Island habitat linked to tameness in lizards
UCR professor Theodore Garland and two other researchers have published a study that confirms that island-dwelling lizards take longer to flee from predators than their mainland counterparts, a trait in island-dwelling animals that has long been observed, but never proven.
The study chiefly measured flight initiation distance, or the distance at which prey begins to flee from a predator it has observed, in 66 species of lizards. Controlling for body size and the speed of an approaching predator, the researchers found that flight initiation distance decreases as distance from the mainland increases.
Garland specializes in evolutionary physiology and has previously researched motivation in mice, finding that increases in voluntary activity resulted in natural selection for traits that increased the motivation and ability to perform those actions. “I like understanding how things work and that’s what physiology is all about: how things have come to be,” Garland explained. In evolutionary physiology, “you get to combine those two things.”
The research took approximately one and a half years to complete, with much of it spent on compiling the data the researchers obtained. The principal author of the study, William E. Cooper Jr., worked alongside Garland and another author, R. Alexander Pyron.
In terms of future research, Garland says, “We’re going to focus now more on the locomotor abilities of the animals. Obviously that’ll impinge on how close to a predator you can go. We’d like to take a more integrated view and understand how these abilities play into their tameness.”
Research on fly taste buds could lead to better insect traps
Entomologists have long known that fruit flies have eight different sweet taste receptors. However, nobody knew what specifically those receptors were responding to.
To answer this question, a team of UCR researchers recently published a study that proves that each of the eight receptors reacts to at least one sweet tastant, a substance that stimulates the sense of taste. The researchers were then able to classify the receptors into roughly two groups based on the tastants they responded to.
“What’s exciting about our findings is that this is the first instance in which anyone has been able to express a taste receptor in another neuron and obtain sensitivity to taste compounds,” entomology professor Anupama Dahanukar said. “What’s more, we also expressed a mosquito taste receptor in the fly neuron and found that it worked. That motivates us to test other receptors from mosquitoes or other insects.”
Dahanukar worked with Erica Freeman, the first author of the paper and a bioengineering graduate student, to test what each taste receptor responds to. Both were assisted by neuroscience graduate student Zev Wisotsky, who validated Freeman’s findings.
The researchers were able to expand the research to include a single receptor from a mosquito, and Freeman says that future research will focus on mosquitoes.
“We can now determine how insects detect sweet compounds which answer a fundamental question in insect taste behavior,” Freeman said. “Furthermore, insight from this research will lead to better trap designs for pest and disease controls.”