ to identify gene function.
studies
Species that are _____ species can occur in the same location and are phenotypically different.
sympatric
_____ is the study of the evolutionary relationships among organisms.
systematics
The field of _____ involves the reconstruction and study of evolutionary relationships among organisms, whereas _____ uses that information to place organisms into taxonomic groups.
systematics; classification
A term used to indicate species or higher level groups, such as genera or families, is
taxa or taxon
The science of classifying organisms is termed
taxonomy
In frequency-dependent selection
the fitness of a phenotype depends on how common it is in the population
True or false: Genetic drift, mutations, and nonrandom mating are three agents that can act to produce evolutionary changes in a population.
true
True or false: It appears that polyploidy has occurred numerous times during the evolution of plants.
true
Artificial selection may result in traits that are
unintended undesirable intended desirable
Attempts to domesticate silver foxes by artificial selection resulted in the _____ selection of traits which produced silver foxes that were as tame as domestic dogs.
unintentional
The pace of evolution is ______.
variable
According to genome comparisons, the most likely hypothesis that explains why many microbes have a mix of bacterial and archaeal genes is
very high rates of horizontal gene transfer in the early history of prokaryotes
Prior to 1850, the melanic form of the peppered moth in Europe was:
very rare
Two types of structures in adult organisms that provide anatomical evidence for evolution are _____ and _____ structures.
vestigial and homologous
Which have genomes that can evolve in a matter of days?
viruses bacteria
Match the beak shapes of Galapagos finches to their feeding habits.
warbler finches- small narrow beaks ground finches- crushing beaks "vampire" finches- sharp beaks
The medium ground finch of the Galápagos islands feeds on small seeds, produced in abundance during _____ years.
wet
Fill in the blanks to complete the sentence. Early horses inhabited woody areas where they probably browsed leaves and escaped predators by dodging through openings; this explains why those animals had _____ feet and _____ legs.
wider feet; shorter legs
The short legs and broad feet of early horses made them well adapted to their habitat which was
wooded areas
As a result of epistasis, the selective advantage of an allele
would vary from one genotype to another.
Select all of the following that could cause evolutionary change by natural selection.
A moth that has a gene for cryptic coloration A plant with an enzyme that makes it disease-resistant
Select all of the following events that could lead to a population bottleneck.
A natural disaster such as an earthquake or flood An infectious disease that kills a large proportion of the population Human destruction of habitat
The diversification of Drosophila species in the originally vacant niches and frequently isolated habitat patches of the Hawaiian Islands is an example of which of the following?
Adaptive radiation
Why do humans have one fewer chromosome (when considering the haploid number) than great apes?
Because two medium sized chromosomes have fused together in humans.
The production of pheromones by an animal contributes to which of the following types of prezygotic isolating mechanisms?
Behavorial
The idea that species are defined based on the ability to interbreed with each other and exchange genes is the basis of which species concept?
Biological species concept
Kettlewell released peppered moths in Birmingham, a highly industrialized area, and Dorset, then an unpolluted wood. In which of the two areas did he recapture a higher proportion of dark moths?
Birmingham
According to the handicap hypothesis, why does a female benefit from choosing the male with the largest handicap?
By choosing males with a large handicap females ensure that their offspring will have genes that confer better survival chances despite the handicap.
How is a cladogram constructed?
By using shared derived characters are to construct clades within clades
Which of the following accurately describes the rates of variation in different parts of the human genome, as determined by the 1000 Genomes Project?
Certain parts of the human genome contain more variation than others.
Which of the following is a process in which natural selection favors individuals with traits that allow them to use resources differently than other individuals, and over time the species diverges in phenotype and resource use?
Character displacement
In a cladogram, what word describes an ancestral species and all of its descendants?
Clade
Which of the following are ways in which genome analysis is used to treat and prevent human diseases?
Comparing individual human genomes. Comparing the genomes of pathogens with those of its host. Comparing genomes between humans and closely related species.
The evolution of these organisms is an example of adaptive radiation because populations were isolated and adapted to newly formed islands or habitat patches formed by lava flows.
Hawaiian Drosophila
Which of the following is the most direct evidence for evolution?
