June 28, 2009
Perusing our friend Timberwraith’s blog, Haunted Timber, I came across an amazing story I had to share. It is about two 24 year old Swedish parents who are raising their child not as a boy or a girl, but as a child. I recommend reading what Timberwraith had to say here. You can go here to read the story in english, or here for some Swedish.
Let me start by saying that this was not intended to be a Pseudoscience Chronicles post (I just enjoyed the story) until I read what one of the interviewees had to say ten paragraphs in. I was shocked at first by what Susan Pinker said (in the english version of the story), but then was not surprised to find out that she is a psychologist and journalist:
‘“Ignoring children’s natures simply doesn’t work,” says Susan Pinker, a psychologist and newspaper columnist from Toronto, Canada, who wrote the book The Sexual Paradox, which focuses on sex differences in the workplace.’
‘“Child-rearing should not be about providing an opportunity to prove an ideological point, but about responding to each child’s needs as an individual,” Pinker tells The Local.’
It’s ironic how she claims that raising a child should be about responding to each child’s individual needs, then goes on to say we should force children into preconceived gender-roles. If anything, keeping the child’s sex a secret allows the parents to respond to their child’s actual needs rather than the artificial needs implanted by a cultural construction that attempts to fit every single person in the world into one of two restricted categories. So I guess what she was actually trying to say was that child-rearing should only be about providing an opportunity to prove an ideological point if that ideological point is ‘gender exists get used to it’.
Pinker goes on to make some more crazy claims:
‘“I don’t think that trying to keep a child’s sex a secret will fool anyone, nor do I think it’s wise or ethical,” says Pinker. “As with any family secret, when we try to keep an elemental truth from children, it usually blows up in the parent’s face, via psychosomatic illness or rebellious behaviour.”’
Of course, the parents are not keeping any truth from the child (I don’t even know how they would do that). They are simply allowing the child to grow into what it wants to be. They are responding to their child’s needs as an individual. They are being good parents.
With that, I would like to welcome Susan Pinker to the Pseudoscience Chronicles.
(Header Image: Hijras India’s Third Gender)
June 23, 2009
Seeing that Iran is prominent in the news lately, I thought this would be an interesting post to import from the old blog today. Enjoy:
I was reading Greg Laden’s blog entitled “The natural basis for gender inequality” over at ScienceBlogs and it got me thinking about sexism. Especially the way that a lot of religious people use the fact that scientific naturalism sometimes leads ill informed people to hold sexist beliefs as a reason that science should not be trusted. Obviously this is not true, no one who actually understands the relationship between biology and society would claim that biology dictates that women do not deserve the same rights and opportunities as men, and Greg does a great job of explaining this in his article. However, sexism is a problem that I feel passionately about and so, for my part, I decided to post a paper that I wrote for a religion class highlighting the roles of religion and culture in developing a person’s beliefs about gender norms. With no further introduction, here it is:
The First Step
by: Bryan Perkins
Religion and culture are and have been intertwined throughout history. Whether religion affects the zeitgeist or merely reflects it, there is a correlation between the beliefs of the dominant religion in a society and the majorly accepted cultural norms. Religion’s fingerprint can be found on every aspect of culture. Many of the most highly regarded pieces of art were created with religious intentions. Pastors preach politics from their pulpits, telling parishioners which way to vote. Religious groups attempt to control the educational system and change school curriculums to fit their beliefs. In all of these instances the religious beliefs of people alter an aspect of culture in some way. In other instances it is not as clear whether religion is affecting or reflecting culture. Gender norms have always been, and still are, pervading issues in every society throughout history. Views on homosexuality and gender roles are often key dividing issues among large groups of people. An overreaching commonality shared by all modern cultures is the dominance of the masculine at the expense of the oppression of the feminine. The unspoken pact between society and religion concerning the acceptance of sexual inequality has perpetuated the problem of sexism, and until sexism is openly discussed as an issue that persists today the loop will never be broken and the problem will never be fixed.
Do a woman’s prayers count in the eyes of God? Rodger Kamenetz thinks that this question is a silly one (63). Others however, like Yitz Greenberg, seem to take it a little more seriously.
[Waldoks] chanted reference that Wednesday morning to not having a minyan touched on a sore point. Ten Jews, the required quorum, were present, but only if Jewish women counted. However, for Yitz Greenberg, the women did not count because the Talmud defines a minyan as ten Jewish males.
