March 24, 2011
Once again, I have taken a sabbatical from this blog. While I have been away, the earth has been shaken by both agitated tectonic plates and agitated world leaders. Also, one of science’s stalwarts, Darwin’s theory of evolution, may be agitated by the ungrateful, invasive and ugly cane toad.
After humans foolishly introduced the toads to Australia, the cane toad invasion took off. The toads spread across the continent at unbelievable speeds. And they were reproducing like mad, as well. Survival of the fittest and screw any native species in the way, right? But scientists noticed that the adaptations for speedy dispersal did not necessarily create fitter individuals. In fact, the toads that dispersed the fastest had the highest mortality rates. But those same toads only had other toads with the adaptations for speedy dispersal to choose for mates. So they reproduced.
The scientists who noticed this phenomenon call it “spatial sorting.” They claim that natural selection is still the supreme overlord of the situation since if the speedy dispersal genes stopped the toads from reproducing all together, the genes would die out. However, the spatial distribution of the genes is an important evil minion deciding which genes are passed on. If toads can only mate with other toads with the fast genes, they will be passed to the next generation even if those genes create individuals that are more likely to break their spines.
I don’t quite understand how this is different from natural selection. Cane toads are currently invading much of Australia and speedy dispersal genes are advantageous for those on the front lines. Longevity does not necessarily mean fitness as long as the toads reproduce anyway. Maybe in a hundred years when cane toads are dispersed throughout the continent, the speedy dispersal genes will no longer be advantageous and the high percentage of the genes might be detrimental to the population. Maybe then the genes from the cane toads who stayed behind and moved slower will become more dominant in the overall population. Right now, it seems like speedy dispersal genes aren’t really that bad as cane toads are thriving.
This is very theoretical and the scientists behind the study acknowledge that it is difficult to separate natural selection and spatial sorting. I like the idea because I enjoy thinking spatially. I think I need to read more on the theory to truly understand why spatial sorting might be separate from rather than a component of natural selection.
February 25, 2011
In honor of the world ski championships in Oslo, I think that the scientists who recently discovered a new dinosaur in Utah should considered a new scientific name. The dinosaur is currently named Brontomerus mcintoshi and nicknamed ‘Thunder Thighs’ because it has a large thigh bone to which scientists presume massive thigh muscles were attached. According to the article, the thigh muscles may have been used “as a weapon to kick predators, or to help travel over rough, hilly terrain.” Not only that, but the dinosaur has upper body strength as well, as indicated by the ‘unusual bumps’ on its shoulder blades. The researcher added, “It’s possible that Brontomerus mcintoshi was more athletic than most other sauropods… so perhaps Brontomerus lived in rough, hilly terrain and the powerful leg muscles were a sort of dinosaur four-wheel drive. Doesn’t that sound a bit cross country skier-ish?
Check out this ‘kick’ over rough, hilly terrain:
and these powerful forelimb and leg muscles:
and then tell me that Brontomerus mcintoshi shouldn’t from this day forth be called
February 21, 2011
Yesterday as I was skiing up Brackett Creek, a snowshoe hare spastically crossed the trail directly in front of me. Considering how many hare tracks I have seen off the trail, I probably have passed by multiple snowshoe hares sitting stock still under a fir tree but failed to see them because they are white and so is snow. This was the first one I have seen up at Bohart and as I said, it was running across the trail in the helter-skelter manner of hares so it was hard to miss.
Snowshoe hares are one of the cool animal species that actually change color between winter and summer. Because hair is a dead tissue, however, the actual color of each hare hair (ha!) does not change color. Instead, the hare has to shed its entire coat and grow a new one every fall and spring. The new coat color is induced by hormones reacting to the changing light conditions and changing the biochromes in the hare’s hair cells (I just can’t help myself). Luckily this can happen gradually or else we would have some hairless hares running around. As it is, it takes the hares 10 weeks to fully change color. Hopefully there are some snow patches in those 10 weeks on the front and tail end of winter, or the hairy camouflage of hares can work against them.
