Genetic Diversity and the Green Revolution

One of the common criticisms environmentalists make of the Green Revolution is that it supposedly reduced the genetic diversity of crops. Usually environmentalists complain that by doing so, the world’s crops are open to being wiped out by a single catastrophic crop disease. This scenario is certainly scary, but is it true?

Melinda Smale of the International Maize and Wheat Improvement Center set out to examine the status of genetic diversity in wheat. Her paper on the subject, “The Green Revolution and Wheat Diversity: Some Unfounded Assumptions,” maintains there is insufficient evidence for claims that the Green Revolution caused either genetic erosion of wheat crops or an increase in genetic vulnerability to disease.

First, Smale notes that much of the environmentalist concern is highly exaggerated even if their worst fears were accurate. As she notes, there doesn’t at the moment seem to be any shortage of potential genetic wheat combinations,

Given the size of the wheat genome and possibilities of incorporating genes from wild relatives or unrelated species through biotechnology and other breeding techniques, genetic combinations do not seem determinate in number.

There also doesn’t seem to be much risk of genetic vulnerability to disease in and of itself leading to catastrophic crop failure. The classic case of such a scenario is the destruction of 15% of the U.S. corn crop in 1970 due to disease, but as Smale notes that was hardly catastrophic. The real weakness to catastrophic crop failure is not so much genetic vulnerability but a lack of infrastructure in some countries to deal quickly and efficiently with outbreaks.

That said, when it comes to bread wheat the act of domestication itself appears to have significantly decreased genetic diversity. Smale writes,

According to some scientists, the utilization of bread wheat landraces maintained in collections offers only limited possibilities for diversification within the gene pool constituted after domestication … Continued farmer selection and modern plant breeding have extended wheat cultivation into new and different area, creating diversity in one sense and narrowing it in another. Statements about the relative breadth of the genetic base of wheat over time seem more a matter of scientific intuition than of scientifically proven fact.

In other words, what those who claim a lack of genetic diversity fail to realize is that agriculture by its very nature involves a selection process which reduces genetic diversity.

Which explains when it comes to the supposed increased in vulnerability to disease, Green Revolution varieties seem no more prone to disease and may in fact be more resistant thanks to the process whereby hybrids such as dwarf wheat were chosen than traditional varieties. Smale writes,

Data from screening nurseries for advanced breeding lines used in the developing world also show a gradual increase in the level of resistance to rust since the late 1960s.

Smale’s paper certainly does not rule out the possibility of declining genetic diversity in wheat and other crops, but it does mean that those who make the claim must step up to the plate with more concrete numbers and analysis beyond the vague claims and predictions that have so far been presented.

The full text of Smale’s article appears in World Development, Vol. 25, No. 8, pp. 1257-1269, 1997.

Free African Trade, Free Africa from Poverty

In 1955, Africa accounted for 3.1% of total global exports, but by 1990 its share had fallen to only 1.2%. Why?

Francis Ng and Alexander Yeats, economists with the World Bank, argue that it is in part due to the protection policies African nations adopted in the post-colonial period which explain Africa’s wretched economic performance.

The key problem with those projectionist policies in Ng and Yeats view is that the generally high tariffs on raw materials and capital equipment placed African entrepreneurs and producers at a distinct disadvantage.

As they summarize their findings,

The key point that emerges … is that African tariffs on those production inputs are often very high and place domestic producers at a substantial direct cost disadvantage vis-à-vis the fast growing exporters. For the 11 product groups listed (agricultural materials, crude fertilizers and ores, all chemicals, manufactured fertilizers, iron and steel, machinery and equipment, non-electric machinery, electric machinery, transport equipment, professional equipment) … the greatest discrepancy between Africa’s tariffs and those of the fast growing exporters occur for the agricultural raw materials and the crude fertilizer groups. In the former, African duties average 23.6% which is more than 3.2 times their corresponding level in the fast growing countries, while duties for crude fertilizers are 3.6 times higher. This undoubtedly has major adverse implications for Africa’s trade and growth prospects.

This makes eminent sense, but it’s amazing the extent to which many people believe the key to making places like Africa prosper is through protection of local markets. I regularly read leftist accounts which complain about cheap imports being available in developing nations.

Think about it, though — how are African farmers supposed to prosper and feed that continent’s growing population when their own government makes it more expensive for them to buy fertilizer and farm equipment than someone in Singapore or Thailand has to pay? Who benefits from high tariffs which temporarily preserve some local industries while ensuring that many businesses will simply never be created due to high marginal costs?

