The Elements of Evolution (83) Soil & Human Fertility

Soil & Human Fertility

Until about the last 2 centuries, in every part of the world, nearly everyone lived on the edge of starvation. ~ Clive Ponting

Agriculture was not a panacea for food supply. Instead, it created a boom/bust cycle in population growth.

The initial burst in food supply from cultivation begat a burgeoning population. Ill-founded optimism resulted in food shortages, along with other ills. Domesticated animals brought new diseases: influenza from ducks, measles from cattle, plague from rats.

Woodlands were cut down for building and heating fuel. Deforestation was a habit that men would never kick.

After several years, soil productivity waned. Soil fertility was a mystery to early farmers.

While agriculture developed in the Near East 11 TYA, animal dung was not used for anything other than fuel for fires until 3 TYA. Conversely, while late to farming, some of the earliest European soil tillers caught on to fertilizing their crops with manure 8 TYA. The practice spread.

Early farmers were often less healthy than hunter-gatherers in their heyday, as farming was a hard way to live. Teeth rotted more often. The contrast between nascent farmers and hunter-gatherers may be something of an apples-and-oranges comparison. Hunter-gatherers may have been in better health because the weak were dead.

The advent of settled society swapped high mortality for high morbidity. Relief from the chronic warfare of roving tribes meant grinding out an existence in one spot rather than being ground out of existence altogether.

Crop failure could be catastrophic. Food supplements from the nearby forest were largely lost as residents had deprived the animal life that once lived there of a decent habitat. The critters not killed prudently moved on.

One constant of human history has been a disregard for sustaining natural resources, demonstrating an impressive lack of planning and a sense of entitled self-interest that lessened the quality of life for future generations. From the earliest humans on, casual environmental destruction has been ceaseless in pursuit of immediate gain.

Food shortages shrank human height 15 cm in the early centuries of agriculture. Populations plummeted 30–60%. This was as bad as the Black Death: the bacterial epidemic that devastated Europe 1348–1350, carried by gerbils from central Asia where it spawned.

Land left fallow for a few years regained its vigor for crops. Those that lived through the tough times were more cautious – but then optimism would regain its hold and the cycle would begin again.

Despite severe initial setbacks, a dramatic rise in human population numbers occurred during the Neolithic.


Food storage in Neolithic communities played no small part in dietary choice, especially with variable climate. Seed crops kept well, whereas tubers do not. That difference had knock-on effects.