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

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. -Which pair would probably have agreed with the process that is depicted by this tree?

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. -Which of the following observations helped Darwin shape his concept of descent with modification?

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. -How many separate species,both extant and extinct,are depicted in this tree?

Of the following anatomical structures,which is homologous to the bones in the wing of a bird?

What is the best explanation for the emergence of resistant strains of Staphylococcus aureus?

The cow Bos primigenius (which is bred for meat and milk)has a smaller brain and larger eyes than closely related wild species of ungulates.These traits most likely arose by

A biologist studied a population of squirrels for 15 years.During that time,the population was never fewer than 30 squirrels and never more than 45.Her data showed that over half of the squirrels born did not survive to reproduce because of both competition for food and predation.In a single generation,90% of the squirrels that were born lived to reproduce,and the population increased to 80.Which inference(s)about this population might be true?

Scientists are worried about the rise of methicillin-resistant Staphylococcus aureus (MRSA)because