Poison hypotheses

Sensory conflict might seem to be enough to explain why extra burden arises, but it does not seem to imply that nausea would result. Scientists wonder what the evolutionary origins might be for responsible this and related symptoms. Note that humans have the ability to naturally nauseate themselves from spinning motions that do not involve technology. The indirect poison hypothesis asserts that nausea associated with motion sickness is a by-product of a mechanism that evolved in humans so that they would vomit an accidentally ingested toxin [329]. The symptoms of such toxins frequency involve conflict between visual and vestibular cues. Scientists have considered alternative evolutionary explanations, such as tree sickness in primates so that they avoid swaying, unstable branches. Another explanation is the direct poison hypothesis, which asserts that nausea became associated with toxins because they were correlated throughout evolution with activities that involved increased or prolonged accelerations. A detailed assessment of these alternative hypotheses and their incompleteness is given in Section 23.9 of [173].