Teaching Marine Biology in the Classroom

Sep 30 2009

Written by Ava

Charles Darwin relied on observations of marine life, fish, and coral reefs in developing his theory of how species were created through evolution and natural selection.

The National Center for Science Education, America’s leading organization in defending and promoting the teaching of evolution in the public schools, suggests more ways to bring evolution into the marine biology classroom.

Who better to speak on this topic on behalf of the organization than Dr. Louise Mead, the group's Education Project Director, who devoted her childhood years to volunteering at the New England Aquarium, scuba diving, and combing the beach for marine-related finds. She later used her knowledge of marine biology to help students and teachers understand how evolutionary biology has come into play in creating a vast diversity of living organisms.

Was it enough? Let's see what she has to say.

What is NCSE and what purpose does it serve?

The National Center for Science Education is a non-profit, largely member-supported, organization that has been involved with defending the teaching of evolution in the public school classroom for over 25 years. As an organization we do a number of things: interact with citizen science groups, parents, teachers and administrators who are concerned when non-science topics such as creationism and intelligent design are required, promoted, or introduced into the science curriculum; outreach (talks, workshops, published papers) to the scientific, educational, and faith communities; and review antievolution material and consult on evolution education material.

Tell me about your background in studying and understanding the evolutionary process and why you chose to be part of an organization like NCSE?

First, my interest in evolutionary biology started as a young girl, with a fascination for nature in general, and marine biology more specifically. I spent time as a young girl beach combing, learned to scuba dive before I learned to drive a car, volunteered at the New England Aquarium during summers in high school, and specifically remember learning about evolution and the Galapagos Islands in high school biology and thinking Charles Darwin's ideas made the entire world make sense. An interest in marine biology developed into an interest in rain forest ecology and biodiversity while teaching high school science. I originally thought when applying to graduate school I'd study newt ecology but I became more interested in evolutionary questions, and specifically the evolution of a large group of lungless salamanders, primarily because they showed interesting evolutionary patterns and many questions about their diversity and ecology are still unanswered. A comparable aquatic system, although much more diverse, would be cichlid fish - extensive diversity, driven by ecological and sexual selection.

As a graduate student I examined patterns of genetic variation (both at the protein and molecular level), and behavioral differences in courtship. As a postdoc I also examined behavioral and molecular components of the pheromone these salamanders use during courtship, work done with Lynne Houck. However, my background and interest has always been in education, and when the position at NCSE became available it seemed a perfect fit. At NCSE I have the opportunity to combine my training in evolutionary biology with my background in science education in an active way to better help people understand evolution.

You actually used quantitative genetic methods to study the sexual habits and speciation of salamanders form northern California? How did you get to do that topic and tell me about the experience, what you learned, etc.

One of the strengths of scientific research into evolutionary processes lies in the possibility of examining multiple lines of evidence - morphology, behavior, molecules, and development. When different lines of evidence indicate similar patterns of evolutionary change, scientists can more assuredly make statements about the support of the evidence for a particular explanation or hypothesis. I started my work on plethodontid salamanders with Steve Tilley and Laura Katz at Smith College by examining geographic patterns of genetic variation and differences in courtship behavior. Because sexual selection (in conjunction or in opposition to natural selection) can lead to divergence in populations over time, and observing sexual selection over any length of time in populations of salamanders is impossible, I, in collaboration with Stevan Arnold at Oregon State University, simulated the process using quantitative genetic models.

When people think of sexual selection they often think of the tail of a peacock, traits hypothesized to evolve in response to some type of runaway process as females who prefer males with longer tails produce sons with longer tails and daughters with preferences for longer tails. While runaway sexual selection may occur, it is unstable. A more stable scenario involves sexual selection that results in the male trait and female preference for the male trait moving toward a line of equilibrium, first evolving together and potentially resulting in the increase in male tail size, but eventually reaching a point of equilibrium where natural and sexual selection balance one another and limit further change. We explored what happens when populations reach such a line of equilibrium, specifically asking whether the evolution or loss of sexually selected traits would lead to speciation between two populations. Under certain genetic parameters, our models indicate that speciation can occur.

