The Origin of Agriculture
Naresh Aery
Wednesday, 14 October 2009 06:35 UTC
For thousands of years Man lived as hunters and gatherers. The origin and evolution of agriculture represents a major shift in the adaptation of human populations. What led him to leave the nomadic habit and acquire the sedentary life style as farmer and start growing plants and domesticating animals is still not resolved.
It is said that the quality of human life deteriorated due to the introduction of agriculture and there are views which affirm that agriculture represents a maladaptation and is the “worst mistake in the history of human race”. Notwithstanding the criticisms, agriculture has proved to be the hoist for advancement of society as well as the whole human civilization.
The subject has attracted the attention of archaeologists, botanists, agricultural scientists as well as historians. evolution thinkers are fascinated about the origin of agriculture since long. A number of models have been proposed but every model has been criticized extensively. For a quite long time it was believed that the domestication of plants and animals took place in Western Asia and spread to other regions of the globe through diffusion. But archeological evidences indicate independent development of agriculture in various areas of the world within the last 5,000 to 10,000 years. The different centers include Near East/ “fertile crescent”, Northern China, Southern China, Central Mexico, Peruvian Andes, Eastern North America, West Africa, Papua and Amazonia etc.
The role of climate in the origin and evolution of agriculture and domestication of animals can not be underestimated. Evidences indicate that early Holocene was warmer and wetter enough to raise crops like wheat and rice whereas late Holocene was comparatively dry and it was during this period, about 4000 years back, that rainy season crops like maize, millets, and lentils were introduced. Vedas describe agnihotra farming technique which probably synchronizes the bio rhythms with planetary rhythms to improve the agricultural production. Surapala the author of Vrikshayurveda an ancient Indian treatise on agriculture, describes Kanupa, a manure that contains bones of horned animals that improves agricultural production.
The modern humans developed newer agricultural technologies such as irrigation methods, tractor, ploughs, other mechanical devices, and use of fertilizers. The excessive use of chemical fertilizers, however, destroys soil flora and fauna thereby disturbing natural properties of the healthy soil. The above problem can be overcome by adopting PROM technology.
The nutrient composition of our food plants is changing ever since we started domesticating the plants. Genetic engineering techniques are being used to improve the quality and yield of crops. Canola, cotton, maize and soybean are the major biotech crops that have been grown commercially on a large scale during the past decade. Needless to say that the modern agricultural techniques should go hand in hand with natural farming techniques such as recycling the farm organic wastes as manure to the farm lands.
-
Replies
-
Anonymous
I have a theory that may explain why hunter gatherers adapted to agricultural lifestyle. It is possible that when the evolving human brain had reached a size which began to make the childbirth process more difficult and extended it forced humans to adapt to a safer fixed environment in order for babies to be born in safety so the species would survive.
While previously the nomadic woman in labor could have delivered their smaller brained babies with relative speed and ease now the birthing process of larger brained babies had become one that demobilized the woman for many hours and caused considerable pain.
At the time when Agriculture emerged the brain of homo sapien sapien is said to have reached its present day size. This means that the ballooning of the Cerebral cortex (especially the Frontal Lobes which deal with the executive functions of self-control, planning, reasoning and abstract thought) had reached its present day size. Thus the shift to agriculture marks a significant advancement in our physical and congnitive evolution.
It thus would have become dangerous to deliver babies “on the road” so to speak because the mother and tribe would have had great difficulty avoiding exposure and escaping predators. The agricultural lifestyle was the solution to the problem. To me it seems that adapting to the agricultural lifestyle was the only way we could have survived as a species.
It must also be noted that if the average human brain became any larger then natural child birth would be extremely difficult – if not impossible unless the female pelvis also evolves.
-
I made that first post but it came through as Anonymous – I’’ try again:
I have a theory that may explain why hunter gatherers adapted to agricultural lifestyle. It is possible that when the evolving human brain had reached a size which began to make the childbirth process more difficult and extended it forced humans to adapt to a safer fixed environment in order for babies to be born in safety so the species would survive.
While previously the nomadic woman in labor could have delivered their smaller brained babies with relative speed and ease now the birthing process of larger brained babies had become one that demobilized the woman for many hours and caused considerable pain.
At the time when Agriculture emerged the brain of homo sapien sapien is said to have reached its present day size. This means that the ballooning of the Cerebral cortex (especially the Frontal Lobes which deal with the executive functions of self-control, planning, reasoning and abstract thought) had reached its present day size. Thus the shift to agriculture marks a significant advancement in our physical and congnitive evolution.