Moreover, [Greenberg] could not participate when Rabbi Levitt’s turn came to lead the service (Kamenetz 59).
Obviously the Jewish faith as a whole does not subscribe to this idea or it would not be possible for Joy Levitt to be a rabbi, yet some Orthodox Jews still hold on to the belief that sex is important in the eyes of God. As Kamenetz points out, the excuse that somehow a woman praying with men is a distraction is hardly believable (63). This being the only explanation offered we are forced to divine the reasoning behind these actions for ourselves. The seemingly obvious reason that a woman’s voice would not count when performing a minyan is that God places more importance on the voice of men than the voice of women. Women of the Jewish faith are given little access to a spiritual life outside the traditional roles of wife and mother (134). The Kabbalah has many fine things in it that stress the importance of the feminine, but as a whole, Jews are very far from coming to terms with a feminine god, so the ideas remain very theoretical (220). To this day, the Jewish religion remains patriarchal (218), and women and homosexuals often feel excluded from Jewish spiritual life (238).
Buddhism has also played its part in allowing sexism to persist in the world. The Dalai Lama affirms that “from the Buddhist view point, all sentient beings are the same,” but while explaining this he implies that historically Buddhism has accepted sexual inequality without trying to change it (217). Even Buddhists, who respect all forms of sentient life to such an extent that they frown upon the eating of meat, have knowingly stood by and allowed inequality between human beings to exist without acknowledging and trying to abolish the obvious immorality of sexism. The Tibetan word for woman, skyes dman, means ‘lowborn’. This makes it apparent that the Dalai Lama’s egalitarian theory does not apply to the generally accepted Tibetan customs (218). Tibetan and other Asian cultures give women a very low social status, and this is reflected in the treatment of an ani or female monastic (134), a term that “means something like ‘auntie’—hardly a term of respect” (218). When Thubten Pemo was a nun in Switzerland the monks would not even help her and the other nuns in obtaining the basic necessities of life. “I went to the cook for the food he was throwing in the garbage,” Pemo remembers, “I lived on the carrot ends for a month” (134).
One of the most cited examples of a religious influence that imposes sexism on a society is that of the Muslim religion. The instances of misogyny in Islam are numerous. Sharia law is a glaring example of the preference of Islamic cultures for the masculine over the feminine. There have been many instances in which, under the guidance of Sharia law, the physical and mental abuse of women was not considered sufficient grounds for divorce by a ruling judge, in some cases the judge not only refused the wife’s request for divorce but tried to blame her for her husband’s beatings (Nafisi 273). In such courts child custody always goes to the father (286). There is something fundamentally wrong with a society that accepts a legal structure that does not allot all human beings equal rights. With laws in place that allow husbands to beat their wives and then keep custody of any children after the divorce, it is impossible for a woman to feel secure in the only role left available to her by the society that created such laws, that of wife and mother (318). Those few women that are able to succeed in breaching the traditional female roles have to work twice as hard as their male counterparts. “Women [are] the backbone of the family, the ones on whom everyone depend[s]. They [work] at home and they [work] outside the home” (62).
Another frequently cited example of sexism in Islam is that of the required veiling of women while in public. To some the veil is a symbol of a woman’s sacred relationship with God, but at times, especially during the Islamic Revolution, it has been perverted and used as a tool of control, “turning the women who wore them into political signs and symbols,” which many of the devout followers of Islam resented (103). Followers of the Islamic Revolution urged that “veiling [was] a woman’s protection” (26) and “a woman in a veil is protected like a pearl in an oyster shell” (200), but this does not represent what the women who are forced to wear the veil feel. One woman “described the pain of being required to wear a veil, calling it a mask behind which women were forced to hide” (328). At one point in Tehran, four gun-carrying men and women called the Blood of God patrolled the streets to make sure that women wore their veils properly and did not wear makeup (26). “Women were banned from singing, because a woman’s voice, like her hair, was sexually provocative and should be kept hidden” (108). In her novel Reading Lolita in Tehran, Azar Nafisi recounts instances in which women were reprimanded for running upstairs when they were late for classes, for laughing in the hallways, for talking to members of the opposite sex (9), and even for eating apples too seductively (59). The religious regime that ruled them tried to make the personal identities and histories of these women irrelevant; they had no means of freeing themselves from the regime’s definition of them as Muslim women (Nafisi 28). Nafisi notes that when her students took off their scarves and robes during their private classes together her students gradually regained their individuality as humans (5). Being forced to wear a veil strips a woman of her identity, the issue is “not so much the veil itself as the freedom of choice” (Nafisi 152).
