Biology

53 "mute" species caught vocalizing, suggesting single chatty ancestor

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Researchers have found that turtles and other species long thought "mute" do in fact vocalize
Researchers have found that turtles and other species long thought "mute" do in fact vocalize
The researchers recorded vocalizations from tuataras, a reptile native to New Zealand previously thought to be mute
Gabriel Jorgewich Cohen

Birds sing, dogs bark, and turtles – well, it turns out they have a surprisingly wide vocabulary too. A new study has found that they, along with dozens of other “mute” species, do actually vocalize, leading to the conclusion that all acoustic communication can be traced back to a single ancestor more than 400 million years ago.

Vocalizations are specifically sounds that animals make with their mouths by drawing air from their lungs, and animals use them to communicate a wide range of messages to their own and other species. They might be singing to attract mates, calling to warn allies about predators, or grunting to scare off rivals.

These sounds are pretty well studied in many groups of animals, including mammals, birds and frogs, but others are generally thought to be more or less mute. Or at least, that was the assumption. A new study has examined some of these animals and found that many actually do vocalize after all.

A team led by the University of Zurich took recordings and observations of vocalizations from 53 species that had been thought non-vocal. That included 50 species of turtle, expanding on only a few that were known to vocalize, as well as three other clades of vertebrates in which no members had ever been known to vocalize – lungfishes, reptiles endemic to New Zealand called tuataras, and eel-like amphibians called caecilians.

The researchers recorded vocalizations from tuataras, a reptile native to New Zealand previously thought to be mute
Gabriel Jorgewich Cohen

“This, along with a broad literature-based dataset including 1,800 different species covering the entire spectrum shows that vocal communication is not only widespread in land vertebrates, but also evidence (of) acoustic abilities in several groups previously considered non-vocal,” says Gabriel Jorgewich-Cohen, first author of the study.

Next, the team mapped vocal communication across the vertebrate tree of life, and the results were surprising. Previous studies had found relatively patchy vocalization across the tree and came to the conclusion that the ability had evolved several times in different species. However, with the newfound talkers filling in the gaps, the researchers found that it evolved just once, and all vocalizations can be traced back to a single point of origin.

“We were able to reconstruct acoustic communication as a shared trait among these animals, which is at least as old as their last common ancestor that lived approximately 407 million years before present,” said Marcelo Sánchez, lead author of the study. “Our results now show that acoustic communication did not evolve multiple times in diverse clades, but has a common and ancient evolutionary origin.”

The research was published in the journal Nature Communications.

Source: University of Zurich

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4 comments
Late Boomer
It's a pity the researchers don't know anyone who owns a tortoise. I have two (one desert, one Amazonian) that will each make a prolonged hissing/coughing sound when displeased, sometimes chirping, but regularly make clicking sounds when they want a change of venue - "I'm hungry", "Put me down", "I want to walk" or "Bedtime". The clicking increases in frequency and volume the longer it takes to figure out what they want. The little guy squeals when he burps and I've been told he has vocal fits with something approaching honking noises when he wakes up in a wet bed in the middle of the night, while the other simply walks off to find a dry place to sleep. Neither is a daily offender, so it's not a big deal. But, yeah, they talk.
EH
Acoustic communication also is found in invertebrates, such as insects, so it either evolved separately or it goes back more than 400 Myr, or both. If it evolved separately in invertebrates and vertebrates, then it may have evolved different times within the vertebrates as well. I expect acoustic sensitivity is pretty much universal and goes way, way back evolutionarily, acoustic emission happens fortuitously/unintentionally without selection (more often there is selection for being silent rather than making noise), but sometimes the fortuitous sound-making gets selected, and this has happened many times in different species, with the meaning of the communication not inherited from a distant ancestor, just the sound-making and hearing capacities. The meaning of the communication, I think, must have mostly evolved independently over and over again. (Perhaps aside from the sounds of something getting killed, which have had a universal meaning.)
Michael Irving
EH: Insects do make noise to communicate, but they don't vocalize - that's specifically defined as making noise with the mouth from air expelled from the lungs, which insects don't have. This research was focused on vocalization, which the team concludes has only evolved once in vertebrates.
TpPa
That was a nice demonstration of the animals vocalizing!!!!!!!!!
For those people that actually didn't know this, I really do pity your sheltered city lifestyle, hell turn on Nat Geo, there are some awesome shows & specials on there, they do wonderful work.