Friday, September 23, 2016

Hybrid Vigor

World food security has generally kept pace with the world population explosion of the last 200 years. Regional famines have occurred since man appeared on Planet Earth. A widespread famine involving billions of Earth residents, however, has been averted as the planet population inexorably headed from one billion to over seven billion in the past two centuries. Gifted and inspired agriculturalists have avoided disastrous worldwide food shortages with food crop initiatives—among them vigorous application of hybridization.

The history of hybridization is a food production success story. We are reminded of God’s Genesis mandate to “subdue the earth.” The Creator provided Earth’s raw materials and its living things. He also provided the intellectual ability to discover and apply the potential of living things—how to develop and manage methodology to engage plant and animal life in the service of human needs. Nutritional requirements have been at the forefront.

Gregor Mendel in 1865 published “Experiments in Plant Hybridization.” His ideas did not receive much attention until the early 20th century. George Harrison Shull first described the term “hybrid vigor” in 1908. He described the phenomenon that plant crosses (hybrids) outperform their parents. An Italian scientist, Nazareno Strampelli, performed early work on wheat hybrids from 1904 to World War II. He laid the groundwork for the Green Revolution of the 1960s. Our previous posts on Norman Borlaug describe his work on intense development of artificially selected and hybridized wheat and rice during the heyday of the Green Revolution, said by some analysts to have saved one billion people from starvation.

Hybridization is the cross-breeding of two true-breeding varieties. A true breeding plant produces vegetation of the same variety when they self-pollinate. Many old varieties raised in our grandparents’ day were true-breeding varieties. Their plants were able to produce seed for planting on their farms the following year, but yields were static year after year. The purchase and use of hybrid seeds removed the difficult problem of saving and planting self-raised seed, provided new vigor, and increased production dramatically. 

Widespread hybridization is a relatively new agricultural practice. Corn hybrids were responsible for increasing productivity from 30 bushels/acre in the 1940s to 150 bushels/acre in the 2010s. This year, 2016, US farmers will harvest an all-time record of 175.1 bushels/acre. That is a productivity increase five times greater than 1940 and a yield increase six or seven times greater than 1940. US production of corn (maize) is almost double the next largest world producer, China. 

The other main US grain crop is soybeans. The US narrowly outproduces Brazil in annual world production of soybeans. Since 1940 US soybean production per acre has increased almost two and one half times. Worldwide production of soybeans has increased enormously since 1940; it is now a far more important crop than in former years. From the SOYINFO website comes this quote: “The dramatic and sustained exponential growth in world soybean production is unequalled by any other crop in the world.” By weight, soybeans supply 36% protein. Animal feed is produced by the majority of soybean and corn crops worldwide. In wheat production, the US ranks fourth worldwide. Hybridization has also dramatically increased worldwide wheat production.

One wonders about past world population growth if artificial selection and hybridization had not impressively increased plant productivity, the foundation of human food supply. Beyond population growth we conjecture on the current health of our teeming millions had hybridization practices not been applied in the past century.

Along with the blessings wrought by hybridization of crops, valid concerns also exist. The potential for environmental harm exists in the resulting widespread monoculture of agricultural crops. Monoculture is the “cultivation of a single crop in a given area.”  In the Midwestern “breadbasket” states vast stretches of farmland produce but a single crop. No longer is there a natural reseeding pattern of native plants in the present era of widespread hybrid seed purchases, heavy application of fertilizers, and novel technologies. Runoff of dissolved chemical fertilizers into our waterways is a serious problem. Much natural plant diversity no longer exists. Soil erosion and adequate water supply is a constant challenge. Scientists are laboring to solve these problems.  

Along with our ability to produce food at record levels we must prudently address related problems with the help of divine wisdom. Plant scientists must continue to apply their creative gifts to balance the benefits of artificial selection and hybridization with diligent efforts to maintain the health of Earth’s agricultural legacy. We are thankful that scientists are working to achieve this balance.     



Monday, September 19, 2016

Designer Plants

Our post title, Designer Plants, suggests a commonly used meaning: plants of interest to landscape designers and plant retailers—beautiful, utilitarian, exotic, unusual, or even bizarre. In contrast, we use our post title as it applies to the improvement of food quantity and quality for earth dwellers. As such, we focus on how humans have improved plants to increase production of food. Food security is of vital importance for long term healthy survival of humanity. How have biological scientists handled the subject of improvement of the world’s food resources? Our web searches have revealed much information which inspires further investigation. In particular, in this post, we focus on maize (corn) as a designer plant.

