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Corante Blogs examine, through the eyes of leading observers, analysts, thinkers, and doers, critical themes and memes in technology, business, law, science, and culture.

The Press Will Be Outsourced Before Stopped

Vin Crosbie, on the challenges, financial and otherwise, that newspaper publishers are facing: "The real problem, Mr. Newspaperman, isn't that your content isn't online or isn't online with multimedia. It's your content. Specifically, it's what you report, which stories you publish, and how you publish them to people, who, by the way, have very different individual interests. The problem is the content you're giving them, stupid; not the platform its on."
by Vin Crosbie in Rebuilding Media

Travels In Numerica Deserta

There's a problem in the drug industry that people have recognized for some years, but we're not that much closer to dealing with it than we were then. We keep coming up with these technologies and techniques which seem as if they might be able to help us with some of our nastiest problems - I'm talking about genomics in all its guises, and metabolic profiling, and naturally the various high-throughput screening platforms, and others. But whether these are helping or not (and opinions sure do vary), one thing that they all have in common is that they generate enormous heaps of data.
by Derek Lowe in In the Pipeline

Disrobing the Emperor: The online “user experience” isn't much of one

Now that the Web labor market is saturated and Web design a static profession, it's not surprising that 'user experience' designers and researchers who've spent their careers online are looking for new worlds to conquer. Some are returning to the “old media” as directors and producers. More are now doing offline consulting (service experience design, social policy design, exhibition design, and so on) under the 'user experience' aegis. They argue that the lessons they've learned on the Web can be applied to phenomena in the physical and social worlds. But there are enormous differences...
by Bob Jacobson in Total Experience

Second Life: What are the real numbers?

Clay Shirky, in deconstructing Second Life hype: "Second Life is heading towards two million users. Except it isn’t, really... I suspect Second Life is largely a 'Try Me' virus, where reports of a strange and wonderful new thing draw the masses to log in and try it, but whose ability to retain anything but a fraction of those users is limited. The pattern of a Try Me virus is a rapid spread of first time users, most of whom drop out quickly, with most of the dropouts becoming immune to later use."
by Clay Shirky in Many-to-Many

The democratisation of everything

Over the last few years we've seen old barriers to creativity coming down, one after the other. New technologies and services makes it trivial to publish text, whether by blog or by print-on-demand. Digital photography has democratised a previously expensive hobby. And we're seeing the barriers to movie-making crumble, with affordable high-quality cameras and video hosting provided by YouTube or Google Video and their ilk... Music making has long been easy for anyone to engage in, but technology has made high-quality recording possible without specialised equipment, and the internet has revolutionised distribution, drastically disintermediating the music industry... What's left? Software maybe? Or maybe not."
by Suw Charman in Strange Attractor

RNA Interference: Film at Eleven

Derek Lowe on the news that the Nobel Prize for medicine has gone to Craig Mello and Andrew Fire for their breakthrough work: "RNA interference is probably going to have a long climb before it starts curing many diseases, because many of those problems are even tougher than usual in its case. That doesn't take away from the discovery, though, any more than the complications of off-target effects take away from it when you talk about RNAi's research uses in cell culture. The fact that RNA interference is trickier than it first looked, in vivo or in vitro, is only to be expected. What breakthrough isn't?"
by Derek Lowe in In the Pipeline

PVP and the Honorable Enemy

Andrew Phelps: "Recently my WoW guild has been having a bit of a debate on the merits of Player-vs.-Player (PvP) within Azeroth. My personal opinion on this is that PvP has its merits, and can be incredible fun, but the system within WoW is horridly, horribly broken. It takes into account the concept of the battle, but battle without consequence, without emotive context, and most importantly, without honor..."

From later in the piece: "When I talk about this with people (thus far anyway) I typically get one of two responses, either 'yeah, right on!' or 'hey, it’s war, and war isn’t honorable – grow the hell up'. There is a lot to be said for that argument – but the problem is that war in the real historical world has very different constraints that are utterly absent from fantasized worlds..."
by Andrew Phelps in Got Game

Rats Rule, Right?

Derek Lowe: "So, you're developing a drug candidate. You've settled on what looks like a good compound - it has the activity you want in your mouse model of the disease, it's not too hard to make, and it's not toxic. Everything looks fine. Except. . .one slight problem. Although the compound has good blood levels in the mouse and in the dog, in rats it's terrible. For some reason, it just doesn't get up there. Probably some foul metabolic pathway peculiar to rats (whose innards are adapted, after all, for dealing with every kind of garbage that comes along). So, is this a problem?.."
by Derek Lowe in In the Pipeline

Really BAD customer experience at Albertsons Market

Bob Jacobson, on shopping at his local Albertsons supermarket where he had "one of the worst customer experiences" of his life: "Say what you will about the Safeway chain or the Birkenstock billionaires who charge through the roof for Whole Foods' organic fare, they know how to create shopping environments that create a more pleasurable experience, at its best (as at Whole Foods) quite enjoyable. Even the warehouses like Costco and its smaller counterpart, Smart & Final, do just fine: they have no pretentions, but neither do they dump virtual garbage on the consumer merely to create another trivial revenue stream, all for the sake of promotions in the marketing department..."
by Strange Attractor in Total Experience

