the.com/thumb
the rebel finger that opposed the others and built civilization with one defiant point.
means The short, thick, somewhat opposable first digit of the human hand, set apart from the four fingers and crucial for gripping.
from From Old English 'thuma,' which traces back to a Proto-Germanic root (compare German 'Daumen,' Dutch 'duim'). Scholars connect it further to a Proto-Indo-European root meaning roughly 'to swell' — the thumb as the fat, swollen digit, the same family that may have given us 'tumor' and 'tumescent.' The silent 'b,' added later by writers who liked the look of words like 'dumb' and 'limb,' was never actually pronounced.
own musclesNine separate muscles control it alone
bone countHas two bones while other fingers have three
genetic splitSome people can bend it backward, some can't
thumbs upWas reportedly an insult in ancient Rome
brain spaceCommands a huge chunk of motor cortex