Exam 1 Barry
A few individuals of a population become separated and begin populating a new area. The resultant genetic make-up of this population would be a consequence of _____________ founder effect bottleneck effect gene flow none of these
founder effect
Soon after the island of Hawaii rose above the sea surface (somewhat less than 1 million years ago) and organisms colonized the island, the evolution of life on this new island should have been most strongly influenced by ________. habitat differentiation genetic bottleneck founder effect sexual selection
founder effect
A few individuals move between populations. This is an example of what? Gene flow, non-random mating, genetic drift, or natural selection?
gene flow
What does the biological species concept use as the primary criterion for determining species boundaries? niche differences gene flow morphological similarity molecular (DNA, RNA, and protein) similarity geographic isolation
gene flow
Small populations are especially susceptible to what?
genetic drift
What term is used to describe all the alleles at every focus for all individuals within a population?
gene pool
Evolution is a change in the _____ of a _____ over time Fill in the blank: individual phenotype population gene pool equilibrium
gene pool population
For a biologist studying a small fish population in the lab, which Hardy- Weinberg condition is the easiest to meet? no gene flow random mating no genetic drift no selection no mutation
no gene flow
Which assumption must be met for a population to be in Hardy-Weinberg equilibrium for a specific gene?
no genetic drift can affect allele frequencies for the gene.
Which of the following could be a vicariance event? The level of water in a lake recedes, creating two lakes, where there used to be one Radiation near Chernobyl increases mutation rates, causing an increase in autopolyploidy Some insects get blown in a storm to a new mountain range, where they lay eggs
The level of water in a lake recedes, creating two lakes, where there used to be one
In the Sierra Nevada mountains of California, the monkeyflower Mimulus lewisii lives at high elevation and attracts bumblebee pollinators, whereas the closely related monkeyflower M. cardinalis lives at lower elevation and attracts hummingbird pollinators. Which type(s) of prezygotic or postzygotic mechanisms of reproductive isolation apply? The monkeyflowers are experiencing mechanical isolation because they are attracting different pollinators, which means the sperm in the pollen from one population will not be carried to the eggs in the ovules in the other population. The monkeyflowers are experiencing behavioral isolation because they live at different elevations. They also have habitat isolation because they are attracting different pollinators, which means the sperm in the pollen from one population will not be carried to the eggs in the ovules in the other population. The monkeyflowers are experiencing a gametic barrier because the sperm in the pollen from one population will not be carried to the eggs in the ovules in the other population. The monkeyflowers are experiencing habitat isolation because they live at different elevations. They also have behavioral isolation because they are attracting different pollinators, which means the sperm in the pollen from one population will not be carried to the eggs in the ovules in the other population.
The monkeyflowers are experiencing habitat isolation because they live at different elevations. They also have behavioral isolation because they are attracting different pollinators, which means the sperm in the pollen from one population will not be carried to the eggs in the ovules in the other population.
Which species concept would be most useful to a team of biology students conducting a biodiversity survey on their campus? The biological species concept All species concepts would be equally useful. The phylogenetic species concept The morphospecies concept
The morphospecies concept
If you understand how ancestor−−descendant relationships are shown in trees, you should be able to draw a small tree that shows the relationship between humans and our closest living relatives, chimpanzees, and label and explain what the node means. The node represents an outgroup, a taxon that is not part of the taxonomic groups being studied. The node is the point where the chimpanzee and human branches meet. This is the inferred ancestor of chimpanzees and humans (which is neither chimpanzee nor human). The node represents an ancestral trait that existed in a common ancestor. The node represents the root, the most ancestral branch in the tree.