Fossils
How did modern tobacco arise?
From a cross between two Nicotiana species with subsequent genome duplication
Speciation is more likely in geographically isolated populations because which of the following does not occur?
Gene flow
Which of the following agents of evolutionary change occurs when alleles move from one population to another?
Gene flow
Why do genomes evolve at different rates?
Generation times differ among taxa. Transposable elements commonly remodel the genomes of certain taxa.
How can model organisms such as the mouse be used to determine the cause of human diseases?
Genes shared by mice and humans can be studied in mice and the results can be applied to treat human diseases.
Evolutionary change is not caused by phenotypic variation if the phenotypic variation lacks which of the following?
Genetic basis
What process can promote speciation through random changes between isolated populations?
Genetic drift
Many 19th century scientists believed that natural selection always favored an optimal form, and therefore would tend to reduce or eliminate which of the following?
Genetic variation
To what degree are plant and animal genes conserved?
Great
How does natural selection affect allele frequencies?
It causes beneficial alleles to become more common. It causes detrimental alleles to become less common.
How does homoplasy affect cladistic analysis?
It causes organisms to seem closely related when they are not.
How has phylogenetic analysis been used in studies of the human immunodeficiency virus (HIV)?
It has revealed that HIV evolved from a simian virus. It has been used to track the transmission of the virus among individuals.
Which of the following are limitations of the biological species concept?
It is difficult to determine whether geographically isolated species would interbreed in nature as they do in artificial settings. Reproductive isolation cannot explain speciation in organisms that reproduce asexually. Interspecies hybridization occurs in nature more often than was thought.
By favoring different phenotypes at different times, oscillating selection acts in which way?
It maintains genetic variation in a population.
Which of the following statements are true regarding the use of the molecular clock?
It may be used to determine the timing of clade branching events for a particular molecule. The evolutionary changes in genes with a constant rate of change can be determined.
Geographic isolation can accelerate speciation due to which of the following reasons?
It restricts gene flow.
How has phylogenetic analysis led to a greater understanding of HIV and AIDS?
It revealed that multiple HIV strains arose independently from SIV. It revealed that humans have acquired HIV from multiple species.
Which of the following are true of the mass extinction that occurred at the end of the Permian period?
It was the most severe mass extinction. As many as 96% of all species went extinct.
Consider a gene with two alleles, one dominant, and the other recessive. If this population is in Hardy-Weinberg equilibrium with respect to this gene, what would happen to the dominant allele from generation to generation?
Its frequency will remain unchanged
Once the data are assembled, the first step in a cladistic analysis is to polarize the characters—that is, to determine whether particular character states are ancestral or derived.
Jaws
Which of the following is true about the reproductive strategies of males and females?
Males are selective in choosing a mate much less frequently than females.
How does the biological species concept define a species?
Members of a species are able to interbreed in nature and are reproductively isolated from members of other species.
Which of the following statements is true in regard to how scientists define species based on the biological species concept?
Members of different species may be able to successfully hybridize under artificial conditions, but don't do so in the wild.
Which of the following situations are consistent with partial reproductive isolation?
Members of two populations mate primarily with members of their own population, but occasionally hybridize. Hybrid offspring have lower fitness than non-hybrid offspring, but some hybrids survive and reproduce. Members of two populations live in the same habitat, but they do not breed due to differences in their mating rituals.
Early horses had four toes on the front feet and three toes on the hind feet, all encased in fleshy pads. What statement correctly describes how the toes have changed during the evolution of modern horses?
Modern horses have a single toe enclosed in a bony hoof.
Which of the following is not an example of convergent evolution?
Muscles that wiggle the ears of humans and other mammals
What can a duplicated gene do after gene duplication that will result in a novel trait?
Mutate without a detrimental effect on the organism
How does homoplasy arise in DNA sequences?
Mutation of the same nucleotide base occurs independently in two lineages.
Select all of the following processes that can cause changes in allele or genotype frequencies in populations.
Mutations Genetic drift Gene flow Natural selection Nonrandom Mating
The following graph plots the relationship between beak depth of medium ground finches and their offspring. What can you conclude from that graph (choose all that apply)?
