ScientificInterests

The study of (non-)adaptation
"The beauty and infinite complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection."

There was a time when I believed it was every biologist's privilege and duty to testify the power of natural selection by demonstrating the beauty and complexity of adaptation. Dirk Bauwens, known for his natural delicacy, firmly destroyed this romantic idea. He showed me the spandrels of San Marco, and pointed out the ridiculous length of human sperm ducts. Suddenly, aptness lost its glance, and imperfection became exciting. I became interested in evolutionary constraints
Darwin, The Origin of Species, chapter IV

Evolutionary constraints may lurk both in the performance- and in the fitness-gradient. Therefore, understanding imperfection requires understanding how genetic variation translates into design variation into performance variation into fitness variation (or why it doesn't). That's cool, because it allows me to sample and combine the flavors of more than one discipline in biology. In an attempt to capture its amphibious nature, this area of research has been termed 'ecological morphology' or 'ecological physiology', depending on the design function under study.
Ecological morphology

Ecological morphology, or ecomorphology, studies the relationship between the morphology of organisms and their ecology. The fact that the morphology of animals and plants so gracefully fits the requirements of their natural surroundings, has long been considered evidence for a Devine Creator. Somewhat ironically, Darwin turned the same observation into one of the most convincing arguments in favor of his theory of evolution by natural selection.

More recently, it has appeared that ecomorphologists may have been a bit too confident. Accusations of adaptive story telling have been uttered. Even worse, on several occasions, the fit between form and function has proved conspicuous by its absence. Nature's perfection is starting to show cracks.

Evolution of locomotor capacity

"THE AUSTRALIAN FRILLED LIZARD, WHICH IS AT PRESENT TRYING TO BECOME A BIPED"
(from Thomson J.A. 1922. The outline of science - A plain story simply told. G.P. Putnam's Sons, New York)

Most animals swim, run, jump, or fly to catch food, to avoid becoming food, or to achieve copulations. Most likely, whether an individual animal will survive and procreate will depend on various aspects of its locomotor capacity: speed, endurance, manoeuvrability, acceleration, etc. Each of these aspects depend on a number of biochemical, physiological and morphological characteristics, and some sets of performance aspects require different and conflicting designs. Individual variation in locomotor capacity seems repeatable and heritable in at least some species of animals. With all that, no wonder that locomotion has become one of the model functions of ecological morphology.

In our study of the evolution of the locomotor system, we try to go all the way. We want to know the genetic basis for the variation in capacity, and we want to learn about the performance and the fitness gradient. Hence we breed animals, we measure morphology, we do performance tests, we capture and release.

Evolutionary physiology

Perhaps even more than traditional ecomorphology, traditional environmental physiology has long time assumed aptness. Physiological systems, it was said, evolved to do what they are supposed to do: keep the animal's homeostasis in the prevailing environmental conditions. Individual variation was considered noise: annoying and unimportant.
In the past two decades, evolutionary physiologists have begun to question these assumptions. On several occasions, traditional tenets proved simply wrong.

Evolution of thermal physiology

Temperature is probably the single most important environmental factor. Animals and plants have evolved an astonishing variety of ways to avoid temperatures that are too cold or too warm. Endotherms have taken the expensive option and use home-made heat to thermoregulate. Ectotherms (the majority of plants and animals) cannot afford this. They either thermoregulate behaviorally, or not at all. A faithful adaptationist would expect that in ectotherms, the thermal dependence of ecologically relevant functions would have evolved to match the distribution of environmental temperatures. Sometimes it did, sometimes it didn't. I wonder why.

In our study of the evolution of thermal physiology, we try to see how (well) ectotherms cope with the variation in environmental temperatures. The approach is not so different from the one taken in our ecomorphological studies. We measure performance for an ecological relevant function (often locomotion!) at different temperatures, and look for variation in thermal characteristics.

Intra- and interspecific variation

Although the process of adaptation probably revolves around variation between individuals within a species, much can be learned from interspecific analyses. Differences among (closely related) species are often more readily measurable. We tackle questions on ecomorphology and ecophysiology at different levels: within populations, among (geographically isolated) populations, and among related species.

Starring

Lizards have starred in our research projects from the very beginning. Deceptively named the 'common' lizard, Lacerta vivipara was my first love. Later I became enchanted by Mediterranean and Canarian members of the lacertid family. Lacertid lizards are agile, heliothermic ectotherms that are (relatively) easy to work with both in the field and in the lab. For the fields of ecomorphology and ecophysiology, lizards are fine model animals.

Ok, lizards are not the only cool animals. In honour of August Koch, I also work with snakes, frogs and toads, fish, and carabid beetles.

