Xenophyophores Reach New Depths: Giant Amoebae Found in Mariana Trench

This microscopic relative of the xenophyophores has prominent pseudopods. Photograph by Neon.

Giant single-celled animals have recently been discovered living in the deepest place on Earth – the Mariana Trench in the western Pacific Ocean. Using a “dropcam” (a digital video camera encased in a glass bubble designed to resist the massive water pressures encountered on the ocean floor), researchers from the Scripps Institution for Oceanography at […]

The Ubiquitous Nematode: How a Simple Worm Conquered the Earth

Soybean cyst nematode and her egg

Although often called “nematode worms,” members of the Phylum Nematoda are only distantly related to earthworms in the garden and marine worms in the sea. They are among the most diverse of all animals, though most people in developed countries are only ever likely to encounter them in the form of the pinworm (threadworm), a common […]

Evolution in Action: Three Experiments Demonstrating Natural Selection

The number of spots on male guppies is determined by natural selection.

Like any scientific theory, the theory of evolution by natural selection can be tested by experiment. Since the publication of On the Origin of Species in 1859, biologists have devised many ingenious ways to examine the effect of natural selection on living organisms. This article looks at three such studies. Endler’s Guppies In the late […]

Animals in Disguise: An Introduction to Camouflage and Mimicry

This flounder is almost invisible against gravel on the seabed. Photograph by Moondigger.

Escaping predation and finding food are challenges faced by all living creatures. Hiding and hunting are obvious solutions, but many animals – both prey and predator – have evolved a more subtle approach. By disguising themselves as other animals, plants or even inanimate objects, mimics and camouflaged creatures have an evolutionary advantage over their less duplicitous counterparts. Camouflage: Hiding in […]

Endosymbiosis in Aphids: Nutrients from Symbiotic Bacteria Help Greenfly Survive on Plant Sap


The humble aphid may appear unremarkable, but it is cleverly adapted to its plant-sucking way of life. Symbiotic bacteria greatly increase the ability of plant lice, also known as greenflies, to grow and reproduce, causing annoyance to gardeners and damage to crops worldwide. Plant Sap Provides Insufficient Nutrients In general, aphids disregard the flowers, fruits […]