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Table of Contents: Add active learning to large classes Using the Web to teach science Tips for designing a WIM course Tips on leading stimulating discussions Alternatives to large group discussions
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Instructors have assigned the following study questions to help students grasp particular topics. TABLE OF CONTENTS:
Adaptation J.B. Losos, D.J. Irschick, and T.W. Schoener. 1994. Adaptation
and constraint in the I'd like to use these papers as a case study for natural selection and adaptation and constraint. There are 2 separate experiments presented by Losos. The 1994 paper is an example where they had predictions of evolutionary response in 2 species of lizards, but did not see any change over time. The 1997 Nature paper presents the results of a separate long term experiment using one of the species of Anolis lizards, where they claim to see adaptive evolution. The Case paper is a review of the 1997 Losos study. Think about the criteria for evolution via natural selection. Have they demonstrated evolution? Have they demonstrated evolution via natural selection? If so, what are the strongest pieces of evidence? If not, are there pieces of information that are missing? In the 1997 paper they use several multivariate statistics to answer the question: Are the island colonists morphologically different from the source population? They measured several morphological characters and want to determine whether the overall shape of the critters is different from different populations. They used principle component analysis to do this. In fig. la, think of the axis as two measures of shape, regardless of size (they have statistically removed the effect of size already). The x axis (PCA 1 principle component axis 1) could be thought of as lamellae width and hindlimb length. The y axis Labeled PCA 2) is essentially mass of the critter. Fig lb is another pictorial representation of the same data. Are the experimental island and the source population morphologically
distinct? In The Adaptationist program. A case study: The Aquatic Ape debate. After our general discussions about adaptation we will debate
the merits of a specific case study. PRO: CON: Coevolution Williams and Gilbert. 1981. Insects as selective agents on
plant vegetative On Thursday we have the rare opportunity to talk with one
of the authors of the papers we are reading. Dr. Larry Gilbert
from the University of Texas, Austin will be visiting Cornell
and has agreed to meet with this class. Texas has one of the
best programs in evolutionary biology in the world, and Larry
has been a leader in the department. For over 30 years, he has
studied the evolution and ecology of Heliconius butterflies
and Passiflora vines in the New World Tropics, especially
in Costa Rica. He has also been responsible for helping set up
and manage one of Costa Rica's National Parks. More recently,
he has worked on the biological control of fire ants which destroy
the native insect communities of the southern U.S., besides being
a major pest of humans and livestock. His students have worked
on a bewildering array of topics in evolutionary biology and
on a range of organisms from insects to amphibians to mammals.
Development and evolution What processes explain the production of discontinuous pheotypes from continouos genotypic change? What role does development play in explaining the diversity of phenotypes we see in nature? We have spent much of the semester analyzing how natural selection creates and maintains variation in nature. But is that it? Is natural selection sufficient in explaining the diversity of life? Oster and Alberch ask: how can developmental process control th eexpression of morphological variaiton and generate the rules of phenotypic change? They propose a model for the development of skin organs like fathers, teeth, hair, etc. Please pay specific attention to the Introduction and Part I and V where they put their model in a broad contextual background. Note Fig. 11. Murray writes about a related model (a reaction diffusion
model) of how pattern formation in mammal coats develops. This
simple model simulates zebra stripes, and leapord spots without
using genetics. What is a morphogen? Global Warming 1. Where did the idea of global warming originate?
Human impact 1. What are the basic requirements (in general) that must
be met for an organism / species
Bethell, T. 1976. Darwin's mistake. Harper's Magazine 252:70-75. The Bethell article caused quite a stir when it was published, even among evolutionary biologists. It brought home an issue raised in the philosophical literature about the scientific and theoretical status of natural selection. Gould responded almost immediately, but it is still not clear today that evolutionary biologists have come to grips with the issues Bethell's article raises. The issues are actually fairly complex and will require some thought on your part. I suggest reviewing your class notes on natural selection and the handout from the natural selection exercise. The following study questions are somewhat difficult, but are designed to get you thinking. 1) Use a dictionary to define tautology. In what sense is
Bethell using the word? Is there a broader sense of the word
'tautology' which might apply to the presentation of natural
selection from lecture? Boag and Grant, 1981.The Beak of the Finch, Ch. 1-7; 1. What is sexual selection? How is it different from natural
selection? How did it manifest
Neutral theory Kimura, M. 1979. The neutral theory of molecular evolution.