Given the evidence of three major religions promotion and/or acceptance of sexism it seems impossible that anyone could deny the existence of sexual inequality in the world today. But, any complaints on the part of women are attributed to ‘feminine’ outbursts and they are not taken seriously by those who currently have the power to change the course of society (190). The pervading acceptance of misogyny by the major religions and modern cultures causes the demands for change by women to fall on deaf ears and allows the problem of sexism to persist in spite of the fact that it is as ignoble as any other bigotry. To discriminate against someone based on sex, something that they have no control over, is just as wrong as discriminating against someone based on race. However, the majority of religions and cultures do not agree that sexism is an important enough problem to warrant change, therefore women still suffer through the injustices wrought on them by the patriarchal societies that claim that sexual inequality does not exist anyway. As a famous religious organization once put it, “the first step toward change is admitting that you have a problem.” The problem of sexual inequality will not be solved until society and religion can finally admit that it exists and can acknowledge that sexism is morally wrong and needs to be changed.
Kamenetz, Rodger. The Jew in the Lotus. New York: HarperCollens, 1994.
Nafisi, Azar. Reading Lolita in Tehran. New York: Random House, Inc., 2003.
(Header Image: Cover of Reading Lolita in Tehran)
June 23, 2009
Posted by Bryan under Blogs
| Tags: Anthropology
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Sophie, an author from the old Science. Why not?, has a shiny new wordpress blog as well. She calls it A Wonderful Day for Anthropology. Here is a little from the About page:
‘Originally interested in Psychology and Sociology, I finally found my calling in the holistic field of Anthropology. Although I haven’t declared a concentration, I anticipate this blog will be a helpful resource. I hope to explore Archaeological, Biological, Cultural, and Linguistic Anthropology to the fullest extent and learn from others who share my passion for the field.’
You can find her first post here. Read it, leave comments, and enjoy. I know I will.
June 21, 2009
I don’t read Time Magazine much, but I recently acquired some old issues and I found one I would like to share with everyone. On February 23 Time printed the ‘Mind & Body Special Issue: How Faith Can Heal’, and I had a few problems with the article entitled ‘The Biology of Belief‘ by Jeffrey Kluger.
The article begins with a subtitle that sets the stage for the rest of the piece:
‘Science and religion argue all the time, but they increasingly agree on one thing: a little spirituality may be very good for your health.’
From the start we can smell the agenda behind Kluger’s words. ‘Scientists increasingly agree’ likely means that there have been a couple of new studies published attempting to convince us that any correlation between spirituality, in the broadest sense of the word, and health absolutely proves causation. ‘A little spirituality is good for your health’ will likely be transformed into ‘religion heals ills when medicine just can’t do it’. But let’s try not to make too many presumptions yet.
In the first two paragraphs Kluger claims that the parietal lobe makes ‘your brain the spiritual amusement park it can be.’ He obviously knows the names and locations of some brain regions, but he gives no clear description of what each lobe does and how they produce a ‘spiritual amusement park’ in your brain. Either he hopes to explain it to us later, or we just have to take his word for it.
Five paragraphs into the article we finally get to it. ‘A growing body of scientific evidence suggest that faith may indeed bring us health.’ Boom! ‘People who attend religious services have a lower risk of dying in any one year than people who don’t attend.’ Boom! ‘People who believe in a loving God fare better after a diagnosis of illness than people who believe in a punitive God.’ Boom!?!
Kluger does the arguing for me in the very next paragraph:
‘You live longer if you go to church because you’re there for the cholesterol-screening drive and nurse visiting service. Your viral load goes down when you include spirituality in your fight against [disease] because your levels of cortisol–a stress hormone–go down first.’
Faith and religion are not what is causing an increase in life expectancy, there is nothing supernatural about it. There is no reason to use spirituality and religion to explain coincidental correlation.