Despite their very cool adaptation for avoiding being eaten, snowshoe hares are an important prey species for pretty much every northern predator. Because of their population cycles, they and their mortal enemies, the canada lynx, are the classic example of predator-prey population dynamics. They are also animals who know how to pick the best habitats – snowy and northern with a good dose of elevation thrown in.
Unfortunately, in honor of my birthday last week I have to admit that I, like the hare, have some white hairs growing in. Maybe it just means that in 10 years I will be super sneaky around the trails in winter.
February 8, 2011
Sage grouse country is desolate by most standards. The large members of the grouse family live on the high elevation sage steppes of the Rocky Mountains. If you happen to want to visit a sage grouse, you will find many poky dry plants, no trees and any spectacular alpine scenery (or flowing water for that matter) you might see is generally off in the distance or in your dreams. I don’t think many people in Manhattan generally think about sage grouse planning out their strut for the annual mating call at the lek each year, but today, sage grouse made the NY Times.
Why would people even read this article about a species in a remote part of the US? Because this desolate, windy and shadeless landscape is full of flatulence of the natural variety along with some coal and oil for good measure and the last thing that the oilmen who live in their mansions in Texas and ranchers who raise sheep in the harshest climate in which sheep could possibly survive want is for sage grouse to go on the endangered species list. The Endangered Species Act is often cited as the most powerful piece of environmental legislation passed anywhere. Ever. So if sage grouse do make the list (and they probably should considering how low their numbers are) there wont be any new oil or gas wells and ranchers won’t be funded, but will be required, to make environmentally sound decisions.
If the ESA scares people/the government into protecting habitat before a species is put on the list, then great. The article, at least, made the Sage Grouse Initiative sound like a plausible alternative to strict federal regulation. It also made it sound like it was applying science to policy. WAHOO! With a reactive management plan based on results. YEEHAW!
I am still a little skeptical after seeing the vast oil/gas fields and the roads connecting them in Wyoming. The Initiative is protecting high quality habitat and providing funding for ranchers to manage their lands for sage grouse, but there is a hell of a lot of BLM land that isn’t included in the project. Maybe sage grouse can survive on a little less land, but can migratory pronghorn and mule deer? What will happen when the populations on these habitat patches become completely isolated from each other? Will the people who read the NY Times care more about filling up their tanks or about a funny-looking bird in the high desert?
February 2, 2011
I couldn’t think of a better title than the one I found in this Wired article. It is perfect. It starts scary and you think, “uh oh the carnivorous plants are going to eat me” and then you find out they EAT POOP! This is hilarious in itself until you then read that the poop isn’t just normal run-of-the-mill everyday poop, it’s from tiny bats! I love it. Seriously. If you want to discover my sense of humor, read the title of this post.
But the article is actually interesting too. It talks about the symbiotic relationship between the carnivorous plants (a species of pitcher plant) and the tiny bats (Hardwick’s woolly bat) in the marshes of Borneo. As with plants in bogs, marshes and fens across the world, the limiting nutrient for the pitcher plants is nitrogen. Carnivorous plants get some nitrogen from the insects they absorb with their acidic juices and they could get some nitrogen if they attempted to absorb the entire bats. However, the ‘pitcher’ opening of plants is smaller than the bats so they don’t fall into the pit of fly despair. They do, however, roost in the upper part of the plant, which is free of the blood-sucking parasites apparently found elsewhere in the marshes of Borneo. Not only do they sleep, but they poop and people who use guano as a fertilizer know that bat poop is chock full of nitrogen.
So the bats get a cozy safe place for their daytime abode and the plants get a meal of poop. It doesn’t sound like that good of a trade unless you are a nitrogen-starved marsh plant, but hey, if it works for them, it works for me.
On a related note, I am pumped to have 5th graders up at Bohart again. The curriculum is based on ecosystems and interspecies relationships and one of the things we talk about sometimes is symbiotic relationships. Last time my big examples were birds on bison and lichen. Just wait until I throw this one at the kids!
