人類的對生拇指最早出現(xiàn)在200萬年前

人類的對生拇指最早出現(xiàn)在200萬年前

The arrival of the opposable thumb was a big moment for humankind, and while its importance has long been agreed upon, questions have endured as to exactly when these beauties emerged. Now, new research published in the journal Current Biology has lifted the lid on these snazzy appendages, providing insights as to when thumbs became so dexterous, and how their emergence ties in with novel behaviors in humans.

對生拇指的出現(xiàn)對人類來說是一個重大的時刻，盡管人們對它的重要性早已達成一致，但關(guān)于這些美麗事物究竟何時出現(xiàn)的問題一直存在?，F(xiàn)在，發(fā)表在《當(dāng)代生物學(xué)》雜志上的一項新研究揭開了這些時髦的附體的面紗，提供了關(guān)于拇指何時變得如此靈巧的洞見，以及它們的出現(xiàn)是如何與人類的新奇行為聯(lián)系在一起的。

The study used virtual muscle modeling to assess the biomechanics and efficiency of thumb morphologies across different species among our ancestors. The approach is the first time muscular as well as skeletal structure has been taken into account while examining thumb function. They then compared the ages of the thumb specimens and their dexterity to key steps in the development of human behavior to see what our ancestors were working with when they made significant leaps in their evolution.

這項研究使用虛擬肌肉建模來評估我們祖先中不同物種的拇指形態(tài)的生物力學(xué)和效率。該方法是第一次在檢查拇指功能時將肌肉和骨骼結(jié)構(gòu)考慮在內(nèi)。然后，他們將這些拇指標(biāo)本的年齡和它們的靈巧度與人類行為發(fā)展的關(guān)鍵步驟進行比較，以了解我們的祖先在進化過程中取得重大飛躍時是如何工作的。

"Our methodology integrates cutting-edge virtual muscle modeling with three-dimensional analysis of bone shape and size," said first author and hand biomechanics expert Alexandros Karakostis, in a statement. "This process includes the precise 3D study of the areas of the bones where muscles attach in life. Importantly, we were able to validate the predictions of our models by confirming that the differences observed between living taxa –chimpanzees and modern humans – reflect those reported from past experimental studies."

“我們的方法整合了尖端的虛擬肌肉建模和骨骼形狀和大小的三維分析，”第一作者、手部生物力學(xué)專家Alexandros Karakostis在一份聲明中說。“這一過程包括對生活中肌肉附著的骨骼區(qū)域的精確3D研究。重要的是，我們能夠驗證我們模型的預(yù)測，通過確認(rèn)觀察到的現(xiàn)存類群——黑猩猩和現(xiàn)代人類之間的差異，反映了過去實驗研究的報告。”

Rachael Funnell

Their findings suggest that a key ingredient to the thumb’s success as an opposable digit first emerged around 2 million years ago. The remains of those given access to the dexterous upgrade lived in what we now call South Africa and likely belonged to either an early Homo species or the extinct hominin side branch Paranthropus robustus. Interestingly, the pivotal thumb adaptation wasn’t present in the hands of Australopithecines, according to the study, despite being alive around the same time as our opposable-thumb-wielding SA specimens.

他們的發(fā)現(xiàn)表明，拇指成功成為對生手指的一個關(guān)鍵因素大約出現(xiàn)在200萬年前。那些被賦予了智能性升級的人的遺骸生活在我們現(xiàn)在所稱的南非，很可能屬于一個早期的人或滅絕的類人猿分支的粗壯傍人。有趣的是，該研究表明，盡管與我們擁有對生拇指的SA物種生活在同一時期，但關(guān)鍵的拇指適應(yīng)性在南方古猿的手中并不存在。

Their new-and-improved thumb structure gave these early humans roughly the same dexterity as modern humans. This finding is of particular significance as the timeframe encompassed by the trait’s emergence includes some major steps forward in human behavior as they began their first forays into animal exploitation and became more reliant than ever before on stone tool technologies.

新改良的拇指結(jié)構(gòu)讓早期人類擁有了與現(xiàn)代人類大致相同的靈巧度。這一發(fā)現(xiàn)具有特殊的意義，因為這一特征的出現(xiàn)所包含的時間范圍包括人類行為的一些重大進步，因為他們開始第一次嘗試?yán)脛游?，并比以往任何時候都更加依賴石器工具技術(shù)。

"Increased manual dexterity in the form of efficient thumb opposition was among the early defining characteristics of our lineage, providing a formidable adaptive advantage to our ancestors," said researcher Katerina Harvati of the Eberhard Karls University of Tübingen. "It is likely a crucial element underlying the development of complex culture over the last 2 million years, shaping our biocultural evolution… These consistently high dexterity levels in species of Homo are indicative of the great adaptive value of thumb opposition for human biocultural evolution,"

Eberhard Karls大學(xué)的研究人員卡特琳娜·哈瓦蒂說:“以有效的拇指對位的方式增加了手的靈活性，這是我們祖先早期的定義特征之一，為我們的祖先提供了強大的適應(yīng)性優(yōu)勢。這很可能是過去200萬年復(fù)雜文化發(fā)展的一個關(guān)鍵因素，塑造了我們的生物文化進化……智人物種中持續(xù)存在的高靈巧水平，表明了拇指對抗對人類生物文化進化的巨大適應(yīng)價值。”

The team behind the research now want to take a closer look at specific groups including Neanderthals to paint a bigger picture of the range of manual dexterity in early humans and how they may differ from the dexterity we maintain today. It’s hoped further investigation will also reveal new insights into the emergence of systematic tool use among our distant relatives.

研究團隊現(xiàn)在想要更深入地研究包括尼安德特人在內(nèi)的特定群體，以描繪出早期人類靈巧手的更大范圍，以及他們與我們今天保持的靈巧手有何不同。希望進一步的調(diào)查也能揭示出我們的遠親中出現(xiàn)的系統(tǒng)工具使用的新見解。