Among many other achievements, Haldane played a central role in marrying Darwinian principles of evolution to the genetic work of Gregor Mendel to produce what is known to geneticists as the Modern Synthesis.

在其他成就方面，小霍尔丹还把达尔文的进化论与格雷戈尔·孟德尔在遗传方面的成就结合起来，提出了被遗传学家称之为“新途径”的理论。