Ecology

I believe this is already the 2nd time that Nick has graced the pages of the world’s leading science journal. See: Predicting a state shift in the biosphere, and communicating it. Looks like it is the cover story too! Nick and I have been opponents in the ID / Evolution debate for years. I’m glad that scientists of his caliber visit UD and debate with us. Congrats Nick. PS The other time I congratulated Nick was here: Congrats Nick Matzke for Publishing ID Sympathetic Paper

In “Antibiotic resistance found in ancient bacteria” (CBC News, Aug 31, 2011), Emily Chung reports, The same genes that make disease-causing bacteria resistant to today’s antibiotics have been found in soil bacteria that have remained frozen since woolly mammoths roamed the Earth. “We’ve shown for the first time that drug resistance is a really old phenomenon and it’s part of the natural ecology of the planet,” said Gerard Wright, a biochemist at McMaster University in Hamilton, Ont. Five years ago, Wright had discovered harmless soil bacteria, Actinobacteria, that showed resistance to antibiotics (not, presumably, directed at them). He then sought bacteria that had never been exposed to human efforts against microbes. Geologist Duane Forese suggested taking soil samples from under Read More ›

At ScienceDaily we learn, “Scientists Uncover an Unhealthy Herds Hypothesis” (June 24, 2011), Biologists worldwide subscribe to the healthy herds hypothesis, the idea that predators can keep packs of prey healthy by removing the weak and the sick. This reduces the chance disease will wipe out the whole herd, but could it be that predators can also make prey populations more susceptible to other predators or even parasites? Biologists at the Georgia Institute of Technology have discovered at least one animal whose defenses against a predator make it a good target for one opportunistic parasite. In principle, that should be no surprise; most defense strategies carry a cost, for water fleas or nations. That’s because while growing larger keeps Daphnia Read More ›

No, this isn’t about what you think. For once, we are talking about frogs and newts.

A friend notes that an evolutionary biologist puzzles as follows:

“One of the most puzzling paradoxes in the evolution of toxins is why organisms evolve to be deadly – contrary to venoms, for which deadly effects have a clear benefit. Extreme toxicity occurs repeatedly, from saturniid caterpillars to dart poison frogs. Selection favors the most-fit individuals, and those should be the ones that avoid predation. Killing an individual predator does not give an advantage over simply deterring one, especially if the prey has to be handled or eaten by a predator to deliver the poison. How, then, can we explain the evolution of deadly toxicity?” (Brodie, E. D., III. 2009. Toxins and venoms. Current Biology 19: R931-R935.)

Brodie, I’m told, is a leading researcher on evolutionary arms races at the University of Virginia. He goes on to suggest a solution: “arms races between predators and prey … drive the exaggerated evolution of toxicity in general, without resulting in deadly consequences to the primary selective agent.” (R933) He suggests as an example is the predator-prey relationship between garter snakes and a newt that produces tetrodotoxin powerful enough to kill 10-20 humans or thousands of mice. But the interesting thing is that the snakes, which seem to be the “primary selective agent” for newts, in the sense of selecting them for dinner, are resistant to the toxin. Brodie attributes the newts’ heightened toxicity to coevolution with the garter snakes.

My friend asks, “But how does that solve the paradox? Newts with a higher level of toxicity would only accrue selective advantage if those higher levels of toxicity protected them against the predators.”

Well, I suspect the answer lies in another question: Read More ›

British physicist David Tyler writes at Access Research Network (10 December 2009): With millions of eyes on Copenhagen, this seems an appropriate time to ask whether ID thinking has any relevance to understanding the Earth’s environment. Can design concepts help us weigh the diverse and often conflicting messages? I think ID is helpful, because features of the Earth’s environments and ecologies start to take on new meaning. In this blog, I am thinking particularly of negative feedback mechanisms. Human design engineers will use negative feedback to promote stability and positive feedback to amplify an input signal. They select the mechanisms they need to achieve the desired effect. By analogy, if the Earth is designed for life, we would expect to Read More ›