Sandom et al. support statistical evidence for extinctions of a causal link with H. sapiens onset. Agriculture is probably specific to near east and would be justified by avoiding crop grazing, but evidence in possibly weaker. http://rspb.royalsocietypublishing.org/content/281/1787/20133254

There is a temporal correlation between the expansion of the range of Homo sapiens and extinctions of elements of the megafauna in various parts of the world.  A man with the family name of Martin was influential in this area of research in the 1960s.  From a lectrure he gave at the U of Alberta, He wrote a book on the subject.  I remember that Madagascar was one example, also the Americas.   His contention was over-hunting was a major factor.  The expansioist agricultural policies in USA and Canada in the 1800s were, without doubt, a causal factor in the near extinction of bison, but there were other rather nastier political forces at work, too.  The recent book by J. Diamond deals a lot with agriculture and the rise and fall of civilizations coupled with overexploitation of renewable resources (to the point of non-renewability).  I am sure that he has remarks on the demise of elements of the megafauna (also domestication of some of the elements). I am not aware of statistical analyses on the correlations you ask about, but that is rather outside my field.  The matter of cause and effects is another matter and needs deeper consideration and analysis.

Cheers,  Peter

You should probably also factor in climate change since it certainly was a factor, first, in diminishing populations of mega-herbivores (and their predators) and, second, in providing conditions that might have been suitable for growing crops.

Whilst pollinators are clearly not "mega-fauna" our recent paper on British bee and wasp extinctions may be pertinent here as they were precipitated by large-scale changes in agricultural practice.  

Article Pollinator declines. Extinctions of aculeate pollinators in ...

Actually, I hypothesized that the extinction of the mega-fauna would have propitiated an fertile terrain to the rise of agriculture. Once the concentrated calories of mega-mammals could not support the dense human populations they sustained, humans would turn into concentrating calories in their surrounding by planting and herding to maintain their previous populations densities. However, the rise of agriculture after the extinction of mega-fauna did not occur in several places, such as Australia for instance. However, the extremely poor soils and dry climate of Australia contribute to the failure of any large scale plant growing intent. Thank you all for the answers. This discussion is awesome.

Dear Jeff Ollerton,

Despite the lack of long term studies for Brazil, looking the short term ones in Brazil and studies elsewhere, I can say that modern agriculture has been an ecological disaster. In Brazil, the widespread production of commodities, is not only an ecological disaster, but also an socioeconomical disaster, as this kind of agriculture is only sustained by cheap oil prices together with subsides from the Brazilian treasure, with the dividends going to a small fraction of the society. Even some of our agronomists recognize that the mainstream agriculture model is eco-socio-economically unsustainable. Alternatives that treat all these issues (including the biodiversity issue) at the same time exist and are being implanted in small scale with or without government support.

I can only agree Carlos!

Consider  the following:

Alroy, John. (2001). “A Multispecies Overkill Simulation of the End-Pleistocene Megafaunal Mass Extinction.” Science 292:1893-

1896.

Edwards, William Ellis. (1967). “The Late-Pleistocene Extinction and Diminution in Size of Many Mammalian Species.” In

Pleistocene Extinctions: The Search for a Cause. Paul S. Martin and H.E. Wright, Jr., eds. Pp. 141-154. New Haven: Yale

University Press.

Gingerich, Philip G. (1984). “Pleistocene Extinctions in the Context of Origination-Extinction Equilibria in Cenozoic Mammals.” In

Quaternary Extinctions: A Prehistoric Revolution. Paul S. Martin and Richard G. Klein, eds. Pp. 211-222. Tucson: University of

Arizona Press.

Grayson, Donald K. (1984). “Archaeological Associations with Extinct Pleistocene Mammals in North America.” Journal of

Archaeological Science 11(3):213-221.

Grayson, Donald K. (1991). “Late Pleistocene Mammalian Extinctions in North America: Taxonomy, Chronology, and Explanations.”

Journal of World Prehistory 5(3):193-231.

Guilday, John E. (1967). “Differential Extinction During Late-Pleistocene and Recent Times.” In Pleistocene Extinctions: The Search

for a Cause. Paul S. Martin and H.E. Wright, Jr., eds. Pp. 121-140. New Haven: Yale University Press.

Haynes, C. Vance. (1984). “Stratigraphy and Late Pleistocene Extinction in the United States.” In Quaternary Extinctions: A

Prehistoric Revolution. Paul S. Martin and Richard G. Klein, eds. Pp. 345-353. Tucson: University of Arizona Press.

Hester, James J. (1967). “The Agency of Man in Animal Extinctions.” In Pleistocene Extinctions: The Search for a Cause. Paul S.

Martin and H.E. Wright, Jr., eds. Pp. 169-192. New Haven: Yale University Press.

Hildebrandt, William R. and Kelly R. McGuire. (2002). “The Ascendance of Hunting During the California Middle Archaic: An

Evolutionary Perspective.” American Antiquity 67(2):231-257.

Horton, David R. (1984). “Red Kangaroos: Last of the Australian Megafauna.” In Quaternary Extinctions: A Prehistoric Revolution.

