Question 1

Summarize the four main observations that make up Darwin's theory of natural selection.

Accepted Answer

The answer of Summarize the four main observations that make...

Question 2

There are two species of larkspur that have two different size flowers; Delphinium decorum has large, fully opened flowers and Delphinium nudicaule has small bud, like flowers. These two species are both fertilized by insects, but they cannot be fertilized by the same type of insect because the smaller flower of D. nudicaule will not permit larger insects to reach the nectar of the flower and the larger flower of the D. decorum is typically fed on by larger insects. Which type of isolating mechanism would this be?

Accepted Answer

This is an example of mechanical isolation, as the physical structure of the flowers prevents certain types of insects from reaching the nectar and fertilizing the flower.

Question 3

The model of evolution that proposes rapid periods of speciation followed by long periods of stasis is known as

Accepted Answer

The model that proposes rapid periods of speciation followed by long periods of stasis is known as punctuated equilibrium.

Question 4

Name the isolating mechanisms that exist within nature and indicate which ones are prezygotic and which ones are postzygotic.

Accepted Answer

The answer of Name the isolating mechanisms that exist within...

Question 5

The difference between phyletic gradualism and punctuated equilibrium is that

Accepted Answer

Phyletic gradualism and punctuated equilibrium are both theories about the pace of evolution. Phyletic gradualism posits that evolution occurs slowly and steadily over long periods of time, while punctuated equilibrium suggests that evolutionary change happens quickly in short bursts, followed by long periods of stasis. Therefore, the correct answer is B, as it accurately reflects the difference between the two theories.

Question 6

The American toad and the Fowler's toad are closely related species whose ranges overlap. The American toad mates in the early part of summer, while the Fowler's toad mates later in the season. What type of reproductive isolating mechanism keeps these toads separate species?

Accepted Answer

The temporal isolation mechanism keeps these toads separate species as they mate at different times of the season.

Question 7

If a population goes from an allele frequency of 0.12 A & 0.88 a to 0.23 A & 0.77 a in the course of seven generations, we can conclude the population is evolving.

Accepted Answer

The change in allele frequency over generations indicates that the population is undergoing evolution.

Question 8

Taxonomy is the branch of systemic biology that studies the evolutionary relatedness among groups of organisms.

Accepted Answer

Taxonomy is the branch of science concerned with classification, especially of organisms; systematics is the branch that studies the evolutionary relatedness among groups of organisms.

Question 9

Lake Tanganyika, the oldest of the Great Ancient Lakes in East Africa, harbors about 250 species of cichlid fish which evolved from a single ancestor into a diverse group of species that each exploits the resources of the lake environment in a different way. The evolution of one species of cichlid into many species within Lake Tanganyika is an example of

Accepted Answer

The evolution of one species of cichlid into many species within Lake Tanganyika is an example of adaptive radiation. Adaptive radiation is a process in which a single species diversifies into several new species, each adapted to a unique ecological niche or similar adaptive trait. In this case, the cichlids evolved into many different species each exploiting different resources within the lake.

Question 10

Which of the following is used by phylogeneticists specifically when constructing a cladogram?

Accepted Answer

Shared derived characteristics are used by phylogeneticists specifically when constructing a cladogram because they are the only type of characteristic that can be used to infer the evolutionary relationships between organisms. Homologous structures are not always shared derived characteristics, and morphological data can be misleading due to convergent evolution. DNA sequences can be used to construct cladograms, but they are not the only type of data that can be used.

Question 11

All living organisms share characteristics such as DNA, the molecule that passes information between generations; metabolic processes like glycolysis; and the ability to utilize specific energy sources. This is thought to be due to

Accepted Answer

The shared characteristics across all living organisms are thought to be due to a common ancestor from which all life on Earth evolved.

Question 12

List the five conditions required for a population to be in Hardy-Weinberg equilibrium.

Accepted Answer

The answer of List the five conditions required for a...

Question 13

Phylogeny refers to the

Accepted Answer

Phylogeny refers to the evolutionary history of a species, including its relationships with other organisms and how it has evolved over time. It is used to construct cladograms and phylogenetic trees to visualize these relationships.

Question 14

According to the proposed three-domain system,

Accepted Answer

The three-domain system, proposed by Carl Woese, divides cellular life forms into archaea, bacteria, and eukarya. It suggests that archaea and eukarya share a more recent common ancestor with each other than either does with bacteria, based on differences in their ribosomal RNA sequences.

Question 15

Within the field of systematic biology, scientists use the characteristics of living and fossil organisms to infer the evolutionary relationships among organisms.

Accepted Answer

This is a correct statement. Systematic biology, also known as phylogenetics, is the study of the evolutionary relationships among living and fossil organisms based on similarities and differences in their physical and genetic characteristics. Through this process, scientists develop hypotheses about the evolutionary history of different groups of organisms.

Question 16

According to Lamarck, which variable would have the greatest influence on the evolution of an organism?

Accepted Answer

Lamarck believed in the concept of "acquired traits," where an individual could pass on characteristics that it acquired during its lifetime to its offspring. According to him, these acquired traits were influenced by the environment in which the organism lived. Therefore, he believed that the environment had the greatest influence on the evolution of an organism.

Question 17

If you were assigned the task of constructing a cladogram representing the evolutionary relationship between amphibians, turtles, lizards, snakes, crocodiles, birds, and mammals, what feature could you use as the shared derived trait?

Accepted Answer

Four limbs are a shared derived trait among amphibians, turtles, lizards, snakes, crocodiles, birds, and mammals. All of these animals have four limbs, or are descended from ancestors that had four limbs. This trait is not found in any other group of animals, so it is a useful characteristic for constructing a cladogram that shows their evolutionary relationships.

Question 18

Which piece of evidence did Darwin observe during his 5-year journey aboard the HMS Beagle?

Accepted Answer

During his journey, Darwin observed that the finches on the Galápagos Islands had distinct beak shapes depending on their diet. He also observed a similar species of finch on the South American mainland that had a beak shape similar to one of the Galápagos finch species. This led Darwin to hypothesize that a common ancestor had adapted to different environments and evolved into different species with different beak shapes.

Question 19

The three-domain system is primarily based on

Accepted Answer

The three-domain system is primarily based on molecular data showing prokaryotes are far more diverse than previously thought. This system recognizes the fundamental division between archaea and bacteria, based on their unique molecular and genetic characteristics. The Eukarya are placed in a separate domain due to their distinct membrane-bound nucleus and other cell structures. The system was proposed by Carl Woese in 1977 based on his studies of ribosomal RNA sequencing.

Quiz 27: Evolution of Life