The study of (non-)adaptation	"The beauty and infinite complexity of the coadaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection."
There was a time when I believed it was every biologist's privilege and duty to testify the power of natural selection by demonstrating the beauty and complexity of adaptation. Dirk Bauwens, known for his natural delicacy, firmly destroyed this romantic idea. He showed me the spandrels of San Marco, and pointed out the ridiculous length of human sperm ducts. Suddenly, aptness lost its glance, and imperfection became exciting. I became interested in evolutionary constraints	Darwin, The Origin of Species, chapter IV
	Evolutionary constraints may lurk both in the performance- and in the fitness-gradient. Therefore, understanding imperfection requires understanding how genetic variation translates into design variation into performance variation into fitness variation (or why it doesn't). That's cool, because it allows me to sample and combine the flavors of more than one discipline in biology. In an attempt to capture its amphibious nature, this area of research has been termed 'ecological morphology' or 'ecological physiology', depending on the design function under study.
Ecological morphology
Ecological morphology, or ecomorphology, studies the relationship between the morphology of organisms and their ecology. The fact that the morphology of animals and plants so gracefully fits the requirements of their natural surroundings, has long been considered evidence for a Devine Creator. Somewhat ironically, Darwin turned the same observation into one of the most convincing arguments in favor of his theory of evolution by natural selection.
More recently, it has appeared that ecomorphologists may have been a bit too confident. Accusations of adaptive story telling have been uttered. Even worse, on several occasions, the fit between form and function has proved conspicuous by its absence. Nature's perfection is starting to show cracks.
	Evolution of locomotor capacity
"THE AUSTRALIAN FRILLED LIZARD, WHICH IS AT PRESENT TRYING TO BECOME A BIPED" (from Thomson J.A. 1922. The outline of science - A plain story simply told. G.P. Putnam's Sons, New York)	Most animals swim, run, jump, or fly to catch food, to avoid becoming food, or to achieve copulations. Most likely, whether an individual animal will survive and procreate will depend on various aspects of its locomotor capacity: speed, endurance, manoeuvrability, acceleration, etc. Each of these aspects depend on a number of biochemical, physiological and morphological characteristics, and some sets of performance aspects require different and conflicting designs. Individual variation in locomotor capacity seems repeatable and heritable in at least some species of animals. With all that, no wonder that locomotion has become one of the model functions of ecological morphology. In our study of the evolution of the locomotor system, we try to go all the way. We want to know the genetic basis for the variation in capacity, and we want to learn about the performance and the fitness gradient. Hence we breed animals, we measure morphology, we do performance tests, we capture and release.
Evolutionary physiology
Perhaps even more than traditional ecomorphology, traditional environmental physiology has long time assumed aptness. Physiological systems, it was said, evolved to do what they are supposed to do: keep the animal's homeostasis in the prevailing environmental conditions. Individual variation was considered noise: annoying and unimportant. In the past two decades, evolutionary physiologists have begun to question these assumptions. On several occasions, traditional tenets proved simply wrong.
	Evolution of thermal physiology
	Temperature is probably the single most important environmental factor. Animals and plants have evolved an astonishing variety of ways to avoid temperatures that are too cold or too warm. Endotherms have taken the expensive option and use home-made heat to thermoregulate. Ectotherms (the majority of plants and animals) cannot afford this. They either thermoregulate behaviorally, or not at all. A faithful adaptationist would expect that in ectotherms, the thermal dependence of ecologically relevant functions would have evolved to match the distribution of environmental temperatures. Sometimes it did, sometimes it didn't. I wonder why. In our study of the evolution of thermal physiology, we try to see how (well) ectotherms cope with the variation in environmental temperatures. The approach is not so different from the one taken in our ecomorphological studies. We measure performance for an ecological relevant function (often locomotion!) at different temperatures, and look for variation in thermal characteristics.
Intra- and interspecific variation
Although the process of adaptation probably revolves around variation between individuals within a species, much can be learned from interspecific analyses. Differences among (closely related) species are often more readily measurable. We tackle questions on ecomorphology and ecophysiology at different levels: within populations, among (geographically isolated) populations, and among related species.
	Starring Lizards have starred in our research projects from the very beginning. Deceptively named the 'common' lizard, Lacerta vivipara was my first love. Later I became enchanted by Mediterranean and Canarian members of the lacertid family. Lacertid lizards are agile, heliothermic ectotherms that are (relatively) easy to work with both in the field and in the lab. For the fields of ecomorphology and ecophysiology, lizards are fine model animals. Ok, lizards are not the only cool animals. In honour of August Koch, I also work with snakes, frogs and toads, fish, and carabid beetles.