But Bryan, didn’t you read? ‘People who believe in a loving God fare better after a diagnosis of illness than people who believe in a punitive God.’ Who cares? This tells me nothing. Do people who believe in a loving God live longer than those who believe in a punitive God, or do they simply take the news better when they are told that they are going to die? If they don’t survive longer, then this has nothing to do with the effect of spirituality on physical health. This evidence simply compares two subsets of spiritual people who believe in different types of God. On the one hand spirituality is good for you but on the other it isn’t good for you. Faith can heal, but only the right faith. All this does is underle the subjectivity of religion. I wonder how atheists fare after being diagnosed with an illness, but I am sure that didn’t fit with the intended message of Kluger’s article.
IT’S ALL IN YOUR HEAD
Kluger then goes on to discuss the work of Dr. Andrew Newberg a professor of radiology, psychology, and religious studies at the University of Pennsylvania. ‘Newberg and his team have come to recognize just which parts of the brain light up during just which experiences.’ (By this I assume that Kluger means they took brain scans of individuals performing particular activities and determined which areas were in use when). Yet again this holds no support for the idea that faith and spirituality will give you good health. We merely see that for every activity that we as humans perform, there is some region of our brain that is involved.
Not only did Newberg and Team determine which areas are involved in each task, they also scanned the brains of people before and after meditation training. What they found was that meditation training increased the size of certain lobes of the brain, and as the lobes bulked up memory improved. In other words, intense mind training increases the size and functionality of a person’s brain. (No $&!# Sherlock?)
Of course there was no comparison between the improvement of a person who was subjected to calculus training or learned how to play a musical instrument, I am sure they too would have an increase in brain size and memory capacity. But who cares about finding all of the evidence when the evidence you have now supports the hypothesis that you want to be correct?
Kluger goes on to describe ‘one of the staples of traditional wellness protocols and traditional religious rituals the cleansing fast, which is said to purge toxins in the first case and purge sins or serve other pious ends in the second.’ And again, in the very next paragraph, he explains and then immediately dismisses science that counters his claim that spirituality (in this instance fasting) is healthful:
‘The brain is a very energy-intensive organ, one that requires a lot of calories to keep running. When food intake is cut, the liver steps into the breach, producing glucose and sending it throughout the body — always making sure the brain gets a particularly generous helping. The liver’s reserve lasts only about 24 hours, after which, cells begin breaking down the body’s fats and proteins — essentially living off the land. As this happens, the composition of the blood — including hormones, neurotransmitters and metabolic by-products — changes. Throw this much loopy chemistry at a sensitive machine like the brain and it’s likely to go on the blink. “There are very real changes that occur in the body very rapidly that might explain the clarity during fasting,” says Dr. Catherine Gordon, an endocrinologist at Children’s Hospital in Boston. “The brain is in a different state even during a short-term fast.” Biologically, that’s not good…’
Biologically fasting is not good for your health; even if the ‘light-headed sense of peace, albeit brief, that comes with it reinforces the fast and [seemingly] rewards you for engaging in it all the same.’ So far that is the most revelatory news I have read in this article. Not because it wasn’t obvious that fasting is not good for your health in the first place. Rather because the most concrete evidence that Kluger has presented thus far is the exact opposite of what he is trying to claim. He as shown only that spirituality (particularly fasting) is not good for your health.
HOW POWERFUL IS PRAYER
This is one of my favorite sections in this article. Kluger begins by telling us that most believers and very serious theologians ‘believe in the power of so-called intercessory prayer to heal the sick.’ Plus, Kluger tells us, some very serious scientists have ‘looked at’ this question as well. More than 6,000 studies have been published on the topic since 2000. I wonder which of these 6,000 studies Kluger will use to support the idea that prayer will help your health, let’s see:
‘As long ago as 1872, Francis Galton, the man behind eugenics and fingerprinting, reckoned that monarchs should live longer than the rest of us, since millions of people pray for the health of their King or Queen every day. His research showed just the opposite — no surprise, perhaps, given the rich diet and extensive leisure that royal families enjoy. An oft discussed 1988 study by cardiologist Randolph Byrd of San Francisco General Hospital found that heart patients who were prayed for fared better than those who were not. But a larger study in 2005 by cardiologist Herbert Benson at Harvard University challenged that finding, reporting that complications occurred in 52% of heart-bypass patients who received intercessory prayer and 51% of those who didn’t. Sloan says even attempting to find a scientific basis for a link between prayer and healing is a “fool’s errand” — and for the most basic methodological reason. “It’s impossible to know how much prayer is received,” he says, “and since you don’t know that, you can’t determine dose.”‘
Wait. So your saying the widely excepted research suggests that 52% of patients who did receive prayer suffered complications and 51% of people who did not receive prayer suffered complications. Meaning there is no significant difference between patients who recieve prayer and patients who don’t. So, again, spirituality is not helping.
