Exam 22: Descent with Modification: A Darwinian View of Life

In the mid-1900s,the Soviet geneticist Lysenko believed that his winter wheat plants,exposed to ever-colder temperatures,would eventually give rise to ever more cold-tolerant winter wheat.Lysenko's attempts in this regard were most in agreement with the ideas of

Cuvier,a French scientist,noted that the older the strata,the more dissimilar the fossils in it were,compared to current life forms.He also observed the appearance and disappearance of species.Cuvier proposed that the differences among fossils and species extinctions were a result of

Ichthyosaurs were aquatic dinosaurs.Fossils show us that they had dorsal fins and tails,as do fish,even though their closest relatives were terrestrial reptiles that had neither dorsal fins nor aquatic tails.The dorsal fins and tails of ichthyosaurs and fish are

Logically,which of these should cast the most doubt on the relationships depicted by an evolutionary tree?

DDT was once considered a "silver bullet" that would permanently eradicate insect pests.Today,instead,DDT is largely useless against many insects.Which of these would have been required for this pest eradication effort to be successful in the long run?

The following questions refer to the figure below,which shows an outcrop of sedimentary rock whose strata are labelled A-D. -Currently,two extant elephant species (X and Y)are placed in the genus Loxodonta and a third species (Z)is placed in the genus Elephas.Assuming this classification reflects evolutionary relatedness,which of the following is the most accurate phylogenetic tree?

In contrast to Cuvier's ideas,geologists James Hutton and Charles Lyell,proposed that earth's geological features could be explained by

What is true of pseudogenes?

During a study session about evolution,one of your fellow students remarks,"The giraffe stretched its neck while reaching for higher leaves; its offspring inherited longer necks as a result." Which statement is most likely to be helpful in correcting this student's misconception?

Which of these conditions should completely prevent the occurrence of natural selection in a population over time?

Which of the following concepts/ideas reflects Lamarck's perception of evolution?

Which of the following statements about natural selection is a misconception?

The following questions refer to the description below. You have read that soapberry bugs,Jadera haematoloma,adapt to available food sources.For example,in southern Florida,soapberry bugs feed on seeds of a native plant,the balloon vine.In central Florida,the balloon vine is rare and soapberry bugs have switched to eating seeds of an introduced species,the goldenrain tree.The seeds of the goldenrain tree fruits are much closer to the fruit surface than the seeds of the native balloon vine fruit.As a result,natural selection results in beaks that are shorter in soapberry bugs that utilize goldenrain tree fruits than those that feed on balloon vine fruit seeds. -A conservation organization has been trying to eliminate introduced species and encourage the growth/spread of native species.After several years,the balloon vine has almost totally replaced the goldenrain tree in the experimental plot.Based on your knowledge of evolution,which of the following outcomes would appear to be the most logical?

The following questions refer to the figure below,which shows an outcrop of sedimentary rock whose strata are labelled A-D. -If x indicates the fossils of two closely related species,neither of which is extinct,then their remains may be found in how many of these strata?

The following questions refer to the evolutionary tree shown below. The horizontal axis of the cladogram depicted below is a timeline that extends from 100 000 years ago to the present; the vertical axis represents nothing in particular.The labelled branch points on the tree (V-Z)represent various common ancestors.Let's say that only since 50 000 years ago has there been enough variation between the lineages depicted here to separate them into distinct species,and only the tips of the lineages on this tree represent distinct species. -According to this tree,what percentage of the species seem to be extant (in other words,not extinct)?

Which of the following must exist in a population before natural selection can act upon that population?

The following questions refer to the description below. You have read that soapberry bugs,Jadera haematoloma,adapt to available food sources.For example,in southern Florida,soapberry bugs feed on seeds of a native plant,the balloon vine.In central Florida,the balloon vine is rare and soapberry bugs have switched to eating seeds of an introduced species,the goldenrain tree.The seeds of the goldenrain tree fruits are much closer to the fruit surface than the seeds of the native balloon vine fruit.As a result,natural selection results in beaks that are shorter in soapberry bugs that utilize goldenrain tree fruits than those that feed on balloon vine fruit seeds. -Within six months of effectively using methicillin to treat S.aureus infections in a community,all new infections were caused by MRSA.How can this result best be explained?

A high degree of endemism is most likely in environments that are

Natural selection is based on all of the following except

Over evolutionary time,many cave-dwelling organisms have lost their eyes.Tapeworms have lost their digestive systems.Whales have lost their hind limbs.How can natural selection account for these losses?