Final answer:
The hypothesis regarding light skin being less susceptible to frostbite and its evolutionary advantage in areas with less sunlight is known as 'directional selection' related to skin pigmentation.
Step-by-step explanation:
The hypothesis that the presence of light skin is associated with being less susceptible to frostbite is likely related to the concept of evolutionary adaptation to varying levels of ultraviolet radiation from the sun due to geographical location and climate. Humans that migrated to areas further from the equator were exposed to less ultraviolet radiation, necessitating the need for lighter skin pigmentation to adequately produce vitamin D. Conversely, in tropical areas, darker skin pigmentation would prevent excessive amounts of vitamin D synthesis and protect against sun damage. Thus, the term for this hypothesis is generally referred to as 'directional selection' related to skin pigmentation.