Below are six biological wonders that should help to confirm the sophisticated intelligence of nature. They are a mere sample of what we are discovering about the animals and plants that share this planet with us, a reminder that is particularly appropriate since our behaviour has initiated the sixth major extinction event in Earth’s history.
• Of the 790 neurons that paper wasps use to identify familiar objects, 35 are specifically designed to identify the individual face patterns on their fellow wasps. These neurons are similar in design to those in primates, including humans, that perform the same function. This evidence suggests that paper wasps can recognize other individual wasps based on their distinctively coloured facial markings. (New Scientist, Dec. 1/24.)
• An ant with an injured leg can have that leg amputated by other ants before an infection can spread to its body and result in its death. The surgeon ants can distinguish between different leg injuries in order to amputate accordingly. Some ant species apply antimicrobial compounds to the wounds of nest-mates to reduce the risk of infection (New Scientist, July 2/24). Red wood ants, a genus of Formica, carry chunks of tree resin to their nests, spray it with their formic acid excretions to enhance the antimicrobial properties, and then distribute small pieces to reduce the growth of unwanted pathogens (National Geographic, February 2025).
• Cyanobacteria, one of the simplest forms of life, seem to have a memory that protects them from approaching cold weather. When a sample of bacteria has been exposed to shorter periods of light, an indication of approaching winter, the spawned progeny of that bacteria survive two to three times better in subsequent freezing weather. But this advantage only occurs four to six days later, even though the cyanobacteria spawn a new generation every few hours. This means that the experience of shorter days must be remembered through several generations. Cyanobacteria have existed for about 2 billion years, so they have had lots of time to learn the survival strategy. (New Scientist, Sept. 14/24).
• A particular breed of cucumber is able to fire its seeds many metres away by building up hydrologic pressure within its fruit. The explosion is so fast that it can barely be seen with the naked eye. Amazing as this is, even more amazing is the plant’s behaviour prior to the actual firing. Since the fruit dangles vertically from the end of its vine, its ejected seeds would normally only travel horizontally, which would not maximize the distance the seeds could reach. So prior to dropping its fruit, the cucumber pumps hydrologic pressure into its attaching stem, drawing the fruit up to the 45 degree angle that is needed for maximum trajectory distance. Then, at the precise moment that the fruit releases on its fall to the ground, before it has had time to lose its opportune height and angle, the seeds are fired. (Quirks and Quarks, CBC Radio, December 7/24.)
• Various mollusc species cultivate algae inside their shells because these primitive plants can use photosynthesis to make sugars for them. The problem for the molluscs, however, is that the algae needs sunlight to generate the sugars, and not much is available inside a closed shell. Most molluscs solve this problem by opening their shells sufficiently to let in enough light for the algae to thrive, but this is a risky strategy. The heart cockle has a more ingenious solution. It has tiny transparent windows in its shell that act like fibre optic tubes. Crystals of aragonite let in light and the chitin “cladding” directs it to the cockle’s tissue where the algae live. They get the light that they need for photosynthesis in exchange for a safe place to live, and the cockle gets its sugars from its symbiotic relationship with the algae. As an added benefit, the aragonite crystals filter out the ultraviolet that might harm both the cockle and the algae. (The Economist, “Bivalve Broadband”, November 2/24.)
• Green sea turtles (Chelonia mydas) travel thousands of kilometres at sea from their feeding areas to their natal beaches by using the unique magnetic configurations that are imprinted on the young turtles as hatchlings. When they have extricated themselves from their shells, the hatchlings then have to make their way upward through many centimetres of sand, an arduous process that can take one to four days of “swimming”. Tiny accelerometers, attached to their backs by scientists, indicate that they spend at least 67% of their time moving vertically in “minute-long bursts of activity.” Then, when the hatchlings near the surface, in a magical choreography of genetic sophistication, they move only at night, which is when they emerge out of the sand to minimize the risk of predation (New Scientist, October 5/24).
Ray Grigg for Sierra Quadra
Top image credit: green turtle – photo by Bernard Dupont via Flickr (CC BY-SA 2.0)