the wildlife full of a variety of sounds — from singing birds and croaking frogs the lion’s roar, and “laughter” of hyenas. Vocalization helps animals avoid danger, to attract partners, to interact in the group.
But what was the root cause of the appearance of acoustic communication and how it developed?
Answers provides a new study by scientists from the United States and China. They studied the evolution of vocalizations of vertebrates that live on land.
the Authors have created an evolutionary tree 1800 types of mammals, birds, reptiles and amphibians and tracked their relationships over 350 million years.
From the scientific literature, the researchers received information about the absence or presence of acoustic communication in each species and is noted on the created tree.
Using statistical analytical tools, scientists tested whether acoustic communication independently in different groups (and if so, when), whether this was due to nocturnal activity and vocalization is preserved in one way or another “bloodline”.
the result was that the ancestors of terrestrial vertebrates not used for the production of sounds, the respiratory system, i.e. had the ability to communicate through vocalizations.
Instead, it turned out that acoustic communication evolved independently in different terrestrial vertebrates in the last 100-200 million years (depending on group).
in addition, the study showed that the origin of vocalization is closely related to nocturnal.
Logically, in the absence of light the animals were not able to share any visual signals to intimidate rival, attract a partner or other purposes. Therefore, acoustic communication gave vertebrates, leading nocturnal, many benefits.
May, acoustic communication is more stable evolutionary trait that the othere types of alarms, such as painting.Photo Global Look Press.
based On their analysis, the authors also concluded that acoustic communication is present in more than two thirds of terrestrial vertebrates. And it’s not just familiar birds chirping or the croaking of frogs. Crocodiles and some turtles also have a “vocal abilities”.
it is also Interesting that many of the animals that “came out of the gloom” and today lead a day life, have kept sound communication.
“In the development of acoustic communication has an advantage when you are active night. But it becomes a disadvantage when you switch to a daytime activity, says co-author John Vince (John Wiens) from the University of Arizona. — We have examples of preservation of acoustic communication in frogs and mammals that have become active during the day, although hundreds of millions of years ago were nocturnal”.
Another striking example is birds, who also refused vocalizations. And they sing, usually at dawn, that it is possible (though speculative) to calculate the result of night way of life that took place hundreds of millions of years ago, researchers say.
They also believe that acoustic communication is surprisingly stable evolutionary trait, a more robust that other types of signaling, such as painting, for example.
in addition, the analysis showed that the ability to vocalization is not the driving force of diversification. That is, it did not affect the rate of appearance and development of new vertebrate species.
to illustrate this unexpected conclusion, Vince cites the example of birds and crocodiles. Both lines have acoustic communication, and evolutionary history has lasted for a hundred million years. But if the birds there are about ten thousand species, the order of crocodiles — only about 25.
Another example: scientists know of about ten thousand species of lizards and snakes, most of which do without vocalizing. Among the mammals thereUte about six thousand species, and 95% of them communicate through sounds.
“If you look at this on a smaller scale, e.g. a few million years ago and within certain groups such as frogs and birds, the idea that acoustic communication leads to speciation, it works. But we looked 350 million years of evolution, and acoustic communication [in this case] does not explain patterns of species diversity that we see,” said John Vince.
More information about this work is discussed in an article presented in the journal Nature Communications.
by the Way, earlier “Conduct.Science” (nauka.vesti.ru) talked about the delightful cooing of the dinosaurs and contagious laughter of parrots, and also about why the wolves and argue about the Egyptian flying dogs.
Text: To.Science
