Evolution

Humans and many other species have biologically endowed abilities for discriminating “quantities” to some degree (e.g., subitizing), but only humans, via the distinct capacity of “symbolic reference” exhibit “number” — i.e., exact symbolic quantification. Language, with its symbolic properties although present in all human cultures, is a necessary condition for “number” but it is not a sufficient condition for it. UC San Diego professor Rafael Nuñez discusses the comparative analysis of “quantity” and “number”, and the implications it has for debates about the origins of other human special capacities such as geometry, music, and art. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37386]

Sialic acid-recognizing immunoglobulin-type lectins (Siglecs) are a family of cell surface proteins prominently expressed on immune cells in mammals. Siglec-11 is an example of an inhibitory Siglec. It was the first protein in the brain found to be “human-specific”: non-human primates express Siglec-11 in other tissues but not in the central nervous system. UC San Diego School of Medicine professor Ajit Varki discusses the importance of Siglec-11 and the paired receptor Siglec-16, and how they play significant roles in regulating inflammation, and have several uniquely human features including expression in brain. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37380]

Language is a human cognitive specialization, and as such, is expected to be supported by human neurological specializations. The arcuate fasciculus is a white matter fiber tract that connects Wernicke’s and Broca’s language areas in the human brain, and also connects the homologues of Wernicke’s and Broca’s areas in non-human primate brains. Emory University professor James Rilling discusses the difference of arcuate fasciculus between human and non-human primate brains and how the specialization of speech has helped humans evolve. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37381]

During embryogenesis, the three germ layers (endoderm, ectoderm, mesoderm) differentiate into epithelial and non-epithelial cells, which eventually form differentiated tissues and organs. Abundant data now indicates that we humans are very closely related to other hominids including chimpanzees, bonobos, gorillas, and orangutans, the so-called "great apes". UC San Diego School of Medicine professor Nissi Varki discusses the incidence of carcinomas, including the rarity of occurrence of common human carcinomas in captive chimpanzees. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37382]

Diet has played a major role in the evolution of human and non-human primate digestive systems. Phytanic acid is a potentially toxic branched chain fatty acid that can be acquired in humans by ingesting plant and/or animal products. Although it was established that humans cannot derive phytanic acid from chlorophyll and instead normally obtain it only from meat, dairy, and fish products, less was known about the capacity of non-human primates with proportionally larger hindguts to obtain phytanic acid from plant materials. University of Southern California professor Joseph Hacia discusses studies profiling phytanic acid levels in red blood cells obtained from humans and captive non-human primates all on low phytanic acid diets. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37379]

ABO Blood groups represent the first described human molecular polymorphism. The ABO gene encodes variants of a protein (a glycosyltransferase) that produces the short sugar chains on glycoproteins and glycolipids that define the A, B, or O antigens. These antigens are found on red blood cells, plasma glycoproteins, and other cell types in various tissues. Individual humans can have one of four blood types based on the two alleles inherited from both parents at the ABO locus: blood type A, B, AB, or O. UC San Diego professor Pascal Gagneux discusses how recent comparative genome studies have revealed that this polymorphic system is ancient and shared between humans and non-human primates, this despite the fact that none of the great ape species carries all four ABO blood types. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37378]

Humans are unusual in that we depend on shared foods, especially among families and friends and between potential mates. Food sharing occurs between healthy individuals and those that are infirm or elderly. We also differ from other great apes in our early ages at weaning, late ages at maturity, short birth intervals and survivorship decades past menopause. The emergence of these patterns was crucial to early human development. In light of observations among modern East African hunter-gatherers, University of Utah professor James O’Connell evaluates two alternatives. He discusses one hypothesis that focuses on males acquiring big game meat and marrow to provide for mates and offspring. The other hypothesis surrounds how certain kinds of savanna plant food set up the forager interdependence which propelled all aspects of life history change. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Humanities] [Science] [Show ID: 37384]

Discussion session about The Evolution of Human Physical Activity. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 37188]

Human physical activities differ significantly from other species. How, when and why did these capabilities evolve? What adaptations underlie them? And how did the evolution of human physical activity affect other key human characteristics that have advanced our species? Herman Pontzer explores the evolution of metabolism, Grazyna Jasienska discusses different effects of activity on women's reproductive health and Ellen Breen explores an evolutionary pathway for high endurance activity. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 37187]

Human physical activities differ significantly from other species. How, when and why did these capabilities evolve? What adaptations underlie them? And how did the evolution of human physical activity affect other key human characteristics that have advanced our species? Daniel Lieberman explores how running evolved and David Raichlen explains the effects of physical activity on the brain. Series: "CARTA - Center for Academic Research and Training in Anthropogeny" [Science] [Show ID: 37185]