The node is the point where the chimpanzee and human branches meet. This is the inferred ancestor of chimpanzees and humans (which is neither chimpanzee nor human)
Given that phylogenies are based on shared derived characteristics, which of the following traits is useful in generating a phylogeny of species W, X, Y, and Z? Trait 1 Trait 2 Trait 3 Traits 1, 2, and 3
Trait 2
QUANTITATIVE In a population of 3400, how many babies would you expect to have cystic fibrosis, a homozygous recessive condition, if the frequency of the dominant allele is 0.8 and the population is at Hardy-Weinberg equilibrium? 0.2×0.2×3400=136 2×0.2×3400=136 2×0.8×0.2×3400=1088 2×0.8×0.2×3400=108 80.8×0.2×3400=544 0.8×0.2×3400=544 0.8×3400=2720 0.8×3400=2720
0.2×0.2×3400=136
Plant Species A has a diploid number of 12. Plant Species B has a diploid number of 16 . A new species C, arises as an allopolyploid from A and B. The diploid number would probably be ______
28
What variable in the Hardy-Weinberg equation describes the expected proportion of heterozygotes?
2pq
Genetic drift occurs in a population. Which of the following statements might be TRUE? Genetic drift decreased the population's fitness. Genetic drift increased the population's fitness. The population was relatively small. The population experiences a decrease in genetic variation. Any of these statements can be true.
Any of these statements can be true.
What is wrong with the statement: Archaeopteryx is more closely related to Aurornis than to living birds? Aurornis is more closely related to living birds than to Archaeopteryx. Aurornis and living birds share a more recent common ancestor than either does with Archaeopteryx. Archaeopteryx is actually more closely related to Balaur. Archaeopteryx and living birds share a more recent common ancestor than either does with Aurornis.
Archaeopteryx and living birds share a more recent common ancestor than either does with Aurornis.
The first winged insects appeared in the Devonian period, more than two hundred million years before the first birdlike reptiles appeared in the Jurassic period. Is flight an example of homology or convergent evolution? Explain. Flight must be a convergent trait in birds and insects because of the anatomical similarities of their wings. Since birds and insects are all in the animal kingdom, a monophyletic group, flight must be homologous among birds and insects .Flight in birds and insects is an example of homology since both can achieve powered flight using wings in the gaseous atmosphere. Flight evolved independently in birds, insects, bats, and extinct pterosaurs, so it is an example of convergent evolution.
Flight evolved independently in birds, insects, bats, and extinct pterosaurs, so it is an example of convergent evolution.
true or false: Natural selection creates new traits/ alleles
False
Determine what is incorrect in the following statement: Red deer mutated their genes so that they could have larger antlers to compete for mates. Mutations do not occur because an organism wants or needs them. However, when they happen, they are beneficial for the species. Red deer did not mutate their genes. There are two widely spread species of deer. They look similar but differ in the size of antlers. Mutations do not occur because an organism wants or needs them. They just happen randomly and can be beneficial, neutral, or deleterious. Mutations do not occur because an organism wants or needs them. However, they can happen as a result of migration or change of the food chain.
Mutations do not occur because an organism wants or needs them. They just happen randomly and can be beneficial, neutral, or deleterious.
The common edible frog of Europe is a hybrid between two species, Rana lessonae and Rana ridibunda. The hybrids were first described in 1758 and have a wide distribution, from France across central Europe to Russia. Both male and female hybrids exist, but when the hybrids mate with other hybrids or with adults of either species, they are rarely successful in producing offspring. What can you infer from this information? These two species are likely in the process of fusing back into one species. Prezygotic isolation exists between the two frog species. Postzygotic isolation exists between the two frog species. The hybrids form a separate species under the biological species concept.
Postzygotic isolation exists between the two frog species.
What is wrong with the statement: Tyrannosaurus rex (Tyrannosauroidea) is an ancestor of living birds? T. rex is not an ancestor of living birds as they diverged too long ago. T. rex and living birds share a common theropod ancestor, but T. rex is not a direct ancestor of birds. T. rex is not an ancestor of living birds because they share their ancestor with Enantiornithes. T. rex and living birds share a common bird ancestor, but T. rex is not a direct ancestor of birds.
T. rex and living birds share a common theropod ancestor, but T. rex is not a direct ancestor of birds
There is an island in the middle of a large river that houses a large population of ants. Damming of the river causes the island to flood and only the highest points of the island are now above water. The ants cannot swim, so are now in multiple isolated populations. Which of the following best describes this event? This situation represents a form of sympatric speciation. This situation represents isolation by dispersal. Only a rare development of polyploidy could lead to speciation in this case. This situation represents isolation by vicariance. Speciation will not occur in this case because of gene flow.
