Pounds,J. 2006. Widespread amphibian extinctions from epidemic disease driven by global warming. Nature 439: 161-167.
Handwerk, B. 12 January 2006. "Frog Extinctions Linked to Global Warming". National Geographic News. Accessed 10 October 2011.
1) What specific claim(s) does the news article make about the study? That is, what did the news article say was discovered? For each claim, indicate if the original paper actually makes that claim.
In the news article “Frog Extinctions Linked to Global Warming” by Brian Handwerk of the National Geographic News, the claim is made that Global Warming may be causing widespread amphibian extinctions by triggering lethal species epidemics. This article is taken from the paper “Widespread amphibian extinctions from epidemic disease driven by global warming” by J Alan Pounds et al. The paper makes the claim that a recent mass extinction associated with pathogen outbreaks is tied to global warming. Seventeen years ago, in the mountains of Costa Rica, the Monteverde harlequin frog vanished along with the golden toad. Based on the timing of the species loss in relation to changes in sea surface and air temperatures the study claimed with 99% confidence that the large scale warming of the area from climate change in the past century is the key factor in the disappearances. The warming temperatures are better for the infectious Batrachochytrium and thus is encouraging outbreaks and the propagation of the disease. (Pounds, 2006) The article makes the claim that “Amphibian skin is extremely thin, which makes frogs acutely sensitive to even minor changes in temperature, humidity, and air or water quality. It also makes frogs more susceptible to chytrid fungus.” (Handwerk, 2006) This claim is supported in the paper and is accurate with the papers findings. The article also takes from the paper that global warming has increased evaporation in the tropical mountains of the Americas, which in turn has promoted cloud formation. In turn this cloud cover may have actually decreased daytime temperatures by blocking sunlight as well as serving as an insulating blanket to raise nighttime highs. The article goes on to say that Pounds believes the combination has created ideal conditions for the spread of the frog-killing fungus, which grows and reproduces best at temperatures between 63° and 77°F (Handwerk, 2006).
2) Most technical papers have a "Conclusions" section (often labeled as such). Find this section. Are the items which the original authors highlighted as conclusions of their study discussed in the news article? Indicate "yes" or "no", giving your evidence.
Yes the news article by National Geographic was very thorough in their summary of the paper and its findings. In the paper it is established that climate change is causing the mass extinction of species as well as that climate driven epidemics are an immediate threat to biodiversity. The paper found that large scale warming was the cause of this epidemic in the amphibians and points to a chain of events where this warming accelerates disease development by translating into local temperature shifts beneficial to the infectious disease and its propagation. The paper describes how the products of a warming atmosphere including an intensification of the hydrological cycle together with aerosol pollution are influencing patterns of cloud formation altering the thermal, light, and moisture environments of organisms and threatening species.
3) Most technical papers will describe the uncertainty around their conclusions and discoveries, often discussed in a section labeled "Discussion." Does the original paper describe the degree of confidence the scientists have in their discoveries? If so, describe this, and indicate whether or not the news article also discusses the degree of uncertainty.
The news article takes the uncertainty side of the paper to the next level devoting an entire section to the uncertainty of the claim; “Cynthia Carey, an amphibian-disease expert at the University of Colorado, warns that the study may have shown a circumstantial correlation between temperature data and amphibian deaths. But the report has not shown cause and effect.” (Handwerk, 2006) The article then proceeds to go into details of Careys claims on this matter and reasons for uncertainty in the causal relationship. The argument by Carey is completely valid saying that just because extinction levels and global warming are correlated does not lend itself to correlation because there could be other issues causing it. In the actual paper, alternate hypothesis are proposed and then put to the side with the papers hypothesis on the extinction highlighted as the more plausible reason with 99% (very high) confidence. The alternate hypothesis is that elevation and species sensitivity based on habitat range that frog species can handle is a large cause of the species decline. While this is mentioned in the paper as being a part of the issue the researchers mention that this species vulnerability is there and global warming and the widespread results of global warming are causing the species decline. Global warming affects a network of factors in the ecosystem with intertwined feedback's systems all that are related to climate change and are affecting the species living in the affected areas. While this hypothesis is strongly supported with evidence in the paper there is much that we still do not know about climate change and its feedback's and while this species decline in frogs could be a direct effect of this there is a lot of uncertainty in the correlation between these two factors.
4) It is the job of the news reporter to make whatever item they are reporting on relevant to some larger issue or set of issues; in contrast, a technical paper is often much more focused and may not deal with broader implications of the work. Do you find examples of the reporter discussing "broader implications" not present in the original paper? If so, describe them. Additionally, if so, indicate whether you (as a reader) can see that this broader implication actually does follow from the conclusions of the study.
The broader issue touched on by the article is the importance of biodiversity and the problem we are facing in this day and age with biodiversity loss - "Global warming is wreaking havoc on amphibians and will cause staggering losses of biodiversity if we don't do something fast." (Handwerk, 2006) By doing this the reporter is making the article more accessible to the general public by bringing up a pending issue in the field of environmental science and making the paper more relevant to the big ticket issues in environmental science. The article quotes from Pound that "Disease is the bullet killing frogs, but climate change is pulling the trigger.” (Handwerk, 2006) In other words climate change is the underlying factor that is causing the increase in species extinction in the frogs. This climate change is also a large factor is the biodiversity loss due to species being forced out of their habitable zone by temperature and climate fluxes which was found to be the case in the study the paper outlines.
5) In some technical paper the original scientists might describes previous contradictory work of previous research (often in the "Introduction"), which they presumably consider their new work has overturned. If so, does the news article reflect that this study has resulted in the rejection of a previous hypothesis?
The previous contradictory work that the study mentions are all interconnected to the problem of climate change and thus global warming. All the proposed alternate hypothesis from elevation sensitivity, to pathogen intensification can all be traced back to their theory of the warming climate causing an increase in the vulnerability of these delicate frog species to pathogens which are being enhanced and propagated faster by this warming climate. The article goes into the fact that is new study supports the cause of extinction but it also brings up criticisms of the paper from other scientists and highlights the uncertainty in the paper.
6) Journalists very often couch science news items as "debates between equal sides", even if the weight of the evidence is not equal. Does the news article discuss alternative hypotheses that are not mentioned in the original paper? If so, does the news article give a measure of what degree of evidential support exists for either of the alternative models?
The article brings up other studies that support the findings such as “A two-year-old study by a scientist at Britain's University of Leeds suggests that some 15 to 35 percent of land-dwelling plants and animals, or about a million species, would be extinct or committed to extinction by 2050.”(Handwerk, 2006) which promotes global warming as being the underlying reason for species extinction and biodiversity loss worldwide. The article brings up the fact that global warming has been predicted to cause such effects in species and this study on amphibians is a case study for this and example of this theory becoming realized on the species scale.