Chapter 8 – Learning Curve – Flashcards

The appropriate unit for defining and measuring genetic variation is the:

Adaptation:

Tiktaalik appears to:

While on the voyage of the HMS Beagle, Darwin:

Among the following group of organisms, which of the following would be considered the "fittest" organism?

The consistent accumulation of mutations that creates differences in the DNA sequences of two diverging groups of organisms is referred to as:

When a group of individuals colonizes a new habitat, this is likely to be an evolutionary event because:

Which of the following types of selection is INCORRECTLY matched with its example?

Estimates of evolutionary relatedness based on a "molecular clock" are supported by:

Which of the following is considered a result of natural selection?

Which of the following is incorrectly matched? Biogeography: Patterns in geographic distribution of organisms Comparative anatomy: Growth, development, and body structures of major groups of organisms Laboratory and field studies: Implementation of the scientific method to observe and study evolution Fossil record: Physical evidence of organisms from the past Molecular biology: Examination of life at the level of atoms and compounds

When a group of individuals colonizes a new habitat, this is likely to be an evolutionary event because:

Which of the following types of selection is INCORRECTLY matched with its example? Stabilizing selection: Most babies born are between 7 and 8 pounds. Stabilizing selection: Turkeys have been selected based on increased size of their breast muscles. Directional selection: Cows with the highest milk production are selected for breeding. Disruptive selection: Among salmon, the very large males and smallest, quickly swimming males mate with the greatest frequency. Disruptive selection: The frequency of small and large fish among the salmon population increases.

It is said that the fossil record is an incomplete record, why is that? The soft parts of an organism almost always decay rapidly and completely after death. Only a few environments demonstrate reduced forces of decomposition resulting in the preservation of the organism's hard parts (i.e., teeth, bones). Scientists know the number of fossils embedded in this earth due to radiometric testing, but they have only been able to locate about 10% of them. The fossil record is no longer considered to be incomplete. That is an outdated concept that has since been rejected. Both the first and second choices best explain this statement.

The appropriate unit for defining and measuring genetic variation is the:

____________ selection favors organisms that have character values at both extremes of the phenotypic distribution.

Radiometric dating is useful in conjunction with the study of the fossil record because:

Which scientist is incorrectly matched to his scientific/evolutionary contribution?

An organism's fitness is measured: relative to other genotypes/phenotypes in the population. only for a specific environment. by reproductive success. for a given point in time. All of the above.

Most mutations: are beneficial to the organism in which they occur. are random, meaning that they only occur in small populations. are random, meaning they are unrelated to how useful or harmful they might be to the organism in which they occur. are in response to natural selection. migrate from one population to another.

Which of the following statements best describes artificial selection? Artificial selection results in greater numbers of mutated organisms due to its reliance on forced mutations. Artificial selection is not something seen in everyday life; it is, however, studied in highly sophisticated research labs. Artificial selection does not produce variable offspring. Artificial selection results after a large catastrophe strikes a region and results in the death of >90% of the individuals in a population. Artificial selection still exhibits differential reproductive success; however, mating and crossing is directed by humans and not nature.

Which of the following best describes worldwide views before and after Darwin? BEFORE: Earth is about 6,000 years old. AFTER: Earth is at least 10 billion years old. BEFORE: God created all living things. AFTER: Over time, species evolved, but it all started with one organism. BEFORE: The amount of species on this planet will forever remain unchanged. AFTER: The amount of species on this planet will fluctuate, but true extinction remains questionable (since evolution can bring back old species). Worldwide views before and after Darwin remained the same, since many people reject Darwin's accuracy in his statements. BEFORE: Earth is mostly unchanging. AFTER: The geology of the earth is not constant, but always changing; however, scientists recognize that it will undoubtedly reach a finite point.

The amino acid chains making up hemoglobin in different species: differ depending how long it has been since the species last shared a common ancestor. reflect differences in how the hemoglobin functions in the species. can only be compared among mammalian species since non-mammalians do not possess hemoglobin. are identical; otherwise, the hemoglobin cannot function properly. differ depending on whether the species are marine or terrestrial.

Which of the following best supports the idea that the frequency of recessive alleles does not decrease over time? Genetic drift alters the allele frequencies, making the recessive allele more advantageous. The dominant allele causes individuals to die off. Mutations alter the allele frequencies, making the dominant allele appear less frequently. There is no random mating in the population. Using Hardy-Weinberg equilibrium, it can be demonstrated that X allele frequencies will always produce the same genotype frequencies, retaining the allele frequencies.

Australia is a largely isolated habitat filled with unique organisms. Given the fact that placental mammals are not commonly found in Australia, which of the following would best explain this phenomenon? The bottleneck effect has resulted in the "wipe-out" of placental mammals from Australia. Biogeography best explains this phenomenon since Australia is a large, isolated habitat with an unique biogeographic pattern. The placental mammals mutated into marsupials, which are commonly found in Australia. Marsupials are better adapted than placental mammals to the habitat of Australia. There is no explanation for this phenomenon. Scientists are still studying why placental mammals cannot thrive in Australia.

Which of the following are true about marsupial mammals? They fill many niches in Australia that are occupied by placental mammals in other parts of the world. They are less fit than placental mammals. They have gone extinct as a result of the greater fitness of placental mammals. They are more closely related to each other than they are to placental mammals. Both the first and fourth answer choices are correct.