This situation represents isolation by vicariance.
Three populations of crickets look very similar, but the males have courtship songs that sound different. What function would this difference in song likely serve if the populations came in contact? a postzygotic isolating mechanism a gametic reproductive isolating mechanism a behavioral reproductive isolating mechanism a temporal reproductive isolating mechanism
a behavioral reproductive isolating mechanism
Evolution in a population of lizards can be caused by the following: natural selection genetic drift gene flow all of the above both natural selection AND genetic drift
all of the above
House finches were found only in western North America until 1939, when a few individuals were released in New York City. These individuals established a breeding population and gradually expanded their range. The western population also expanded its range somewhat eastward, and the two populations have recently come in contact. If the two forms were unable to interbreed when their expanding ranges met, it would be an example of _____. autopolyploidy sympatric speciation reinforcement prezygotic isolation allopatric speciation
allopatric speciation
Over time a new stream has formed from water run off down the mountain face. If the speciation event occured due to the formation of the stream, what type of speciation is described?
allopatric speciation
Triticale (a hybrid formed by crossing wheat and rye) is an ______- polyploid. If wheat and rye grew together in the wild and the cross naturally occured , it would be considered an example of ____- patric speciation
allopolyploid, sympatric
f gene flow into a population introduces a _______ allele, fitness will _____; but if gene flow introduces a _______ allele, fitness will ________.
beneficial allele, go up,deleterious allele, go down
fill in the blank Disruptive selection is the selection for _________. This causes an _____ in genetic diversity only one phenotype average phenotype no phenotype increase decrease no change
extreme phenotypes increase
The average seed size of palms has ________in the absence of toucans, presumably because _________ seeds have _____ fitness in the absence of toucans.
declined, smaller, and higher
The relatively rapid speciation of Galapagos mockingbirds on the different Galapagos islands from a single ancestral species is an example of __________
dispersal and allopatric speciation
In a population of insects, both very large and very small individuals are successful at mating, but medium sized individuals are not. This is an example of
disruptive selection
Which of the following is most likely to produce an African butterfly species in the wild whose populations show two strikingly different color patterns? stabilizing selection disruptive selection sexual selection artificial selection directional selection
disruptive selection
On the G-table, the total number of expected individuals should be... equal in number to the observed individuals greater in number than the observed individuals equal to the natural log of the observed individuals always a fraction of the number of the observed individuals
equal in number to the observed individuals
Martin Wikelski and L. Michael Romero (Body size, performance, and fitness in Galápagos marine iguanas, Integrative and Comparative Biology 43 [2003]: 376-86) measured the snout-to-vent (anus) length of Galápagos marine iguanas and observed the percent survival of different-sized animals, all of the same age. The graph shows the log snout-vent length (SVL, a measure of overall body size) plotted against the percent survival of these different-sized classes for males and females. Wikelski and Romero (2003) found that large marine iguanas had higher reproductive success than smaller iguanas. However, the large iguanas were generally in poor body condition because they could not eat enough; at higher temperatures, their foraging efficiency improved, allowing them to eat more. Thus, Wikelski and Romero hypothesized that iguana size will ________ as global climate change increases air and water temperatures in the Galápagos Islands.
increase
Which of the following groups could be identified using the biological species concept? Select all that apply. bacteria living today lizard species living today sunflower species living today extinct dinosaurs
lizard species living today sunflower species living today
According to the biological species concept, a species is a naturally occurring group of organisms that ____
produce viable and fertile offspring cannot produce viable and fertile offspring with another species interbreed in nature
Most Swiss Starling produce four to five eggs in each clutch. Starlings producing fewer or more than this have reduced fitness. Which of the following best describes this situation?
stabilizing selection
Considering the phylogenetic trees shown here as strictly hypothetical and applying the principle of parsimony to the trait "ability to fly," which of the two phylogenetic trees shown is better? Tree 1 Tree 2 Both trees are equally parsimonious. Since the trees show different evolutionary relationships, you cannot determine which is more parsimonious.
tree 1
True or false? Gene flow can either increase or decrease the average fitness of a population.
true