Let’s make a backward leap to memories from my childhood. Hybridization became more dominant in plant science in the 1920s and 1930s. The process heightened the potential of artificial selection by which Mesoamerican Indians had developed hundreds of useful varieties of maize since 10000 BC. My father was an agent for a hybrid seed corn company which marketed their seeds as Funk’s G Hybrids until 1990.  The current Syngenta agribusiness company claims Funks G as one of their original seed firms. When my father was an agent for a Landisville PA company, Hoffman Farm Seeds, in the 1940s, he approached farmers in his agency area, New York State, with appeals to purchase the new higher yielding corn hybrid seeds. As with many new technologies, some farmers were dubious. They did not take kindly to hybrid seeds. A modern parallel is the intense current resistance to genetically modified seeds (GMOs). We refrain from discussing this complex issue in anticipation of future posts.

As an elementary/middle schooler in the immediate years following World War II, I was not especially interested in genetics of farm seeds. By default, however, I was exposed to the early days of promotion of hybrid corn seeds to farmers. Many terms were discussed by my farm seed-agent father with his friends and with me. For example, I recall discussion of “double-cross hybrids.” Many farmers did not understand what that meant. My father attempted to explain the term to them and to a 10-year old, probably without much success.

One element of success, however, was achieved by my observation of Dad’s “test plots.” These were little parcels of land devoted to planting samples of heirloom and hybrid seeds for their demonstration value. But he also skillfully piqued the imagination of farmers with some highly unusual seeds. The results were interesting rows of highly unusual corn plants. I recall the “Indian corn,” “pod corn,” popcorn, and sweet corn Dad planted on our own family lot. One variety of corn plant was over 15 feet in height. (I have pictures to prove this.) “Dent corn,” was the focus of Dad’s professional promotion: Raise the dent-corn Funk’s G hybrids G-6, and G-10, he advised, and reap better crops!

My father understood the varieties of corn which originated in an ancestral “corn” called teosinte. 9000 to 10000 years ago only teosinte existed in the key area of Mesoamerica (Central Mexico). Teosinte was domesticated and spread by indigenous groups. By 2500 BC, the Mesoamerican Indian population had deliberately selected the best plants for their future plantings thousands of times. They developed many useful varieties of maize as a result. Their “selective” breeding, centuries of selecting plants with bigger kernels, larger size cobs, and other different and more desirable forms, had contributed to the development of a trade network based on a surplus of varieties of New World corn long before explorers from the Old World arrived. By 2500 BC, precursors of today’s six main types of corn existed. The six types are flint corn, also known as Indian corn, flour corn from which corn meal is made, dent corn, the staple grain raised by farmers, pop corn, pod corn in which each kernel is enclosed in a cover, and sweet corn, a summertime table favorite.

All of these varieties originate from teosinte as we detailed in our preceding post. The remarkable origin and development of maize is inappropriately cited as an example of organic evolution as now taught in our educational institutions. They have taught that millions of modern species of plants and animals have evolved from “natural” selection and accidental mutation. Currently many more novel hypotheses are entering the evolutionary theorists’ explanatory lexicon. 

Organic evolution implies changes in genetic composition as new life forms appear.        Logically, evolutionists must explain speciation of many millions of existing species. Different species of earth life are generally unable to interbreed. On rare occasions where they interbreed, the progeny usually manifests genetic problems. Modern maize varieties easily form additional varieties by additional man-controlled selective breeding and hybridization processes because they are all of the same species.

We quote UC Berkely’s website Understanding Evolution: “Natural selection is the simple result of variation, differential reproduction, and heredity—it is mindless and mechanistic; it’s not striving to produce “progress” or a balanced ecosystem…..Natural selection just selects (my emphasis) among whatever variations exist in the population. The result is evolution.” 

This quote from the Berkeley site leaves many tenets of evolutionary theory unanswered. It also triggers new sets of questions about the broadly accepted paradigm of molecules to man evolution. Among the questions is the marvel that maize diversity is explained by subtle genetic changes in a minuscule set of only five genes in the nucleus of every maize variety currently in existence. How were these subtle changes accomplished? How is selection involved? 