Paul S. Martin and Richard G. Klein, eds. Pp. 639-680. Tucson: University of Arizona Press.

Jelinek, Arthur J. (1967). “Manʼs Role in the Extinction of Pleistocene Faunas.” In Pleistocene Extinctions: The Search for a Cause.

Paul S. Martin and H.E. Wright, Jr., eds. Pp. 193-200. New Haven: Yale University Press.

Kaplan, H. and K. Hill. (1985). “Food Sharing Among Ache Foragers: Tests of Explanatory Hypotheses.” Current Anthropology 26:

223-245.

Kiltie, Richard A. (1984). “Seasonality, Gestation Time, and Large Mammal Extinctions.” In Quaternary Extinctions: A Prehistoric

Revolution. Paul S. Martin and Richard G. Klein, eds. Pp. 299-314. Tucson: University of Arizona Press.

Martin, Paul S. (1967). “Prehistoric Overkill.” In Pleistocene Extinctions: The Search for a Cause. Paul S. Martin and H.E. Wright,

Jr., eds. Pp. 75-120. New Haven: Yale University Press.

Martin, Paul S. (1984). “Prehistoric Overkill: The Global Model.” In Quaternary Extinctions: A Prehistoric Revolution. Paul S.

Martin and Richard G. Klein, eds. Pp. 354-403. Tucson: University of Arizona Press.

McDonald, Jerry N. (1984). “The Reordered North American Selection Regime and Late Quaternary Megafaunal Extinctions.” In

Quaternary Extinctions: A Prehistoric Revolution. Paul S. Martin and Richard G. Klein, eds. Pp. 404-439. Tucson: University

of Arizona Press.

Roberts, Richard G. et al. (2001). “New Ages for the Last Australian Megafauna: Continent-Wide Extinction About 46,000 Years

Ago.” Science 292:1888-1892.

The human impact on Pleistocene megafauna is not clear at all.

See Lorenzen et al., 2011 paper in Nature :

Despite decades of research, the roles of climate and humans in driving the dramatic extinctions of large-bodied mammals during the Late Quaternary period remain contentious. Here we use ancient DNA, species distribution models and the human fossil record to elucidate how climate and humans shaped the demographic history of woolly rhinoceros, woolly mammoth, wild horse, reindeer, bison and musk ox. We show that climate has been a major driver of population change over the past 50,000 years. However, each species responds differently to the effects of climatic shifts, habitat redistribution and human encroachment.

http://www.nature.com/nature/journal/v479/n7373/full/nature10574.html

http://www.nature.com/nature/journal/v479/n7373/full/nature10574.html

In the Middle East and Africa, the major predators including lions limited human agriculture.  Thus when Sir Henry Rawlins captained a British gunboat sailing up the Tigris River in 1845, he reported great difficulty avoiding the Plane logs that were floating down stream (His diary is in the Royal Geographical Society archives in London).  At the Arch of the Ctesiphon, villagers asked him to send a party to kill a man-eating lion that was raiding the village.  They did so, hunting the animal in the jungle around the arch.  The last lion was killed at Beled Ruz in 1890, according to the records.  By 1955, all I could find at the Arch was desert and a blind beggar playing a local violin, asking for alms.

It is similar in Africa.  The villagers were confined to the area they could walk in by day, but return to the thorn-bush-protected village by nightfall.  When the lions were killed, they could spread out and hunt other game as well as expanding agriculture in a fragile environment.  This has lead to decimation of some prized species and severe environmental damage in some areas.

 The answer from Professor Harris add a new factor to my question: the predation and danger of predation offered by megafauna to human villagers. These factors may also be included while relating the expansion of agriculture and the megafauna extinction.

Thank you all! I hope you are enjoying these amazing discussion.

Interesting assumption. However, can we actually take into consideration how humans adapted to post-megafaunal extinction events? Even though megafauna presence influenced the environment, can we take into account how humans adapted to smaller-animal hunting?

The difference of demographic density after adopting a different kind of forager diets, the potential for some plants to give humans the ideal calory dose, the lithic industry post megafaunal extinction trends...

Trying to find a single answer is impossible. In each part of the world, there has been a unique history of the arrival of man and the type of cultural history he brought with him. Thus the Inuit and the Indian tribes to the south were most successful if they respected the local environment and fitted in with it and did not destroy it. Predation by Humans as well as by carnivores was a problem and increase in population, development of new methods of transportation, and bartering of products soon made the relationships more complex. Human greed, the urge to find easy ways of making money without working too hard, conquest of neighbors, wars, development of new technologies and more recently, alternative facts disseminated to the masses electronically, have greatly complicated the former relatively simple relationships between Man and his environment. Finally, the explosion of the Human population has resulted in severe problems with carrying capacity of the Earth, assuming people want a reasonable standard of living as in the developed countries. Thus it is impossible to live with modern conveniences in the Arctic without vast and impossibly large expenditures of money. However, it is relatively easy to survive comfortably in parts of the Tropics relatively cheaply. However, Man always seems to want what others have regardless of whether it is really needed.

Stuart.