Notes for Understanding Evolution - Chapter 1

Click link to return to Biology 404 Schedule
or ahead to UE Chapter 2 or to Zimmer Chapter 1

The following lecture notes will use the following conventions:
        Clicking on web links is "optional" but they will help illustrate

            points made in lecture and by the authors of your text
        The web is very visual, links will help you visualize
        I expect you to read the entire assigned chapster in the text
           unless I indicate particular assigned pages, e.g.,
           Ch. 1: 1-10 (in this case, the entire chapter)
        Review questions (RQ) refer to those corresponding to a
           chapter, for example, RQ1:1 is the first review question
           for Chapter 1.
        Certain boldface text terms will be featured as Key Terms
        Certain animals will be a Featured Animal
        Certain events will be a Featured Event

        Certain people will be a Featured Scientist

Chapter 1 - Variation in Populations


a) What is distinction between environmental and genetic basis of observed phenotypic variation in population (Multi-leg bullfrog example)
b) How does one test for this difference?
c) In cases with genetic basis, what is expected phenotypic expression (i.e., for case of simple Mendelian recessive allele)


I. Environmental Modification

Key Terms: teratogens (various substances that can cause environmental modification, not due to genetic makeup of the individual), expression of a gene vs. the gene itself

RQ1.1: Explain why a cross of two multilegged bullfrogs might provide valuable insight as to why such deformaties might exist.

II. Lamarckism

Featured Scientist: Jean Baptiste de Lamarck

source of image

Links: 1 - 2 - 3 - and especially 4 (Michael Ghiselin's excellent account of textbook falacies about what Lamarck said)

RQ1.2: Why does evolution depend on heritable variation?

III. Heritable Variation

Key Terms: allele, recessive vs. dominant allele, carrier (heterozygous for recessive deleterious allele, e.g., the one that when homozygous causes Ellis-van Creveld syndrome, due to a faulty protein produced by a gene on the short arm of human chromosome 4)

RQ1.3: In the bullfrog example, if the multi-leg condition did have a heritable component, why is it potentially significant that the multilegged frogs did not survive long enough to reproduce?

IV. Hypothetico-Deductive Reasoning

Key Terms: hypothesis, deduction, hypothetico-deductive style of reasoning, theory vs. "truth"

RQ1.4: Why do you think that, unlike physics, biology doesn't seem to have much in the way of laws?


Click link to return to Biology 404 Schedule
or ahead to UE Chapter 2 or to Zimmer Chapter 1

This page created 8/16/01 © D.J. Eernisse, Last Modified 1/30/03, Links Last Completely Checked 1/30/03