Beak of the Finch Questions

.docx

School

San Jose State University *

*We aren’t endorsed by this school

Course

121

Subject

Biology

Date

Dec 6, 2023

Type

docx

Pages

Uploaded by AgentDragonPerson948 on coursehero.com

1 Biol 101; Origin of life Beak of the Finch Name: Andrea Martinez Homework (Ch 1-7) Due April 24th 25 questions 75 points (3 points each question) SID__________________________________ Suggestion: As you answer these questions, mark the page number(s) on that sheet where you got the Information! Chapter 1 1. What measurements do the Grants take on each finch? - On each finch, the Grants took measurements of the shapes and sizes of beaks. (Page 30) 2. How does Darwin describe natural selection? - On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life is the title of Charles Darwin’s book on natural selection. Darwin describes natural selection as life changes, down through the generations. He so famously writes “that natural selection is daily and hourly scrutinising, throughout the world, the slightest variations; rejecting those that are bad, preserving and adding up all that are good; silently and insensibly working, whenever and wherever opportunity offers. ... We see nothing of these slow changes in progress, until the hand of time has marked the lapse of ages, and then so imperfect is our view into long-past geological ages, that we see only that the forms of life are now different from what they formerly were.” (Page 20) 3. Did Darwin ever observe natural selection in action? - No. Darwin states that this process is at work right now around us, “whenever and wherever opportunity offers.” The action and reaction are too slow to watch. (Page 21) 4. Why are the finches on Daphne Island such an ideal population to study? - The finches on Daphne Island are an ideal population to study on account that in order to study the evolution of life through many generations you need an isolated population, one that is not going to run away, one that cannot easily mix and mate with others and, by mixing, mingle the changes induced in one place with the changes induced in others. Islands are ideal for this purpose, because it is hard for your subjects to leave them, and it is hard for outside influences to invade. (Page 24) Chapter 2 1. Why are the Galápagos finches referred to as nature's "most famous toolkit?" - The Galapagos finches are referred to as nature’s “most famous toolkit” due to the array of thirteen beaks. Robert Bowman, an evolutionist who studied the finches before the Grants, once

2 drew a chart Comparing the birds’ beaks to different kinds of pliers. Cactus finches carry a heavy-duty lineman’s pliers. Other species carry analogues of the high-leverage diagonal pliers, the long chain-nose pliers, the parrot-head gripping pliers, the curved needle-nose pliers, and the straight needle-nose pliers. (Page 34) 2. What hints do we have that Linné wondered about evolution? - The hints present that Linnaeus wondered about evolution were present about this metaphysical gulf between varieties and species. A few species of plants in his collections, including certain South African geraniums, seemed to have arisen by crossing—by hybridization. Linnaeus did not take this problem much further than hints in his diary and in the later editions of his folios. But he began to wonder if not only varieties but also these species were, as he put it, “daughters of time.” (Page 41) - 3. How did Charles Lyell's Principles of Geology influence Darwin? - Charles Lyell’s Principles of Geology, heavily influenced Charles Darwin through Lyell’s argument that although animals and plants on this planet had indeed been created by God in an instant, and never changed since, the planet itself had been changing restlessly beneath them.To Darwin the the idea that the sculpting of the earth’s surface is still going on seemed new and outrageous. He was fascinated by the thought that in this sphere, small changes can accumulate with big effect. (Page 42) 4. How did John Gould's discovery that there were 14 (13) species of finches on the Galápagos help spark Darwin's revolutionary ideas? - John Gould's discovery that there were 14 (13) species of finches on the Galápagos helped spark Darwin's revolutionary ideas because Year after year these revelations fanned the ember of Darwin’s secret thought. To Darwin all these species, marooned in their lonely archipelago, had diverged from their ancestral stocks and then gone right on diverging. They had broken the species barrier. (Page 44) 5. Why did Darwin begin the Origin with a detailed description of pigeon breeding? - Darwin began the Origin with a detailed description of pigeon breeding since Darwin knew that breeders could shape not only animals’ bodies but their very instincts. Since breeders called the art of choosing “selection,” they called any changes in a breed that did not take place because of their conscious efforts—all of the casual, frustrating, and inexplicable changes in their flocks and herds behind their backs—“natural selection.”To see the selection process firsthand, Darwin took up the breeding of pigeons. (Page 48) Chapter 3

3 1. Why might "Barnacle Bill" have been a good nickname for Charles Darwin? - “Barnacle Bill” may have been a good nickname for Charles Darwin since Darwin studied the variation problem most deeply not in birds but in barnacles. In October 1846 he began trying to classify a single curious barnacle specimen that he had found on the southern coast of Chile. It was the very last of his Beagle specimens, an “illformed little monster,” the smallest barnacle in the world. To classify that barnacle he had to compare it with others. Soon the working surfaces of his study were littered with barnacles from all the shores of the planet. Darwin hated barnacles. (Page 55) 2. What is Darwin's explanation for the lack of transitional forms between species? - Darwin's explanation for the lack of transitional forms between species as Very briefly, Darwin’s explanation is that the same process that makes varieties also destroys them. In the struggle for existence, some variants do better than others. When we look around us in the Galápagos or in Jersey or in New Jersey, the species of animals and plants we see are survivors. Varieties in between them have died off and disappeared, so that, after the long lapse of ages, we see only the victors and not the intermediate forms; we see the spines but not the webbing of the Japanese fan. (Page 57) 3. Describe the large, medium, and small ground finches with respect to their beaks. What kind of adaptations do you think the finches' beaks represent? - There comes a trio that has become as familiar to the Grants as Goldilocks’ Three Bears. There is a large ground finch, G. magnirostris ; a medium ground finch, G. fortis ; and a small ground finch, G. fuliginosa. The large ground finch has a large beak, the medium ground finch has a medium-sized beak, and the small ground finch has a small beak. For instance, the species in the middle of the trio, the medium ground finch, fortis , sometimes shades into the species above it, magnirostris , or the species below it, fuliginosa. The very biggest specimens of fortis are just as big as the very smallest specimens of magnirostris , and so are their beaks. At the same time the very smallest specimens of fortis are just as small as the biggest fuliginosa , and so are their beaks. (Page 60) Chapter 4 1. Why did 19th and early 20th century biologists fail to recognize the importance of variation in beak size among Darwin's finches in the Galápagos? - 19th and early 20th century biologists failed to recognize the importance of variation in beak size among Darwin's finches in the Galápagos because even after half a century, Darwin’s point Regarding variations was still being defended with imaginary illustrations, and attacked for being imaginary. Natural selection is supposed to scrutinize the slightest variations in nature, “daily and hourly.” But as far as Darwin could say after his five weeks in the Galápagos, natural selection is blind to the beak of the finch.These biologists were impatient and did not give enough time for natural selection to occur to be detected by the naked eye. There was too much focus on similarities rather than differences. (Page 70) 2. How did David Lack's observation of the distribution of finch species in the Galápagos lead him to conclude that natural selection had indeed been at work?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version