Spicy foods elicit a pungent or hot and painful sensation that repels almost all mammals.Here, we observe that the tree shrew (Tupaia belangeri chinensis), which possesses aclose relationship with primates and can directly and actively consume spicy plants. Ourgenomic and functional analyses reveal that a single point mutation in the tree shrew’s tran-sient receptor potential vanilloid type-1 (TRPV1) ion channel (tsV1) lowers its sensitivity tocapsaicinoids, which enables the unique feeding behavior of tree shrews with regards topungent plants. We show that strong selection for this residue in tsV1 might be driven byPiper boehmeriaefolium, a spicy plant that geographically overlaps with the tree shrew andproduces Cap2, a capsaicin analog, in abundance. We propose that the mutation in tsV1 isa part of evolutionary adaptation that enables the tree shrew to tolerate pungency, thus wid-ening the range of its diet for better survival.