Male dragonflies are known to engage in mid-air "dogfights" to defend their breeding territory, using different maneuvers than those they employ when hunting prey. A new paper published in the Journal of the Royal Society Interface concluded that relatively simple rules drive that behavior, namely that male dragonflies are trying to maintain a tactical position. This mirrors the tactics of human fighter pilots. The research could lead to the development of smarter drones capable of navigating with simple, vision-based guidance rather than complex computation.

Classic pursuits involving prey or mating rituals are asymmetric: there is a chaser and an evader, with each role requiring different maneuvers. In the case of male-on-male interactions, however, it is more of a mutual pursuit, per the authors, who thought that studying flight trajectories of insects or raptors could yield useful insights into the guidance laws that underlie the behavior. They chose the Trithemis Aurora species of dragonfly for study because the males are "fiercely territorial," and there are usually multiple males around a given pond, intent on defending their chosen perches. The dragonflies are also crimson-colored, making them easier to track.

Much of the prior research on dragonfly interactions relied on visual observations or single-camera recordings. For this study, the authors set up a portable stereovideographic rig with two shutter-synchronized cameras to record dragonfly interactions in both color and monochrome, and then reconstructed 102 paired male-on-male flight trajectories to capture the 3D kinematics. They also reconstructed nine trajectories for dragonflies intercepting prey for comparative purposes. This enabled the authors to develop a model for the rules governing the flight behavior.

Read full article

Comments

Understanding the origin of life requires addressing a collection of overlapping scientific questions. We've made a lot of progress toward explaining how simple chemicals present on an early Earth built the complex molecules used by life and how some of those chemicals built the first genetic/catalytic molecules. But we're much further from understanding a key conundrum: How did membranes end up surrounding the first cells?

It's relatively easy to make membranes spontaneously form in water, and they'll enclose anything dissolved in that water, including nucleic acids. But the membranes then cut their interior off from everything else in the solution. Any interesting chemical reactions enclosed there would eat through the raw materials and grind to a halt.

Now, a lab at the University of Minnesota has announced that it has developed a simplified system in which a membrane encloses some genetic material but can continually import new materials supplied to it. The system also spontaneously divides, producing a few generations of "offspring" before things start failing. It's still extremely dependent upon human intervention, but it might provide a new avenue to explore questions about the origin of life and what a truly minimalistic form of life might look like.

Read full article

Comments