Ecology and Evolutionary Biology : An Interview with Bizymoms Top Blogger 2010 Recipient Marc Cadotte

1. What made you focus on the subjects of Evolutionary Biology and Ecology?

As a child I spent many days trampling through bogs and forests in northern Ontario in Canada, fascinated by the diverse forms that life takes. All of my studies and experiences in my undergraduate years at the University of Windsor, Canada, reinforced the drive to study Biology.

In the writings of Charles Darwin, the study of Ecology and Evolution were inseparable. Evolutionary Biology and Ecology really became separate disciplines in the 1920s to 1940s, due to differences in what questions people were asking and the accepted methodologies to test these questions. I was trained as an Ecologist but quickly came to realize that viewing Ecology and Evolution as separate fields limited my ability to obtain fuller understanding of species diversity and its implications. Now, my major drive is to work in the meeting ground between Ecology and Evolution, and use this understanding to better inform conservation decisions.

2. Please describe some specific aspects of your work. How did you get started with Evolutionary Biology?

I work at the interface of Ecology, Evolution and Conservation Biology. In Ecology we are interested in how interactions among species and their environments shapes diversity patterns, and I am interested in how patterns of diversity are generated. But more importantly, I study why diversity is important. We live in an era of elevated extinctions caused by human activities, and as we lose aspects of the Earth's diversity, what are the ecosystem function (e.g., producing biomass, pollinators services, carbon sinks, etc.) consequences of losing species? However, species are not all equal in their contributions to the functioning of ecosystems, and two species that largely fill the same niche are likely redundant and the loss of one of these could be compensated for by the other. On the other hand, unique species -filling their own niche, contribute unique aspects to ecosystem function and their loss would leave a hole unfilled. I study the functioning of plant ecosystems and evaluate the evolutionary uniqueness of species and their contributions to function. To do this, I get genetic sequences to reconstruct the evolutionary relationships among species, and then test hypothesis about the contribution to functioning by species with many close relatives (those that are likely redundant) to those that have few relatives.

3. What are the biggest unanswered questions that the Evolutionary Biology subject consists of?

Evolutionary Biology is an extremely broad area of research, describing change at many levels of biological organization, from molecular and cellular changes to differences between isolated populations. I think that two of the biggest unanswered questions are from opposing time and organizational scales. The first would be: how do small changes in the genetic code correspond to physical changes in an organism? We know that not all genetic changes are equal in their effect. Some genetics changes do nothing, some cause cancer and some result in profound changes. For example, biologists have found that there are some genes that activate large developmental pathways and changes in these genes result in changes in whole pathways. They have shown this by altering one of these activator genes and producing fruit flies with extra legs where antennae should be.

The second major question is how and why do speciation rates (that is the rate at which new species are born) change throughout Earth's history? It appears as though once a new trait emerges, that species quickly gives rise to numerous daughter species, as they invade new niches. For example, the family of composite plants (daisies, sunflowers, dandelions, etc.) is relatively young (about 40 million years old) and is also one of the most diverse with more than 23,000 species. What was about the evolution of composite flowers that resulted in this massive diversification?

4. What types of methods do you use in your experiments and research on Evolutionary Biology and Ecology?

My research mainly involves using experiments that manipulate patterns of plant diversity. From these, I measure annual plant growth across all species, which is a measure of the amount of carbon being sequestered from the atmosphere into living tissue. I also use genetic sequences from the species to reconstruct their evolutionary history and then measure diversity not as the number of species, but rather the total amount of evolutionary change represented by these species. I also used highly controlled laboratory experiments with micro-organisms, to test hypotheses about the role of species differences in allowing coexistence.

5. Do you think that humans are still evolving? Why do you think so?

This is an interesting question. And the answer is undoubtedly, yes. The only thing that could stop evolution is a lack of genetic diversity. In species where all individuals are nearly genetically identical, the ability for them to change is extremely limited. In humans, we have a plethora of genetic diversity. Living in Toronto, the world's most diverse city, I just need to look at the faces of the 500 students in my introductory ecology class to realize just how much diversity the human species contains. Further, with the movement of humans among all countries means that genes are moving into populations where they would not have been able to before. My wife is ethnically Chinese and so our daughter has a genetic make-up unthinkable 5,000 years ago, and this is likely the future of humanity.

6. What are the most common misconceptions of evolutionary biology and ecology?

Well, there are a plethora of misconceptions about evolution, as people with limited training in Biology attempt to sneak religious, or non-scientific content into secondary school science curricula. Most of these attempts are guided by people with sincere beliefs and are genuinely concerned about the spiritual wellbeing of others. However, evolution, like any other scientific discipline, only attempts to explain natural phenomena and patterns with observations, hypothesis testing and experimentation, and our understanding of how biological diversity came to be is extremely sophisticated. Most attempts to combat evolution are based on antiquated views of evolution from the early 1900s and seldom even attempt to deal with understanding the genetic underpinnings of the physical attributes of an organism. Scientists largely work by understanding mechanisms and evolution deniers work through metaphor, which makes communication and mutual understanding very difficult.

7. What are some of the biggest threats to the environment that you see through the subjects of Evolutionary Biology and Ecology?

Evolution and ecology, fundamentally being about diversity, are concerned about what is happening with biological diversity around the world. Biological diversity can be measured across a number of scales from the number genes a population has to the number of species in a country. Through habitat destruction, over-harvesting, climate change and the importation of exotic species, we are losing biological diversity across all scales. I am mainly concerned about this for two reasons. The first is pragmatic. As diversity is lost, natural systems lose the ability to adapt to future environmental changes. As global climate change alters our Earth, a depauperate ecosystem will not have the necessary pieces to adapt to these changes. Ecosystem will function less efficiently. The second concern is more ethical. As we lose biological diversity, we lose aspects of the Earth that have taken millions of years to appear. We lose our ability to understand the world and where it came from and our place in it. We also lose the ability to learn from nature, to learn new engineering possibilities from the way organisms deal with environmental problems to learning about new medicines from the chemicals plant produce.