篮球竞彩nba www.xvrnl.com Some Prehumans Feasted on Bark Instead of Grasses
Almost two million years after their last meals, two members of a prehuman species in southern Africa left traces in their teeth of what they had eaten then, as well as over a lifetime of foraging. Scientists were surprised to find that these hominins apparently lived almost exclusively on a diet of leaves, fruits, wood and bark.
If you are what you eat, the new research and other recent studies suggest there was more diversity in the diets of early prehumans, both within and between species, than previously understood. And this could in part account for the recently recognized physical diversity among the long intermediate line of hominins belonging to the genus Australopithecus.
如果說吃什么就變什么的話，最新的調查和近期的研究都表明，不管是在同一物種內部，還是不同物種之間，早期原人的食物結構，都比人們先前所知的更多樣化。而這可能在一定程度上解釋了最近發現的南方古猿屬 (Australopithecus) 各原人種之間物理特征的多樣性。
The dietary pattern of the enigmatic species, Australopithecus sediba, discovered four years ago in the Malapa caves northwest of Johannesburg, was unexpected for several reasons. It contrasted sharply with available data for other hominins in the region and elsewhere in Africa; they mainly consumed grasses and sedges from the savanna.
四年前在約翰內斯堡 (Johannesburg) 西北的瑪拉帕 (Malapa) 山洞里發現的南方古猿源泉種 (Australopithecus sediba) 是一個非常神秘的物種。從好幾個方面來看，它們的飲食結構都有些出乎意料。 首先，它和在同一地區以及非洲其他地方得到的關于其他原人的數據明顯不同;后者主要的食物是熱帶草原上的青草和莎草。
The Au. sediba diet also appeared to be a matter of choice, not necessity. Other evidence from animal fossils and sediments in the area indicated the presence at the time of vast grasslands in the vicinity. Yet these hominins, their skeletons adapted for tree climbing as well as upright walking, chose to feed themselves in adjacent woodlands. In this, scientists said, their behavior was more like that of modern chimpanzees, which tend to ignore savanna grasses, or perhaps the more apelike hominin Ardipithecus ramidus, which lived largely on hard foods some 4.4 million years ago.
此外，南方古猿源泉種的飲食結構看起來更像是基于選擇，而不是必然。從動物化石和當地沉積物中得到的其他證據表明，當時周圍出現了遼闊的草原。然而，盡管它們的骨骼既能爬樹也適應直立行走，但這些原人卻選擇去附近的林地覓食?？蒲Ъ頤僑銜?，在這一點上，它們的行為更接近現代黑猩猩——因為黑猩猩就不吃草原上的草——或是一種叫做地猿始祖種 (Ardipithecus ramidus) 的古類人猿。地猿始祖種生活在約440萬年以前，基本上以堅硬的食物為生。
An international team of scientists led by Amanda G. Henry of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, reported on Wednesday the research that supported their findings. Their paper was published online by the journal Nature and will appear later in a printed edition.
由德國萊比錫馬普研究所人類進化學協會 (Max Planck Institute for Evolutionary Anthropology) 的阿曼達·G·亨利 (Amanda G. Henry) 領導的一個國際科學家小組周三發表了支持他們結論的研究報告。他們的文章被《自然》(Nature) 雜志發表在網上，隨后會出現在雜志的印刷版上。
“If these individuals are representative of the species,” the scientists wrote, “Au. sediba had a diet that was different from those of most early African hominins studied so far.”
They also concluded that the “inferred consumption” of woodland products “increased the known variety of early hominin foods.” But there is still much that is unknown or unclear about the newfound species: how or if it is related to modern humans and just where it fits on the hominin family tree.
The discovery, by Lee Berger of the University of Witwatersrand in Johannesburg, of two partial skeletons — one an adult female, the other a juvenile male — was the basis for the announcement two years ago of the new hominin species. These and at least one other adult specimen indicate that these hominins stood little more than four feet tall and had small brains and a mix of primitive and more modern anatomies. Dr. Berger was an author of the new journal report.
這兩具不完整骨骸是由約翰內斯堡金山大學 (University of Witwatersrand) 的李·伯杰 (Lee Berger) 發現的，其中一具屬于成年女性，另外一具屬于未成年男性。兩年前，依據這兩具化石，科學家確定了這個新的類人物種。這兩具化石以及另外至少一具成年人化石標本表明，這些類人生物直立身高略高于四英尺，大腦較小，解剖學特征有的依然原始，但有的已經比較現代。伯杰博士是這篇報告的作者之一。
Few other paleoanthropologists agree with Dr. Berger’s contention that the new species is the most plausible known ancestor of archaic and modern humans. Dr. Henry’s group said that studies of additional fossils from the Malapa caves “will provide a better understanding of the dietary ecology of Au. sediba.”
伯杰稱，這個新物種最有可能是遠古人類和現代人類的已知祖先。但幾乎沒有其他古人類學家贊同他的觀點。亨利博士領導的團隊稱，對瑪拉帕山洞其他化石的研究“會更有助于了解南方古猿源泉種的飲食生態。” 紐約時報中英文網 //www.xvrnl.com
Ian Tattersall, a paleoanthropologist at the American Museum of Natural History in New York, who was not involved in the research, called the findings “intriguing” and the research “an imaginative and multisided approach that makes you want to know more about this morphologically unusual species.”
伊恩·塔特索爾 (Ian Tattersall) 是紐約美國自然歷史博物館 (American Museum of Natural History) 的一名古人類學家，他沒有參與研究。他認為，研究結論“很有趣”，并表示這項研究“是一次富有想象力的嘗試，有很多方面的意義，讓人們想要更多地了解這個從形態學上來看很不同尋常的物種。”
“Fortunately,” Dr. Tattersall added, “rumor has it that more specimens are on the way.”
Dr. Henry’s team followed three lines of research. One was an analysis of carbon isotopes extracted by laser from tooth enamel, one of the most durable and least contaminated body parts, and one that preserves chemical signatures of what was eaten in one’s youth. The type and amount of isotopes left from a diet of tree leaves, fruit and bark were well outside the range of those seen in all previously tested hominins — at least 95 percent forest food.
A second approach was an examination of dental microwear, which can reveal pits, scratches and cracks left by hard foods consumed shortly before death. Dr. Tattersall said that this “doesn’t help much to clarify the situation, since it appears to differ significantly between the two individuals.”
Finally, microscopic plant particles, called phytoliths, were recovered from dental tartar for the first time from a very ancient hominin (but from only one of the two individuals). Scientists said this apparently confirmed the carbon isotopic evidence for woodland diets.
Benjamin H. Passey, a geochemist at Johns Hopkins University, who conducted the tests determining the high ratio of carbon isotopes indicating a diet mostly of forest foods, explained why the research was important to an understanding of human evolution.
本杰明·H·帕西 (Benjamin H. Passey) 是約翰·霍普金斯大學 (Johns Hopkins University) 的一名地球化學家。他主持進行了碳同位素檢測的實驗，就是他的實驗檢出了高比例碳同位素，說明該物種的飲食主要是森林植物。關于這個研究對了解人類進化的重要意義，他說：
“One thing people probably don’t realize is that humans are basically grass eaters,” Dr. Passey said in a statement. “We eat grass in the form of the grains we use to make breads, noodles, cereals and beers, and we eat animals that eat grass. So when did our addiction to grass begin? At what point in our evolutionary history did we start making use of grasses? We are simply trying to find out where in the human chain that begins.”