Niles Eldredge and Stephen Jay Gould researched the lenses of the eyes of fossil trilobites of

different species. In 1972 they published a paper in which they described the tendency of a

species to remain the same until a sudden change in the environment causes a new related

species to appear.

Which hypothesis was most challenged by the work of Eldredge and Gould?

• Redi’s hypothesis that spontaneous generation does not occur

• Haeckel’s hypothesis that embryological development mimics the evolution of species

• Wallace’s hypothesis that geography affects the distribution of species

• Darwin’s hypothesis that the development of species is a slow, gradual process

The diagram shows light- and dark-colored beetles that live on a tree.Which result is most likely to occur to the beetle population due to predation over time?

• The number of light-colored beetles in the population will increase.

• There will be more dark-colored beetles than light-colored beetles.

• The number of light-colored beetles will decrease.

• The dark-colored beetles will move to a different type of tree.

The gray squirrel, Eastern fox squirrel, and red squirrel are all different species of squirrels.

Why is having a scientific name for each species of an organism important?

• To prevent existing named organisms from having their names changed as they become

  extinct

• To keep the classification system from being altered as new organisms are discovered

• To allow organisms to be placed in many classification levels at the same time

• To standardize the naming and organization of organisms to avoid confusion

Scientists can determine relatedness among organisms by comparing partial amino acid

sequences. The table shows four partial amino acid sequences from four organisms.Which organism is the LEAST related to the other three organisms?

• Organism 1

• Organism 2

• Organism 3

• Organism 4

A prey population consists of individuals with a variety of running speeds. The adaptation that allows some of these animals to run fast would be an example of natural selection if it helps them —

• survive and undergo mutations in their DNA

• lower the mortality rates of the population

• produce offspring that run at average speeds

• reproduce and increase the frequency of their genes in the population

Bactrian camels, dromedaries, llamas, and alpacas are all members of the same taxonomic family, Camelidae. Members of this family all have two toes, no hooves, true canine teeth, and a split upper lip. The family Camelidae originated in North America. The physical features of animals in this family and the family’s geographical origin provide evidence that all these animals —

• live in the same type of ecosystem

• have slowly evolved to become herbivores

• have a common ancestor

• exchanged DNA at some point in the past

Arthropods are joint-legged animals. Spiders, crabs, pill bugs, centipedes, and millipedes

are examples of the many types of arthropods. Which of these arthropods are most closely

related?

• Arthropods of the same family

• Arthropods of the same class

• Arthropods of the same genus

• Arthropods of the same species

Scientists estimate that there are more than 20,000 species of ants. The species range in size from 1 mm long to 38 mm long and live in most environments. The diets of ants range from flowers and seeds to fluids from their own larvae. Ants have been able to successfully inhabit so many different environments because their populations have been able to --

• hybridize with other species of insects

• adapt to a variety of habitats and food sources

• fill niches usually occupied by mammals

• occupy habitats that have no other life-forms

Two populations of mice living in the same forest are separated by a large water-filled ditch. After a rainstorm, flooding brings several mice from one population to the other population. When the mice from the first population reproduce with members of the second population, which of the following will likely occur?

• All of the offspring will die as a result of reproductive mutations.

• The offspring will be forced to leave the second population.

• The offspring will be genetically identical to their parent from the first population.

• The offspring in the second population will have greater genetic variety.

Organisms are classified today using the Linnaean system, and the following table shows the taxonomic classification of two marine organisms living along the Pacific Coast.

Taxonomic classification is important to marine biologists because it provides a way to -

• prove that marine evolution occurs

• discover and name every marine organism on Earth

• designate Latin as the universal language of marine biology

• identify marine organisms and find evolutionary relationships between them