Wild Things: Life as We Know It
Earth’s Orbit and Mammalian Evolution
Every 1 million years, Earth’s tilt shifts, and every 2.5 million years, its orbit becomes rounder. These wobbles have a profound impact on mammalian evolution. A study from Utrecht University in the Netherlands found that extinctions of rodent species in Spain coincided with these orbital changes. The cooling effect of these wobbles in the Northern Hemisphere may be a contributing factor to these extinctions.
Genetic Inheritance of Facial Expressions
Common sense suggests that facial expressions are primarily learned from parents. However, a study from the University of Haifa in Israel challenges this notion. Researchers filmed interviews with congenitally blind people and found that their facial expressions were remarkably similar to those of their close relatives. This suggests that frowns, smiles, and scowls may have a genetic basis.
Zebra Tarantulas’ Silky Secret
While studying zebra tarantulas, researchers in Germany discovered an unexpected phenomenon: silky footprints. These footprints were not produced by the tarantulas’ abdominal silk glands, but by tiny structures on their feet. This discovery indicates that these hefty spiders use silk for traction on slippery rainforest leaves.
Parasitic Plants: The Plant Kingdom’s Sniffer Dogs
Cuscuta pentagona, a parasitic plant known as dodder, has a remarkable ability to detect airborne chemicals emitted by its preferred host, the tomato plant. This “sniffing” ability, discovered by researchers at Pennsylvania State University, allows dodder seedlings to locate their hosts quickly, maximizing their chances of survival. This discovery could lead to new methods for controlling this noxious weed.
Avian Taxonomy and Conservation
In the Colombian Andes, ornithologist Thomas Donegan of Fundación ProAves discovered a new subspecies of the yellow-breasted brush-finch. Traditionally, new animal species were established based on preserved specimens. However, authorities now permit the use of evidence from living specimens. Donegan is one of only three scientists to have done so, using photography and DNA sampling to identify this new subspecies.
Conservation and the Release of a New Bird Subspecies
Donegan’s discovery highlights the importance of conservation efforts. Instead of preserving the specimen, he released the bird back into the wild. This approach balances the need for scientific documentation with the preservation of biodiversity.
The Interplay of Science and Nature
These studies shed light on the complex and interconnected nature of life on Earth. From the influence of orbital changes on mammalian evolution to the genetic basis of facial expressions, from the hidden behaviors of tarantulas to the remarkable abilities of parasitic plants, and from the conservation of avian species to the release of a new subspecies, science continues to reveal the wonders and intricacies of the natural world.