Some biology etymology

for the curious, and useful in dinner party chat.

Canopy cover is vital in arboriculture, in description of those overhead limbs that weave together and block some of the sun’s rays, but what about those trees whose branches seem to avoid touching those of other trees? Do they actually exist? There are several. The phrase describing them is crown shyness, and it takes place in some forests, particularly those with lodgepole pines, eucalyptus, mangroves and some other tropical trees. Why? Botanists don’t have an answer yet, but it might have to do with a far-red (one down from infra-red) light reflected from neighborhood foliage which makes twigs at the end of branches shy away from each other.

On a completely different note, two unrelated  creatures have a similar problem and thus develop similar solutions. Like porcupines (rodents) and hedgehogs (insectivores). Convergent evolution describes how they develop similar spines. You knew that, probably.

Dewlap is a word Dickens might utilize to describe the chins of an elderly person to comical effect, but in biology it refers to the wobbly flap of skin under the chin of large herbivores such as the moose, eland – African antelope —  or kouprety — a rare species of wild cattle in Asia. Iguanas also have dewlaps that fold up until they need to inflate them to impress females. As if they’re not cool enough already.

The cute little worm lizard, termed an amphisbaenian, is blind and legless, and neither worm nor lizard. What it has is a sharp set of teeth, and it belongs to a distinct set of reptiles found mainly in Africa and the Americas. They spend their lives burrowing under the ground. Fun! Some scientists believe they are closely related to the ancestors of mammals.

Conservationists sometimes seem to focus a little too heavily on flagship species such as the giant panda or wolves or elephants in order to gain funding. No matter how tired you might be of panda appeals (or maybe you’re not and never will be sick of pandas) it’s a good thing. The protection of their habitats protect less charismatic threatened mammals, amphibians and bird.

Batesian mimicry occurs when a harmless insect, say the marmalade hoverfly,  mimicks the markings of more dangerous insects like wasps and bees to gain protection by association. I know they would fool me. Named for Norman Bates?

Spiders and scorpions have book lungs, their way of extracting oxygen from their surroundings and expelling carbon dioxide. These are enclosed in under-body pouches that resemble a loosely bound book – it’s thought that they evolved from the underside of an aquatic ancestor resembling horseshoe crabs. Are horseshoe crabs edible? Just an idle query.

Scientists have described it as the single most important event in anyone’s life: gastrulation, the moment when a simple cluster of cells folds in on itself to produce a gut, a front and back end, and the basic tissue types. In vertebrates (us, but also creatures like the starfish) that first dent in the cluster’s surface becomes the anus. In everything else it becomes the mouth.