Chapter 22 Evolution Quiz / Review On Evolution

Based on Darwin's observations of organisms in the Galapagos Islands, he reasoned that organisms had adapted to new environments, giving rise to new species. This conclusion is drawn from Darwin's observation of variations among species on different islands, as well as the presence of unique traits that allowed them to survive and reproduce in their specific environments. Darwin's theory of natural selection suggests that these adaptations over time lead to the formation of new species. Therefore, the correct answer is that organisms had adapted to new environments, giving rise to new species.

The introduction of gravel in the lake bottom creates a mottled appearance, which is similar to the coloration of the mottled fish. This change in the environment provides camouflage for the mottled fish, making it harder for the large birds to spot and prey on them. Consequently, the mottled fish have a higher chance of survival compared to the light brown fish. As a result, over time, more mottled fish will survive and reproduce, leading to an increase in the proportion of mottled fish in the population.

The statement is incorrect. Charles Darwin was not the first person to conclude that organisms evolve. The concept of evolution had been proposed by earlier scientists such as Jean-Baptiste Lamarck and Alfred Russel Wallace. Darwin's contribution was his theory of natural selection, which explained how evolution occurs.

The second and third observations mentioned in the options led to Darwin's major inferences. The observation that members of a population vary in their heritable traits is important because it suggests that there is variation within a species, which is necessary for natural selection to occur. The observation that many offspring do not survive despite the ability of organisms to produce large numbers of offspring is also significant because it implies that there is a struggle for survival and only the fittest individuals are able to survive and reproduce. These observations support Darwin's theory of natural selection as the mechanism for evolution.

Alfred Russel Wallace is the correct answer because he independently developed a theory of evolution by natural selection that was similar to Charles Darwin's. In fact, Wallace's work on the theory of evolution prompted Darwin to finally publish his own ideas. Wallace's theory, like Darwin's, proposed that species evolve over time through a process of natural selection, where individuals with advantageous traits are more likely to survive and reproduce. This similarity in their theories led to a joint presentation of their work in 1858, which is now recognized as a pivotal moment in the history of evolutionary biology.

Embryos of dissimilar organisms, such as sharks and humans, resembling each other challenges traditional ideas about species because it suggests a common ancestry or evolutionary relationship between these organisms. This finding indicates that despite their different adult forms, these organisms share similar developmental processes and structures during embryonic development. This supports the idea that species are not fixed and distinct entities, but rather have a common evolutionary history and are connected through common ancestors.

An adaptation is a trait that gives an organism a reproductive advantage in the current environment. This means that the organism with the adaptation is more likely to survive, reproduce, and pass on its genes to the next generation. Adaptations can be physical, behavioral, or physiological and they help organisms better survive and thrive in their specific environment. By having traits that increase their chances of successful reproduction, organisms with adaptations are more likely to contribute to the gene pool of future generations and potentially give rise to new species over time.

The correct answer is the fossil record of the evolution of the modern cataceans. The fossil record provides evidence of how ancient species have changed over time and can be used to track the evolution of specific groups of organisms, such as modern cataceans (whales, dolphins, and porpoises). By examining the fossils of these animals, scientists can observe the gradual changes in their anatomy and behavior, providing insights into the pattern of evolution that has occurred.