Ng and Yeats concede this is not the whole explanation of Africa’s sorry state. Political instability and other factors also play major roles in reducing economic growth. But high tariffs are just one more nail in the coffin that has kept Africa destitute while the developing world is on the path to prosperity.

The full text of Ng and Yeats article, “Open Economies Work Better! Did Africa’s Protectionist Policies Cause its Marginalization in World Trade?,” was published in World Development, Vol. 25, No. 6, pp. 889-904, 1997.

Julian Simon Writing for Intellectual Capital

Everyone’s favorite cornucopian Julian Simon is apparently going to be writing regularly for Intellectual Capital, an online magazine of generally conservative/free market thought. In the October 2 issue, Simon wrote a piece full of his usual optimism entitled The Big Picture: Spectacular Progress.

As one of the subheads in his article puts it, Simon believes we live in “an era of unprecedented good times.” He outlines the decline in mortality, the ever declining cost of transportation and other statistical measures of human progress.

The Overpopulation FAQ joins the ‘brownlash’

Reading a recent newsletter at the Zero Population Growth web site, I realized this site is solidly part of the “brownlash.” For those unaware, “brownlash” is the term used by Paul and Anne Ehrlich to describe “a body of anti-science — a twisting of the findings of empirical science — to bolster a predetermined worldview and to support a political agenda.”

I know, I know — it sounds like a description of Ehrlich’s books, but Peter H. Kostmayer, Executive Director of ZPG, thinks Ehrlich has a point and as an example of the “brownlash” cites Michael Sanera and Jane Shaw’s book Facts Not Fear: A Parents Guide to Teaching Children about the Environment. For those like me who haven’t read Sanera and Shaw’s book, Kostmayer describes the chapter on population “particularly distressing” and provides the following quote from page 67 of the book as an example:

With this background, you can readily answer questions that your children may ask about food and population. For example:

Are there too many people? No. The Earth’s ‘carrying capacity’ is enormous. Human ingenuity is more than equal to the challenge of meeting the demands of a growing population.

Does population growth cause starvation? No. Food production has increased faster than world population, and this trend is likely to continue.

Is the claim that “food production has increased faster than world population” a distortion of scientific truth for political gain? In their book The World Food Outlook Donald O. Mitchell, Merlinda D. Ingco and Ronald C. Duncan provide the following chart illustrating the growth of world cereals production and population based on data from the United Nations and the United States Department of Agriculture.


World cereals consumption and population growth, 1960 to 1990 (per cent increases)

1960-1970

1970-80

1980-90

Industrial economies
Total cereals consumption

30.8

17.1

9.5

Population

11.0

8.4

6.1

Developing economies

Total cereals consumption

42.9

46.6

26.8

Population

27.7

25.0

23.3


Mitchell, et al, along with numerous other experts on world agriculture argue world food production will continue to outpace population growth and food prices will continue to fall.

So somebody remind me — who here is twisting science to further political agendas?

Werner Fornos’ anti-immigration efforts

Werner Fornos, with the Population Institute, made his way through Michigan on a speaking tour a few weeks ago, but my child was sick that day and I missed his lecture when he was in town. I did get a friend to tape it for me, though, so expect to see a critique of Fornos’ particular message of doom and gloom added to the Overpopulation FAQ soon.

In the mean time, the Detroit News, one of Michigan’s two major dailies for which I occasionally do freelance work for, did send a reporter to cover Fornos when he spoke in Detroit and wrote an excellent editorial entitled Apocalypse Deferred pointing out the errors in Fornos’ anti-immigrant fearmongering. Check it out.

Food: we can make it better, more abundant and cheaper?

A recently published book claims much of the environmentalist rhetoric about running out of food is fundamentally flawed. The World Food Outlook is the product of two economists with the World Bank, Donald O. Mitchell and Merlinda D. Ingco, and Ronald C. Duncan of the National Centre for Development Studies at the Australian National University.

The book jackets summarizes the main points of the book this way:

The fact is that the world food situation has improved dramatically for most of the world’s consumers. Output of cereals, the world’s main food source, has increased 2.7 per cent per annum since 1950, while population has grown by about 1.9 per cent per annum. Cereal yields have increased at 2.25 per cent per annum. Not all people in the world today have adequate diets and there is no doubting the desperate circumstances of some peoples, but diets for most of the world’s consumers have improved dramatically and per capita calorie consumption in developing countries has increased by some 27 per cent since the 1960s. It should continue to improve, and food will be cheaper than it is today.

The trio also estimate that to feed future population, agricultural growth needs to achieve at least 1.4 percent annual growth (current growth is about 1.7 percent), and a growth rate of 2 percent annually would allow up to 11 percent of the world’s crop land to be returned to other uses while still maintaining adequate food security.