Friday, September 29, 2006

Is There Really a Connection between E. coli and Farming Methods?

Last Saturday, I linked to a WorldChanging post that said that E. coli O157 is linked to factory farming because it prefers to grow in grain-fed cows. I have just become aware that Tara Smith at Aetiology has written on this topic and the issue is not really clear-cut. There may indeed be a connection between grain-feeding and pathogenic E. coli, but the evidence is hardly unequivocal. Tara mentions a study that found
that when a long-term diet of hay was fed (greater than a month), the cattle still shed O157 (Appl Environ Microbiol. 2005 71:7974-9.) Another one found diet had no effect on O157 (J Anim Sci. 2006 84:2523-32). If anything's clear, it's that the link between diet and shedding of O157 *isn't* clear, despite what Plank claims.
Of course, knowing where our food comes from is important for many reasons and some links between factory farming and disease, like the evolution of antibiotic-resistance bacteria, are widely accepted. However, it is important that we base our decisions on the best science available and learn to tolerate some uncertainty.

Friday Random Ten

An unusual amount of very good stuff came up today. I guess it's my lucky music day!
  • Bruce Cockburn, "All the Diamonds in the World". Cockburn's usual lyrical imagery, spirituality and perfect guitar. Good stuff!
  • Kathy Mar, "Flowering Green". A fairy tale for the modern world.
  • Kathy Mar, "Everybody's Moon". Thoughful but light folky song.
  • Jackson Browne, "For Everyman". Life will be good for all of us or none of us.
  • Echo's Children, "O, Sumer!". An allegory describing the sacking of ancient Sumer.
  • Jackson Browne, "Tender is the Night". Searching for that right person.
  • Julia Ecklar, "Burnish Me Bright". The story of a mute child who learns to communicate through mime.
  • Gaia Consort, "Moon in Your Teeth". Spare and mystical.
  • Collin Raye, "It Could Be That Easy"
  • Peter, Paul and Mary, "The Times They are a' Changin'". Wrong generation? Maybe not...

Wednesday, September 27, 2006

What Does It Mean to Respect Nature?

I've never watched Steve Irwin, but I'm a member of the ECOLOG mailing list and lately my inbox has been filling up with ecologists' commentary on his approach to education and entertainment. Commenters seem to fall into two categories: those who admired Irwin and those who thought he wasn't serious enough, that his wildlife-based entertainment had little value.

I can't comment on Irwin specifically, but two assumptions came up often enough in the writings of the second group that I feel they must be discussed. The first is that respecting nature means taking a hands-off approach as much as possible. The second is that scientific research is intrinisically more valuable than, say, entertainment.

The title of the Charles Jonkel article linked to above, "Save a Grizzly, Visit a Library", exemplifies the first assumption. To a certain extent, I share it. Humans certainly are capable of harming nature and animals while enjoying them. But must I be a pair of eyes on a stick? While some of Steve Irwin's actions may certainly have been questionable, is there anything seriously wrong with my herpetology professor's lizard-catching or my munching on various woodland edibles? Promoters of the "hands-off" attitude often decry the fact that many modern kids learn more about nature from TV and computers than first-hand experience, but isn't this perfectly consistent with the "do not disturb" ethic? Under what circumstances may we participate in nature, and doesn't even posing the question separate us from the rest of the natural world?

Several list members have commented that handling, marking and sometimes even killing wild animals is justified only if it is for scientific purposes. Entertainment, even if educational, just isn't good enough. This claim is frequently followed by the assertion that the use of wild animals in research is acceptable because it helps with conservation or management. However, most zoological research has essentially nothing to do with conservation or management! While I agree that animal welfare is extremely important, I would argue that mist-netting 100 birds to band them is more problematic than capturing one or two such birds to show off on television. Furthermore, many (if not most) biologists chose their careers because they love nature and the outdoors. Biologists generally enjoy their work and this enjoyment is the primary motivation for the work. However, it is hard to argue that the satisfaction of a scientist's curiousity is inherently more worthwhile than the satisfaction of another person's desire for entertainment.

When animals are used in either science or entertainment, the animal's well-being must be paramount. Beyond that, it is hard to criticize Steve Irwin.

Tuesday, September 26, 2006

Kudzu, Hurricanes and Soybean Rust

I may be a fungus freak, but learning life cycles is, well, a necessary evil. Rusts, plant pathogens with up to five types of spores, are a particular pain. So today's lecture on rusts in my mycology class was a bit less than exciting -- that is, until we got to soybean rust. The organism is not particularly fascinating, but the story of how it got to the United States is worth telling.

Like soybeans, soybean rust is native to East Asia. As soybean cultivation spread worldwide, so did the rust. In the 1950s and 1960s, it spread through South Asia and Australia. In 1994, it reached Hawaii, but the continental US was protected by long distances and careful inspection of imported plants.

The beginning of the end of this isolation came in 1997, when a cyclone carried the fungus from India to central Africa. In a few years, it reached both South Africa and the Atlantic coast. Then, transported by either wind or airplanes, the rust showed up in Paraguay in 2002. From Paraguay, the fungus' highly mobile spores dispersed to Venezuela and Brazil. After that, it was only a matter of time before soybean rust showed up in the continental US.

It didn't take long. In September 2004, Hurricane Ivan blew spores from South America to the American South, introducing the rust to Louisiana, Mississippi, Georgia and Florida. Farmers are now trying to control the pathogen, which attacks a wide range of legumes. So far, damage has not been serious.

So what's up with kudzu? It turns out that this vine, a Japanese import ubiquitous in the South, is one of the hosts of soybean rust. This means it can become a reservoir for the disease -- unfortunately, without sustaining much damage itself. You gotta love ecology!

Monday, September 25, 2006

Cool Space Blogging

Have you heard of Anousheh Ansari? She's a space tourist, the fourth one in history and the first woman, and she has a blog that gets updated several times a day. (She can't blog live because of Internet connection outages during orbit; instead, she sends down emails that her friends post on the web.)

Only the very wealthy can afford space travel right now, but what will happen in 15 or 20 years? Will the merely well-off be able to go up? Will there be private space stations catering to the ultimate in tourism? And what would happen if many people experienced a view of Earth from space? That could be one of the drivers of Homo sapiens' maturation.

On a related note, Thomas P.M. Barnett notes a New York Times article about Mike Griffin, the director of NASA, visiting China. I hope we do start to cooperate in space.

Two Tales of Missing Tails

A lizard and a dolphin.