Test Bank- Exam 1 Flashcards
Darwin and Wallace’s theory of evolution by natural section was revolutionary because it________.
Stated species are not constant and emphasized the importance of variation and change in populations.
Catastrophism was Cuvier’s attempt to explain the existence of________.
the fossil record
With what other idea of his time was Cuvier’s theory of catastrophism most in conflict?
Uniformitarianism
Prior to the work of Lyell and Darwin, the prevailing belief was that Earth is______.
A few thousand years old, and populations are unchanging.
During a study session about evolution, one of your fellow students remarks, “the giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result.” Which statement is most likely to be helpful in correcting this student’s misconception?
characteristics acquired during an organism’s life are generally not passed on through genes.
When Cuvier considered the fossils found in the vicinity of Paris, he concluded that the extinction of species_______.
Occurs, but that there is no evolution
If x indicates the location of fossils of two closely related species, then fossils of their most-recent common ancestor are most likely to occur in which stratum?
the layer under where the x is located because it is their most recent common ancestor.
If x indicates the fossils of two closely related species, neither of which is extinct, then their remains may be found in how many of these strata?
two strata
phylogony
Which pair of scientists would probably have agreed with the process that is depicted by this tree
Lamarck and Wallace
The cow Bos Primigenius (which is bred for meat and milk) has a smaller brain and larger eyes than closely related wild species of ungulates. These traits most likely arose by______.
artificial selection, because changes in these traits co-occurred with human selection for high milk output and high muscle content
Starting from the wild mustard Brassica oleracea, breeders have created the strains known as Brussels sprouts, broccoli, kale and cabbage. Therefore, which of the following statements is correct?
in this wild mustard, enough heritable variation
which of the following scientists argued that variation among individuals allows evolution to occur?
Wallace
which of these conditions are always true of populations evolving due to natural selection?
Condition 1: The population must vary in traits that are heritable.
Condition 2: Some heritable traits must increase reproductive success.
Condition 3: Individuals pass on most traits that they acquire during their lifetime.
Conditions 1 and 2
A farmer uses triazine herbicide to controls pigweed in his feild. for the first few years, the triazine works well and almost all the pigweed dies; but after several years, the farmer sees more and more pigweed. What is the best explanation for why this happens?
Triazine-resistant weeds were more likely to survive and reproduce.
After the drought of 1977, researchers on the island of Daphne Major hypothesized that medium ground finches that had large, deep beaks, survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus Cistoides fruits. If this hypothesis is correct, what would you expect to observe if a population of these medium ground finches colonizes a nearby island where Tribulus Cistoides is the most abundant food for the next 1000 yrs? Assume that (1) eve the survivors of the 1977 drought sometimes had difficulty cracking the tough T. Cistoides fruits and would eat other seeds when offered a choice; and (2) food availability is the primary limit on finch fitness on this new island.
Evolution of yet larger, deeper beaks over time
After the drought of 1977, researchers hypothesized that on the Galápagos island Daphne Major, medium ground finches with large, deep beaks survived better than those with smaller beaks because they could more easily crack and eat the tough Tribulus cistoides fruits. A tourist company sets up reliable feeding stations with a variety of bird seeds (different types and sizes) so that tourists can get a better look at the finches. Which of these events is now most likely to occur to finch beaks on this island?
increased variation in beak size and shape over time.
Darwin and Wallace were the first to propose_____.
Natural Selection as the mechanism of evolution
a population of organisms will not evolve if________.
all individual variation is due only to environmental factors
Which of the following represents an idea that Darwin learned from the writings of Malthus?
Populations tend to increase at a faster rate than their food supply normally allows.
Given a population that contains genetic variation, what is the correct sequence of the following events under the influence of natural selection?
- well-adapted individuals leave more offspring than do poorly adapted individuals.
- a change occurs in the environment
- genetic frequencies within the population change.
- poorly adapted individuals have decreased survivor ship.
2-4-1-3
what must exist in a population before natural selection can act upon that population?
