Abstract
The sophisticated feature of human speech allows us to turn much information encoded by language in the brain into sounds and to communicate it with others rapidly and efficiently. Understandings of the speech evolution shed light on the evolution of the language with which we are endowed today, while the two faculties may have arisen independently in the human lineage. Human speech shows highly sophisticated activities of the supralaryngeal vocal tract (SVT) through voluntary regulation of the vocal apparatuses, which is usually regulated involuntarily in other mammals. Advances in our understandings on the speech physiology underlie any arguments about the distinctions between speech in humans and vocalization patterns in nonhuman primates. Paleoanthropologists have continued to debate the “origin” of language, evaluating distinct morphological features, which are presumed to underlie just human speech. Unfortunately, such continued efforts have no consensus on the age of the origin. On the other hand, recent advances in empirical studies on the development of the SVT anatomy and on its potentials of dynamic manipulation in nonhuman primates endorse the idea that many of the separate biological foundations of speech had evolved independently before the origin of human beings, under different selection pressures unrelated to speech. Although the efforts have contributed to our better understanding on the mosaic processes of the speech evolution, the information on the static anatomy and manipulation potentials needs to be integrated in kinematic or kinetic terms. Such integration promises to pave the way to reevaluate the unique nature of the speech physiology in the light of vocalization in nonhuman mammals. It could contribute greatly to exploring the long “evolutionary history” of speech and language in paleoanthropological terms.
