The "Four Ds" are not "The Four Divas" but two groups of conflicting scientists who laid the ground for the world most of us are destined to live , reproduce and die in - the 21st century.
John Dalton and Charles Darwin, scientists from the 19th century, still bulk out 21st science education for most of us, thanks to the ego issues of the teaching class, who can not accept that the world is not fully composed of definite answers to definite questions.
But our century is actually the dialectic result of the WWII clash between the scientific certitudes of Darwin and Dalton colliding with the scientific uncertitudes promoted by Paul Dirac and Henry Dawson, scientists definitely of the 20th century.
Plenty of irony in the latter pair.
Dirac's QUANTUM PHYSICS said the behavior of a billion radioactive atoms are predictable in true Daltonian fashion, but the activities of any one individual radioactive atom is not.
In contrast, Dawson's QUORUM BIOLOGY agreed that a single individual bacteria was as dumb as Darwin said all the"primitive races" were, but that collectively a billion bacteria were collectively (and unpredictably) smart in ways we are only beginning to comprehend.
Both agreed that the smallest entities of matter and life were not as stable and as dumbly inert as civilized man had assumed.
Conversely, WWII itself seemed proof enough that civilized man was not as smart as he had thought.
From above, such Phaetons as Albert Einstein fell back earthward, while from inside the ground itself, Penicillium rose up in our esteem to meet Einstein midway to dine with him at Life's commensal table...