How does this process relate to marine environments, marine life, marine topics?

First, the questions asked and tools used to examine patterns of genetic, behavioral, molecular, and protein variation in salamanders can be applied to most any other system, whether marine, freshwater, or terrestrial.

For example, mitochondrial DNA has been used to examine the genetic structure of various marine fish. Molecular studies of this type can also be used to identify the source of invasion events or cryptic species (populations that appear to be morphologically similar but are reproductively isolated). Sea urchins provide a model marine system for similar types of work on reproductive isolation and its influence on patterns of speciation, and molecular studies have shown evidence of selection at the level of the proteins on the surface of the egg. Cichlid fish are an example of a model system for studying sexual selection.

What does NCSE do to promote the importance of marine influence in the evolutionary process?
As Education Project Director I'm always open to forming new connections and promoting evolution education. Specific outreach to marine organizations has not led to any current collaborations, but we certainly welcome working with any organization interested in evolution education.

How does the NCSE promote the teaching of evolution in a marine biology sense?

Whenever we at NCSE gives a talk on the evidence for evolution, we almost certainly include whale evolution, as it provides one of the best examples of evolution, descent with modification from a common ancestor. Fossils have been found that exhibit transitional features important in a move from a terrestrial to an aquatic environment. The molecular data, and more recently morphological data, support a shared ancestry between cetaceans and hippos. Furthermore, there are numerous shared features (e.g., the structure of the forelimb, mammary glands, etc.) and vestigial structures (e.g., the pelvic girdle) that provide evidence that whales have a shared ancestry with other mammals and that evolutionary changes have occurred that correspond to living in an aquatic environment.

Do you network with any marine organizations or any science organizations that include marine science as an element of its group?

While we do not network specifically with any marine organizations, we publish a book entitled Voices for Evolution, now in its third edition, that includes statements in support of evolution from education, religious, and scientific organizations which include marine science divisions (such as the Society for Integrative and Comparative Biology, the Ecological Society of America, the National Academy of Sciences, and the American Institute of Biological Sciences).

How would one teach marine biology in school using the evolutionary theory?

I always return to the quote by Theodosius Dobzhansky (1971) when thinking about why evolution is important and how to include evolution into the curriculum: “[s]een in the light of evolution, biology is, perhaps, intellectually the most satisfying and inspiring science. Without that light it becomes a pile of sundry facts some of them interesting or curious but making no meaningful picture as a whole.” Just as evolution can be integrated throughout the general biology curriculum by asking how common ancestry informs our understanding and explains the similarities and patterns we observe (for example between mitochondria and some species of bacteria), so too can evolution be used as the cornerstone in teaching marine biology. For example, lessons focused on the ecology of intertidal communities can include the evolutionary history of species within communities, as well as the evolutionary history of communities themselves by examining evidence from fossil communities.

Why is it important to teach evolution in public schools and to defend this topic?

As stated above, evolution is the organizing principle of all biology, and accepted by all major scientific organizations. To leave it out of the science curriculum is pedagogically unsound and scientifically dishonest.

What is NCSE's take on some of the issues going on in the marine world including climate change, ocean acidification, lack of marine conservation, etc. Does evolution play a part? Does it help or hurt? How does one educate on these topics using the mission of NCSE and the evolutionary theory?

NCSE focuses pretty closely on evolution education, and doesn't have the resources to take a stand or lend a hand with issues outside of its mission. But as these issues relate to the nature of science and improving science education, we certainly keep ourselves informed. An understanding of climate change, the importance of marine conservation, etc. must include knowledge of the ecological response of organisms over a few generations and the evolutionary response over multiple generations. Finally, we know misconceptions about the nature of science can lead people to reject evolution. We see similar responses by the public to an understanding and acceptance of global climate change and certainly want to work together to help the public better understand any scientific issue.