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Descent of Man In this lecture, beginners can familiarize themselves with basic information and terms used to describe the evolution of humanity beginning with the origin of primates through the comings and goings of Genus Homo. |
Migration Of Modern Humans
Posted: Wednesday, May 28, 2003
Source: Stanford University
Scientists Use DNA Fragments To Trace The Migration Of Modern Humans
Human beings may have made their first journey out of Africa as recently as 70,000 years ago, according to a new study by geneticists from Stanford University and the Russian Academy of Sciences. Writing in the American Journal of Human Genetics, the researchers estimate that the entire population of ancestral humans at the time of the African expansion consisted of only about 2,000 individuals.
"This estimate does not preclude the presence of other populations of Homo sapiens sapiens [modern humans] in Africa, although it suggests that they were probably isolated from one another genetically, and that contemporary worldwide populations descend from one or very few of those populations," said Marcus W. Feldman, the Burnet C. and Mildred Finley Wohlford Professor at Stanford and co-author of the study.
The small size of our ancestral population may explain why there is so little genetic variability in human DNA compared with that of chimpanzees and other closely related species, Feldman added.
The study, published in the May edition of the journal, is based on research conducted in Feldman`s Stanford laboratory in collaboration with co-authors Lev A. Zhivotovsky of the Russian Academy and former Stanford graduate student Noah A. Rosenberg, now at the University of Southern California.
"Our results are consistent with the `out-of-Africa` theory, according to which a sub-Saharan African ancestral population gave rise to all populations of anatomically modern humans through a chain of migrations to the Middle East, Europe, Asia, Oceania and America," Feldman noted.
Ancient roots
Since all human beings have virtually identical DNA, geneticists have to look for slight chemical variations that distinguish one population from another. One technique involves the use of "microsatellites" - short repetitive fragments of DNA whose patterns of variation differ among populations. Because microsatellites are passed from generation to generation and have a high mutation rate, they are a useful tool for estimating when two populations diverged.
In their study, the research team compared 377 microsatellite markers in DNA collected from 1,056 individuals representing 52 geographic sites in Africa, Eurasia (the Middle East, Europe, Central and South Asia), East Asia, Oceania and the Americas.
Statistical analysis of the microsatellite data revealed a close genetic relationship between two hunter-gatherer populations in sub-Saharan Africa - the Mbuti pygmies of the Congo Basin and the Khoisan (or "bushmen") of Botswana and Namibia. These two populations "may represent the oldest branch of modern humans studied here," the authors concluded.
The data revealed a genetic split between the ancestors of these hunter-gatherer populations and the ancestors of contemporary African farming people - Bantu speakers who inhabit many countries in southern Africa. "This division occurred between 70,000 and 140,000 years ago and was followed by the expansion out of Africa into Eurasia, Oceania, East Asia and the Americas - in that order," Feldman said.
This result is consistent with an earlier study in which Feldman and others analyzed the Y chromosomes of more than 1,000 men from 21 different populations. In that study, the researchers concluded that the first human migration from Africa may have occurred roughly 66,000 years ago.
Population bottlenecks
The research team also found that indigenous hunter-gatherer populations in Africa, the Americas and Oceania have experienced very little growth over time. "Hunting and gathering could not support a significant increase in population size," Feldman explained. "These populations probably underwent severe bottlenecks during which their numbers crashed - possibly because of limited resources, diseases and, in some cases, the effects of long-distance migrations."
Unlike hunter-gatherers, the ancestors of sub-Saharan African farming populations appear to have experienced a population expansion that started around 35,000 years ago: "This increase in population sizes might have been preceded by technological innovations that led to an increase in survival and then an increase in the overall birth rate," the authors wrote. The peoples of Eurasia and East Asia also show evidence of population expansion starting about 25,000 years ago, they added.
"The exciting thing about these data is that they are amenable to a combination of mathematical models and statistical analyses that can help solve problems that are important in paleontology, archaeology and anthropology," Feldman concluded.
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The research was supported by grants from the National Institutes of Health, the National Science Foundation and the Russian Foundation for Basic Research.
Relevant Web URLs:
http://www-evo.stanford.edu/
http://news-service.stanford.edu/news/2003/january8/genetics-18.html
http://news-service.stanford.edu/news/november8/chromosome-1108.html
http://www.neanderthal-modern.com/genetic1.htm
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Posted: Friday, May 23, 2003
By Paul Rincon, BBC Science
A 400,000-year-old stone object unearthed in Morocco could be the world's oldest attempt at sculpture.