The term “select” in the Berkeley quote suggests a deliberate, intelligent process directed by an intelligent mind. This explains why we titled our post “Designer Plants.” Humans have “intelligently designed” maize plants over the rather brief human time span of 10000 years. Evolution’s “mindless” and “mechanistic” selection process does not explain the wondrous development of the world’s maize by human artificial selection. Rather, we intuitively recognize our maize varieties as a biological bequest to humanity from God, the Creator of All Things. 




Wednesday, September 14, 2016

Food Security

Food security is a term indicating access to sufficient, safe, and nutritious food to meet dietary needs for an active and healthy life. One of humanity’s most significant challenges is how to address food security. Historically, most people would be startled to discover that hundreds of famines have struck periodically in many societies in past thousands of years. They are documented by historians in many cultures.

In our last post we highlighted the work of Norman Borlaug, father of the Green Revolution which originated during the mid 20th century in Mexico where food productivity had fallen alarmingly. His success in selecting certain desirable plants for repeated breeding and hybridizing different varieties to achieve disease resistance and increased productivity were monumental agricultural forward leaps. The success achieved by Borlaug spread to Latin American nations and other nations such as India, Pakistan, and the Philippines.

Many issues of present and future world food security still exist. The formula for an adequate supply of food has been sought ever since man first appeared on this planet. However, since the world’s population began to climb inexorably from one billion to over seven billion beginning about 1800, the issue of food security has become increasingly urgent.

Man’s recent quest to enhance the world’s food supply relates to a series of events beginning with the famous evolutionist Charles Darwin. He suggested that living things, animals and plants alike, were subject to change over time—a startling proposal. Inherent in his proposition, even though he was not concerned with this aspect of his theory of evolution, was the possibility that the food producing characteristics of plants could be altered and enhanced. 

We may remember Gregor Mendel (1822-1884) from our early biology classes. Mendel was famous for cross-breeding different types of pea plants. He was able to predict traits of offspring. Decades after his original research from 1856-1863, his findings were rediscovered by scientists in the early 20th century. They confirmed Mendel’s early interpretation of a mathematically predictable internal mechanism, a precursor of modern genetic knowledge.

Mendel’s cross-breeding of different types of pea plants provided the foundation of knowledge of inheritance. Hydridization, in turn, was introduced to farmers in the 1930s. Today’s plant hybridization practices followed thousands of years of artificial selection to achieve desirable traits in plants which provide human food. An outstanding example is the corn (maize) plant. Its ancestor is a wild grass called teosinte, a New World plant which originally bore little resemblance to corn varieties which survive today. In the past several thousand years humans selected the most desirable plants generation after generation. They searched for plants with more plentiful, tastier kernels on larger cobs and sturdier stalks to produce seeds for ensuing crops. Today’s corn varieties are all descendants of ancient teosinte.

Over thousands of years humans have altered teosinte in a fashion similar to the manner in which Norman Borlaug altered the wheat varieties for Mexico, India, and Pakistan to produce the Green Revolution. It appears the process may be hastened as we gain additional knowledge of genetics. Corn is the most popular food grain in the New World.

At the DNA level corn and teosinte are surprisingly alike. They are genetically similar in their number of chromosomes and their remarkably similar gene arrangements. Teosinte can cross-breed with modern varieties of corn and form hybrids able to reproduce naturally. In a similar phenomenon in the animal world, different breeds of dogs are genetically similar. Humans have selectively bred dogs generation after generation, mostly in the past few hundred years, to produce diverse breeds manifesting the traits desired by modern dog lovers. Different breeds of dogs are really the same species and are able to interbreed and reproduce.

The process of selective breeding to increase food supply and improve the world’s concern with food security is a wonderful achievement of agricultural geneticists. Selective breeding techniques increase production of animal as well as plant products for human consumption. Norman Borlaug and a host of other modern visionaries have provided farmers with knowledge of necessary technology for irrigation, fertilization, and other chemical substances to enhance their plentiful yields. Methods of harvest, processing, transportation, storage, and distribution of food resources in our world of seven billion souls also contributes to world food security.

