Evolving invaders

This post is a guest contribution by Kathryn Turner, a PhD student at the University of British Columbia, who studies the evolution of invasive thistles. Kathryn writes about her scientific interests at the slyly named site Alien Plantation and tweets under the handle @KTInvasion.

ResearchBlogging.orgInvasive species are a big problem. A real big problem. In the US alone, invasive species cost nearly $120 billion in damages per year (Pimentel 2005). 42% of species on the Threatened and Endangered list are there primarily because of invasive species.

Which leaves us with two questions. First, most obviously, how is it that a species is able to come into a new environment that it is not adapted to, surrounded by new environmental conditions and foreign biological interactions, and thrive? Thrive so exaggeratedly, that it can out-compete and displace species which have been there for millennia, adapting precisely to those environmental conditions and biological interactions? How can an individual survive to propagate a population? How can any species accomplish this? Second, less obviously: why can’t more species do it? Humans transport animals and seeds (and spores and larvae, etc, etc) around all the time, but only 10% establish self-sustaining populations, and only 1% spread to new habitats, becoming potentially invasive; this is known as the ‘tens rule’ (Williamson 1993) – a funny ‘rule of thumb’ for which I could never quite figure out the math.

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Friday coffee break


Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.

From Sarah: For whales, taking in a mouthful of krill is more complicated than you might think.

A rorqual whale’s feeding lunge was “one of the largest biomechanical events on Earth”, said Dr Pyenson.

“This shows us how they do it so quickly, co-ordinating the inflation of the throat pouch with the opening of the jaws… and closing their mouth to prevent prey escaping – all in under 10 seconds.”

And from Jeremy: Will you live longer if you order an extra shot in that latte? Probably not.

During the time of the data collection (1995-2008), of the total 402,260 people, 52,515 of them died. At first blush, the risk of death (comparing the people who died to the people who didn’t and their demographics) was higher among the coffee drinkers.

But when you break it down, a large number of the heavy coffee drinkers (more than 2 cups/day) were also smokers, which is a very high risk of death in and of itself. When you controlled for the smokers, the authors got the OPPOSITE effect, this time coffee drinking (more than 2 cups per day), decreased the risk of mortality by 10% in males and 15% in females.

Ecological complexity breeds evolutionary complication

ResearchBlogging.orgIt is a truth universally acknowledged in evolutionary biology, that one species interacting with another species, must be having some effect on that other species’ evolution.

Actually, that’s not really true. Biologists generally agree that predators, prey, parasites, and competitors can exert natural selection on the other species they encounter, but we’re still not sure how much those interactions matter over millions of years of evolutionary history.

On the one hand, groups of species that are engaged in tight coevolutionary relationships are also very diverse, which could mean that coevolution causes diversity. But it could be that the other way around: diversity could create coevolutionary specificity, if larger groups of closely-related species are forced into narower interactions to avoid competing with each other.

Part of the problem is that it’s hard to study a species evolving over time without interacting with any other species—how can we identify the effect of coevolution if we can’t see what happens in its absence? If only we could force some critters to evolve with and without other critters, and compare the results after many generations …

Oh, wait. That is totally possible. And the results have just been published.

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Tell the White House: Make government-funded research open-access

As J.B.S. Haldane put it, “I think … that the public has a right to know what is going on inside the laboratories, for some of which it pays.” He was referring to the need for scientists to explain their work in popular media—which, amen, brother Jack!—but the point holds with regard to access to original scientific articles, too.

It doesn’t make much sense that U.S. citizens, whose taxes fund most of the basic science in this country, are then expected to pay upwards of $50 for a single PDF copy of a journal article presenting government-funded research results. The National Institutes of Health already requires that research it funds be archived online and accessible to the general public free of charge—why not expand that to all government-funded research? And hey, there’s a way to suggest exactly that out to the man in charge: a petition on WhiteHouse.gov.

We believe in the power of the Internet to foster innovation, research, and education. Requiring the published results of taxpayer-funded research to be posted on the Internet in human and machine readable form would provide access to patients and caregivers, students and their teachers, researchers, entrepreneurs, and other taxpayers who paid for the research. Expanding access would speed the research process and increase the return on our investment in scientific research.

The highly successful Public Access Policy of the National Institutes of Health proves that this can be done without disrupting the research process, and we urge President Obama to act now to implement open access policies for all federal agencies that fund scientific research.

