The notion of the existence of a so-called "molecular clock" was first attributed to Émile Zuckerkandl and Linus Pauling who, in 1962, noticed that the number of amino acid differences in hemoglobin between different lineages changes roughly linearly with time, as estimated from fossil evidence.
A noción da existencia dun "reloxo molecular" atribúese a Emile Zuckerkandl e Linus Pauling que, en 1962, s decataron de que a cantidade de diferenzas en aminoácidos na hemoglobina entre diferentes liñaxes cambiaba aproximadamente de forma linear co tempo, como se estimaba polas evidencias fósiles.