Personal visits to the supermarket may help us put the topic of food security in perspective. Modern culture may be more focused on consumption rather than production. We must actively remind ourselves of the multitude of event sequences which result in a virtual surfeit of food goods on market shelves. We start with the complex genetic capability of thousands of plant and animal species used by man for food. Miracles of plant and animal reproduction and growth processes, enhanced in our day by modern methods of plant breeding, hybridization, and lately, genetic modification, may trigger renewed awareness of our reliance on divine enablement to provide food for Earth’s teeming multitudes. It is not frivolous to suggest that our visits to the supermarket may become a worship experience as we give glory to the Creator of all things.    




Friday, September 9, 2016

Agricultural Bounty

The midwestern US is enjoying the prospect of bountiful crops during the upcoming 2016 harvest season. It is doubtful the corn crop has ever been taller. When the soybeans were in their full growth, I joked that some fields appeared as tall as the corn.  Bountiful appears to be an understatement. Both the US and many world countries have been enjoying bountiful crops since the Green Revolution arrived in the 1960s. Green in this context does not apply to its commonly used environmental activist connotation. In this case we refer to a startling revolution having past, present, and future life saving potential for the human race.

In the United States corn and soybeans are the two primary agricultural crops. In investigating the Green Revolution, we discovered that wheat is the third most important agricultural crop in the US. Wheat production has improved dramatically in the US, but perhaps the increases in wheat production in Mexico and countries such as India and Pakistan have been even more important for their well being and survival.

In mid-20th century the world continued on a trajectory of exploding human population. Dire predictions of world-wide famine were published because of concerns with food security. In particular, in the developing world the expanding population outstripped their ability to feed their people. The less developed countries of the 1950-1970 era were blessed by the work of Norman Borlaug who is responsible for what came to be known as the Green Revolution. Introduction of new, high-yielding varieties of cereals, especially wheat and rice, along with chemical fertilizers, pesticides, irrigation technology, and new methods of mechanized cultivation was a blessing said to have saved the lives of one billion people worldwide.

In Mexico agricultural productivity had fallen in mid 20th century, but new man-engineered breeds of plants and improved agricultural methods rescued their outlook for healthy survival. Peasant farmers abandoned their old methods and set Mexico on a path of food self-sufficiency. Mexico switched from being a wheat importer to a wheat exporter by 1963. Many other developing countries such as Pakistan and India doubled their wheat production, saving their countries from disastrous famine.

Norman Borlaug’s ancestors came from Norway in 1854, settling first in Wisconsin and later in Iowa. After spending years on the family farm in Iowa, he enrolled in the University of Minnesota. In the latter years of his education he became interested in plant pathology. Over many years he developed brilliant methods for producing high yield strains of disease resistant wheat and rice, thereby improving the physical condition of high population countries. The story of Norman Borlaug is one of tireless energy and inspiration. He was honored for his immense contributions to the welfare of man in 1970 as a Nobel Laureate. 

Borlaug’s scientific achievements do not connect with any apparent religious faith. His unique insights and abilities were manifestations of God’s gift of common grace—diverse gifts of God common to all mankind. Such gifts are an important distinguishing feature of man’s innate abilities as a manifestation of the imago dei.

Psalm 65:11 is a devotional exultation during harvest time: You crown the year with your bounty, and your carts overflow with abundance (NIV). In a real physical sense we credit the record-breaking 2016 bounty of agriculture in the US Midwest and all the world over as a gift of common grace to all mankind. The special gifts God confers to all humanity in various ways is a manifestation of common grace. In contrast, special grace is the gift of eternal salvation through Christ. Defined this way, it is grace of an even higher value than common grace.   


Saturday, September 3, 2016

Vacation Science and Geography

Summer 2016 provided opportunity for personal travel to three different vacation venues to visit with family in different regions of our country. Two journeys were extended automobile trips; one was by commercial airline. Each trip provided occasions for scientific and geographic observation and interesting conversation and potential for research when we returned.

Traveling east by automobile or airplane on our spherical planet we were obligated to advance our clocks in order to keep them synchronized with the apparent motion of the sun. Conversely, traveling west we set our clocks back for the same reason. Most human activity correlates with the sun’s apparent motion, particularly in mid-latitude (temperate) and tropical regions where most earth residents live. Frequent adjustment of clock time is an interesting phenomenon of our mobile society. 

From season to season other interesting differences in hours of daylight versus hours of darkness exist between northern and southern cities. We discovered residents of  Ft. Myers, FL experience January day length 1 1/2 hours longer than our nearest large northern city—Chicago, IL. In July, however, summer daylight is 1 1/2 hours longer in Chicago than in Ft. Myers. Our spherical, axis-tilted, rotating earth provides a variety of wonders to enrich our life experience.

