A dash of cryptozoology for your Saturday. A Montana rancher shot and killed a wolf-like animal that was in “stalking distance” of his herd. Because, of course he did.
The dead animal’s canine teeth were too short, the front paws were tiny for a wolf, and the claws on those paws were too long. The ears were too big as well, experts told The Washington Post, and the coat was wrong. This was no wolf.
This mystery animal … is almost certainly a plain old dog, because dogs display a huge amount of variability. But maybe not. Canids that are difficult to identify are not all that uncommon. Wolves and coyotes may eat dogs, but they also hybridize with them. They’re flexible that way. Results of cross-breeding can bring an interesting mix of features—and need not necessarily look like either of the parents.
There’s a pair of famous examples from the cat side of mammalian predator pool: Ligers and tigons. Ligers are produced from a male lion (Panthera leo) and a female tiger (Panthera tigris). Tigons are verse-visa. Ligers are big. They can be at least as large as the largest male lions—making them about the same size as the Saber-toothed cat Smilodon. (Look up a picture of a liger next to people if you want to see what our ancestors had to deal with. Half a ton of cat.) But where ligers are a product of zoos, circuses, and cult films, canids have overlapping habitats, so they get can get busy out there in the wild. Which can make for some mixes that would generate a genuine “huh” even from a specialist.
Then there are the effects of diseases, both genetic and all-too ordinary. The number of “Chupacabras” filmed, shot, or recovered from the roadside in the the southern US that have turned out to be plain old dogs or coyotes afflicted with skin disorders is … many. The Montana specimen could be similar affected by anything from parasites to malnutrition.
It would be nifty to think that there is another North American canid that, somehow after all this time, managed to hold out in some tiny area of the northern Rockies. It’s extraordinarily unlikely, but maybe we missed something as large as a subspecies. The Timber Wolf, Eastern Wolf, and even the Red Wolf, which was formerly considered a separate species, are all just variants on the plain old Gray Wolf (Canis lupus). Maybe there’s a Snub-nosed Wolf. Except … almost certainly not.
In any case, the most important thing here is … a rancher shot it. For being sorta, kinda close to a cow. There are a smidge under 40 million cows in the lower 48 states. There are about 5,000 wolves. And if you’re thinking “Well, that’s just one example, and this the US, which is a pretty built-up place.” Tune in on Monday. We’re going to talk about this. Anyways, stop staring at your dog and come in. Let’s science.
Paleontology
The “dinosaur killer” asteroid warmed up the planet for 100,000 years.
This is one of those examples where decoding the title of an article (Postimpact earliest Paleogene warming shown by fish debris oxygen isotopes), is the key to finding out that what’s inside has interest beyond that of specialists. In the article, a quartet of geologists from the University of Missouri, SUNY, University of Colorado, and University of Tunis looked at something pretty obscure — the relative level of oxygen isotopes in fossilized “fish debris” — to discover something pretty big: The asteroid that smashed into the Earth near Chicxulub didn’t just trigger world-wide fires, a globe-blanketing cloud of smoke, and a secondary rain of dust, pebbles, and flaming rocks that laid waste to much of the Earth and did in the non-avian dinosaurs. It also opened a period of about 100,000 years when the Earth saw a sharp upward increase in temperature. Rather than a nuclear winter, it kicked off an asteroid summer.
The change looks to be about 5°C. That’s a big change. Changes of that scale, even without the accompanying impact event, are associated with some of the largest extinction events in history. And the beginning of this hot spell appears to have been very abrupt, coincident with the impact. It’s not the first study to reach this conclusion. Previous looks at other types of fossils have estimated post impact greenhouse warming as high as 8°C.
There were other factors that probably helped keep the temperature up. There were some notable volcanic events during the period, though possibly not any more than you’d find in any other closely studied 100k year slice. But the impact so disrupted the carbon cycle by decimating both land and sea ecosystems, that any gases produced by volcanoes in this period lingered much longer in the atmosphere.
Math
An algorithm shows that fewer taxis could better serve passengers.
Both Michael Cohen and potential Uber competitors had better check the math. Mathematicians, led by number killers Mohammad Vazifeh and Paolo Santi at MIT, have generated an approach that shows how fewer taxis can do more work. But it requires a couple of things: Cooperative taxis and cooperative passengers.
Here we provide a network-based solution to the following ‘minimum fleet problem’, given a collection of trips (specified by origin, destination and start time), of how to determine the minimum number of vehicles needed to serve all the trips without incurring any delay to the passengers. By introducing the notion of a ‘vehicle-sharing network’, we present an optimal computationally efficient solution to the problem, as well as a nearly optimal solution amenable to real-time implementation.
The results show a New York City with one-third fewer taxis and service at least equal to, if not better than, current waiting times. The precision and cooperation needed to bring off the fewer-taxis / better service plan may seem unlikely, and they are given both current technology and current attitudes. But in an interview with Nature, Vazifeh talks through how both of those requirements can be reached.
