Who knew he was the alpha male?

How do you know if a stranger will be nice or nasty? Professor Cliff Summers’ group at the University of South Dakota has found that you can predict the social status of male lizards before they fight. What is more, green Anolis lizards show their fighting fitness through a colour signal on their face.

Wayne Korzan has discovered that how fast you recover from stress, to participate in feeding and courtship, can also foreshadow dominant social rank. Fast lizards are dominant lizards. As in humans, when anoles are stressed their adrenaline levels shoot up. As well as causing the ‘fight or flight’ response, adrenaline results in black eyespots developing behind the lizards’ eyes.

In a fight, the male who develops these eyespots fastest is dominant and usually wins. When the researchers painted artificial black signals onto a male lizard, they found that other lizards became subordinate to the animal with fake eyespots. Wayne will be presenting this work at the annual SEB meeting in Edinburgh from 29th March to 2nd April 2004 [session A3.31].

The researchers are studying the effects of neurotransmitters such as dopamine and serotonin to understand how these influence social behaviour. “Animals with high levels of dopamine in the regions of the brain that are involved in motivation and locomotion tend to win their fights” say Korzan and Summers; “Animals that initiate the stress response faster and recover from stress faster tend to win”. Conversely, animals with high levels of dopamine in the region of the brain associated with fear are usually subordinate and lose fights.

Interestingly, serotonin also increases during fights, and like dopamine is mediated by stress-related responses. Serotonin may help the lizards adapt to the stressful nature of the fight. Anolis lizards may prove to be a useful model system for studying stress, aggression and depression in humans. The group hopes that a better understanding of the brain neurochemistry of these lizards may help the development of future treatments for stress and depression in humans.

Media Contact

Yfke van Bergen alfa

All news from this category: Life Sciences and Chemistry

Articles and reports from the Life Sciences and chemistry area deal with applied and basic research into modern biology, chemistry and human medicine.

Valuable information can be found on a range of life sciences fields including bacteriology, biochemistry, bionics, bioinformatics, biophysics, biotechnology, genetics, geobotany, human biology, marine biology, microbiology, molecular biology, cellular biology, zoology, bioinorganic chemistry, microchemistry and environmental chemistry.

Back to the Homepage

Comments (0)

Write comment

Latest posts

Yeast mating — more than meets the eye

Pheromones mediate asymmetric mating behavior in isogamous yeast. Researchers from the Max-Planck Institute for Terrestrial Microbiology have discovered a surprising asymmetry in the mating behavior of unicellular yeast that emerges…

New super-resolution microscopy method approaches the atomic scale

Scientists at Weill Cornell Medicine have developed a computational technique that greatly increases the resolution of atomic force microscopy, a specialized type of microscope that “feels” the atoms at a…

‘Wonder material’ can be used to detect COVID-19 quickly, accurately

Researchers show a graphene-based sensor can detect SARS-CoV-2. Researchers at the University of Illinois Chicago have successfully used graphene — one of the strongest, thinnest known materials — to detect…

Partners & Sponsors