Finally, Kluger goes on to discuss his only relevant scientific claim in this whole article, that of the placebo effect. If I opened up this issue and read a four page article about the placebo effect I would have no problem with it. They could mention that prayer, religion, faith, and spirituality can all have a placebo effect, but also that the placebo effect can be produced by much more. They would tell us that it can also be produced by sugar tablets, sham surgery, or belief in any false information (including that of faith and religion already discussed). They would not exaggerate the affectiveness of spirituality to undermine the truth that evidence supports. The fact that spirituality is about as good for your health as sugar pills.
In conclusion, welcome to The Pseudoscience Chronicles Jeffrey Kluger.
(Header Image: ‘Gris-gris‘ by: Charles M. Gandolfo; New Orleans Historic VooDoo Museum)
June 20, 2009
“The recent discovery that the hippocampus is able to generate new neurons throughout a human’s lifespan has changed the way we think about the mechanisms of psychiatric disorders and drug addiction,” says Wen Jian and colleagues in a study published in the Journal of Clinical Investigation in 2005. It appears that cannabinoids are able to modulate pain, nausea, vomiting, epilepsy, ischemic stroke, cerebral trauma, multiple sclerosis, tumors, and many other disorders. Cannabinoids act on two types of receptors, the CB1 receptors (found mainly in the brain) and the CB2 receptors (found mainly in the immune system). The CB1 receptor is one of the most abundant G protein coupled receptors in the mammalian brain and it accounts for most, if not all, of the centrally mediated effects of cannabinoids. Cannabionoid receptors are evolutionarily conserved amoung various vertebrates and invertebrates which have been separate for 500 million years.
Hippocampal neurogenesis is suppressed following chronic administration of the major drugs of abuse (including opiates, alcohol, nicotine, and cocaine). However, CB1-knockout mice display significantly decreased hippocampal neurogenesis, suggesting that CB1 receptors activated by endogenous, plant-derived, or synthetic cannabinoids may promote hippocampal neurogenesis.
Wen Jiang and colleagues have given the first evidence suggesting that both embryonic and adult hippocampal neural stem/progenitor cells (NS/PCs) express CB1 receptors. Cannabinoids can regulate the proliferation of hippocampal NS/PCs by acting on CB1 receptors. They found that both the synthetic cannabinoid HU210 and the endocannabinoid anandamide profoundly promote embryonic hippocampal NS/PC proliferation.
Chronic, but not acute, HU210 significantly increases the number of newborn hippocampal neurons in adult rats by promoting NS/PC proliferation. These promoting effects are not the outcome of hippocampal neuronal death, as no neuronal loss or dying hippocampal neurons were detected following chronic HU210 injection. A significant increase was observed in the hipoppocampal newborn neurons of mice following twice-daily HU210 injection for 10 days.
It has been shown that acute, high doses of cannabinoids produce anxiety-like effects in rats and depression-like effects in mice. But chronic administration of high, but not low, doses of HU210 exerts anxiolytic- and antidepressant-like effects. This suggests that cannabinoids are the only illicit drug that can promote adult hippocampal neurogenesis following chronic administration. “This increase in hippocampal neurogenesis underlies the mechanism of anxiolytic- and andtidepressant-like effects produced by a high dose chronic HU210 treatment.”
Source: Jiang W, Zhang Y, Xiao L, Cleemput JV, Ji S-P, Bai G, & Zhang X (2005). Cannabinoids promote embryonic and adult hippocampus neurogenesis and produce anxiolytic- and antidepressant-like effects. Journal of Clinical Investigation, 115, 3104-3116
June 15, 2009
Here are some ‘funny’ cigarette ads from the Stanford School of Medicine website. This is the kind of thing that really hurts the public’s trust of science. Alas, enjoy:
It’s a Fact! Cigarettes embody an ‘energizing effect’, a quick restoration of the natural flow of body energy, and a delightful relief from fatigue and irritability. Not only that, but the ‘wholy natural’ and ‘utterly delightful’ energizing effect of Camel cigarettes has ‘recieved full scientific confirmation’.