Parents with small beaks tend to have offspring with small beaks Beak depth seems to be a genetically inherited trait Parents with large beaks tend to have offspring with large beaks
In Northeastern South America, which of the following is the main predator in streams found just below waterfalls?
Pike cichlids
The extinction of the dinosaurs led to adaptive radiation in what group of animals?
Placental mammals
The presence of three or more chromosome sets is called
Polyploidy
_____ is the state of a cell or organism having more than two paired sets of chromosomes.
Polyploidy
Which of the following correctly links geographic isolation to speciation?
Populations living in geographically separated areas can undergo allopatric speciation
Which type of selection favors common phenotypes and tends to eliminate variation?
Positive frequency-dependent selection
Choose all the components of fitness from the list below:
Production of viable, numerous offspring Individual survival Mating success
When constructing phylogenies, the assumptions of the principle of parsimony may be violated under what conditions?
Rapid evolution of characters
How has rock and fossil dating changed since Darwin's times?
Relative dating was used in the past; today we use absolute dating.
What type of isolation occurs when members of one species are unable to successfully interbreed with members of another species?
Reproductive
Which characteristic of cichlids enabled them in their evolutionary radiation?
Second set of functioning jaws
A deer's antlers, a ram's horns and the bright plumage of a male paradise bird are all examples of which of the following?
Secondary sexual characteristics
How is the size of a population related to the likelihood that the population will experience genetic drift?
The larger the population, the lower the chance of genetic drift is.
What appears to determine variations in the coloration, size and maturation of guppies in northeastern South American streams?
The location of streams relative to waterfalls
What is gene flow?
The movement of alleles into or out of a population.
Select the conditions that must be met for a population to be in Hardy-Weinberg equilibrium.
The population is very large. No new mutations occur. Mating is random.
Select all of the following that can result from assortative mating.
The proportion of heterozygotes in the population decreases. The proportion of homozygotes in the population increases.
When genotypes differ in their resource requirements, which genotype has an advantage (assuming different resource types are equally abundant)?
The rarer genotype
Outside of mass extinctions, how has the rate of speciation compared to the rate of extinction over the past 600 million years?
The rate of speciation has surpassed the rate of extinction.
What is fitness?
The relative likelihood that a genotype will contribute to the gene pool of the next generation
What is systematics?
The study of evolutionary relationships among organisms
Select all of the following that are true about SNPs.
These are defined as single-base differences between individuals that exist in the population at more than 1%, several million have been noted in the human genome.
In Michigan, two different species of gray treefrogs, Hyla versicolor and Hyla chrysoceles, can exist in the same pond at the same time. The two species are anatomically very similar, but their mating calls differ. How would you describe the existence of such similar species in the same location?
They are sympatric species.
How can pharmaceutical researchers use genome sequence information to create new drugs against pathogens?
They can search the pathogen genomes for genes that are suitable drug targets.
In many animals, structures used for fighting, such as horns, have evolved to be larger in males because of which of the following?
They confer an advantage in intrasexual competition
Which describes male guppies located below South American waterfalls where predation is high?
They exhibit drab coloration.
Which of the following is true about transitional fossils (choose all that apply)?
They illustrate how major transitions in life occurred. They help to fill in the gap in the fossil record between two separate groups.
Organisms that exhibit polyploidy have how many sets of chromosomes?
Three or more
Most of the species that we use as food do not look like their ancestral species anymore. How have humans achieved that?
Through artificial selection
Where has industrial melanism been observed?
Throughout Eurasia and North America
How has the fossil record changed since Darwin?
Today the fossil record is far more complete.
How are traits produced by convergent evolution different from homologies?
Traits produced by convergent evolution have not evolved from a common ancestral trait, while homologies have.
True or false: Populations of a single species that connect those that are more geographically separated are often intermediate phenotypically when compared to the separated populations.
True
True or false: Some populations that are considered to be separate species can interbreed and produce fertile offspring.
True Reason: However, they do not do so under natural conditions. An example is the tiglon, which is a hybrid of lions and tigers. It can be produced in captivity, but is not found to occur in the wild.
