Biology Ch 23: Broad Patterns Of Evolution

Hadean Eon

Archaean Eon

Proterozoic Eon

Paleozoic Era

Mesozoic Era

Cenozoic Era

Researchers investigated whether differing modes of dispersal could explain differences in the longevity of fossil species in one taxon of marine snails, the family Volutidae. Some volute snails had planktonic larvae that could disperse over great distances on ocean currents. Other volute snails had nonplanktonic larvae, which developed directly into adults without a swimming stage. The dispersal of snails with nonplanktonic larvae was limited by the distance they can crawl as adults. The researchers studied the distribution of volute snail fossils in outcrops of sedimentary rocks along North America's Gulf Coast. The rocks formed during the early Paleogene period, between 66 and 37 million years ago, and contain many well-preserved snail fossils. Based on features of the snail's shell, the researchers classified each fossil species as having planktonic or nonplanktonic larvae. Each bar in the figure shows how long one snail species persisted in the fossil record. You can estimate quantitative data (fairly precisely) from a graph. The first step is to obtain a conversion factor by measuring along an axis that has a scale. In this case, 25 million years (from 60 to 35 million years ago on the x-axis) is represented by a certain distance in centimeters. Measure that distance on your screen or in your textbook. Then use that distance to generate a conversion factor (a ratio) of million years/cm. To estimate the time period represented by a horizontal bar on this graph, measure the length of that bar in centimeters and multiply that measurement by the conversion factor. For example, if you calculated a conversion factor of 3.6 my/cm, a bar that measures 1.1 cm on the graph represents a persistence time of 1.1 cm × 3.6 my/cm = 4 million years. Estimate the mean (average) persistence of species with nonplanktonic larvae. 1 million years 2.2 million years 5 million years 28 million years

Estimate the mean (average) persistence of species with planktonic larvae. 2.2 million years 4.4 million years 9 million years 15 million years

How many new species of snails with nonplanktonic larvae arose between 50 and 35 million years ago? How many new species of snails with nonplanktonic larvae arose between 50 and 35 million years ago? 5 species 8 species 21 species 28 species

How many new species of snails with planktonic larvae arose between 50 and 35 million years ago? How many new species of snails with planktonic larvae arose between 50 and 35 million years ago? 5 species 7 species 8 species 13 species

Select a plausible hypothesis to explain the difference in mean persistence of snail species with planktonic and nonplanktonic larvae. Select a plausible hypothesis to explain the difference in mean persistence of snail species with planktonic and nonplanktonic larvae. Snails with nonplanktonic larvae produce fewer offspring than snails with planktonic larvae. Snails with nonplanktonic larvae have more limited distributions than snails with planktonic larvae. Snails with nonplanktonic larvae have higher survival rates of larvae and young adults than snails with planktonic larvae.

Reptiles first appeared during the _____ era. Paleozoic Triassic Mesozoic Cenozoic Jurassic

We are living during the _____era. Neogene Cenozoic Paleozoic Paleogene Mesozoic

Dinosaurs went extinct during the _____. Devonian Precambrian Mesozoic Cenozoic Carboniferous

_____ were the dominant vertebrate life form during the Paleozoic era. Amphibians Reptiles Sponges Dinosaurs Mammals

Life arose during the _____. Precambrian Cenozoic Triassic Paleozoic Mesozoic

Flowering plants first appeared during the _____. Devonian Precambrian Mesozoic Cenozoic Carboniferous

The Mesozoic era began approximately _____ million years ago. 4,600 570 251 65 25

The Precambrian time began at least _____ million years ago. 4,600 570 245 65 25

Seed plants first appeared during the _____. Paleozoic Triassic Mesozoic Cenozoic Jurassic

The first prokaryotic cells appeared during the _____. Jurassic Cretaceous Paleozoic Triassic Precambrian

Animals first appeared during the _____. Mesozoic Paleozoic Precambrian Silurian Cenozoic

The Cenozoic era began approximately _____ million years ago. 4,600 570 245 65 25

_____ were the dominant vertebrate life form during the Mesozoic era. Dinosaurs Mammals Fish Birds Amphibians

Most modern animal phyla evolved during the _____ era. Paleozoic Cenozoic Mesozoic Precambrian

Bony fish first evolved during the _____ . Mesozoic Paleozoic Cenozoic Precambrian Cretaceous

The oldest fossils usually __________. are found above younger fossils are found in the deepest strata contain more radioactive isotopes than younger fossils have the longest half-lives are found in sediments formed during the Cenozoic era

Radiometric dating __________. relies on the fact that the daughter isotope decays to the parent isotope at a constant rate allows us to indirectly date fossils up to billions of years old based on minerals in surrounding volcanic strata allows us to determine an absolute, errorless date only works on rocks younger than 75,000 years

Which of the following statements about adaptive radiation is correct? Adaptive radiation occurs in the presence of competitors. Adaptive radiation occurs within a single lineage. Adaptive radiation occurs very slowly over time. Adaptive radiation occurs in species that live in one habitat.

Which organisms are not examples of an adaptive radiation? Honeycreeper songbirds of the Hawaiian islands Horses and deer in the post-dinosaur age Anolis lizards of the Caribbean Mammals and reptiles in the post-dinosaur age

True or false? Convergent evolution is said to have occurred if the mouse species on two islands with similar habitats are found to have similar characteristics even though they originated from different species that did not have these characteristics.