It thus would have become dangerous to deliver babies “on the road” so to speak because the mother and tribe would have had great difficulty avoiding exposure and escaping predators. The agricultural lifestyle was the solution to the problem. To me it seems that adapting to the agricultural lifestyle was the only way we could have survived as a species.
It must also be noted that if the average human brain became any larger then natural child birth would be extremely difficult – if not impossible unless the female pelvis also evolves.
Tina Ryan
-
Dear Tina Ryan,
The size of human brain increased due to the introduction/invention of agriculture or increased human brain size forced humans to invent the agriculture? Or both of these processes somehow happened concurrently/ simultaneously?
Thanks,
DMR Sekhar -
You are correct – there are 3 options(or a 4th if we decide none are the case).
But I would argue vigorously in favor of the second option i.e.
Dangers posed by increased brain size necessitated the need to adapt to safer agricultural lifestyle. Of course the lifestyle challenges now posed by new agriculture no doubt helped humans to forge new neural paths in the brain and further develop cognitive capacity.
-
Brain size increased in the pleistocene long before agriculture and our brain size has become slightly smaller since. Homo erectus had a larger brain 1.7 mya.
“In the last 3-4 million years brain volume within the hominid lineage has increased from less than 400 ml to roughly 1400 ml. The first clear increase in hominid brain size is seen in early Homo at c.2 m.y.a. in East Africa (most reliably in cranial specimen KNM-ER 1470). This is an evolutionarily significant change that cannot be simply accounted for in terms of increased body size alone. From the appearance of H. erectus at c.1.7 m.y.a. to the present, the brain increases nearly twofold: from c.800 ml to 1500 ml in Late Pleistocene H. sapiens, without any apparent change in body size.”
http://www.massey.ac.nz/~alock/hbook/brain.htmIt is extremely doubtful that agriculture improved either birth or maternal mortality rates. The agricultural diet was if anything significantly inferior to the gatherer hunter diet because the diversity of food species was lost and populations depended on a few stables providing only marginal nutritional requirements. Population grew but not infant or maternal survival rates.
-
Dear Tina Ryan and Chris King,
It is really important to know if invention of agriculture resulted into increased head/ brain volume or increased head/ brain volume lead to the invention of agriculture or both these processes were complimentary to each other that is co evolution. May I request you to kindly focus on this issue?
Thanks,Sekhar.
-
I have already said the main increase in brain size is far older than agriculture but there are some genes which could be involved in the cultural phase.
You need to refer to our chapters in Sexual Paradox:
http://www.dhushara.com/paradoxhtm/culture.htm
Highlighting unique features of human genetic evolution, are two key genes whose mutations cause microcephaly, consistent with increased brain size, whose rapid spread through the human population may coincide with spurts in human culture. Microcephalin (R198) appeared ~37,000 years ago coinciding with the birth of culture and ASPM spread from the Near East around 5000 years ago (R466). However studies linking these variants have failed to find differences in intelligence and results remain highly controversial (DOI:10.1126/science.314.5807.1872). Nevertheless, these results are consistent with an overall examination of linkage disequilibrium in single nucleotide polymorphisms (Moyzis et. al. R493) which indicate that about 7% of our genes have been subject to selection in the last 50,000 years, a figure similar to domestication of maize, including genes for protein metabolism, disease resistance and brain function.
http://www.dhushara.com/paradoxhtm/homo.htm
The “Out of Africa” hypothesis may be consistent with a degree of regional development involving some sexual interbreeding with Neanderthals and Homo erectus. Specific genes such a s PDHA1 consist of two families with the last common ancestor 1.8 million years ago, and microcephalin variants appearing 40,000 years ago (p 105) also have differences suggesting an original divergence 1 million years ago suggesting ‘introgression’ from Neanderthals (Jones R347). An even more ancient divergence in the pseudogene RRM2P4 in East Asian people suggests interbreeding with Homo Erectus. Some evidence from skeletons is also consistent with this picture. However more recent sequencing of the Neanderthal nuclear genome suggests little or no interbreeding with Homo sapiens and has cast doubt on the existence of the microcephalin variant in Neanderthals, as well as a gene associated with increased fertility in Icelanders also attributed to transfer from Neanderthals.
-