That is the claim of a prehistoric art specialist who says the ancient rock bears clear signs of modification by humans.
The object, which is around six centimetres in length, is shaped like a human figure, with grooves that suggest a neck, arms and legs. On its surface are flakes of a red substance that could be remnants of paint.
The object was found 15 metres below the eroded surface of a terrace on the north bank of the river Draa near the town of Tan-Tan. It was reportedly lying just a few centimetres away from stone handaxes in ground layers dating to the Middle Acheulian period, which lasted from 500,000 to 300,000 years ago.
Cultural controversy
The find is likely to further fuel a vociferous debate over the timing of humanity's discovery of symbolism. Hominids such as Homo heidelbergensis and Homo erectus, that were alive during the Acheulian period, are not thought to have been capable of the symbolic thought needed to create art.
Writing in the journal Current Anthropology, Robert Bednarik, president of the International Federation of Rock Art Organisations (IFRAO), suggests that the overall shape of the Tan-Tan object was fashioned by natural processes.
But he argues that conspicuous grooves on the surface of the stone, which appear to emphasise its humanlike appearance, are partially man-made. Mr Bednarik claims that some of these grooves were made by repeated battering with a stone tool to connect up natural depressions in the rock.
"What we've got is a piece of stone that is largely naturally shaped.
"It has some modifications, but they are more than modifications," Mr Bednarik told BBC News Online.
Mr Bednarik tried to replicate the markings on a similar piece of rock by hitting a stone flake with a "hammerstone" in the manner of a punch. He then compared the microscopic structure of the fractures with those of the Tan-Tan object.
Sceptic's view
However, Professor Stanley Ambrose of the University of Illinois, Urbana-Champaign said he saw no evidence for tool marks and that, although the figure was evocative, it was most likely the result of "fortuitous natural weathering".
"He [Mr Bednarik] has effectively presented all the information necessary to show this is a naturally weathered rock," Professor Ambrose told BBC News Online.
Professor Ambrose points to Mr Bednarik's observation that some rocks in the vicinity of the figure were weathered and even rounded from transport by water. Professor Ambrose believes that rocks and artifacts found at the site could have been disturbed by flowing water in the past.
Mr Bednarik also observes that flecks of a greasy substance containing iron and manganese on the surface of the stone could be red ochre, a substance used as paint by later humans.
"They [the specks] do not resemble corroded natural iron deposits, nor has any trace of this pigment been detected on any of the other objects I have examined from Tan-Tan," writes Mr Bednarik in the paper.
A 200,000-300,000-year-old stone object found at Berekhat Ram in Israel in 1986 has also been the subject of claims that it is a figurine. However, several other researchers later presented evidence that it was shaped by geological processes.
The Tan-Tan object was discovered in 1999, during a dig directed by Lutz Fiedler, the state archaeologist of Hesse in Germany.
http://news.bbc.co.uk/1/hi/sci/tech/3047383.stm
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Race: The Power of an Illusion Posted: Tuesday, May 13, 2003
By Esther Iverem, SeeingBlack.com via www.alternet.org
May 13, 2003
Slowly, in movies and books, it has become the norm to talk about race without talking about racism. De-fanged of its institutional nature in works such as the 2001 New York Times "race series," race becomes a benign topic about individual prejudices and personal discomfort. Reactionary pundits have actually begun using the famous quote by the Rev. Martin Luther King – about people not being judged by the color of their skin – to justify attacks on affirmative action remedies.
It is in this atmosphere of race doublespeak that "Race: The Power of an Illusion" (premiering Thursday, April 24, 10 p.m. on PBS) is one of the most important, sweeping and groundbreaking documentaries in recent memory. Taking full advantage of scholarship documenting how the United States invented modern ideas of "race" and "whiteness," the producer – California Newsreel – illustrates how racism has been used institutionally, socially and politically to create an affirmative action for Whites.
This is not fancy movie-making – interviews with scholars are juxtaposed with historical footage and photos with narration by CCH Pounder – but it is powerful. Airing in three parts on consecutive Thursdays, the series will either build its reputation over three weeks or see its impact diluted by this questionable scheduling. Hopefully, it will experience the former scenario. The first episode, "The Difference Between Us," follows the progress of a DNA workshop for high school students and illustrates how scientists have proven the lack of genetic difference between human beings classified as being from different races.
