アメリカ自然史博物館さんのインスタグラム写真 - (アメリカ自然史博物館Instagram)「When you sit down for Thanksgiving dinner tomorrow, you’ll use all five of your taste receptors—sweet, bitter, sour, salty, and umami, also known as savory—to enjoy every bit of the annual feast. Penguins, however, seem to have lost three of the five receptors; it’s thought they only have the ability to taste sour and salty! Researchers think that drastic cooling in Antarctica millions of years ago may have affected the taste receptors of the penguins’ common ancestors. Why? A protein responsible for sending sweet, umami, and bitter taste signals to vertebrate nervous systems doesn’t work well at lower temperatures. Photo: Polar Cruises」11月28日 13時02分