Which of the following is the cause of Chagas disease?
Trypanosoma cruzi, an insect-borne protozoan, kills about 21,000 people in Central and South America each year.
Select all of the following that contributed to the adaptive radiation of Darwin's finches on the Galápagos Islands.
Vacant ecological niches Lack of many types of mainland birds Geographic isolation
Select all of the following criteria that must be present for natural selection to occur and cause evolutionary change in a population.
Variation must result in differences in the number of offspring surviving in the next generation. Variation must have a genetic basis. Variation must exist among individuals.
Research regarding the pace of evolution in well-documented groups of species has shown that the pace of evolution does which of the following?
Varies depending on the group of species
How are genes transferred during vertical and horizontal gene transfer?
Vertical - from parents to offspring; horizontal - between different species
Which of the following are anatomical features that provide evidence for evolution?
Vestigial structures Early embryonic similarities Homologous structures
Sometimes two different species can hybridize. If the hybrid undergoes a genome duplication, the result is an organism called
an allopolyploid
Derived characters are only shared with the most recent common ancestor of a clade, whereas _____ characters are shared with the most recent common ancestor as well as earlier ancestors.
ancestral or plesiomorphic
A clade consists of a common _____ species and all of its _____ species.
ancestral; descendant
The duplication or loss of a single chromosome (instead of the entire genome) is called
aneuploidy
Consider two populations (population A and population B) of the same plant species and the gene Xx. Researchers discover that there is constant flow of the x allele from population B into population A. This allele happens to be detrimental to individuals in population A because of the local soil conditions. In this case gene flow
appears to be constraining evolutionary change.
Most of the species that humans use as food have been modified through _____ selection.
artificial
The great variety of breeds of cats, dogs and other domestic animals have arisen through
artificial selection
The odd proportions of dachshunds have resulted from
artificial selection for dogs that could enter narrow badger holes
A seemingly irreducible complex structure can evolve by natural selection because
as natural selection acts to modify a complex system, the system is functional at each evolutionary stage.
The type of nonrandom mating in which phenotypically similar individuals mate is called _____ mating.
assortative
In _____, the genome of one species is duplicated because of a meiotic error leading to four copies of each chromosome, while _____ results from a hybridization of two species followed by genome duplication.
autopolyploidy; allopolyploidy
Polyploid individuals can arise in two ways. In _____, all of the chromosomes come from a single species and in _____ two species may hybridize.
autopolyploidy; allopolyploidy
The ______ species concept defines a species as a group of individuals that is able to interbreed, producing viable and fertile offspring.
biological
Genome sequencing has revealed many organisms that contain a mix of _____ and _____ genes.
bacterial; archaeal
When researchers raised guppies in laboratory pools with high levels of predation, the guppies in those aquariums
became smaller and drab in coloration as a result of natural selection after about 10 generations.
After a gene duplication event, which is not one of the most likely fates of the duplicate gene?
become a transposon
The following graph indicates the actual size of beaks of ground medium finches in a given year for almost two decades. Would you predict a span of wet years, a span of dry years, or a span of average years for the finches in the left box?
dry years What you should focus on is the change in beak size over time. In the left box there is a sharp increase of average beak size, therefore, you can conclude those years were dry.
In humans, the three most gene-rich chromosomes have undergone the highest amount of gene ______.
duplication
______ isolation is another term for environmental isolation.
ecological
We know that selection can occur based on climatic conditions, because biologists have found that
enzyme allele frequencies can vary with geographic latitude.
Regarding the three domains of life, current thought suggests that Archaea are more closely related to _____ than they are to _____
eukaryotes; bacteria
In theory, if mutation rates were high enough, alleles could be maintained in a population
even if the alleles are not favored by natural selection.
Genetic variation is necessary for _____ change to occur.
evolutionary
Phylogenies can be used to determine _____ relationships between species.
evolutionary
Gene duplication provides an opportunity for genes to _____ in their functions because after duplication a "backup" pair of genes is in place.
evolve
According to the phylogenetic species concept, a species is a population that
has evolved independently of other groups of populations
Consider a gene with two alleles, A1 and A2. If the fitness of A1A2 individuals is higher than the fitness of both A1A1 and A2A2, we are observing
heterozygote advantage.