But while the show proves that race isn't real on a biological level, it segues into how "race" is very real as a social construct. A history is given of how "scientific" research was used to justify enslavement and attacks on people of color in this country, as well as the violent takeover of Cuba, the Philippines and Hawaii during the era of colonial expansion. These same scientific theories from early in the last century were also used abroad, for example by Hitler in Germany, to build support for ideas of Aryan superiority and the extermination of other populations.
The series really kicks into high gear in the second episode, "The Story We Tell," airing May 1, with a history of the creation of race and whiteness in the United States. It was easy and convenient, for example, to create a system that equated black people with slavery and inferiority, and that built a sense of cohesion and new national identity among whites. Moving beyond blacks and whites, this show details the demarcation created between those from Europe and Native Americans, Chinese and Mexicans. This divide would define who would be considered really "American." White settlers would receive land forcibly taken from Native Americans and would be the only ones granted the full rights of citizenship. Even New Deal legislation of the 1930's, considered a step forward for all Americans, would discriminate against domestic workers and agricultural workers – who were almost all people of color – and against skilled people of color banned from all-White labor unions that could bargain collectively for better wages and work conditions.
The final show, "The House We Live In," airing May 8, goes a long way to illustrating why, in the United States, the worth of the average White family is ten times that of the average Black family. Moving beyond the violence of slavery and Jim Crow laws, it details how the federal government, particularly through the Federal Housing Administration, set in motion a series of laws that allowed for the creation of wealthy white suburbs and impoverished black communities.
By initiating a system of appraisal whereby white communities were automatically given a higher value than black or "mixed" communities, and by providing federal grants and tax incentives for the construction of white suburbs that excluded people of color, the federal government not only segregated much of the country's housing, it set in motion a process through which white families have become wealthier, because their homes are worth more. In addition, the equity in these more highly valued homes, and the wealth passed on from previous generations, snowball into more opportunity, including money to pay for a college education, to start a business or to assist family members.
Race may not be "real," but when it comes to opportunity and survival, cold hard cash is no illusion.
Esther Iverem, a journalist, cultural critic and poet, is founder of SeeingBlack.com
http://www.alternet.org/story.html?StoryID=15897
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Study: Human DNA Neanderthal-Free Posted: Monday, May 12, 2003
By Jennifer Viegas, Discovery News
May 12, 2003 — Neanderthals did not contribute to the gene pool of modern humans, according to a recent study that compared the DNA of two ancient Cro-Magnons with that of four Neanderthals.
While Neanderthals and early humans coexisted in Europe for a few thousand years 40,000 years ago, the findings suggest they did not interbreed, an action that would have made Neanderthals a direct ancestor of modern humans.
The study also supports the "Out of Africa" theory. According to this view, modern humans evolved in East Africa and then spread into Europe and Asia through the Middle East.
This opposes the "multiregional mode of expansion" theory, which holds that early humans, including Neanderthals, were unique but related populations within one evolving species.
For the study, published in the current Proceedings of the National Academy of Sciences, researchers extracted mitochondrial DNA from Cro-Magnon skeletons found in the Paglicci cave of Southern Italy. The first set of remains dated to approximately 23,000 years ago. The second individual lived around 24,720 years ago.
Mitochondrial DNA is inherited unchanged from the mother only, allowing researchers to trace unadulterated DNA back hundreds of thousands of years.
When the Cro-Magnon mtDNA was compared with existing mtDNA data from four Neanderthals dating between 29,000-42,000 years ago, virtually no similarities were found.
The genetic information then was compared with that of four prehistoric Europeans who lived between 5,500-14,000 years ago, and also with a database of mtDNA information for 2,566 modern Europeans and Near Easterners.
No matches were found when Neanderthals were compared with ancient and modern humans. Cro-Magnons, however, had genetic sequences present in 14 percent of the modern humans represented in the database, particularly individuals from the Near and Middle East.
"In samples from Yemen, Syria, Iran, Palestine are found individuals with a sequence belonging to the same group as the Paglicci samples," explained Giorgio Bertorelle, an author of the PNAS paper and an assistant professor of population genetics and genetic epidemiology at the University of Ferrara in Italy.
The link to the Near and Middle Eastern countries seems reasonable, Bertorelle said, because this was the likely route of expansion that early humans followed.
