Showing posts with label classic. Show all posts
Showing posts with label classic. Show all posts

Tuesday, January 27, 2015

50 years of applying theory to ecological problems: where are we now?

Fifty years ago, the seminal volume ‘The Genetics of Colonizing Species’ edited by Herbert G. Baker and G. Ledyard Stebbins was published, and it marked a new phase for the nascent sciences of ecology and evolutionary biology –namely applying theories and concepts to understanding applied issues. Despite the name, this book was not really about genetics, though there were several excellent genetics chapters, what it was really about was the collective flexing of the post-modern synthesis intellectual muscles. Let’s back up for a minute.

The modern synthesis, largely overlooked and forgotten by modern course syllabi, is the single most important event in ecology and evolution since the publication of Darwin’s Origin of the Species. Darwin’s concepts of evolution stand as dogma today, but after publishing his book, Darwin and others recognized that he lacked a crucial mechanism –how organismal characteristics were passed on from parent to offspring. He assumed that whatever the mechanisms, offspring varied in small ways from parents and that there was continuous variation across a population.

For more than 30 years, from about 1900-1930, evolution via natural selection was thought disproven. With the rediscovery of Mendel’s garden pea breeding experiments in 1900, many influential biologists of the day believed that genetic variation was discontinuous in ‘either-or’ states and that abrupt changes typified the appearance of new forms. Famously, this thinking lead to the belief that ‘hopeful monsters’ were produced with some becoming new species instantaneously. This model of speciation was referred to ‘saltationism’

Of course there were heretics, most notably the statisticians who worked with continuous variation (e.g., Karl Pearson, and Ronald Fisher) who refuted the claims made by saltationists in the 1920s. Some notable geneticists changed their position on saltationism because their experiments and observations provided evidence that natural selection was important (most notably T.H. Morgan). However, it wasn't until WWII that the war was won. A group of scientists working on disparate phenomena published a series of books from 1937-1950 that showed how genetics was completely compatible with Darwinian natural selection and could explain a wide variety of observations from populations to biogeography to paleontology. These ‘architects’ and their books were: Theodosius Dobzhansky (Genetics and the Origin of Species); Ernst Mayr (Systematics and the Origin of Species); E. B. Ford (Mendelism and Evolution); George Gaylord Simpson (Tempo and Mode in Evolution); and G. Ledyard Stebbins (Variation and Evolution in Plants). With this, they unified biology and thus the modern synthesis was born.
Now back to the edited volume. Which such a powerful theory, it made sense that there should be a theoretical underpinning to applied ecological problems. The book grew out of a symposium held in Asilomar, California Feb. 12-16, 1964[1], organized by C. H.Waddington, who originally saw an opportunity to bring together thinkers on population genetics. But the book became so much more. According to Baker and Stebbins:
“…the symposium … had as its object the bringing together of geneticists, ecologists, taxonomists and scientists working in some of the more applied phases of ecology –such as wildlife conservation, weed control, and biological control of insect pests.”

Thus the goal was really about modern science and the ability to inform ecological management. The invitees include a few of the ‘architects’ (Dobzhansky, Mayr, and Stebbins) and their academic or intellectual progeny, which includes many of the most important thinkers in ecology and evolution in the 1960s and 70s (Wilson, Lewontin, Sakai, Birch, Harper, etc.).

Given the importance of the Genetics of Colonizing Species in establishing the role that theory might play for applied ecology, it is important to reflect on two important questions: 1) How much have our basic theories advanced in the last 50 years; and perhaps more importantly, 2) has theory provided key insights to solving applied problems?

This book is the fodder for a graduate seminar course I am teaching, and these two questions are the focus of our comparing the chapters to modern papers. Over the next couple of months, students in this course will be contributing blog posts that examine the relationship between the classic chapters and modern work, and they will muse on these two questions. Hopefully by the end of this ongoing dialogue, we will have a better feeling of whether basic theory has advanced our ability to solve applied problems.