The results also edge toward an idea that seems deeply tied with self-driving cars: Why own a car at all? Even for people in relatively low density areas, if you can step outside and have a vehicle waiting in minutes, isn’t that better than making your second-largest investment in something that requires frequent attention, degrades in value, and spends the great bulk of it’s time not doing what it was designed to do? And, like many other topics these days, it brings up the question of just what all those taxi and Uber drivers are going to do when Johnny-Cab takes over.
Medicine
A new class of chloride channel inhibitors could be a big deal for medicine.
Many, make that MANY, areas of activity in the body are handled by transmission along chloride channels. To give an idea range involved, problems with these transmissions are thought to be associated with diseases as diverse as cystic fibrosis, macular degeneration, and many forms of kidney disease. Drugs that could promote or inhibit these transmissions have tremendous potential, but they’ve pretty rare in the world’s pharmacopoeia because they don’t tend to be all that selective. A drug that deals with a muscle issue isn’t all that great if it causes kidney damage. Saving your eyes at the cost of damaging your heart is not a great bargain.
So while this Stanford-led research may not immediately provide a cure to a big-name illness, it looks like it opens the door for a whole new class of drugs.
This work introduces a class of inhibitors with unprecedented selectivity for a single CLC homolog, CLC-Ka. … Our findings provide tools for studies of CLC-Ka function and will assist subsequent efforts to advance specific molecular probes for different CLC homologs.
This is something that’s likely to come up again.
Evolution
Sexual selection by females drives evolution more directly than sexual selection by males.
There might be a few words missing from that headline that make it a little less … sexy. Those words are “in fruit flies.” Still, since I’m obsessed with all forms of selective pressure (I kind of wrote a whole book on the topic), I couldn’t resist this article.
And the results might not be so fly-oriented as all that.
… experimental results show that the evolution of pheromones can only be driven through female choice of males because genetic relationships exist between pheromones, mating success, and fitness. Male choice of females, however, cannot drive evolutionary change by itself because the correlation between pheromones and mating success is generated by environmental rather than genetic variation. Therefore, the traits targeted in females by male choice are likely to evolve through correlated responses to selection on males.
This is a very specific circumstance, but it’s easy to project toward features that might face similarly unequal sexual selection in other species.
Meta-Science
Including better “instructions” with experimental results.
Many different fields of science have been shaken recently by failures to reproduce some of the most groundbreaking studies. The resulting hue and cry over reproducibility has made it seem that some of these studies are false, fakes, or just poorly done.
But, writing in Nature, Phillip Stark lays a lot of the blame on something that should be more immediately addressable: Making sure that scientific papers do a better job of actually describing the critical factors needed to reproduce an experiment.
Communicating a scientific result requires enumerating, recording and reporting those things that cannot with advantage be omitted. This harks back to the idea of science as a way to build knowledge through careful experimentation. Ushering in the Enlightenment era in the late seventeenth century, chemist Robert Boyle put forth his controversial idea of a vacuum and tasked himself with providing descriptions of his work sufficient “that the person I addressed them to might, without mistake, and with as little trouble as possible, be able to repeat such unusual experiments”.
And that’s a big problem with many of the experiments that people are trying to reproduce. The original simply lacks enough information that someone reading only that paper can reproduce the work. There are a lot of steps to this: Better standardization of vocabulary and procedure, full descriptions of steps that may, for the originating lab, have become common practice. It all sounds a bit boring. It also sounds a bit difficult when studies are of necessity conducted at the ragged edge of what’s known. It’s all absolutely necessary.
Most papers fail to report many aspects of the experiment and analysis that we may not with advantage omit — things that are crucial to understanding the result and its limitations, and to repeating the work. We have no common language to describe this shortcoming.
I’m voting that every experiment should come with instructions that can be reproduced in IKEA pictograph form and conducted with a standard white and orange box of tools. That may be unrealistic, but it’s a worthy goal.
ECONOMICS
Long-term predictions of large economic measures are inaccurate.
In this case it would almost seem that title could be preceded by the word “Given that ...” But Carnegie Mellon researcher M. Granger Morgan has made it even more clear than usual.
People make predictions about the future all of the time. Often these predictions take the form of single-value best estimates, with no associated statement of uncertainty. Sometimes that is just fine. For example, if you need to know to within a few meters where Venus or the Earth will be located with respect to the sun at noon Greenwich Mean Time on January 1, 2100, experts in orbital mechanics can tell you, and single-value answers will be more than sufficient. …
In other cases, people routinely make forecasts in the form of single-value or point estimates when in fact uncertainty is very high. Slowly but surely different communities have come to understand that doing this can result in serious problems and have begun to characterize uncertainty with probability distributions.
And among those highly uncertain measures are almost every means by which we estimate the economy, from unemployment to GDP. Which only reinforces the idea that when some Congress-person makes a claim about the long-term effects of a tax cut, or in fact any piece of legislation, you can be highly certain that they’re just making it up.
Sorry. No psychedelic drugs this week. But that discussion, and the comments, were a lot of fun.
Image
This week’s image is from Andy Brunning at Compound Interest. As usual, visit his site for a larger version that’s easier to read.