Alan Cooper, professor of zoology at Oxford University, agreed with the findings, but suggests that Neanderthals should not be ruled out just yet as direct human ancestors.
"There is still a remote possibility that only nuclear DNA was contributed, or that any Neanderthal mtDNA lineage has been lost during human population bottlenecks in the last glacial max, but the odds appear pretty slim," said Cooper.
Henry Harpending, professor of anthropology at the University of Utah, also hesitated to rule out the possibility of a human-Neanderthal connection. Harpending further believes that the multiregional mode of expansion theory still is plausible, as "mtDNA seems to have a different history than much of the rest of the genome."
http://dsc.discovery.com/news/briefs/20030512/neanderthal.html
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Yields Young Stars In Andromeda Halo Posted: Friday, May 9, 2003
Source: Space Telescope Science Institute
Deepest View Of Space Yields Young Stars In Andromeda Halo
Relying on the deepest visible-light images ever taken in space, astronomers using NASA's Hubble Space Telescope (HST) have reliably measured the age of the spherical halo of stars surrounding the neighboring Andromeda galaxy (M31).
To their surprise, they have discovered that approximately one-third of the stars in Andromeda's halo formed only 6 to 8 billion years ago. That's a far cry from the 11-to-13 billion-year age of the stars in the Milky Way's halo.
Why the difference in halo ages? You might call it a tale of rich galaxy/poor galaxy. Apparently, M31 must have gone through a major "corporate merger" with another large galaxy, or a series of mergers with smaller galaxies, billions of years ago. Astronomers cannot yet tell whether this was one tumultuous event or a more continual acquisition of smaller galaxies. The newly discovered younger stars in Andromeda's halo are richer in heavier elements than the stars in our Milky Way's halo, or in most of the small dwarf galaxies that surround the Milky Way. Indeed the level of chemical enrichment seen in these younger stars is characteristic of relatively massive galaxies, containing at least a billion stars.
This suggests three possibilities: (1) Collisions destroyed the young disk of M31 and dispersed many of its stars into the halo; (2) a single collision destroyed a relatively massive invading galaxy and dispersed its stars and some of Andromeda's disk stars into the halo; and/or (3) many stars formed during the collision itself.
Astronomers say it will take more detailed observations to unravel the acquisition history of these early cataclysmic events. Located only 2.5 million light-years away, the magnificent Andromeda galaxy, visible as a naked-eye spindle of light in the autumn sky has long been considered a near twin to our Milky Way in terms of size, shape, and age. This new finding promises to offer new clues on how giant galaxies like M31 and our Milky Way formed by gravitationally shredding galaxies, like a cosmic Cuisinart, and then devouring them.
Dr. Tom Brown of the Space Telescope Science Institute (STScI) is reporting the findings today in Baltimore at the STScI May Symposium, "The Local Group as an Astrophysical Laboratory." His team used Hubble's Advanced Camera for Surveys (ACS) to peer into a small sample of the Andromeda halo for 120 Hubble orbits. This allowed for a study of the entire demographics of the halo population, down to its extremely faint stars.
Previously, telescopes could only see the bright giant stars in the halo population, but the population of "normal" stars like our own Sun was beyond our grasp, because such stars in M31 are so faint. The ACS is the first astronomical camera to combine ultra-sharp vision and sensitivity to ferret out M31's faint halo population.
An estimated 300,000 of these never-before-seen halo stars can be resolved, peppering Hubble's narrow sample of the halo population. Looking far beyond the halo stars, Hubble reveals thousands of background galaxies (down to 31st magnitude) billions of light-years away.
A large fraction of the background galaxies in the image also have peculiar shapes due to collisions. This reinforces the fact: we live in a vibrant and dynamic universe undergoing constant change.
The original news release can be found here.
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How Complex Functions Can Evolve Posted: Thursday, May 8, 2003
Source: National Science Foundation
Artificial Life Experiments Show How Complex Functions Can Evolve
Arlington, Va. -- If the evolution of complex organisms were a road trip, then the simple country drives are what get you there. And sometimes even potholes along the way are important.
An interdisciplinary team of scientists at Michigan State University and the California Institute of Technology, with the help of powerful computers, has used a kind of artificial life, or ALife, to create a road map detailing the evolution of complex organisms, an old problem in biology.