‘So whenever you feel run down, tired and irritable, just light a Camel.’
‘You can smoke just as many of these delightful Camels as you want. You can increase your flow of energy over and over again. And you need never worry about your nerves. For remember: Camel’s costlier tobaccos never get on your nerves.’
‘Everyone knows that sunshine mellows – that’s why TOASTING includes the use of the Ultra Violet Ray. LUCKY STRIKE – the finest cigarette you ever smoked, made of the finest tobaccos – the Cream of the Crop – THEN – “IT’S TOASTED” – Everyone knows that heat purifies and so TOASTING removes harmful irritants that cause throat irritation and coughing. No wonder 20,679 physicians have stated LUCKIES to be less irritating.’
‘Consistent with its policy of laying the facts before the public’, The American Tobacco Company invited one Mr. L. J. Horowitz to review the reports of the people who have witnessed Lucky Strike’s famous Toasting Process. Of course he has no scientific background to add credibility to his claim of ‘Clear Evidence’, but he is the Chairman of the Board for Thompson-Starrett Co., Inc. builders of the new Waldorf-Astoria Hotel, the Paramount Building, the Equitable Building, New York; the General Motors Building in Detroit, and the Palmer House in Chicago. That sure makes me want to trust his scientific opinion in this advertisement that gives his company almost as much publicity as the cigarettes.
Phillip Morris tobaccos are pasteurized for your protection and Thermo-vised for better taste. I guess pressure cooking might help keep the flavor in a cigarette, but I have no idea how pasteurization (or the previous toasting for that matter) would have any effect on how irritating a cigarette is when smoked. You burn the tobacco and breath the smoke either way.
This picture is best left described by the site:
‘Popular faith in medicine was exploited by a series of industry-sponsored “research” and “surveys.” In this era, before the coming of the atomic bomb, little of today’s cynicism concerning the abilities of science to overcome societal problems existed. To exploit this popular sentiment, the industry sponsored “research institutes” & scientific symposia, many of which amounted to little more than propaganda based upon dubious methodology. Health claims were then made on the basis of these supposed studies, as when Chesterfields were advertised (in 1952) with the assertion that “Nose, throat, and accessory organs [were] not adversely affected” after a six-month period of medical observation (including X-rays) by ear, nose, and throat specialists.’
‘A real scientist might be concerned about getting ashes on the microscope slide’
Bottom line, don’t trust advertisements. Something that ‘sounds reasonable’ or looks professional today could be laughed at and mocked for years to come. And, if you liked those science destroying cigarette advertisements you can see more pseudoscience related ads here at the Stanford School of Medicine website, just select view images by theme and you will see Pseudoscience as an option. Also, you can look here if you want to see a large collection of tobacco ads that are not necessarily Science related. There you can search the ads by country, company, brand, or ad type (just select Camel if you want to see the infamous Joe). And finally, for any more of your tobacco knowledge needs, you can try here at the Tobacco Wiki. They are looking for your help to mine the millions of pages of previously-secret, internal tobacco industry documents now posted on the Internet.
June 14, 2009
June 13, 2009
The Attini tribe rely solely on the cultivation of Fungus Gardens for food. When an Attine Daughter Queen leaves her maternal home, she must carry within her mouth a Nucleus of Fungus to serve as the Starting Culture for her new Garden (Schultz and Brady 2008).
THE DEVELOPMENT OF AGRICULTURE
In a paper published in PNAS in 2008, Schultz and Brady provide detailed insights into the transition from simple agriculture to complex agriculture of the Attini tribe. The study suggests the Attini first developed agriculture approximately 50 million years ago in the forests of South America, coinciding with the early Eocene climatic optimum (50-55 mya). During this time there was a period of global warming and an extraordinary diversity of tropical plants occurring at middle and high latitudes in South America. The methods used in Attine agriculture have been divided into five distinct systems:
1. Lower Agriculture (practiced by the majority of the Attine)
2. Coral Fungus Agriculture (practiced by the “Pilosum Group”)
3. Yeast Agriculture (practiced by the “Rimosus Group”)
4. Generalized Higher Agriculture (practiced by the “Higher Attine”)
5. Leaf Cutting Agriculture (practiced by the Atta and Acromyrmex)
(Schultz and Brady 2008)
All five systems of agriculture utilize remarkably proficient planting, manuring, weeding, and sheltering techniques (Mueller and Rabeling 2008).