January 6, 2011
After a long hiatus involving driving through blizzards, eating lots of good food, skiing on rolling terrain, driving some more and spending 12 hours straight in the bathroom violently ejecting all of the aforementioned food from my body, I am finally writing another blog post. In honor of the new year, the topic is resolution – namely my personal life goal #27.
To see a wild musk ox.
Musk oxen were the subject of a recent New York Times article (in which the author fails to deduce that caribou and reindeer are the same species). They are often overshadowed by cute white furry things, but despite their lack of whiteness unless covered in snow, they are very well adapted to living one of the coldest, most imperiled and most captivating regions on earth – the arctic. They have outrageously thick fur, they efficiently extract calories from their food and they can dampen their metabolisms so they use less energy. Musk oxen live in tight social groups and defend their calves from marauding wolves.
They are also funny-looking enough to be super cute. They have horns, long fur and beards! I laugh every time I see a picture. I bet they are even funnier in real life.
December 13, 2010
Today is a lame. 1. it is raining on my day off 2. my external hard drive is corrupted and I am waiting to see if any data is salvageable and 3. it is raining on my day off. However, even today I am supremely happy that I am not a clownfish in a coral reef.
Here is why.
Humans have been exploiting the oceans since Mr. and Mrs. Caveman first discovered that the icky slimy things on the beach actually could be tasty and filling. The best part is that we can’t see the damage we’ve done so we can go along in our happy-go-lucky piscivorous ways. The last blue-fin tuna? That’ll go well in a sushi roll with avocado. Case in point: the Grand Banks of the Maritime provinces. Rewind a thousand years and Basque fishermen traveled all the way across the Atlantic Ocean to bring back ‘bacalao’ for their families. At present there are apparently barely enough Atlantic cod to fill a couple fishing boats.
Now we have another pressure to add to overfishing, maelstroms of garbage and dead zones. According to a new report by the UN, the acidity of oceans has increased by 30% in the last 150 years. Acid eats away at things like coral, which is the structural support of many of the most diverse areas in the world, and the shells of many sea creatures, like mussels and conchs. Increased acidity also can inhibit bone growth in juvenile fish, including otoliths. Otoliths are the small bone fragments in our and fish’s inner ears that allow us to know up from down and left from right. The variable growth in the otoliths apparently can cause confused movements and changes in behavior that threaten the survivability of Nemo’s brethren.
Life under the ocean is hard to see, hard to get to and hard to study. We understand relatively little about the complexities and connections within the ocean ecosystem, but we still rely on the ocean for food, transport and stable weather patterns. The abundance and diversity of life in the ocean has been declining for thousands of years. We don’t know when the ocean if is going to call ‘uncle’ and give up or somehow fight back with a vengeance. Both sound scary to me.
November 20, 2010
In the last 48 hours, the temperature has dropped almost 50 degrees! I am sitting curled up on the couch with my trusty pooch warming my toes trying to regain my core body heat after skiing up Sourdough this afternoon and I am reminded of my very favorite scientific study which happened in another very cold place, Siberia.
Rewind to about 50 years ago to frigid Novosibirsk, USSR. In 1959, a guy named Dmitry Belyaev, spurned by the scientific elites of the Soviet regime, started an experiment on silver foxes. Belyaev had 100 foxes and he chose to mate only foxes that did not react aggressively toward humans. He classed them into three categories, I – foxes that are friendly toward the experimenters, II – foxes that allowed themselves to be petted but did not act friendly and III – foxes that were aggressive toward humans. By the sixth generation, they had to add a fourth category, the domesticated elite (remember this is Soviet Russia), which were eager to establish a relationship with humans. In the tenth generation 18% of foxes were elite and 40 years into the experiment 70-80% of the foxes were elite!