In an article in the May 8 issue of the international journal Nature, Richard Lenski, Charles Ofria, Robert Pennock, and Christoph Adami report that the path to complex organisms is paved with a long series of simple functions, each unremarkable if viewed in isolation. "This project addresses a fundamental criticism of the theory of evolution, how complex functions arise from mutation and natural selection," said Sam Scheiner, program director in the division of environmental biology at the National Science Foundation (NSF), which funded the research through its Biocomplexity in the Environment initiative. "These simulations will help direct research on living systems and will provide understanding of the origins of biocomplexity."
Some mutations that cause damage in the short term ultimately become a positive force in the genetic pedigree of a complex organism. "The little things, they definitely count," said Lenski of Michigan State, the paper's lead author. "Our work allowed us to see how the most complex functions are built up from simpler and simpler functions. We also saw that some mutations looked like bad events when they happened, but turned out to be really important for the evolution of the population over a long period of time."
In the key phrase, "a long period of time," lies the magic of ALife. Lenski teamed up with Adami, a scientist at Caltech's Jet Propulsion Laboratory and Ofria, a Michigan State computer scientist, to further explore ALife.
Pennock, a Michigan State philosopher, joined the team to study an artificial world inside a computer, a world in which computer programs take the place of living organisms. These computer programs go forth and multiply, they mutate and they adapt by natural selection.
The program, called Avida, is an artificial petri dish in which organisms not only reproduce, but also perform mathematical calculations to obtain rewards. Their reward is more computer time that they can use for making copies of themselves. Avida randomly adds mutations to the copies, thus spurring natural selection and evolution. The research team watched how these "bugs" adapted and evolved in different environments inside their artificial world.
Avida is the biologist's racecar--a really souped up one. To watch the evolution of most living organisms would require thousands of years--without blinking. The digital bugs evolve at lightening speed, and they leave tracks for scientists to study.
"The cool thing is that we can trace the line of descent," Lenski said. "Out of a big population of organisms you can work back to see the pivotal mutations that really mattered during the evolutionary history of the population. The human mind can't sort through so much data, but we developed a tool to find these pivotal events."
There are no missing links with this technology.
Evolutionary theory sometimes struggles to explain the most complex features of organisms. Lenski uses the human eye as an example. It's obviously used for seeing, and it has all sorts of parts - like a lens that can be focused at different distances - that make it well suited for that use. But how did something so complicated as the eye come to be?
Since Charles Darwin, biologists have concluded that such features must have arisen through lots of intermediates and, moreover, that these intermediate structures may once have served different functions from what we see today. The crystalline proteins that make up the lens of the eye, for example, are related to those that serve enzymatic functions unrelated to vision. So, the theory goes, evolution borrowed an existing protein and used it for a new function.
"Over time," Lenski said, "an old structure could be tweaked here and there to improve it for its new function, and that's a lot easier than inventing something entirely new."
That's where ALife sheds light.
"Darwinian evolution is a process that doesn't specify exactly how the evolving information is coded," says Adami, who leads the Digital Life Laboratory at Caltech. "It affects DNA and computer code in much the same way, which allows us to study evolution in this electronic medium."
Many computer scientists and engineers are now using processes based on principles of genetics and evolution to solve complex problems, design working robots, and more. Ofria says that "we can then apply these concepts when trying to decide how best to solve computational problems."
"Evolutionary design," says Pennock, "can often solve problems better than we can using our own intelligence."
The original news release can be found here.
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Study Discovers Key To Baby-like Skin Posted: Wednesday, May 7, 2003
Source: Children's Hospital Medical Center Of Cincinnati
For nine months before birth, infants soak in a watery, urine-filled environment. Just hours after birth, however, they have near-perfect skin. How is it that nature enables infants to develop ideal skin in such seemingly unsuitable surroundings?
A new study by researchers at the Skin Sciences Institute of Cincinnati Children's Hospital Medical Center shows that the answer may be vernix -- the white, cheesy substance that coats infants for weeks before they are born, then is wiped off and discarded immediately after birth. If they're right, the healthcare implications for newborns and adults could be remarkable.
The study, to be presented May 6 at the annual meeting of the Pediatric Academic Societies in Seattle, shows that newborn skin with vernix left intact "is more hydrated, less scaly, and undergoes a more rapid decrease in pH than with vernix removed," says Marty Visscher, PhD, executive director of the Skin Sciences Institute and the study's main author. "These beneficial effects of vernix suggest that it should be left intact at birth."
