The scale below provides an indication of how recent the phenomenon of farming is:
The world was formed ca 4, 600 million years ago.
Eukaryotic life forms: ca. 1,000 million years ago
First hominid life forms 4 million years ago (hunter gatherers)
First human farmers: about 12,000 years ago.
Global Agricultural Evolution: 1650 – 1850 AD
Modern Agricultural Evolution: 1950 - present
Some of the food gathering mechanisms utilised by hunter-gatherer societies were relatively advanced.
In such conditions of trial-and-error experimentation and manipulation of species, the scene was set for the domestication of plants and animals. In addition, these hunter-gatherer societies probably paved the way for domestication by developing :
Social structure (promote cooperation)
Knowledge of cultivation techniques
Specialization on particular plant/animal foods
Domestication versus cultivation
However, the primary distinguishing feature between hunter-gatherers and the beginnings of modern agriculture lies in the domestication of species:
Cultivation involves the deliberate sowing or other management of plants which do not necessarily differ from wild populations.
Domestication can be defined as the human modification of a plant/animal – one that is identifiably different from its wild ancestors and its extant wild relatives. In short, domestication involves genetic change through conscious or unconscious human selection.
NB. Hunter-gatherers promoted yield and changed environmental conditions. However, the future seed bank was consistently derived from the plants that they left behind in the field, thus there were none of the selective pressures that promoted domestication.
Areas of domestication
Although there are many scholarly debates about the details, it is widely recognized that there are seven main areas in the world in which domestication of plant and animals arose:
Near East (Fertile Crescent)
South China (Yangtze River)
North China (Yellow River)
Sub-Saharan Africa
South-central Andes
Central Mexico
Eastern USA
Why initiate farming
"Why farm? Why give up the 20-hour work week and the fun of hunting in order to toil in the sun? Why work harder for food that is less nutritious and a supply more capricious? Why invite famine, plague, pestilence and crowded living conditions? Why abandon the Golden Age and take up the burden?" (Harlan, 1992)
Not necessarily because it was a better diet
Not necessarily because it was easier

However, it did increase food production per unit area, making it easier to feed a population from the same amount of land around a settlement. The alternative scenario suggests that man had to reach a certain level of social organization or tool-making development, with a settled mode of life, before agriculture was possible, and this stage of human development was only reached 9 - 10 000 years ago.
The move from shifting agriculture to domesticated agriculture was preceded and made possible by the millennia of accumulated experience of wild plants and animals, and trial-and-error experimentation. There was probably a gradual shift from collecting to cultivation with continued reliance on hunting and gathering. Finally there was almost complete reliance on agriculture as the major source of nutrition.

The stages of harvesting, planting and storing imposed various artificial selection pressures such as the following:
Plants with favoured characteristics are preferentially harvested
Plants preferentially harvested are resown
In more detail, some of these selection pressures involved the following:
Plants provided with a seed bed of open soil encounter diminished competition
Harvesting and resowing of larger clusters of seed heads
Single harvesting event
Seeds with larger food reserves germinate quicker
Quick germination confers competitive advantage, and reduced need for protective seed coat and dormancy.
Over time, these selection pressures produced changes in the crop and seeds that are characteristic of domesticated crops. These changes (referred to as domestication markers) are most pronounced when comparisons are made between the domesticated crop and its wild relatives.
Benefits of animal domestication
Transport
Draft
Food
Wool, hides, dung etc.
Galton (1822 - 1911) identified behavioural and physiologic characteristics of animals which would make them better candidates for domestication i.e. pre-adaptations to domestication:
Hardy, flexible, generalist feeding habits; easily adjusting to new conditions of disease, temperature and confinement
A liking for humans
Comfort-loving
Useful
Breed freely - fewest and least constraining behavioural, situational cues for reproduction
Easy to tend social and roaming animals capable of group interactions
Gregarious, social groups of both sexes, maintain a dominance hierarchy, and are thus predisposed to submission. e.g. goats and sheep are placid, slow-moving foragers, not territorial and form highly social groups with a single dominant leader.

Consequences of food production (from Bender, 1975)
Increased carrying capacity of the land
Development of sedentary societies
Changes in social structure
Craft specialization
Civilization
The progress of farming in Medieval Europe
Improvements of the plough
Horses replace oxen
New crop rotations
Feeding for the winter
New sources of power
Climate change
Global Agricultural Evolution 1650- 1850
Characterized by:
New rotations with leguminous and root crops
Scientific method employed in agricultural research
Use of fossil fuels, increased yields and labour productivity
Invention of mechanized farm equipment
Beginning of food-processing industries
Transfer of crops and livestock from lands of origin as part of the era of European exploration