Most large animals have to chew food extensively and form it into a mushy ball that’s easy to swallow. Cooking makes a huge difference—it softens the food and dramatically reduces eating time. Researchers calculated that if we lived like our non-cooking primate cousins, we’d spend about 48 percent of the day eating. But modern humans spend only about 5 percent of the day chowing down. So when our ancestors invented cooking, it gave them a major survival advantage.

　　So how long have ago did our forebears start barbecuing?

　　The softer food available via cooking allowed for the evolution of smaller molars and a smaller jaw. Researchers therefore compared the molars and body sizes of extinct hominids with modern humans and other primates. Turns out that Homo erectus and Neanderthals had, and modern humans have, molars that are smaller than would be predicted by looking at general primate evolution. The finding is in the Proceedings of the National Academy of Sciences. [Chris Organ et al, Phylogenetic rate shifts in feeding time during the evolution of Homo]

　　Based on the appearance of the smaller eating apparatus, the researchers infer that humanity discovered the benefits of cooking about 1.9 million years ago. And we’ve been enjoying the convenience, speed and taste benefits ever since.

　　—Cynthia Graber

　　人類的牙齒及下顎由于烹飪的發(fā)明而變得越來越小。目前發(fā)現(xiàn)的人類化石表示掌控火候的烹飪技術(shù)可以追溯到190萬(wàn)年前。Cynthia Graber報(bào)道。

　　大部分大型動(dòng)物需頻繁咀嚼食物使之變成糊狀后以便于吞咽。而烹飪改變了這種情況-使食物能夠變得更加容易消化，并且可以大量減少咀嚼的時(shí)間。研究人員指出如果我們像不會(huì)烹飪的靈長(zhǎng)類同類一樣生活，我們得每天花費(fèi)48%的時(shí)間去吃東西，但是現(xiàn)在，我們只需要5%的時(shí)間。正是由于發(fā)明了烹飪技術(shù)才給我們的祖先帶來了巨大的生存優(yōu)勢(shì)。

　　那么我們的祖先是什么時(shí)候開始開始烹調(diào)食物?

　　通過烹飪變得更加容易消化的的食物允許接受更小的牙齒和下顎，學(xué)者因此把現(xiàn)代人種中滅絕的人種還有一些靈長(zhǎng)類動(dòng)物得牙齒和體型做了比較，事實(shí)上，通過觀察一般靈長(zhǎng)類動(dòng)物的演變過程，可以看出直立人，穴居人，還有現(xiàn)代人擁有的牙齒比預(yù)測(cè)的還要小。此結(jié)論摘要在國(guó)家科學(xué)院院士論文中。

　　研究者基于越來越小的進(jìn)食用具的出現(xiàn)推斷出人類發(fā)現(xiàn)烹飪的好處出現(xiàn)在190萬(wàn)年前。自此我們十分享受這方便，快捷和美味的過程。