Vernix is a complex mixture of lipids (fats), proteins and water. Babies born at 32 to 33 weeks are covered with the material. Those who are born full term have already lost a good portion of it. The researchers studied full-term infants, half of whom had vernix wiped off and half left intact on the surface of the skin. Skin hydration, moisture accumulation rate, skin pH and visual dryness were measured at one, four and 24 hours after birth.
Skin Sciences Institute researchers have been studying vernix for several years and found that it is not only a moisturizer but also a wound healer, cleanser, anti-infective and antioxidant. Cincinnati Children's has obtained four patents on vernix technology and hopes to formulate a synthetic equivalent that could be used in a variety of ways: as a film on products ranging from diapers to wound dressings; as a replacement for vernix in low-birthweight, premature infants who are born before vernix develops at about 27 weeks; as a cream or lotion for topical needs; and as a delivery system for other medications.
"We view the production of vernix as analogous to infant formula as a substitute for milk," says Dr. Visscher. "Nature has figured out how to make it. Long term, we hope to be able to mass produce a synthetic equivalent. There is nothing out there now to take care of these preterm babies, and the list of other applications for vernix is endless."
The Skin Sciences Institute views infant skin as ideal skin and focuses on the skin as a primary care interface – a biological spacesuit that separates outer from inner space. "Skin is the largest organ in the body, yet it's often treated as insignificant," says Stephen Hoath, MD, a neonatologist, medical director of the Skin Sciences Institute and co-author of the study. "You can't deliver medical care in the home or hospital without paying attention to this interface, and it has a disproportionate impact on patient satisfaction. People assume you can transplant a liver, but if you can't pull leads off without hurting them, you're not providing good care."
The Skin Sciences Institute has established collaborative relationships with major companies involved in skin care as well as skin barrier structure and function, including the Procter & Gamble Co., the Andrew Jergens Company, Kao Corporation, GOJO Industries, Coloplast Corporation, Kenabo, Becton Dickinson, Vyteris, NOVA Technology Corporation, 3M, and W. L. Gore Industries.
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Pests, Pesticides and Modern Science Posted: Tuesday, May 6, 2003
By Devinder Sharma
It took three decades for the International Rice Research Institute (IRRI) to realise the gravest mistake of Green Revolution - pesticides are unnecessary. But by the time the mistake was realised, pesticides had polluted the environment, poisoned the fertile soils, contaminated the ground water and taken a heavy human toll.
Not far from where IRRI is located, rice farmers in Central Luzon province in the Philippines, had gradually got disenchanted with the indiscriminate use of pesticides. From a peak insecticide use in the mid-1980s, it is now at an historic low. Contrary to what agricultural scientists and the chemical industry had maintained all these years, the decline in insecticides use has been accompanied by an increase in productivity from an average of 2.75 tonnes to 3.25 tonnes per hectare in 2002. It also resulted in savings on an average of up to 1,000 pesos per hectare for these farmers.
Equally significant is the scientific courage with which IRRI's director general, Dr Ronald Cantrell has accepted the reality: "It shows that the mistakes of the Green Revolution - where too much emphasis was sometimes put on the use of chemicals for pest control - have clearly been recognized and corrected," adding, "because of their toxicity, insecticides really should be used by farmers as a last resort, and we are very pleased to see that farmers have realized this for many years, especially here in the Philippines." His colleagues at IRRI are now equally critical of the extent and use of pesticides. Says Gary John, an ecologist: "The simple fact is that, in the rest of Asia, most insecticide use on rice is a waste of the farmers' time and money."
The Philippines is not the only country where farmers have proved the scientists wrong. In Vietnam, almost 2 million rice growers in the Mekong Delta have been persuaded to cut back on using harmful and unnecessary farm chemicals. The campaign - which was a joint effort of a team of Philippine and Vietnamese scientists - has sharply reduced pesticide misuse, and won the collaborative effort the US$25,000 Saint Andrews' Environmental Prize for 2002. The prize money is now being used to extend the campaign to another million rice farmers in the Red River Delta.
"What we hope to learn next is why the farmers of central Luzon have learned these lessons so much more quickly than farmers elsewhere," adds Dr. John. First launched in 1994 in the Mekong Delta - long one of the great rice bowls of Asia - the research and subsequent campaign marked a milestone in rice production for two reasons. IRRI says that first it clearly identified the damage caused by insecticide overuse, which kills off friendly insects and so encourages the pests they would otherwise help control, and it also developed a completely new way of communicating important information to farmers.
