Fri. Jan 21st, 2022

Primates vs. Cobras: how our last common ancestor built poison resistance

Lecturer Bryan Fry. Credit: University of Queensland

The last common ancestor of chimpanzees, gorillas, and humans developed an increased resistance to cobra venom, according to University of Queensland-led research.

Scientists used animal-free testing techniques to show that African and Asian primates developed resistance to the venom of large, diurnal cobras, and discovered that our last common ancestor with chimpanzees and gorillas developed even stronger resistance.

University of Queensland Ph.D. candidate Richard Harris said African and Asian primates developed poison resistance after a long evolutionary arms race.

“As primates from Africa gained the ability to walk upright and spread throughout Asia, they developed weapons to defend themselves against poisonous snakes, which likely triggered an evolutionary arms race and developed this poison resistance,” Harris said.

“This was just one of many evolutionary defenses – many primate groups also appear to have developed excellent vision, which is thought to have helped them detect and defend against poisonous snakes.

“But Malagasy lemurs and Central and South American monkeys, which live in areas that have not been colonized by or come into close contact with neurotoxic venomous snakes, did not develop this kind of resistance to snake venom and have poorer vision.

“It has long been theorized that snakes have strongly influenced primate evolution, but we now have additional biological evidence to support this theory.”

The team studied various snake toxin interactions with synthetic nerve receptors and compared them from primates from Africa and Asia with those from Madagascar – which do not have poisonous snakes – and those from America – where the cobra-related coral snakes are small, nocturnal and burrowing.

Team leader Associate Professor Bryan Fry said the study also revealed that in the last common ancestor of chimpanzees, gorillas and humans, this resistance was greatly increased.

“Our movement down from the trees and more commonly on land meant more interactions with poisonous snakes, thus driving the evolutionary selection of this increased resistance,” said Dr. Fry.

“It is important to note that this resistance is not absolute – we are not immune to cobra venom, just much less likely to die than other primates.

“We have shown in other studies that resistance to snake venom comes with what is known as a fitness disadvantage, whereby the receptors do not perform their normal function as efficiently, so there is a fine balance to be found where the gain should offset losses.

“In this case, partial resistance was enough to achieve the evolutionary advantage, but without the fitness disadvantage being too stressful.

“We are increasingly recognizing the importance that snakes have played in the evolution of primates, including the way our brains are constructed, aspects of language and even the use of tools.

“This work reveals another piece of the puzzle in this complex arms race between snakes and primates.”


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More information:
Richard J. Harris et al., Monkeys around with poison: increased resistance to α-neurotoxins supports an evolutionary arms race between African-Asian primates and sympathetic cobras, BMC Biology (2021). DOI: 10.1186 / s12915-021-01195-x

Provided by the University of Queensland

Citation: Primates vs. Cobras: How Our Last Common Ancestor Built Poison Resistance (2021, December 7) Retrieved December 7, 2021 from https://phys.org/news/2021-12-primates-cobras-common-ancestor-built.html

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