Rolf Degen summarizes: Contrary to earlier believes, humans have at least as many - if not more - Olfactory Receptor genes as monkeys and apes, with color vision being no limiting factor

Evolution of Genes for Color Vision and the Chemical Senses in Primates. Shoji Kawamura, Amanda D. Melin. Chapter in Evolution of the Human Genome I. https://link.springer.com/chapter/10.1007/978-4-431-56603-8_10

Abstract: Primates are generally regarded as visually oriented mammals, trading a sense of smell for good sight. However, recent studies have questioned this simplistic view, and it is not well understood the extent to which senses have evolved interactively or in concert with each other in primates including humans. For example, the number of olfactory receptor genes is not as clearly differentiated between species with different color vision as once asserted. Among senses, receptors of stimuli for vision, olfaction, and bitter/sweet/umami tastes all belong to the G-protein-coupled receptor (GPCR) family, for which the genetic mechanism of signal perception is well understood. Thus, it is now possible to explore the evolutionary correlation among different senses in primates by studying these receptor groups for interspecies divergence, intraspecies diversity, and functional differences among variants. In this chapter, we review recent findings on these receptors and senses in humans and other primates and discuss the future directions of studies on their sensory evolution.



[Screenshot from https://twitter.com/DegenRolf/status/961876566023143424]

People struggle to name odors, but this limitation is not universal. Is superior olfactory performance due to subsistence, ecology or language family? Subsistence.

Hunter-Gatherer Olfaction Is Special. Asifa Majid, Nicole Kruspe. Current Biology, https://doi.org/10.1016/j.cub.2017.12.014 |

Highlights
    •    People struggle to name odors, but this limitation is not universal
    •    Is superior olfactory performance due to subsistence, ecology or language family?
    •    Hunter-gatherers and non-hunter-gatherers from the same environment were compared
    •    Only hunter-gatherers were proficient odor namers, showing subsistence is crucial

Summary: People struggle to name odors [1, 2, 3, 4]. This has been attributed to a diminution of olfaction in trade-off to vision [5, 6, 7, 8, 9, 10]. This presumption has been challenged recently by data from the hunter-gatherer Jahai who, unlike English speakers, find odors as easy to name as colors [4]. Is the superior olfactory performance among the Jahai because of their ecology (tropical rainforest), their language family (Aslian), or because of their subsistence (they are hunter-gatherers)? We provide novel evidence from the hunter-gatherer Semaq Beri and the non-hunter-gatherer (swidden-horticulturalist) Semelai that subsistence is the critical factor. Semaq Beri and Semelai speakers—who speak closely related languages and live in the tropical rainforest of the Malay Peninsula—took part in a controlled odor- and color-naming experiment. The swidden-horticulturalist Semelai found odors much more difficult to name than colors, replicating the typical Western finding. But for the hunter-gatherer Semaq Beri odor naming was as easy as color naming, suggesting that hunter-gatherer olfactory cognition is special.