The air journey from Chicago to Ft. Myers at nearly seven miles altitude was one of the most interesting flights in our memory. Most fascinating was the flight over the Ohio River floodplain. Turbid Ohio River water sometimes blends grudgingly with clearer water from tributaries. The meanders in the river are beautiful features bearing the imprint of geological history. The rich patchwork of farmland testifies to the energy and creativity of early American farmers who have “subdued the earth” (Genesis 1:28) in the last two centuries as world population swelled from one to seven billion souls. Since 1800 the population of the nascent United States of America has increased by many multiples the world rate of increase.

At nearly seven miles (36000 ft) altitude, more than three quarters of Earth’s atmosphere and 99% of Earth’s water vapor is beneath us. Airliners commonly cruise at this altitude where the outside temperature is roughly -55ÂșC. In mid-latitudes the troposphere, the zone where most of earth’s weather occurs, is beneath the altitude of 11 km. Looking out the window of our airliner, we observed a faint haze surrounding the earth. The troposphere is beneath us with its air, water vapor, and dust particles. Gazing out to the horizon, we might imagine we see the curvature of the earth’s surface above the faint haze. Perhaps this is because in the 21st century scientists have provided ample photographic proof of the entire sphere of Planet Earth. But surprisingly, in the childhood years of millions of senior citizens currently alive, our rocket probes had not yet achieved a height of 65 miles above Earth’s surface.

Outer space is acknowledged as anything 62.5 miles above Earth’s surface or higher. Following World War II American scientists used captured German 1946 V-2 rockets to carry cameras to a height of 65 miles. Grainy black and white pictures provided the first photographic proof of the Earth’s curvature, although in 1935 Explorer II balloons had provided a primitive precursor at an altitude of nearly 14 miles. The Russian launch of Sputnik I in 1957 was generally acknowledged as the beginning of the Space Age. Personally, I witnessed the 1957 Sputnik satellite orbiting the Earth as a tiny, slow-moving speck of light in the pre-dawn skies before commuting to my college classes.

Our automobile journeys were blessed with unusually beautiful displays of various cloud formations. Airline pilots need more than a rudimentary knowledge of meteorology. Location and type of cloud signal weather conditions such as fronts, turbulence, precipitation, and storms. Invisible water vapor in the air condenses to visible droplets of liquid water or crystals of ice when air reaches 100% relative humidity. Watching wisps of cumulus clouds vanish from visibility to invisibility is an instructive activity for young people, illustrating that invisible water vapor is always present in our atmosphere. 

The transitions of invisible water vapor to visible precipitation and back again quench  earth’s thirst and provide a return to fair weather following beneficial rains. Even hurricanes (one is traveling up the US eastern coast as I write) and other flooding rainstorms often provide relief from drought and provide climatic balance for earth residents, notwithstanding their inherent danger to our safety and comfort. On our recent trip to the east coast, we transitioned from locations of overly plentiful rainfall in Illinois to a region of crop wilting drought in Ohio in one afternoon’s drive. The Giver of life-sustaining weather conditions, however, blesses humanity with wisdom to cope with disasters both short and long term and to be intelligently prepared for diverse weather events.

Shifting from earth science to life science, we recount one more vacation experience. Our 11-year old grandson excitedly entered our family reunion rental home in Georgia to announce that dozens of frogs were serenading the neighborhood in the rain by the pool. Sure enough, our flashlight revealed many gray tree frogs inflating their throats to produce a unique nighttime trill. A few weeks later in Florida, we spotted an attractive Cuban tree frog sitting motionless on an outside ledge of our hotel when we returned after dark. Sources report he sometimes feeds on ubiquitous brown anole lizards. The frogs and lizards provided fascination for their northern visitors.

If you have been able to bear with the foregoing stream of consciousness ramblings about our vacation experiences, you may also be able to identify with the message of a popular song from a half-century ago. “What a Wonderful World” is an apt description of how we might react to the ordered and intricately designed world that surrounds us. Its lyrics appropriately express sentiments of those who love the Creator and his created world. “I see skies of blue and clouds of white. The bright blessed day, the dark sacred night. And I think to myself what a wonderful world.”