Notes from class 4 3 14 Human Uniqueness Motor homunculus if precentral gyrus Importance of spoken language also shows up in neural control of vocalizations Expansion of facial and hand motor sensory importance shows up in the fossil record o and in HOX genes of the Human Accelerated Regions HAR1 neural development Beyond spoken language humans have written language This is TRULY unique among animal species Fairly recent so not directly of evolutionary significance But it is an extension of symbolic communication which is of significance Other species notice and react to environmental cues We create our own environmental cues for others to notice often in a very abstract and symbolic ways Art is uniquely human Can be for communication or pleasure Is there a selective value to pleasure o Music Origins of music The universal language of humans Rhythms pace and melodies can often tell stories without words Is music uniquely human Songbirds and Gibbons o Have functions Humans have it strictly for pleasure Evolution of music Notes from class 4 3 14 Selective advantages Bonding o Groups individuals mates etc Memory and associations Culture Human culture started with material culture Shows up in our brains o and in HOX genes of the Human Accelerated Regions HAR2 wrist and thumb development Laughter Is laughter unique to humans o Some have argues the chimps laugh o But it is always in response to tickling and is debatable o Starts young continues into old age o Universal among humans o Requires coordination of brain diaphragm lungs larynx mouth and face Involves at least 19 muscles on each side of the face o Selective values Bonding Sex appeal Relaxed physical tension allowing muscles to relax Triggers release of endorphins and dopamine Protects heart by increasing blood flow Boost immune system o Trade offs Nervous laughter Notes from class 4 3 14 Derisive laughter Either can effect your position in a group Evolution trade offs Language art music laughter Boredom Eyes the eyes the sclera exposed Natural selection Humans are unique among primates in having the whites of o Frontation and convergence of orbits in Eocene primates o Sclera probably no exposed until the Pleistocene o Selective advantage Defense against predators as their gaze cannot be determined Chance or by product of something else like the chin o Substantial selection of prefrontal motor cortex devoted to movement of eyelids and eyeballs Also note proximity to vocalization section Could our uniqueness have to do with language and communication Rolling of eyes widened eyes repeated shifts in one direction Baboons roll their eyelids back as a sign of aggression o Could our constantly exposed sclera have been seen by other animals as a threat We are the only species with the ability to look into the distant future We are the only species with the ability to look into the distant past Beauty of Paleoanthropology