The Guardian's "Comment is Free"

Kevin Anderson: "First off, I want to say that I really admire the ambition of the Guardian Unlimited’s Comment is Free. It is one of the boldest statements made by any media company that participation needs to be central to a radical revamp of traditional content strategies... It is, therfore, not hugely surprising to find that Comment is Free is having a few teething troubles..."
by Kevin Anderson in strange
In the Pipeline: Don't miss Derek Lowe's excellent commentary on drug discovery and the pharma industry in general at In the Pipeline

The Loom

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October 02, 2003

Divine Worms

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Posted by Carl Zimmer

As someone who writes a lot about evolutionary biology, I've often had people say to me, "I just can't believe that evolved." Originally, that referred to the lovely side of nature--the beauty of flowers, for example, or the grace of birds in flight. The implication was that these things were so beautiful and intricate that they had to be created for a purpose--a beautiful purpose, obviously.

But after I started writing about parasites, that underwent a fascinating change. Parasites may be deadly and gross, but they also have some mind-boggling adaptations. Most mind-boggling of all is the way many species travel through two or more hosts during their life cycle. Some flukes live first in snails, which cough them up in slime balls, then in the ants that eat the slime balls. Then the flukes drive the ants up a blade of grass, so that they can be eaten by sheep and cows, their final host. There they mate and lay eggs, which then get passed out with the host's dung. Tapeworms live in cows and pigs, and then in humans.

When people find out about these creepy life-cycles, they emphatically say, "I just can't believe that evolved."

That that fascinates me. It reminds me of the way tapeworms were used to prove God's wisdom in the 1800s. At the time people didn't realize that tapeworms lived first in cows and pigs, and then in humans. They had some similarities in both hosts, but in us, they're long and skinny, while in cows and pigs they look like little buttons with fringes of hooks. So some scientists claimed that the tapeworms in cows and pigs were deformed dead-enders in the wrong host. This outraged a devout German doctor named Friedrich Kuchenmeister (a name that invites repeated utterances, I can tell you). Kuchenmeister declared that dead-end tapeworms would be "contrary to the wise arrangement of Nature." He had the brilliant idea that tapeworms went through two hosts. To prove his case, he plucked the button-shaped tapeworms out of a roast pork and fed them in a soup to a criminal about to be executed. After the man was hanged, Kuchenmeister slit open his intestines and discovered the tapeworms maturing into their long, skinny form. Kuchenmeister found a gruesome vindication of his faith (and made a major biological discovery).

It is certainly hard--at first--to imagine how a parasite could evolve from a single host to two or more--including ones as different as snails, ants, and sheep. After all, parasites are exquisitely adapted to their hosts, able to hijack their metabolism, evade their immune system, and sometimes manipulate their brains. So how could a parasite so well adapted to one host evolve to live inside a completely different one. It seems too complex a pattern. It invites the idea that it must have been designed. But what does this mean about the designer of these parasites? That it/he/she gets personally involved in making parasites into exquisitely sophisticated killers, that it/he/she revels in the baroque sadism of these creatures?

Fortunately, the evolution of parasite life cycle is not incomprehensible. This week biologists from the University of Liverpool mapped out some interesting new ideas about how parasites find new hosts. There's a lot of mathematical modeling and parasitological minutae in the paper, but the key is that in most cases, multiple hosts are linked together in food webs. In other words, one eats the other.

Here's a simplified scenario that gives you the gist of their argument. Imagine millions of years ago there's a species of tapeworm that lives only in wildebeest. Fairly often, its hosts get killed by lions. The tapeworms that die with their wildebeest host can no longer reproduce. So now there's an automatic edge for any parasite that can manage to survive a lion attack. Perhaps the first mutations allowed a tiny fraction of the tapeworms eaten by lions to escape with the lion's droppings. Over time, these mutations would become more common because they boosted the tapeworm's chances of reproducing.

As the tapeworms evolved better strategies for surviving in the lions, evolution would begin to favor the ones that could feed on the lion as well as the wildebeest. After all, here's a big, long-lived host who can provide a massive food supply to any parasite that can survive in its gut. So the tapeworms start adapting to the lions as well. After a while, the tapeworms hold off on developing into their adult form until they get into the lion, so that they can take full advantage of their new host. Over time, the wildebeest stage of the parasite comes to look almost completely different from the adult.

Not all parasites can jump into new hosts this way. They have to be able to navigate that intermediate stage, when they can complete their lifecycle in either wildebeest and lions, for example. But as the Liverpool team points out, there are plenty of examples of parasites today that can switch-hit this way.

Ultimately, this research is important not for debates about the wisdom vs the sadism of God's creation, but as medicine. We humans, are the final host not only for tapeworms, but for lots of other parasites, including blood flukes (also carried by snails) and Plasmodium, the mosquito-borne source of malaria. These diseases each have histories of their own, as parasites built up their life cycles and then modified them by switching from one host to another. And new ones will keep coming into existence, so we have to be prepared. You can believe that that didn't evolve, but do so at your peril.

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