According to Gould and Eldredge, the reason why so many links are missing is that they simply do not exist. They take the view that biological evolution proceeds in successive stages of "punctuated equilibrium." Living species would remain unchanged for extremely long stretches of time, and then undergo profound changes in relatively short periods. To borrow a term from the quantum theory of atoms, evolution would occur in "quantum jumps." It is very likely that the spark of life appeared during the first such "jump."
The theory of punctuated equilibrium, proposed by Niles Eldredge and myself, is not, as so often misunderstood, a radical claim for truly sudden change, but a recognition that ordinary processes of speciation, properly conceived as glacially slow by the standard of our own life-span, do not resolve into geological time as long sequences of insensibly graded intermediates (the traditional, or gradualistic, view), but as geologically “sudden” origins at single bedding planes.stephen jay gould