Making sense of our sense of smell

Evolutionary Biology Human olfactory sensory neurons may have adapted specifically to our ecological niche. Saraiva et al. used an RNA sequencing–based approach to assess the diversity of these neurons across mammalian evolution. Full nasal biopsies were conducted on mice, rats, dogs, marmosets, macaques, and humans to catalog and quantify neuronal subtypes. The sensitivity of smell in mammals may have been fine-tuned by selective pressures that modified the diversity of neuronal odorant receptor gene expression. The most abundant neuronal subtypes were those tuned to detect odors more ecologically relevant for specific species, such as pheromones or other communicable odorants. Sci. Adv. 10.1126/sciadv.aax0396 (2019).