The sperm is a unique cell, differing from other cells in physiology and function. It survives an arduous journey through male and female reproductive tracts, to ensure that an intact male genome reaches the site of fertilization. In addition, it has also been recognized to wield epigenetic control over early embryonic development. Environmental degradation over the past years has exposed the human sperm to myriads of toxicants which have adversely affected its structure and function. In correlation, there are reports of decline in sperm counts and fertility, although there is still no concrete evidence to substantiate these claims. Moreover population statistics in most developing nations do not conform to data of declining fertility. In addition there are certain researches, in agreement with our data of normal, fertile volunteers, which also suggest no change in semen characteristics or sperm numbers over the past three decades. These findings indicate that despite the barrage from environmental agents, spermatozoa have withstood the test of time and have emerged resilient. Hence, in addition to the manifold machinery that operate to protect the spermatozoa including toll-like receptors, anti-oxidants, heat shock proteins etc., there possibly exists an in-built, genetically programmed, population specific mechanism that reinforces its nuclear integrity to protect this cell from the onslaught of toxic influences. Research in this direction is underway at our laboratory and other research centers to delve into the enigma of sperm endurance.