Evidence and Fossils
Which piece of evidence listed below best supports that two species share a recent common ancestor?
Their fossils have homologous tetrapod limbs.
Four forelimbs (cat, whale, human, bat) have similar bone arrangements. This similarity indicates they likely evolved:
From a common ancestor in the past (homologous structures)
In the phrase “survival of the fittest,” “fit” most nearly means:
Able to become an adult and reproduce.
Which of the following most likely shows two organisms have a recent common ancestor?
They have similar amino acid sequences.
Differences among members of a species (like different bird beaks) are called:
Variations.
A fossil of an extinct species is found with a similar bone structure to an existing species. This is evidence that:
Evolution has occurred.
The presence of gill slits and tails in embryos of fish, chickens, and pigs suggests:
These animals had a common ancestor.
After a volcanic eruption darkening an island’s beaches, black snails rise from 9% to 84% in one year. This is an example of:
Natural selection favoring darker coloration for camouflage.
Cytochrome c table: chimpanzee differs from human by 0 amino acids; yeast differs by 56. Which inference is invalid?
All of the proteins produced by chimpanzees and humans are identical. (This is not valid.)
Why are advantageous traits more likely to be passed to offspring?
Because they are more likely to survive and reproduce.
Which method is the best to test whether uncovered ancient bones belong to an ancestor of a modern horse?
Perform a DNA comparison of the two subjects.
An illustration shows penguin, bat, alligator, and human forelimbs with homologous bones. What inference does this provide?
They may share a common ancestor.
Mrs. Nash’s aquarium: black flatworms survive cloudy, brown die. The acceptable hypothesis is:
Due to their genetic make-up, the black flatworms were better adapted to survive the new conditions.
A new bacterial species DNA: ACT GCA CCC. Which listed species with ACT GCA CCG is most closely related?
Species IV (sequence differs by one base).
Which statement best illustrates natural selection?
An organism with favorable genetic variations will tend to survive and breed successfully.
In a rock strata diagram, deeper layers are older. If fish fossils appear in middle layers and plant fossils appear below, the most likely scenario is:
A marine environment gradually filled with sediment and became a terrestrial environment.
The embryos of many different vertebrates look very similar at early stages. Which claim best reflects that observation?
Early embryo similarity supports common ancestry (shared developmental patterns).
Fish that use ventral fins to move between pools survive when pools dry up. After many years we expect:
The number of fish using ventral fins as “feet” will increase.
Which technology allows study of DNA from ancient fossils and reveals evolutionary relationships?
DNA amplification and sequencing (convert tiny DNA amounts into large amounts).
Which best describes the role of mutations in natural selection?
A mutation may result in a beneficial trait that makes an organism more likely to survive and reproduce.
Scientists compare ancient cytochrome c amino acid sequences. If two species have nearly identical cytochrome c, what does this suggest?
They are closely related (have a more recent common ancestor).
Homologous structures across vertebrates (e.g., bird wing and seal flipper) most strongly suggest:
All vertebrates have a common ancestor.
During the Industrial Revolution, dark moths increased; after pollution control, light moths increased. Why?
The environment favored the survival of light-colored moths over dark-colored moths (selective pressure changed).
Thousands of years ago giraffes had short necks; today most have long necks. Which mutation type would explain inherited change across generations?
A mutation in the genetic material controlling neck size occurring in reproductive cells of a giraffe.
Which explains why a species might change very little over 5,000 years?
The environment did not change significantly, and those offspring expressing new characteristics did not survive.