This is a guest post by Darlene Cavalier, a writer and senior adviser at Discover Magazine. Darlene holds a Masters degree from the University of Pennsylvania, and is a former Philadelphia 76ers cheerleader. She founded ScienceCheerleader.com and cofounded ScienceForCitizens.net to make it possible for lay people to contribute to science. Happy Thursday. Very pleased to be filling in for Sheril this month. These are big shoes to fill, to say the least. During my time with you, I hope my writings provide a bit of inspiration, provocation, or, failing that, some entertainment to brighten your day. All I ask in return is that you keep doing what you do so well here: share your ideas and comments. Some of you (two, three?) may know me as the Science Cheerleader, a persona who advocates--and creates mechanisms--for public participation in science and science policy. These are broad terms with multiple definitions, depending on the author's intention. Let's dive right into one of this author's intentions: to create a way for citizens and experts to participate in assessments of emerging technologies. Citizens, your time has come! On this day in history, Aretha Franklin released her hit song, Respect. And on THIS day, respect for your ...

After years of serving as your faithful companion to ball games and keeping the brewskies frosty at backyard barbecues, your trusty beer cooler now has a new assignment--cooking up a gourmet meal, sous-vide style. For those of you who don't keep up with high-tech cookery, sous-vide is a method of cooking where food is heated for an extended period at relatively low temperatures. Unlike a slow cooker or Crock pot, the sous-vide process uses airtight plastic bags placed in hot water well below boiling point (usually around 140 Fahrenheit). The idea is to maintain the integrity and flavor of the food without overcooking it (but while still killing any bacteria that may be present). Normally, a sous-vide cooker like the Sous-Vide Supreme would set you back hundreds of dollars, but chef J. Kenzi Lopez-Alt shows us how to use a beer cooler to cook a perfect piece of meat. All you have to do is fill up your beer cooler with water a couple of degrees higher than the temperature you'd like to cook your food at (to account for temperature loss when you add cold food to it), seal your food in a simple plastic Ziplock bag, drop it in, and close ...

Over the last few days, estimates had held that the Gulf of Mexico oil spilling was leaking about 1,000 barrels, or 42,000 gallons, into the water each day—bad, but still not historically bad on a scale like the spill caused by the Exxon Valdez. Except now, after closer investigation, the National Oceanic and Atmospheric Administration says that oil company BP’s estimate might in fact be five times too low.

Rear Adm. Mary Landry, the Coast Guard’s point person, gave the new estimate yesterday as the Coast Guard began its planned controlled burn of some of the oil. While emphasizing that the estimates are rough given that the leak is at 5,000 feet below the surface, Admiral Landry said the new estimate came from observations made in flights over the slick, studying the trajectory of the spill and other variables [The New York Times]. Because the oil below the surface is so hard to measure or estimate, NOAA’s numbers are still rough estimates, too. BP’s chief operating officer told ABC News he thinks the number is probably somewhere between the two estimates.

But if NOAA’s high-end number right, the oil spill caused by the explosion and sinking of the Deepwater Horizon just entered a new class of awful. Do the math: At the previous estimation—1,000 barrels (42,000 gallons) of oil per day—it would have taken this spill 261 days, or more than eight continuous months, to dump as much oil into the sea at the Exxon Valdez did near Alaska in 1989. But, if it’s true that 5,000 barrels (210,000 gallons) are entering the Gulf each day, it would take just 53 days to top the Valdez’ total of 11 million gallons. Already 9 days have passed since the explosion.

While the Coast Guard commenced burning off some of the oil to try to keep the worst of it away from American shorelines, and BP’s attempted to reach emergency valves with undersea robots, company CEO Tony Hayward is preparing a new strategy. The London-based Hayward was in Louisiana on Wednesday looking at progress in fabricating a 100-ton steel dome the company hopes to lower over the oil leak. The dome could be ready by the weekend, but it would take two to four weeks to put it in place, if that can be done at all. The dome would funnel oil, natural gas and seawater into a pipe leading to a floating processing and storage facility [Washington Post]. But while this has been done in a few hundred feet of water before, the Gulf oil spill emanates from thousands of feet below.

Related Content:
80beats: Coast Guard’s New Plan To Contain Gulf Oil Spill: Light It on Fire
80beats: Sunken Oil Rig Now Leaking Crude; Robots Head to the Rescue
80beats: Ships Race To Contain the Gulf of Mexico Oil Spill
80beats: Obama Proposes Oil & Gas Drilling in Vast Swaths of U.S. Waters
80beats: 21 Years After Spill, Exxon Valdez Oil Is *Still* Stuck in Alaska’s Beaches

Image: NOAA

On Friday at our Harvard Kennedy School event, I'm going to be giving my rather pessimistic take--already laid out in Unscientific America, and only amplified by "ClimateGate" and other events since then--on the science blogosphere. I'll talk about how in comparison with the old media, the Internet fragments and narrows the audience for science information, even as there aren't really any norms for responsible conduct--and thus, misinformation, innuendo, and general nastiness abound. I'm sure, however, that others will have a different view. Perhaps Joe Romm will; he has just joined our roster for the event. Certainly, his blog has been a major success and demonstrates many of the upsides of science blogging. Such debate is all to the good; it's why we're having the event in the first place. Indeed, I myself will point out some clear positives when it comes to blogging about science (I'm sure you can guess many of them). But taken as a whole, are blogs broadening the conversation about science by reaching new audiences, replacing what has been lost in terms of science coverage in the old media, or elevating our general science discourse? I have to say, I'm skeptical. There is no going back from this new world, but ...

