Evolution of the cochlea signals that displace the eardrum by a mere picometre. Because of its prominence and preserved state in the fossil record, until recently, the ear had been used to determine phylogeny. The ear itself contains different portions, including the outer ear, the middle ear, and the inner ear and all of these show evolutionary changes that are often unique to each lineage [14]. It was the independent evolution of a tympanic middle ear in the Triassic era that produced strong selection pressures towards improved hearing organs in the separate lineages of land vertebrates. The cochlea is the tri-chambered auditory detection portion
Evolution of the cochlea motor function in land vertebrates, but this developed vastly differently in different lineages. In certain birds and mammals, prestins function as both transporters and motors, but the strongest evolution to robust motor dynamics only evolved in therian mammals. It is hypothesized that this motor system is significant to the therian cochlea at high frequencies because of the distinctive cellular and bony composition of the organ of Corti that allows the prestins to intensify movements of the whole structure. Modern ultra-sound echolocating species such as bats and toothed whales show highly evolved prestins, and these prestins show identical sequence alterations over