Scientific American 1) List 4 observations from molecular studies that Kimura
thought were better explained by neutral evolution (mutation
and drift) than by natural selection. Explain how each of these
observations is a problem for a "panselectionist" theory
of neutral evolution. That is, what would one expect to observe
in these cases if selection were dominant force?
Pest control 1. What is a "pest"? What makes an organism a "pest"?
Phylogeny McDade, L. A. 1992. Pollinator relationships, biogeography,
and The purpose of reading these papers is to provide an introduction
to the sorts of questions that phylogenies can help answer and
to how we make inferences about the past and the course of evolution
from phylogenies. The McDade paper focuses on 2 questions: 1)
is pollination by a particular group of hummingbirds a recently
derived trait in a group of plants, or is it a more ancient trait?,
and 2) what is the biogeographic history of a particular genus
of plants - where did they originate and did they invade new
habitats once or many times? The Vila et al. paper focuses on
3 questions: 1) what is the wild ancestor of the domestic dog?,
2) how long ago were dogs domesticated?, and 3) are dogs the
result of one domestication event or multiple domestication events?
Overall, you should start to see the utility of what is called
"tree-thinking" in answering evolutionary questions. Some vocabulary: McDade. 1992 - trapliner - description of a foraging strategy used by pollinators in which they proceed from one plant to another, often over great distances and often repeatedly in the same order. I think this term is derived from the fur trapping industry. Trappers would often set traps up and down the lengths of rivers (trap line) or in different areas, but would often check them in a consistent manner. Vila et al. 1997. hal2lotyi)e - a DNA sequence that differs from homologous sequences at one or more sites (e.g. ATTGCGTTA would be a haplotype, so would ATTGCGTTC, and ATGGCGTAT, provided these sequences represented homologous places in the same gene). A haplotype is essentially an allele. coalescence - genes have genealogies just like people do. This makes sense given that genes are one of the things passed from parents to offspring. All gene copies in a single population ultimately are descended from a single ancestral gene copy. The genealogy of genes is said to coalesce to a single common ancestor. Analogously, all of us in the classroom could theoretically trace our heritage back to a single individual from whom we are all descendants. The genealogy of individuals would coalesce at this point. monophyletic - a taxon is monophyletic if it consists of all
the known species thought to
Vila et al. 1997
Punctuated Equilibrium Gould, S. J. 1980. Is a new and general theory of evolution
emerging? Paleobiology Gould (1980) Gould and Eldredge (1993)
Species Concept Real world examples to help puzzle
through species concept Darwin titled his book On the Origin of Species...., but what are species? Defining species is one of the most contentious topics in evolutionary biology and related fields. If evolution is about the origin of species, then evolutionary biologists clearly need an unambiguous and practicable definition of species. Otherwise, how do we know what entities to study and how do we identify the entities are the purported outcome of the processes we study? Species are the things that evolve and speciate - can evolutionary theory exist without a definition of species? In discussion on Thursday we will consider the nature of "species," the qualities of various species definitions, and the implications of these definitions for studying @ 6 speciation." Following is a list of some species concepts. Biological species concept - species are groups of
actually or potentially interbreeding Evolutionary - a species is a single lineage (an ancestral-descendant sequence) of populations or organisms that maintains its identity from other such lineages and which has its own evolutionary tendencies and historical fate. Phylogenetic - a phylogenetic species is a cluster of organisms which is diagnosably distinct (has a unique character) and within which there is a parental pattern of ancestry and descent. Recognition - a species is the most inclusive population
of (sexually reproducing) Cohesion - a species is the most inclusive population
of individuals having the potential Ecological - a species is a lineage (or set of closely related lineages) that occupies an adadptive zone (ecological niche) minimally different from that of any other lineage in its range and which evolves separately from all lineages outside its range Morphological (Darwin's) (see Mallet article)....... the complete absence, in a well investigated region, of varieties linking together any two closely-allied forms, is probably the most important of all the criterions of their specific distinctness." Genotypic Cluster (Mallet) - groups that remain recognizable
in sympatry because of the Before Reading During and After Reading
Last updated September 26, 2001 Comments, questions or new links? Contact Anne at astork@cisunix.unh.edu |
