Is infrasound the main driver of evolutionary size growth of some
Mammalian taxa? Thoughts on the connection between vertebrate evolution
and the long-range communication channels and setting up the
communication channel rule
Abstract
Tendency of the vertebrates to increase body sizes during evolution is
recognized in the 19th century. Beside the contradictory Cope’s rule,
other ‘rules’ were recognized, however not fully explained the
evolutionary size growth phenomenon. Recently the resource rule offered
a plausible explanation to this, although it left open the rapid
evolutionary size growth of the Mysticeti (Mammalia, Vertebrata). Here,
the rapid and significant evolutionary size growth of Mysticeti and the
odontocete sperm whale is explained by the innovative application of the
long-range communication channels. Regarding all analysed extant species
using infrasound either in aquatic or terrestrial environs for
long-range communication, a correlation between the body size/mass and
maximum propagation of the applied infrasound is recognized. Correlation
of the body sizes of these infrasound generating vertebrate taxa with
the maximum range of audibility reflects the acoustical characteristics
of the applied long-range communication channels. The wider the
audibility in the communication channel is, the greater the body size of
the species using the SOFAR channel for long-range communication. Other,
non-aquatic, terrestrial vertebrate species (African elephants,
cassowary) also present the same phenomenon suggesting that application
of the long-range communication channels may have universal role in
evolutionary size growth among social animals.