This rate of domestication is much faster than scientists had previously thought possible, but the experiment gets significantly cooler. The domesticated foxes, who were only selected for lack of aggression, started showing morphological traits that we associate with dogs – large floppy ears, curled tails, piebald fur, longer or shorter fur, bark vocalizations and a shortened muzzle. Scientists believe that these traits are associated with a decreased release of adrenaline in domesticated animals compared to wild animals, especially since many of the traits are ubiquitous to the spectrum of domesticated animals. Think of, for example, the blaze of white found on many border collie foreheads, then the same blaze on some breeds of horses, cows and pigs.
Most importantly, all of these traits are considered juvenile. Unlike wild foxes which turn more and more aggressive after about 3 months, the domesticated foxes stayed in puppy phase (only psychologically, since the foxes could breed).
Back in the day, approximately 100,000 years ago, people domesticated wolves, or as some believe, wolves domesticated people. If it would lead to less aggression and more cuteness, I would say that dogs need to work on domesticating their people a little more.
November 17, 2010
Today I went for another ski – praise the snow gods – this time at Bohart. I made it up to Lookout, which was no easy feat with my lack of early season conditioning, and started toward Bracket Creek and in front of me I saw a coyote! As usual with coyotes, especially in the west, I didn’t precisely see the coyote, but the tail end of the coyote and this was one nice bushy tail end. Immediately I thought, “there is something to write about.”
Because it turns out coyotes are one of my obsessions.
I am going to leave it at that and go on with a story from this past summer to illustrate my point. I was at a bar, okay, the bar, in Winnett, Montana. How I got to this bar in Winnett, a town with the motto “You can blink twice, but we are still here” pasted on its welcome sign is for later.
For now, imagine me sitting at a country bar in eastern Montana with Zane the old guy on one side and a construction worker from Billings on the other. This was the night of the last NBA final game and Billings guy had been there for a while. I had three drinks waiting in the form of upside-down dixie cups in front of me bought by Billings guy and his friends and it was 11:00. I was about 2 hours past my social limit.
And then Billings guy brought up coyotes.
Apparently for a drunk guy from Billings, the best way to flirt (even my faulty flirt-dar was blaring warning signals in my head) with a girl who has already admitted to the blasphemy of working for the University of Montana, home of the hated Griz, and to liking plants and animals and sciencey things is to brag about how he lures coyotes close to him by staking out his dogs and proceeds to shoot them. Seriously? Now, I know how alcohol works and I have some idea how stupid men work, so I shouldn’t have been that surprised and I shouldn’t have been that indignant either.
But, unfortunately I could feel the hair on my ruff rising and a bit of a snarl forming on my lips.
People hate coyotes. People hate coyotes enough to risk their dogs and spend hours waiting for the coyotes to come in. People love bragging about how many coyotes they’ve killed. I talked to a guy last summer who kills coyotes for the federal government in Wyoming and he averages 70-80 per day. The government puts canid-specific poison, which of course can easily kill domestic dogs, out on public lands and fails to put adequate signs to warn people. I saw a sign warning of poison literally 200 meters from a campground in a National Forest in Wyoming.
Coyotes are predators. Coyotes kill small defenseless things like lambs and mule deer fawns that people would like the right to kill later. People blame them, along with wolves if wolves are around, for lack of success during deer season. However, I have not found any studies that show that coyotes cause population level decreases in mule deer populations. Moreover, studies by state wildlife agencies, which are not known for being coyote friendly, in Montana, Colorado and Utah, found that coyote removal does not lower fawn mortality even though coyotes are one of the main predators for fawns.
How can this be? This shows one of the limits of this type of science. Fawn mortality is generally deduced by examining fawn carcasses. It is very difficult to tell whether a fawn died of starvation and the carcass was eaten by a coyote or whether the coyote killed it. Even more importantly, the fawn might have been weakened by starvation and would have died even if the coyote hadn’t killed it.
Science is based on testing assumptions and then testing the assumptions that created the assumptions.
People are based on assumptions.
So I told Billings guy he was stupid because I couldn’t help it. Then I turned to Zane the old guy and happily conversed about canoeing the Missouri in the 1980’s.