The basic premise of integrated pest management (IPM) is that no single pest-control method can be successful over a long period. Therefore, a mixture of biological, physical and chemical methods must be considered and integrated into a cohesive strategy designed to sustain a pest-management system. The ultimate goal of IPM is sustainable agricultural systems with minimal or no pesticide use, says an IRRI press release. One wonders when will this new found wisdom be applied in cotton, which alone consumes more than 50 per cent of the total pesticides used.
Well, if that is true, isn't it a fact that agricultural scientists had misled farmers all these years? Isn't it a fact that because of the over-emphasis on the use of chemicals to control pests, more problems have been created rather than being addressed? Isn't it a fact that besides polluting the environment, insecticides have changed the pest profile turning many minor insect species to emerge as major pests? Does it not mean that if scientists had learnt from farmers, probably they could have found simple time-tested technologies that wouldn't have destroyed the fertile lands?
For instance, in the State of Tamil Nadu, situated in the southern part of India, more than 8,000 farmers in some 10 districts have been using herbal pest repellents. Such has been the mental conditioning that no agricultural scientist, graduating from the land grant colleges, will ever accept the efficacy and utility of such an herbal spray. The result being that while expensive and unwanted pesticides are being promoted and pushed by the scientists and extension workers, farmers are looking for safe and ecological alternatives. While Philippino researchers say one of the key factors continuing to influence Philippine farmers is the return of fish, frogs and edible snails to their farms, confirming the positive environmental impact of IPM strategies, it may take some time for Indian agricultural scientists to see the writing on the wall.
A Karikali-based group in Tamil Nadu, prides in calling itself a university with multifarious ecological roles -- Vazhviyal Multiversity. Its herbal pest repellant is based on traditional knowledge listed in the scripture -- Vriksha Ayurveda. The repellant is prepared from the leaves of five plant species that are not eaten by cattle. These can vary from a place to place, but would ideally have neem, tulsi, and datura. The leaves are collected, cut into pieces and then pounded. The biomass is then put in an earthen pot filled with cow urine. The pot is kept in a compost pit for ten days, during which period it gets fermented. Filter the fermented solution with a cotton cloth, add ten times the quantity with water, and the herbal spray is ready.
The only catch being that the herbal spray is applied before the insects appear. Such simple technologies unfortunately do not find any mention in the agriculture textbooks and curriculum. The reason is simple: there is no industry behind it.
Numerous such technologies have been in vogue. But with the advent of modern science, which began to view everything traditional as backward and sub-standard, the collective wisdom of generations of farmers was lost. Such was the massive campaign to discredit everything that was time-tested for ages that modern science, its blind adoption, and extensive application became the essential ingredient for classifying farmers as ‘progressive'. The chemical industry, which gained commercially from the surge in widespread use, very cleverly used agricultural scientists as its promoters. By the time the scientists realized, and thanks to a concerted campaign by some civil society groups and organizations, the damage and destruction had been done.
The chemical industry has meanwhile moved into life sciences. The same industry now decries pesticides and sings virtues for the new 'promising technology' - genetic engineering. Pesticides are now being replaced with genetically modified crops, which perform the same functions. The tragedy is that agricultural scientists are being once again used as promoters of a technology, the negative impact of which have not been fully studied. Once again, agricultural scientists appear more than keen to take the farming community on a faulty garden path. And like the pesticides imbroglio, it may take decades before the disastrous implications of the cutting-edge technology, as genetic engineering is fondly called, become visible.
But then, who is responsible for and should be directed to pay for the clean-up operations to restore the sustainability of the lands and environment? Why shouldn't the ‘polluter pays' principle be applied to the Consultative Group on International Agricultural Research (CGIAR), which governs the 16 international agricultural research centers, and of course the multi-billion dollar chemical industry to pay for the environmental damages? It is time agricultural science is made accountable. It is high time that the CGIAR is directed to cough out the real cost of the environmental destruction its technologies have wrought. Modern science cannot be allowed a free play for un-necessary experimentation that does irreparable damage to the land and water that feeds the world. A beginning has to be made, the sooner the better.
(Devinder Sharma is a New Delhi-based food and trade policy analyst. Email: dsharma@ndf.vsnl.net.in)
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