Genetic variation among individuals
Which of Darwin’s ideas had the strongest connection to his reading of Malthus’s essay on human population growth?
the struggle for existence
if Darwin had been aware of genes and their typical mod of transmission to subsequent generations, with which statement would he most likely have been in agreement?
if natural selection can change gene frequency in a population over generations, given enough time and genetic diversity, then natural selection can cause sufficient genetic change to produce new species from old ones.
the role that humans play in artificial selection is to_____.
choose which organisms reproduce.
Two extant elephant species (x and y) are classified in the genus Loodonta, and a third species (z) is placed in the genus Elephas. What must be true about the three elephants?
Species x and y share a greater number of homologies with each other than either does with species z.
Many crustaceans (lobsters, shrimp and crayfish) use their tails to swim, but crabs have reduced tailsthat curl under their shells and are not used in swimming. This is an example of ______.
vestigial trait- anatomical structure that no longer serves a purpose
what, if discovered, could refute our current understanding of the pattern of evolution?
diverse fossils of mammals in Precambrian rock
Scientific theories______.
are supported by, and make sense of, many observations
DDT was once considered a “silver bullet” that would permanently eradicate insect pests. Instead, DDT is largely useless against many insects. What would have prevented this evolution of DDT resistance in insect pests?
none of the insect pests would have genetic variations that resulted in DDT resistance
If the bacterium Staphylococcus aureus experiences a cost for maintaining one or more antibiotic-resistance genes, what would happen in environments that lack antibiotics?
these bacteria would be outcompeted and replaced by bacteria that have lost these genes.
Of the following anatomical structures, which is homologous to the bones in the wing of a bird?
bones in the flipper of a whale
Structures as different as human arms, bat wings, ad dolphin flippers contain many of the same bones, which develop from similar embryonic tissues. These structural similarities are an example of______.
Homology
Over long periods of time, many cave-dwelling organisms have lost their eyes. Tapeworms have lost their digestive systems. Whales have lost their hind limbs. How can natural selection account for these losses?
costs out-weighed the benefits of these structures given a circumstance that persisted for a long period.
What evidences most strongly supports the common origin of all life on Earth? All organisms______.
use essentially the same genetic code
Members of two different species possess a similar-looking stucture that they use in a similar way to preform about the same function. What would suggest that the relationship more likely represents homology instead of convergent evolution?
The two species share many proteins in common, and the nucleotide sequences that code for these proteins are almost identical
what must be true of any organ described as vestigial?
it must be homologous to some feature in an ancestor
Pseudogenes are_______.
nonfunctional vestigial genes
It has been observed that organisms on islands are different from, but closely related to, similar forms found on the nearest continent. This is taken as evidence that______.
island forms are descended from mainland forms
Given what we know about evolutionary biology, we expect to find the largest number of endemic species in which of the following geological features, which have existed for at least a few million years?
an isolated ocean island in the tropics
The greatest number of endemic species is expected in environments that are_________.
isolated and show little ecological diversity
Evolutionary trees are properly understood by scientists to be__________.
hypotheses
Logically, what should cast the most doubt on the relationships depicted by an evolutionary tree?
relationships between DNA sequences among the species did not match relationships between skeletal patterns.
Modern definition of evolution
descent with modification
What variable is likely to undergo the largest change in value resulting from a mutation that introduces a new allele into a population at a locus for which all individuals formerly had been fully homozygous?
average heterozygosity
what statement best fits the beak size of finches on the island of Daphne Major during a prolonged drought?
each bird’s survival was strongly influenced by the depth and strength of its beak as the drought persisted
what is true about variation?
All new alleles are the result of nucleotide variability
Genetic variation________.
must be present in a population before natural selection can act upon the population
Cysticfibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. If 9 in 10,000 newborn babies have the disease,what are the expected frequencies of the dominant (A1)and recessive (A2) alleles according to the Hardy-Weinberg model?
9—- .0009
sqroot .0009=.0300
p+q=1
1-.0300=0.9700
Dominant- .9700
Recessive- .0300