The sickle-cell anemia allele is maintained at relatively high frequencies in some human populations because
heterozygotes for the disease allele are resistant to malaria.
Heterozygote advantage can maintain an allele that is deleterious when it is recessive because
heterozygotes have the highest fitness.
Artificial selection has resulted in all of the following outcomes in agriculture except
higher susceptibility to disease in tomatoes
_____ structures are those that are derived from the same body part in a common ancestor.
homologous
Similarities between species that occur because the species are derived from a common ancestor are referred to as
homologous traits
______ traits are derived from the same ancestral structure or source whereas _____ traits only appear similar, arising independently through convergent evolution.
homologous; homoplastic
The forelimbs of vertebrates are an example of _____, while the human appendix is an example of a _____ structure.
homologous; vestigial
There are two main types of reproductive isolating mechanisms, depending on whether or not a zygote is formed when two individuals attempt to mate. Behavioral, temporal, and mechanical isolation and prevention of gamete fusion are examples of _____ isolating mechanisms whereas hybrid inviability and infertility are _____ isolating mechanisms. Listen to the complete question
prezygotic; postzygotic
Current evidence suggests that the common ancestor of Bacteria and Archaea was most likely an early
prokaryote
The common ancestor of Bacteria and Archaea was most likely an early
prokaryote
Gene flow may (choose all that apply)
promote evolutionary change. remove alleles from a population. introduce new alleles to a population. reduce evolutionary change.
Genome comparisons aid conservation biology by
providing information on genes involved in diseases
When errors in meiosis rearrange parts of genes, the most common result is the appearance of a
pseudogene
Genes that do not produce a functional product are known as
pseudogenes
One consequence of mass extinctions is that dominant species may go extinct, allowing other species to undergo adaptive _____ to use the newly freed resources.
radiation
Because there is no natural selection against mutations in regions of DNA that are nonfunctional, evolution in those regions occurs more _____.
rapidly
industrial melanism
refers to the phenomenon in which darker individuals come to predominate over lighter ones
Match the type of rock dating with its description.
relative dating- rocks are dated based on their position absolute dating- rocks are dated based on changes in their isotopic composition
Evidence shows that polyploidy has occurred
relatively often during the evolution of plants.
Features that increase the chance that a male will be chosen by a female (for example, bright plumage in many male birds) are known as _____ _____ characteristics.
secondary sexual
According to some critics of evolution, natural selection can produce changes in a population, but it cannot cause substantial changes leading to
the formation of an entirely new species.
On a branching diagram, what does the joining of twigs and branches represent?
the joining of twigs and branches reflects the pattern of common ancestry back in time to the single common ancestor of all life
Peter and Rosemary Grant studied natural selection in Galápagos finches for more than 40 years; which species was the focus of their research?
the medium ground finch
New mutations are not a major factor affecting the allele frequencies in a population because
the rate at which new mutations occur is low
What is the main assumption behind the idea of a molecular clock?
the rate of evolution of a molecule is constant through time
On a branching diagram, where should existing species be placed?
the twigs of the tree represent existing species
Evolution is supported by a substantial body of evidence and explains a wide range of observations, thus it is considered a scientific
theory
For a population to be in Hardy-Weinberg equilibrium,
there must be no migration into or out of the population.
Complex characters, such as the ability to fly or the human eye, usually evolve
through a progression of gradual transitions, starting out as an adaptation for some other purpose
Most complex characters evolve
through a series of evolutionary transitions
The average number of gene pairs is shown here as the Y axis, while time is shown on the X axis. About 75 million years are represented. The arrows pointing to the blue line indicate
times of gene loss after polyploidy
In recent years, scientists have discovered remarkable fossils, such as a four-legged aquatic mammal and a snake with legs. These are examples of
transitional fossils
The relative amounts of _____ elements allows some genomes to evolve faster than others.
transposable
In very distant ancestor genomes several million years ago, sequence analysis suggests that human genome acquired most its
transposons