Chapter 7 - Selection in Action

Notes for Understanding Evolution - Chapter 7

Click link to return to Biology 409 Schedule
or back to Chapter 6 or ahead to Chapter 8

General guide on these review questions here

Notes for Chapter 7: Selection in Action

Introduction

I. Industrial Melanism

source of images of larva and adults

Featured Organism: Biston betularia (peppered moth)
Links: 1 - 2 - 3 (creationist article about how this classical story, as typically abbreviated in textbooks,
is in need of revision) 4 - 5 - 6 (Links 4 and 5 and especially the pdf file at link 6 clarify that it is the
textbook accounts that are typically flawed, with the actual evidence for natural selection still compelling,
especially the careful documentation of the increase in the white morph since pollution has declined -
note: the larvae appear to be equally subject to predation to me, judging from their cryptic appearance
above left.)

Key Terms: industrial melanism, verifiable evidence

RQUE7.1: What sort of verifiable evidence can be collected in a "natural experiment" of the sort involving the peppered moth? What does the evidence collected by Kettlewell suggest? Clarify what these studies explain of the following: 1) how the two melanic morphs originated; 2) how their relative abundance has changed through time; 3) what is responsible for that change.

II. Cancer Cell Heterogeneity

Key Terms: cancer tumor cell heterogeneity, clonal cell growth,
tumors metastasize and promote angiogenesis

RQUE7.2: Why are cancerous growths so difficult to treat?

III. Selection for Resistance
Download pdf of review article: Bacteria are different…

RQUE7.3: What is the danger of treatment of bacterial infections with antibiotics?

IV. Multiple Antibiotic Resistance

RQUE7.4: How is it that bacteria manage to become resistant to multiple antibiotics in a very short time? Include in your response a brief explanation of the association of plasmids and their bacterial hosts.

Key Terms: plasmids, antibiotics, antibiotic resistance, transposons :

sourse of image

Featured Organism: Maize (corn)
Links: 1 - 2 (requires Flash plug-in) - 3 - 4 - 5 - 6
Review Article PDFs: 1 - 2

RQUE7.5: Including in your response details of what has been learned about transposons in maize, characterize how our view of the nature of genes has been revised after the discovery of transposons.

Source of image; Biographies: 1 - 2 - 3

Featured Scientist: Barbara McClintock
Links: 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10

V. "Prudent Use" of Antibiotics in Human Medicine

RQUE7.6: What are some potential ways in which bacteria might circumvent our standard medical practice of treatment of many ailments with antibiotic drugs?

VI. Recombinant DNA

Key Terms: inserting foreign DNA into a plasmid, cloning into a plasmid, restriction endonucleases, recombinant DNA molecule

RQUE7.7: How are restriction endonucleases employed naturally by bacteria in wild populations?

Click link to return to Biology 409 Schedule
or back to Chapter 6 or ahead to Chapter 8