Dr. Daniel MacArthur pointed me to this story, Conn. woman alleges genetic discrimination at work:

A Connecticut woman who had a voluntary double mastectomy after genetic testing is alleging her employer eliminated her job after learning she carried a gene implicated in breast cancer.

Pamela Fink, 39, of Fairfield said in discrimination complaints that her bosses at natural gas and electric supplier MXenergy gave her glowing evaluations for years, but targeted, demoted and eventually dismissed her when she told them of the genetic test results.

Her complaints, filed Tuesday with the U.S. Equal Opportunity Commission and Connecticut Commission on Human Rights and Opportunities, are among the first known to be filed nationwide based on the federal Genetic Information Nondiscrimination Act.

What probability do readers put in regards to this being a legitimate complaint? This seems a large firm, so I doubt that group insurance rates would change because of one person (I have heard of this occurring in small businesses where an expensive employee or employee’s family member can effect the rate for everyone else). So if it is legitimate the main issue would have been their fear of future illness, but the woman in question went through a double mastectomy, which I assume would obviate that concern. What am I missing? Are there expectations that she’d be taking medical leave in the future due to follow up operations or treatment?

Update: Brendan Maher has some follow up from Fink’s lawyer.

Change is quite in the air today, whether it be climate change or human induced habitat shifts. What’s a species in the wild to do? Biologists naturally worry about loss of biodiversity a great deal, and many non-biologist humans rather high up on Maslow’s hierarchy of needs also care. And yet species loss, or the threat of extinction, seems too often to impinge upon public consciousness in a coarse categorical sense. For example the EPA classifications such as “threatened” or “endangered.” There are also vague general warnings or forebodings; warmer temperatures leading to mass extinctions as species can not track their optimal ecology and the like. And these warnings seem to err on the side of caution, as if populations of organisms are incapable of adapting, and all species are as particular as the panda.

That’s why I pointed to a recent paper in PLoS Biology, Adaptation, Plasticity, and Extinction in a Changing Environment: Towards a Predictive Theory below. I am somewhat familiar with one of the authors, Russell Lande, and his work in quantitative and ecological genetics, as well as population biology. I was also happy to note that the formal model here is rather spare, perhaps a nod to the lack of current abstraction in this particular area. Why start complex when you can start simple? Here’s their abstract:

Many species are experiencing sustained environmental change mainly due to human activities. The unusual rate and extent of anthropogenic alterations of the environment may exceed the capacity of developmental, genetic, and demographic mechanisms that populations have evolved to deal with environmental change. To begin to understand the limits to population persistence, we present a simple evolutionary model for the critical rate of environmental change beyond which a population must decline and go extinct. We use this model to highlight the major determinants of extinction risk in a changing environment, and identify research needs for improved predictions based on projected changes in environmental variables. Two key parameters relating the environment to population biology have not yet received sufficient attention. Phenotypic plasticity, the direct influence of environment on the development of individual phenotypes, is increasingly considered an important component of phenotypic change in the wild and should be incorporated in models of population persistence. Environmental sensitivity of selection, the change in the optimum phenotype with the environment, still crucially needs empirical assessment. We use environmental tolerance curves and other examples of ecological and evolutionary responses to climate change to illustrate how these mechanistic approaches can be developed for predictive purposes.

Their model here seems to be at counterpoint to something called “niche modelling” (yes, I am not on “home territory” here!), which operates under the assumption of species being optimized for a particular set of abiotic parameters, and focusing on the shifts of those parameters over space and time. So extinction risk may be predicted from a shift in climate and decrease or disappearance of potential habitat. The authors of this paper observe naturally that biological organisms are not quite so static, they exhibit both plasticity and adaptiveness within their own particular life history, as well as ability to evolve on a population wide level over time. If genetic evolution is thought of as a hill climbing algorithm I suppose a niche model presumes that the hill moves while the principal sits pat. This static vision of the tree of life seems at odds with development, behavior and evolution. The authors of this paper believe that a different formulation may be fruitful, and I am inclined to agree with them.

