black holes and gray matter. in one thousand tangos.


It was an unlikely crime scene: a steep trail used by bears leading to a still, ancient redwood grove. There, a rare old-growth coast redwood had been brutally hacked about 15 times by poachers, a chain saw massacre that had exposed the tree’s deep red heartwood.

The thieves who butchered this and other 1,000-year-old arboreal giants were after the burls, gnarly protrusions on the trees that are prized for their intricately patterned wood. Although timber theft has long plagued public lands, a recent spate of burl poaching, with 18 known cases in the last year, has forced park officials to close an eight-mile drive through old-growth forests, the Newton B. Drury Scenic Parkway, at night to deter criminals. More closings are expected.

While some burls are small and barnacle-like — perfect for souvenir salt-and-pepper shakers — others weigh hundreds of pounds and can fetch hundreds or thousands of dollars per slab.

The poachers, known locally as the “midnight burlers,” are motivated by a sluggish local economy and expensive methamphetamine habits, park officials say, and they have been targeting ever-bigger burls and using increasingly brazen tactics. Last year, a redwood estimated to be 400 years old was felled by thieves who wanted access to a 500-pound burl 60 feet up. It was the first time an entire tree was cut down for a burl…

Old-growth coast redwoods are among the earth’s most tenacious organisms, some living 2,000 years or more. Removing a burl cuts into a tree’s living cambium layer, which can weaken it and make it vulnerable to insects and disease.

Poachers Attack Beloved Elders of California, Its Redwoods

In the Evolution of a Signal, What Comes First: The Signal or the Response?

Sex pheromones are chemical compounds released by an animal that attract animals of the same species but opposite sex. They are often so specific that other species can’t smell them at all, which makes them useful as a secret communication line for just that species. But this specificity raises an intriguing question: When a new species evolves and uses a new pheromone signaling system, what comes first: the ability to make the pheromone or the ability to perceive it?

Here is the conundrum: Among species that use pheromonal signaling systems to attract mates, individuals that are detecting and responding to the scent (the receivers) are using the specificity of the signal as a measure of whether the individuals emitting the scent (the senders) are in fact the right species. Any individuals that make a new and different scent would then be perceived by the receivers as being the wrong species and they won’t attract any mates. If you don’t attract mates, you can’t pass on your new genes for your new scent. This produces a strong pressure to make a scent that is as similar as the scent produced by everyone else as possible (this is called stabilizing selection). With this intense pressure to be like everyone else, how did the incredible diversity of species-specific pheromones come to be?”

Scitable | Nature Education

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