The origins of horticulture are vague because the first acts of plant
cultivation by humans predate historical records. Archaeological data indicate that the cultivation of plants on a large and detectable scale
coincided with global climate changes approximately 10,000 years
ago. The warmer, wetter weather that followed the end of the last ice
age caused changes in sea level, increased edible plant diversity, and
caused human migrations into new areas. This large-scale cultivation
event is referred to as the neolithic revolution.
Cultivation of plants on a small scale may have been practiced
for many thousands of years prior to this. The protection and
encouragement of the growth of wild food plants through weeding,
pruning, irrigation, and pest control, along with the simple
propagation of seeds or cuttings, most likely constituted some of
the first human horticulture. The use of fire to remove dead vegetation
and promote the new growth of desirable plants is another
example of how ancient humans engaged in plant cultivation.
Archaeological evidence suggests that cereal crops were domesticated first. Domesticated crops have genetic and morphological differences from their wild ancestors that make them
better suited for human use. These differences were the result of
natural mutations for characteristics such as a larger grain size in
wheat, which was selected for over time because the early horticulturists
planted only the larger seeds that contained the genetic
sequences for these traits. Most of the domesticated, edible plants
we cultivate today are descended from wild plants found in the
Near East, China, Southeast Asia, and the Americas.