考博英语阅读:《科学美国人》选文四
The paleo diet is a popular high-protein diet that aims to mimic what our hunter-gatherer ancestors ate. But what we buy at the supermarket doesn't quite approximate those ancient foods. Take for example, star lily roots. Heard of those?
"They taste a bit like yams."
Lyn Wadley is an archaeologist at the University of the Witwatersrand in South Africa. Her team recently discovered the charred remains of star lily roots in South Africa's Border Cave—hunks of roasted root that date to 170,000 years ago.
"And there's greater glucose availability once the root vegetables were cooked. And they knew that nearly 200,000 years ago, which I think is extraordinary. Or maybe they didn't know the chemistry of it, but they would have realized they felt far more satisfied after eating a meal that's cooked rather than one that is raw."
It's not easy to identify a charred chunk of ancient food, though. So Wadley's team gathered an array of raw ancient foodstuffs and roasted and charred them in ovens and campfires. They then did visual comparisons to the ancient sample and observed them both in a scanning electron microscope—which revealed that the charred leftovers from that meal, 170,000 years ago, were probably chunks of star lily root.
Details and photos of those roots are in the journal Science.
Wadley says the find also provides a better view of what the ancients ate. "I think the people who assume the paleo diet was based on protein simply haven't done their homework properly."
“原始人饮食法”是一种流行的高蛋白饮食法,旨在模仿我们狩猎采集祖先的饮食。但是我们在超市买到的东西和那些古代食物不太一样。以星百合根为例。你听说过这种食物吗?
“味道有点像山药。”
南非威特沃特斯兰德大学的考古学家林·瓦德利说到。她的团队最近在南非边界洞穴中发现了烧焦的星百合根遗迹,这些大块烤根可追溯到17万年前。
“块根类蔬菜经过烹饪后,葡萄糖的利用率就会上升。他们早在20万年前就知道了这一点,我认为这非常了不起。或许他们不知道其中的化学成分,但他们会意识到,食用烹饪过的食物比吃生食要令人心满意足得多。”
不过,要辨认出大块烧焦的古代食物并不容易。因此,瓦德利的团队收集了大量古代生食,在烤炉和营火中烘烤烧焦。之后,他们将其与古代样本进行目视比对,并用扫描电子显微镜进行观察,结果显示,17万年前那顿饭烧焦的剩饭,很可能是星百合根块。
这些根茎的细节和图片刊登在《科学》期刊上。
瓦德利表示,这项研究也让我们对古代人的饮食有了更深入的了解。“我认为那些认为原始人饮食是以蛋白质为基础的人,根本没有做好功课。”