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 […]
Slime mold is an informal name given to several kinds of unrelated eukaryotic organisms that can live freely as single cells but when food is in short supply, many of these unicellular organisms will congregate to form multicellular structures that move together as a single body. Thus, the aggregation and joint movement require the coordination […]
Looking for a sexual partner outside your species is not very common, but that is what the males of a type of spider mite do. Even more, a recent work suggests that this kinky behaviour could have been key to colonization of new environments. Tetranychus evansi is a species of red spider mite originally from […]