Anthropology • Biology • Evolution • Genetics
Neanderthals ( Homo neanderthalensis ) were a species –some say a subspecies although most authors consider there is enough evidence to consider them as a separate species– of human closely related to us. They were firstly discovered in a cave in the Neander Valley («Tal» in German), about 12 km east of Düsseldorf. There is […]
Hibernation is a state of inactivity and metabolic depression used by some mammals to survive a cold winter. It may last several days, weeks, or months depending on the species, environment temperature, season, and individual’s body condition. Usually, hibernating animals survive the energetic bottleneck of the winter by building stores of body fat in late […]
In multicellular organisms, embryonic stem cells develop into any of the different cell types that will form the adult, and along the development, they silence or activate different parts of the genome, giving rise to distinct cell identities, which are maintained throughout adult life by epigenetic mechanisms. A similar procedure may be at work at […]
One hears blue blood and immediately thinks about royal family members. Some biologists, though, immediately will think about Limulus polyphemus , a marine animal commonly known as the horseshoe crab. Why? Because, very surprisingly, this arthropod actually has true blue blood! Human blood is red because of the hemoglobin inside our red blood cells, which […]
Behavioral lateralization is a significant field of study because it may provide insights into the initial origins of lateralization. Different and very diverse organisms show lateralization. The best known is handedness, a better (faster or more precise) performance or individual preference for use of a hand but it is not unique, many creatures, including humans […]
Complex systems in biology have several levels of organization, establishing a hierarchy of systems and subsystems. An ant colony is a wonderful example with the highest level being the colony itself, formed by hundreds or thousands of insects, each individual ant formed by millions of cells including 10 5 -10 6 neurons, and each cell […]
Animals drift when they enter a fluid (liquid or gas) and are transported to a new location by gravity or currents. Drift is best known from rivers and ocean currents, but can also occur on land, whenever organisms leave their former solid position, pass into the air, and are moved significant distances by the combined […]
The biological world is composed of dense, communicating, and difficult to understand ensembles. Animals living in groups –a school of fish, a flock of birds– have evolved to act in concert, a quality needed for coordinated movement. More complex than just moving together, group carrying is fairly rare in nature and only social spiders, dung […]
Phragmosis is a method by which an animal defends itself in its burrow by using its own body as a barrier. This term was coined by W.M. Wheeler in 1927 to describe a cryptic defensive technique employed by arthropods that use specially modified body structures to block nest entrances. A well example is the mygalomorph […]
Bulldog ants ( Myrmecia pyriformis ) are the most dangerous ants on Earth. The name of these Australian native ants is due to the way they bite and hang off their victims using their mandibles: they sink their teeth and they keep gnawing at it. These mandibles were used by the Australian natives to temporarily […]