2017年6月26日，国际著名学术期刊《美国科学院院刊》在线发表了亚利桑那大学菲尼克斯医学院Matthew C. O’Neill研究组的一篇研究论文，论文揭示了黑猩猩体格和人类骨架关系。

“人们可能认为黑猩猩像超人一样厉害。”Matthew O’Neill表示。但其团队的实验和计算机模型显示，黑猩猩的肌肉只比同样大小的人类肌肉强壮1/3。

该结果与已经完成的几项实验结果相吻合，表明在拉拔和跳跃时，黑猩猩的力量大约是同比人类的1.5倍。不过，O’Neill表示，由于它们的平均体重比人类轻，按照绝对值计算，人类完全可能战胜它们。

该发现还表明，其他猿类的肌肉强度也与黑猩猩类似。“人类是个异数。”他说。O’Neill团队一直在研究直立行走的进化。为了制造反映黑猩猩如何行走的精确计算机模型，研究人员需要弄清它们的肌肉是否异乎寻常的强壮。他们从3只黑猩猩的腿部取了小样本，然后测量了纤维的强度。研究人员也用相同的方式研究人类肌肉。

他们将相关结果与许多其他研究的结果相比较，发现与其他研究不同的是，黑猩猩的肌肉并没有什么特别之处。“在单个纤维的作用下，黑猩猩肌肉和人类肌肉的力量并没有不同。”O’Neill说。

但为何按平均磅数换算，黑猩猩的肌肉强度比人类略高呢?研究小组研究了死于自然原因的黑猩猩的肌肉，发现它们的肌肉中有2/3是由快收缩肌肉纤维构成的，而人类超过一半的纤维是慢收缩肌肉纤维。快收缩肌肉纤维更有力量，但也需要更多能量。

此外，研究人员还发现，黑猩猩的肌肉纤维更长，这也能提高力量。这些证据显示，行走对于黑猩猩而言是一件更消耗体力的事情。因此，人类在进化中可能以丧失部分力量为代价，获得了能长距离行走或奔跑的耐力。

原文链接：

Chimpanzee super strength and human skeletal muscle evolution

原文摘要：

Since at least the 1920s, it has been reported that common chimpanzees (Pan troglodytes) differ fromhumans in being capable of exceptional feats of “super strength,” both in the wild and in captive environments. A mix of anecdotal and more controlled studies provides some support for this view; however, a critical review of available data suggests that chimpanzee mass-specific muscular performance is a more modest 1.5 times greater than humans on average. Hypotheses for the muscular basis of this performance differential have included greater isometric force-GENErating capabilities, faster maximum shortening velocities, and/or a difference in myosin heavy chain (MHC) isoform content in chimpanzee relative to human skeletal muscle. Here, we show that chimpanzee muscle is similar to human muscle in its single-fiber contractile properties, but exhibits a much higher fraction of MHC II isoforms. Unlike humans, chimpanzee muscle is composed of ∼67% fast-twitch fibers (MHC IIa+IId). Computer simulations of species-specific whole-muscle models indicate that maximum dynamic force and power output is 1.35 times higher in a chimpanzee muscle than a human muscle of similar size. Thus, the superior mass-specific muscular performance of chimpanzees does not stem from differences in isometric force-generating capabilities or maximum shortening velocities—as has long been suggested—but rather is due in part to differences in MHC isoform content and fiber length. We propose that the hominin lineage experienced a decline in maximum dynamic force and power output during the past 7–8 million years in response to selection for repetitive, low-cost contractile behavior.

doi:10.1073/pnas.1619071114

作者：Matthew C. O’Neill