American Scientist

Some content in this issue’s printed pages really isn’t in these pages at all. This issue showcases a snippet of a digital feature, available in full only here on our website. The digital feature discusses the confusing behavior of wood ducks, a species that engages in nest parasitism, in which some ducks lay eggs in the nests of others. John M. Eadie and his colleagues have studied this wood duck behavior for decades, using radio-tracking tags, genetics, and videography to tease out the reasons a female would risk putting her eggs in the care of another bird. Is it nest scarcity, lack of experience, physiological stress, a way to increase reproductive output—or is it actually a form of cooperation? The preview (“Putting Eggs in Many Baskets”) gives you a sense of the article’s content, but be sure to go online for the full story and experience, which includes an array of photographs, videos, animations, and data visualizations. And then let us know what you think of the digital feature format. The online platform allows us to integrate multimedia into articles seamlessly, while providing what we hope is an engaging experience.

The development of understanding over time is a theme that comes up in “How Bacterial Pathogens Emerge,” by Salvador Almagro-Moreno. Given the countless number of bacteria and viruses out there, very few become pathogenic. Almagro-Moreno explains the different mechanisms by which a microorganism might gain the genetic material to become dangerous to humans, and the ways that genetic preadaptations might make some strains more receptive to gene incorporation. He also discusses the pathways that microorganisms have evolved to temper their uptake of genes, which can sometimes cause them more harm than good, and how predation on bacteria—by protozoa and amoebae, for example—can lead bacteria to develop evasion mechanisms that have the accidental side effect of increasing their ability to colonize human hosts.

Another convoluted story of discovery can be found in “How Glyphosate Cropped Up.” As Phillip A. Rea details, this ubiquitous herbicide, more commonly known as Roundup, came to be widely applied to crops worldwide before its mechanisms or its health effects were well understood. The compound itself was discovered in a circuitous fashion; initially it was explored as a potential water softener to prevent the buildup of limescale. Through a series of tests, attempts to optimize the compound, and the serendipitous discovery of a resistant bacterium in a wastewater pipe, chemists were able to tease apart the compound’s effects on a pathway found only in plants (a key enzyme in this process is shown above) and use that to best advantage in agricultural production.

Other articles in this issue detail a wide range of discoveries, from sharks’ electrosense (Perspective), to chemical mapping of organs to track pathogen accumulation and body symptoms (Technologue), to the history of the types of glass that were strong enough for lab experiments but found equal success in cookware (“The Chemical History of Superior Glass”). We hope you enjoy unraveling these discoveries with us. —Fenella Saunders (@FenellaSaunders)