Dr. Hans Hofmann

Hans Hofmann finds insects fascinating.

“In general they have very stereotypical behavior,” he says. “Compared to vertebrates, it’s easier to make the causal connection between the activity and the function of a particular insect neuron and the particular behavior.”

Since insect heads are small, they don’t have room for many neurons. Their brains must make do with a few thousand neurons as opposed to the billions of neurons humans have. To accomplish complex tasks such as finding food and escaping predators, their brains dedicate a particular neuron to a particular task.

“One insect neuron will usually do the job of an entire brain region in a vertebrate,” he says.

Hofmann’s current laboratory creature of choice is the cichlid fish - a native of eastern Africa’s Lake Tanganyika, a location to which Hofmann tries to travel with students once every other year. Cichlids are unique because they are descended from a single or few ancestral species, have very complex social behavior, behave the same in a laboratory tank as in nature and exhibit a high degree of phenotype plasticity.

“Most creatures have phenotype plasticity, but in cichlids it’s incredibly pronounced,” he says. For example, cichlid male phenotypes change dramatically depending upon their social structure, which is subject to constant change in the wild. When environmental alterations allow a formerly submissive male cichlid to become the dominant fish, his appearance - including color and musculature - is totally transformed.

A Cichlid Fish

A neurobiologist by training, Hofmann’s work with cichlids hints at evolutionary biology.

“I’m just dabbling in evolution,” he says.

The relationship between genes and environment in forming physiological qualities and behaviors is a focus of Hofmann’s research. “The debate between nature and nurture is like a zombie that keeps coming back,” he says. “Very few people are hard-core naturists or nurturists nowadays. Everybody is an interactionist in a way. The problem is, we don’t understand how these interactions take place.”

Cichlids provide insight into this investigation by their socially-controlled phenotype adaptation. “One of the beauties of biology is diversity,” he says. “Different creatures can come up with very different solutions for the same problem or the same mechanisms can be used for very different ends.”

Coming to UT from an intellectual ivory tower like Harvard is something about which Hofmann is pleased. “In the area of integrative and organismal biology, UT is one of the best programs in the country if not worldwide,” he says. “The intellectual environment is very good.”

In Hofmann’s lab, students are exposed to a broad range of investigation. He has researchers from different backgrounds such as molecular biologists and evolutionary geneticists collaborating, which can initially be a challenge “because of the different languages that people speak,” he says. “It often takes a while before we don’t have to explain basic concepts to one another and can communicate freely. Once we can, it’s very rewarding.”

Hofmann believes exposure to different levels of investigation - behavioral, hormonal and molecular - is essential when faced with the complexities of social behavior. More importantly, insights gained at the molecular level in the lab must be verified by observing the whole organism under natural circumstances. “You must ask yourself if this is a mechanism that is really employed in nature or just something I can create in a laboratory situation,” he says. “It’s important not to get lost in the molecular beauty and forget about the whole organism.”

Students are also afforded the opportunity of accompanying Hofmann to the native waters of the cichlid fish at Lake Tanganyika. Not only are lab specimens collected, behavioral and ecological work is conducted. “We have a good arrangement with the Tanzania government and with the Tanzania Fisheries Research Institute,” he says. “It’s a safe place that I have no problems taking students.”

Those hoping to pursue Hofmann’s career path are advised to have more than one mentor and obtain feedback from those of diverse backgrounds. “Expose yourself to people and situations that are not soothing and comfortable,” he says. “Always look for the challenge and the pressure.”