Reproduction: Morgan and others point to the increased adiposity of human infants, a marked difference from the offspring of other great apes. This is suggested as an adaptation to increased insulation and buoyancy in water for human babies. It is pointed out, that vernix caseosa, a cheesy varnish coating the skin of newborn babies, apart from
cannot walk upright until as much as one year of age, completely unknown among simian offspring, e.g., grassland-dwelling baboons. Morgan also claimed that newborns are adequately suited to swim along with their mother, while being able to hold their breath upwards of 45 seconds.[54] Historically, women throughout the world have experienced a series of potentially life-threatening circumstances delivering above water, while Morgan and others, e.g., the French physician Michel Odent, point to recent decades of studies into baby swimming and water birth, which have become common practices in modern obstetrics and pediatrics to relieve stress and pain effects for both mother and child, with no corresponding observed drowning risks for the child.[55][56]
Morgan also pointed to unique features of both men and women's genitals, and the woman's protruding, fat-filled bosom as possible aquatic adaptations, with alleged convergence observed in sirenia. Presented criticism to these claims include the infant's increased risk of drowning if parting from its mother, coupled with observations of both young children as well as adults developing aquaphobia, while baby swimming and water birth are being rejected as fads.[54]