As I observed above the formalism undergirding this paper is exceedingly simple. On the left-hand side you have the variable which determines the risk, or lack of risk, of extinction more or less, because it defines the maximum rate of environmental change where the population can be expected to persist. This makes intuitive sense, as extremely volatile environments would be difficult for species and individual organisms to track.Too much variation over a short period of time, and no species can bend with the winds of change rapidly enough. Here are the list of parameters in the formalism (taken from box 1 of the paper):

?_c – critical rate of environmental change: maximum rate of change which allows persistence of a population

B – environmental sensitivity of selection: change in the optimum phenotype with the environment. It’s a slope, so 0 means that the change in environment doesn’t change optimum phenotype, while a very high slope indicates a rapid shift of optimum. One presumes this is proportional to the power of natural selection

T – generation time: average age of parents of a cohort of newborn individuals. Big T means long generation times, small T means short ones

?² – phenotypic variance

h² – heritability: the proportion of phenotypic variance in a trait due to additive genetic effects

r_max intrinsic rate of increase: population growth rate in the absence of constraints

b – phenotypic plasticity: influence of the environment on individual phenotypes through development. Height is plastic; compare North Koreans vs. South Koreans

? – stabilizing selection: this is basically selection pushing in from both directions away from the phenotypic optimum. The stronger the selection, the sharper the fitness gradient. Height exhibits some shallow stabilizing dynamics; the very tall and very short seem to be less fit

Examining the equation, and knowing the parameters, some relations which we comprehend intuitively become clear. The larger the denominator, the lower the rate of maximum environmental change which would allow for population persistence, so the higher the probability of extinction. Species with large T, long generation times, are at greater risk. Scenarios where the the environmental sensitivity to selection, B, is much greater than the ability of an organism to track its environment through phenotypic plasticity, b, increase the probability of extinction. Obviously selection takes some time to operate, assuming you have extant genetic variation, so if a sharp shift in environment with radical fitness implications occurs, and the species is unable to track this in any way, population size is going to crash and extinction may become imminent.

On the numerator you see that the more heritable variation you have, the higher ?_c. The rate of adaptation is proportional to the amount of heritable phenotypic variation extant within the population, because selection needs variance away from the old optimum toward the new one to shift the population central tendency. In other words if selection doesn’t result in a change in the next generation because the trait isn’t passed on through genes, then that precludes the population being able to shift its median phenotype (though presumably if there is stochastic phenotypic variation from generation to generation it would be able to persist if enough individuals fell within the optimum range). The strength of stabilizing selection and rate of natural increase also weight in favor of population persistence. I presume in the former case it has to do with the efficacy of selection in shifting the phenotypic mean (i.e., it’s like heritability), while in the latter it seems that the ability to bounce back from population crashes would redound to a species’ benefit in scenarios of environmental volatility (selection may cause a great number of deaths per generation until a new equilibrium is attained).

Of course a model like the one above has many approximations so as to approach a level of analytical tractability. They do address some of the interdependencies of the parameters, in particular the trade-offs of phenotypic plasticity. In this equation 1/?²_b quantifies the cost of plasticity, r₀ represents increase without any cost of plasticity. We’re basically talking about the “Jack-of-all-trades is a master of none” issue here. In a way this crops up when we’re talking of clonal vs. sexual lineages on an evolutionary genetic scale. The general line of thinking is that sexual lineages are at a short-term disadvantage because they’re less optimized for the environment, but when there’s a shift in the environment (or pathogen character) the clonal lineages are at much more risk because they don’t have much variation with which natural selection can work. What was once a sharper phenotypic optimum turns into a narrow and unscalable gully.

Figure 2 illustrates some of the implications of particular parameters in relation to trade-offs:

There’s a lot of explanatory text, as they cite various literature which may, or may not, support their model. Clearly the presentation here is aimed toward goading people into testing their formalism, and to see if it has any utility. I know that those who cherish biodiversity would prefer that we preserve everything (assuming we can actually record all the species), but reality will likely impose upon us particular constraints, and trade-offs. In a cost vs. benefit calculus this sort model may be useful. Which species are likely to be able to track the environmental changes to some extent? Which species are unlikely to be able to track the changes? What are the probabilities? And so forth.

I’ll let the authors conclude:

Our aim was to describe an approach based on evolutionary and demographic mechanisms that can be used to make predictions on population persistence in a changing environment and to highlight the most important variables to measure. While this approach is obviously more costly and time-consuming than niche modelling, its results are also likely to be more useful for specific purposes because it explicitly incorporates the factors that limit population response to environmental change.

The feasibility of such a mechanistic approach has been demonstrated by a few recent studies. Deutsch et al…used thermal tolerance curves to predict the fitness consequence of climate change for many species of terrestrial insects across latitudes, but without explicitly considering phenotypic plasticity or genetic evolution. Kearney et al…combined biophysical models of energy transfers with measures of heritability of egg desiccation to predict how climate change would affect the distribution of the mosquito Aedes aegiptii in Australia. Egg desiccation was treated as a threshold trait, but the possibility of phenotypic plasticity or evolution of the threshold was not considered. These encouraging efforts call for more empirical studies where genetic evolution and phenotypic plasticity are combined with demography to make predictions about population persistence in a changing environment. The simple approach we have outlined is a necessary step towards a more specific and comprehensive understanding of the influence of environmental change on population extinction.

Citation: Chevin L-M, Lande R, & Mace GM (2010). Adaptation, Plasticity, and Extinction in a Changing Environment: Towards a Predictive Theory PLoS Biol : 10.1371/journal.pbio.1000357