sloppy science journalism

This science news in USA Today pissed me off. I am a dogged champion of the idea that insect wings evolved as an aquatic structure. When I read about "two" competing theories of wing evolution I know someone will come up short.

One theory, as Dan Vergano wrote, is "wings are brand new features" that evolved from an insect's shell. The other is that they are modifications of legs. In truth, there are other theories and many possible ways wings may have evolved.

Deciphering evolutionary history from available evidence is science with a dose of art. Pretending only two ideas exist about how wings evolved cuts out the art; vastness of the data set limits understanding of the science. The result is a worn nub of a narrative that misses the best tale: wings were swimming organs long before they became aerial appendages.

Once I read the abstract of the article, I saw my beloved aquatic theory. The omission was in the reporting, not the science. The authors studied mayflies because their tracheal gills are a likely precursors to wings. They concluded that wings grow when regulatory genes triggering leg growth and gill growth are both expressed, affirming the theory that abdominal gills begat thoracic wings as mayflies radiated into fresh waters almost a half billion years ago.

The authors also studied bristletails, a wingless insect that is an ancestor of mayflies. If you could go back a half billion years and watch for a few hundred million, you'd see tiny silverfishy things slithering into fresher water and drier habitats, breathing through gills, then flapping gills, then flapping thoracic gills built for power, which became wings.


This is a dragonfly, an early offshoot of the mayfly lineage. Mayflies spawned all insect lineages.

brake in the storm

While assessing the risks and pace of climate change remains a difficult task, our core understanding of the physics and chemistry of the atmosphere grows ever more complete. Last month a new study was published that helps explain why surface air temperatures have not increased as rapidly over the past decade as have ocean temperatures. According to NOAA researcher Susan Solomon and colleagues, the stratosphere has dried by about 10 percent since 2000, resulting in a 25 percent decline in surface temperature relative to what would have been without the drying effect. The Economist published a good review of the paper.

This research is largely observational. The authors are not sure why less water vapor passed through the tropopause into the stratosphere, and this will surely become an object of study. Climate scientists suspect that increased thunderstorm activity in the tropics caused the drying, with more water vapor exiting the troposphere as rain rather than rising into the stratosphere. Why there were more thunderstorms is not known, but increased variability in weather is one of the basic predictions of global warming.

Atmospheric heat can either dissipate into the oceans and land or it can get converted to entropy. Storms are weather patterns that become organized, thus they represent energy becoming organized into entropy. The most persistent and destructive effect of global warming is thermal expansion of the oceans. Most of the heat that has accumulated in the past century has wound up in the oceans, not the atmosphere, and sea level rise threatens people and economies more than storms. More frequent and powerful storms are a bad thing, but this new study shows there may be a silver lining in those storm clouds. They consume energy and act as a buffer against warming.