The original Attine agriculturalists collected withered plant bits and other debris on which to cultivate an unspecialized fungus that retained close genetic ties to free-living fungal populations (Mueller and Rabeling 2008). The “parasol mushrooms” grown using this method are, so far as is known, entirely capable of free-living existence without the help of the Attine growers. A paraphyletic grade of Escovopsis is known to infect the the paraphyletic fungal food sources used by the Lower Attine; but, like all Attine agriculturalists, they utilize an antibiotic produced by Actinomycete bacteria to control the parasite.
CORAL FUNGUS AGRICULTURE
The “Pilosum Group” of the Attini tribe began to cultivate coral fungi (Pterulaceae) between 10 and 20 million years ago. Recent research indicates that Coral Fungus Agricultural products are infected by a specialized grade of Escovopsis that is derived from an Escovopsis species that infects Lower Agricultural products. This species subsequently gave rise to a clade that switched hosts and began infecting the Higher Attine food sources (Schultz and Brady 2008).
Unlike typical Attine Mycelial Gardens, Yeast Gardens consist of small, irregularly shaped nodules of fungus growing in the yeast phase. Yeast Agriculture is confined to the “Rimosus Group” and originated sometime between 5 and 25 million years ago. The yeast grown are capable of a free-living, feral existence; however, they grow in the mycelial phase rather than the yeast phase. Indeed, these fungi are only known to grow in the yeast phase when attended by the Attine growers (or depending on conditions in artificial culture). The parasite Escovopsis is unknown to Yeast Agriculture (Schultz and Brady 2008).
The transition to higher agriculture and the subsequent origin of leaf cutting are arguably the two most ecologically significant developments in the history of the Attini tribe. The fungi grown by the Higher Attine suggest a significant degree of “domestication”, or modification for life with the Attine. These fungi do not appear capable of free-living existence separable from their growers. And only the fungi grown by the Higher Attine produce “gongylidia”, nutritious swollen hyphal tips that are harvested by the Higher Attine for food(Schultz and Brady 2008).
LEAF CUTTING AGRICULTURE
The development of Leaf Cutting Agriculture (rather than the debris collecting that is used in all the other systems) coincided with marked ecological transitions in South America (5-15 mya). The coincidence of grassland expansion with the development of Leaf Cutting Agriculture supports the hypothesis that early Leaf Cutters may have been Grass Cutting specialists with specializations in Broadleaf Cutting developing later. The most wide ranging Leaf Cutting Agriculturalists originated and expanded within the last 1 to 2 million years. Such a rapid acceleration in diversification and expansion of the Attini tribe underscores the belief that Leaf Cutting Agriculture represents one of the key innovations in Attine history (Mueller and Rabeling 2008).
Mueller, U., & Rabeling, C. (2008). A breakthrough innovation in animal evolution Proceedings of the National Academy of Sciences, 105 (14), 5287-5288 DOI: 10.1073/pnas.0801464105
Schultz, T., & Brady, S. (2008). Major evolutionary transitions in ant agriculture Proceedings of the National Academy of Sciences, 105 (14), 5435-5440 DOI: 10.1073/pnas.0711024105
June 13, 2009
Posted by Bryan under About
| Tags: About
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My name is Bryan Perkins and I am here to recruit you.
On August 12, 1986 I was born into an Air Force family living in Las Vegas, Nevada. Since then I have lived in Nevada, Arizona, California, Germany, Colorado, and Louisiana. In December of 2008 I graduated from Louisiana State University in Baton Rouge with a Bachelor’s Degree in Biology. I would love nothing more than to finally put my degree to proper use and go to graduate school for ecology and evolution, but it is proving to be a much more costly and difficult process than I ever imagined.
When I first thought about creating my own science blog I had no idea what to expect, but I jumped right in nonetheless. After devouring every science blog post that I could stomach (especially those by Bora, Greg, and others) I decided there was no better way to learn what science blogging really entailed than by experiencing it for myself. That is when I created Science. Why not? (for the first time) on December 24, 2008.
Don’t forget to check out my newest project Art. Why not?