The silence of the microfauna

A generation ago Rachel Carson warned us of bird die-offs from pesticides in the classic “Silent Spring”. Now, a new silence might be rocking the world, and causing an increasingly creepy silence: flying insects are dying at an alarming rate and in staggering amounts. A study published last fall documented a 76% decline in total seasonal biomass of insects in Germany, and speculated how widespread their result might be.

Unfortunately, that question is difficult to even approach because of another problem: a global decline of field naturalists who study these phenomena.

Want to learn more about this awkward intersection? Read about it here!

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Rewriting the book on Lichens

As I mentioned on Friday, science communication is all about stories. And this one is a doozy.

After a not so traditional education, Toby Spribille has found that lichens are not what we thought they were. We have long known that lichens are 1 part algae and 1 part fungi.

But it turns out that’s not true. Turns out, it’s 2 parts fungi (two different types of fungi to boot), and 1 part algae. We’ve been getting it wrong for decades.

Read the story of this discovery over at the Atlantic!

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The enemy of my parasite is my… Frenemy?

Parasites are all around and often problematic.

But recent work from Kayla King has demonstrated that some microbial parasites can evolve to be mutualistic and defend against more virulent parasites.  And what’s more this shift from foe to friend can happen rapidly.

Read the paper here, or the synopsis over at National Geographic.

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Crowd-funding a Joshua tree reference genome

(Flickr: jbyoder)

(Flickr: jbyoder)

Remember Joshua trees? If you read this blog, you probably do. They’re an ecological keystone species — and a cultural icon — in the Mojave desert, and they have a fascinating, co-evolving relationship with yucca moths. Some contributors to this very blog, have been studying that pollination relationship and its evolutionary consequences for a decade, building on natural history research that goes back to the time of Charles Darwin.

Up to now, though, modern genetic tools have been of limited use for Joshua trees, because no one has assembled the complete DNA sequence of a Joshua tree. Having a “reference genome” would let those of us who study the trees identify specific genes involved in coevolution with yucca moths, compare the evolutionary effects of that pollination mutualism to natural selection exerted by the harsh environments in which the trees grow, and even use genome-scale data to inform Joshua tree conservation planning.

Well, we’ve decided it’s time to do all of that, and we’re asking for help. A team of folks with expertise in Joshua trees’ natural history, Mojave Desert ecology, and genomic data analysis launched the Joshua Tree Genome Project a couple weeks ago, with a crowd-funding campaign on Experiment.com to pay for part of the DNA sequencing we’d need to assemble a reference genome.

We’re approaching 50% of our funding goal, and leading a competition among projects based at undergraduate universities to recruit the most donors, which could win us $2,000 in matching funds — so even if you give as little as $1, you’re providing a big boost to the project. Go check out the Joshua Tree Genome Project website, and then head on over and pledge your support.

This boring-looking grass can occupy an extra 10,000 square miles, thanks to a helpful fungus

Mutualisms, in which two or more species provide each other with services or resources that they can’t produce on their own, are everywhere you find living things. Mutualists offer protection, help transport pollen, and provide key nutrients.

Even when a mutualist’s services aren’t absolutely vital, they can help make stressful environments tolerable. That’s the insight behind a new study that finds the help from one group of mutualists could allow an unremarkable-looking species of grass to colonize more than 25,000 square kilometers (almost 10,000 square miles) of territory where it otherwise wouldn’t survive.

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Scientists at work among the Joshua trees

When he’s not dismantling racist pseudoscience, Chris Smith studies the evolutionary ecology of species interactions. Willamette University sent along a videographer on Chris’s last field trip to study Joshua trees and the moths that pollinate them in central Nevada, and the result is now posted on Vimeo. It’s mainly geared toward showcasing how Willamette undergraduate students participate in the fieldwork, but I’d say it makes the desert look mighty good, too.

How many moths must a sloth carry off for the sloth to rely on the moths?

Three Toed Sloth

Is it easier being green? Photo by Bas Boemsaat.

Sloths are weird critters. Cute, in a certain light, but mostly weird. They’re members—with armadillos and anteaters—in a superorder of mammals called the Xenarthra, which are united by a unique form of multi-jointed vertebrae. Their diet consists mostly of leaves, which are poor quality food, and hard to digest. Fortunately, they also have one of the slowest, lowest-energy lifestyles of any mammal, using heavily modified limbs to hang upside down from branches while they browse, their most recent meal fermenting in their guts.

David Attenborough got up close with a sloth—which he calls a “mobile compost heap”—in The Life of Mammals. He also observes one of the sloth’s weirdest behaviors: to answer the call of nature, it climbs all the way down to the ground.

Why do sloths go to all that trouble—and risk—just to poop? Well, according to a recent paper in Proceedings of the Royal Society, they do it to feed poop-eating moths that help cultivate nutritious algae in their fur. No, but really.

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The cost of attracting pollinators is … attracting everyone else

Flowers of Dalechampia scan dens, with key measurements indicated. Figure 1 of Perez-Barrales et al. (2013).

Flowers of Dalechampia scandens, with key measurements indicated. Figure 1 of Perez-Barrales et al. (2013).

Flowers that rely on animal pollinators to remix their genetic material have evolved a tremendous diversity of strategies for attracting those pollinators—from beguiling scents to elaborate visual displays to pretending to be a lady pollinator.

But there’s a downside to making a big, showy display to attract pollinators—you might also attract visitors who have less helpful intentions than gathering up some pollen and moving on to the next flower. Showy flowers might attract animals that steal the rewards offered to pollinators—or they might attract animals that eat the flowers themselves, or the developing seeds created by pollination. So the evolution of attractive floral displays might very well be a compromise between attracting the right visitors, and attracting the wrong ones.

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When the going gets tough, mutualism gets going

C. alliodora III

Cordia alliodora. Photo by Karen Blix.

Evolution by natural selection is not usually considered very peaceful—the “survival of the fittest” is usually assumed to come at the expense of competitors for food or shelter or other resources. But the “fittest” can also be those who recruit assistance from other individuals, or other species—and who provide assistance in return.

This was the perspective of Peter Kropotkin, a Russian prince and political anarchist who studied the wildlife of Siberia while working as an agent of the Czar’s government. In the harsh conditions of the Siberian winter, Kropotkin reported finding not a bitter struggle over scarce resources, but what he called “Mutual Aid” among species, as well as in the human settlements that managed to eke out a living.

Something like what Kropotkin described is documented in a new paper by Elizabeth Pringle and colleagues. Examining a protection mutualism between ants and the tropical Central American tree Cordia alliodora, Pringle et al. found that drier, more stressful environments supported more investment in the mutualism.

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