It needs 25,000 virtual signatures within 30 days before it’ll get any meaningful attention, so sign this thing and then start badgering all your online “friends” about it, why don’t you? Especially the jerks who keep filling your update stream with branded product promotions and/or time-sucking adorable cat videos and/or news about how they’ve just spent real money for a virtual cow—post this directly on their “walls,” if those are even still a thing, with or without a witty and/or pleading comment appended.

I mean, it’s Monday morning; it’s not like you’re going to get do anything else for the benefit of humanity in the next minute or two, you slacker.

Friday coffee break

Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.

Simone is in the field at beautiful White Sands, New Mexico, and blogging about it.

The setting is White Sands, NM – an island of gypsum dunes slowly transforming and shifting through the Chihuahuan Desert. The protagonists are three species of small white lizards inhabiting these dunes. The story is recent and rapid evolution: changing ecology, natural selection, and speciation. Our attempt, as field biologists, is to tell that story.

Noah points us to NASA’s satellite images of the Columbia Glacier in southeastern Alaska, which, like a lot of glaciers these days, is getting smaller.

In 1986, the glacier’s terminus was just a few kilometers north of Heather Island. By 2011, it had retreated more than 20 kilometers (12 miles) to the north, moving past Terentiev Lake and Great Nunatak Peak. As the glacier has retreated, it has also thinned substantially, as shown by the expansion of brown bedrock areas. Rings of freshly exposed rock, known as trimlines, are prominent in the later image. Since the 1980s, the glacier has lost about half of its total thickness and volume.

Devin suggests a recent editorial in Science on the need to connect people with graduate-level science expertise to high school science education.

At any one time, there are thousands of U.S. Graduate Students with strong Science expertise and an interest in education who would be more than qualified to stem the critical shortage of secondary chemistry, physics, earth sciences, and biology teachers, but who will most likely never set foot in a high-school (precollege) classroom.

Sarah points out that the BBC has a treasure trove of video on adaptations for defense against predators. (The one titled “snake in the grass” is especially great. —Jeremy)

Friday Coffee Break

Maybe if you have that cup of coffee outdoors, you’ll do better next allergy season?

Every Friday at Nothing in Biology Makes Sense! our contributors pass around links to new scientific results, or science-y news, or videos of adorable wildlife, that they’re most likely to bring up while waiting in line for a latte.

From Noah: AntWeb is a comprehensive online resource for ant taxonomy and identification, with an “insanely awesome variety of ant morphologies expertly captured in focus-stacked photos.”
 Our mission is to publish for the scientific community high quality images of all the world’s ant species. As of May of 2012, AntWeb has 77510 ant images, of 18508 specimens representing over 8304 species. AntWeb provides tools for submitting images, specimen records, annotating species pages, and managing regional species lists.
From Sarah: A recent study of Finnish teenagers found that those living in the countryside had more diverse communities of bacteria living on their skin—wich was associated with lower sensitivities to allergens.

One type of gammaproteobacteria , calledAcinetobacter, was singled out as being “strongly linked to the development of anti-inflammatory molecules”.

“Basically, our study showed that the more you had of this particular gammaproteobacteria on your skin then you had a immunological response which is known to suppress inflammatory responses ( to pollen, animals etc).”

And from Jeremy: Your funiture is probably chock full of potentially toxic fire-preventing chemicals that don’t actually prevent fires, thank in large part to unbelievably dishonest lobbying by the companies that make the chemicals.

[Dr. David] Heimbach’s passionate testimony about the baby’s death made the long-term health concerns about flame retardants voiced by doctors, environmentalists and even firefighters sound abstract and petty.

But there was a problem with his testimony: It wasn’t true.

Records show there was no dangerous pillow or candle fire. The baby he described didn’t exist.

On Molecular Genetics and the Origin of the Polar Bear.

Polar bear

Understanding the history of species is critical to understanding evolutionary processes and for making predictions about how biodiversity will fare in a rapidly changing climate. Information about how species are related (phylogeny) and how their populations have responded to past climate change (historical demography) can inform us about the conditions under which they have evolved and adapted, and how they might respond to changes currently under way.

Modern scientists get at these questions by examining two types of data: the fossil record and patterns of DNA sequence variation. The fossil record is relatively straightforward. You find a fossil in location X. You identify it as species Y and you use some method to (e.g. radiocarbon dating) to infer it was there at time Z. Making inferences from DNA sequence variation, by contrast, involves complex, computer-intensive statistical analyses, and the field is in a state of tumultuous, rapid advance.

A fascinating case study that involves the integration of fossils and DNA sequence data, and illustrates the ways in which rapid statistical advances are changing our understanding of species’ evolutionary histories is that of the origin of the polar bear (Ursus maritimus).

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