Evolution

Look closely at a plant in your local park, your garden or even your kitchen, and you’re likely to see some damage. Whether a caterpillar has chewed away part of a leaf or a mealybug is sucking on sap, animals are constantly feeding on plants. Of course, herbivory, or plant predation, is not ideal for a plant’s survival. So plants have evolved many different defense mechanisms to inhibit this threat, including physical and chemical weapons. For example, cactuses arm their bodies with skin-piercing spines. Herbs such as mint, lavender and rosemary produce volatile scent compounds that can help deter herbivores. Other plants resort to bribing personal bodyguards by secreting thick, sweet nectar. Nectar is most commonly associated with flowers, where it is used to entice bees, birds or butterflies to move pollen from one flower to another. But other plants produce different types of nectar glands called extrafloral nectaries. Plants produce these glands to bribe ants...

Humans have long been fascinated by organisms that can produce light. Aristotle, who was a scientist as well as a philosopher, wrote the first detailed descriptions of what he called “cold light” more than 2,000 years ago. More recently, pioneering researchers like World War II Army veteran Emmett Chappelle and deep submergence vehicle pilot Edith Widder advanced the study of this phenomenon with novel technologies. At least 94 living organisms produce their own light through a chemical reaction inside their bodies – an ability called bioluminescence. Examples include luminous fireflies, algae that create “glow-in-the-dark” bays, small crustaceans with intricate courtship displays, and deep-sea fish and coral. Yet despite its widespread occurrence, scientists don’t yet know when or where it first emerged, or its original function. As marine biologists who specialize in deep-sea habitats, we know that bioluminescence is particularly common i...

In the wake of North America’s recent solar eclipse, another historic natural event is on the horizon. From late April through June 2024, the largest brood of 13-year cicadas, known as Brood XIX, will co-emerge with a midwestern brood of 17-year cicadas, Brood XIII. This event will affect 17 states, from Maryland west to Iowa and south into Arkansas, Alabama and northern Georgia, the Carolinas, Virginia and Maryland. A co-emergence like this of two specific broods with different life cycles happens only once every 221 years. The last time these two groups emerged together was in 1803, when Thomas Jefferson was president. For about four weeks, scattered wooded and suburban areas will ring with cicadas’ distinctive whistling, buzzing and chirping mating calls. After mating, each female will lay hundreds of eggs in pencil-size tree branches. Then the adult cicadas will die. Once the eggs hatch, new cicada nymphs will fall from the trees and burrow back underground, st...

Human-driven climate change is increasingly shaping the Earth’s living environments. Rising temperatures, rapid shifts in rainfall and seasonality, and ocean acidification are presenting altered environments to many animal species. How do animals adjust to these new, often extreme, conditions? Animal nervous systems play a central role in both enabling and limiting how they respond to changing climates. Two of my main research interests as a biologist and neuroscientist involve understanding how animals accommodate temperature extremes and identifying the forces that shape the structure and function of animal nervous systems, especially brains. The intersection of these interests led me to explore the effects of climate on nervous systems and how animals will likely respond to rapidly shifting environments. All major functions of the nervous system – sense detection, mental processing and behavior direction – are critical. They allow animals to navigate their e...

Climate change is threatening the survival of plants and animals around the globe as temperatures rise and habitats change. Some species have been able to meet the challenge with rapid evolutionary adaptation and other changes in behavior or physiology. Dark-colored dragonflies are getting paler in order to reduce the amount of heat they absorb from the sun. Mustard plants are flowering earlier to take advantage of earlier snowmelt. Lizards are becoming more cold-tolerant to handle the extreme variability of our new climate. However, scientific studies show that climate change is occurring much faster than species are changing. Zebrafish have evolved to thrive in water a degree or so warmer than normal, but they struggle to survive at higher temperatures. isoft/E+ Getty Images What is evolutionary adaptation? The word “adaptation” is used in many ways by climate scientists, but it has a...