Which Anolis lizard ecomorph has long legs? Trunk/crown Twig Trunk/ground Crown

Which of the following statements about the evolution of Anolis lizards in the Caribbean islands is true? The phylogeny of ecomorphs on a given island reveals that adaptive radiation has taken place. The genetic relatedness of ecomorphs was determined by comparing their nuclear DNA sequences. Twig ecomorphs can jump very well. A crown ecomorph living on one island is always the same species as a crown ecomorph living on a neighboring island.

What was the main selective pressure behind the evolution of different Anolis lizard species in the Caribbean? Phylogeny Conspecifics Specific ecological niches Competitors

True or false? The evolution of different ecomorphs on the Caribbean islands is an example of stabilizing selection.

How does continental drift affect living organisms? It may cause an increase or decrease in competition among different species. All but one of the listed responses are correct. It happens so slowly that it does not affect living organisms. It causes changes in habitats, such as when large amounts of shallow marine habitat were lost in the formation of Pangaea. It causes climate change, which puts selective pressure on organisms.

Hox genes are thought to play an important role in the development of different morphologies because __________. they affect the timing of reproductive development in the organism they provide positional information in the embryo they affect the timing of development in the embryo they paved the way for the development of multicellular organisms they affect the order of genes on certain chromosomes

96% of marine animal species became extinct in the Permian mass extinction at the end of the Paleozoic, 251 million years ago. Why does the blue curve show only a 50% drop at that time? The species that survived the mass extinction diversified very quickly so that the number of families in existence first plummeted but then rapidly increased to 50% of the number before the mass extinction. Although 96% of marine animal species became extinct, the extinction rate was far lower for terrestrial species. Although the extinction rate of 96% was high, the number of species in existence was also very high, so that even after the mass extinction, many species remained. Families typically contain many species, so the percentage of families that became extinct is lower than the percentage of species that became extinct.

Which factor most likely caused animals and plants in India to differ greatly from species in nearby southeast Asia? India is in the process of separating from the rest of Asia. The species became separated by convergent evolution. India was a separate continent until 45 million years ago. The climates of the two regions are similar.

Adaptive radiations can be a direct consequence of three of the following four factors. Select the exception. genetic drift evolutionary innovation colonization of an isolated region that contains suitable habitat and few competitor species vacant ecological niches

A researcher discovers a fossil of what appears to be one of the oldest-known multicellular organisms. The researcher could estimate the age of this fossil based on __________. the amount of carbon-14 in volcanic layers surrounding the fossil the amount of uranium-238 in the fossil the amount of uranium-238 in volcanic layers surrounding the fossil the amount of carbon-14 in the fossil

A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of farther back helped make possible the evolution of the tetrapod limb. This type of change is illustrative of __________. a change in a developmental gene or in its regulation that altered the spatial organization of body parts paedomorphosis heterochrony the influence of environment on development

A swim bladder is a gas-filled sac that helps fish maintain buoyancy. The evolution of the swim bladder from the air-breathing organ (a simple lung) of an ancestral fish is an example of __________. exaptation adaptive radiation paedomorphosis changes in Hox gene expression

Exaptation

A paleontologist finds a new tyrannosaur in a site she is excavating, and wishes to date the fossil. What is the most likely method she will use? She will determine the fossil's age by measuring the ratio of carbon-14 to carbon-12 in the fossil. She will measure the amount of the radioisotope uranium-238 in the stratum where she found the tyrannosaur. She will infer the age of the fossil by dating layers of volcanic rock above and below the stratum containing the fossil.

Which of the following statements supports the hypothesis of "an RNA world" on early Earth? The oldest known fossils contain traces of RNA molecules. Some RNA molecules are important catalysts in modern cells. Single-stranded RNA molecules are linear and cannot form three-dimensional shapes.

What was the "oxygen revolution," which took place 2.3 billion years ago? The figure shows atmospheric O2 as a function of time. The percentage of the atmospheric O2 rapidly increases from 0.0005 to 5 percent 2.3 billion years ago. The "oxygen revolution" was the rapid increase in atmospheric oxygen that took place 2.3 billion years ago, dooming many prokaryotic groups. The "oxygen revolution" was the rapid increase in atmospheric oxygen that took place 2.3 billion years ago, immediately preceding the origin of animals. The "oxygen revolution" was the rapid increase in atmospheric oxygen that took place 2.3 billion years ago, with the origin of plants.

The figure shows eyes found among living mollusks: a patch of pigmented cells, an eyecup, a pinhole camera-type eye, an eye with primitive lens, and a complex camera lens-type eye. The figure shows eyes found among living molluscs, ranging from a patch of pigmented cells in a limpet to a complex, image-forming eye in a squid. Is it possible that a structure as complex as an image-forming eye evolved by natural selection? No. An image-forming eye needs all of its components to function, so a partial eye would not have been useful. Yes, if the photoreceptor cells and simple eyes that preceded it were useful to the animals in which they arose. Yes. Because an image-forming eye is so useful, natural selection would favor less useful intermediate structures.