Species Contact

Simulating Colonization and Extinction on Islands ExpandForm groups of three. One member of the group will simulate colonization by throwing balls into the groups of cups representing the islands. Another will simulate extinction by rolling dice to randomly remove balls from the cups. The third group member will record the data. Take time to familiarize yourself with the four island stations. NOTE: There are two large islands with 12 cups and two small islands with 6 cups. Two of the stations...

Species Distribution Biogeography is the study of species distribution across geographic space and the processes that shape these distributions. This discipline is based on the assumption that each species within a location must have immigrated from another geographic area or evolved from a local species. Within each habitat, a variety of biotic and abiotic factors act on individual species to shape birth, death, immigration, and emigration rates. To avoid local extinction, the combined birth...

When a solid is dipped inside a liquid, the liquid surface becomes curved near the contact. For some solid–liquid interfaces, the liquid is pulled up along the solid, while for others, the liquid surface is convex or depressed near the solid surface. This phenomenon can be explained using the concept of cohesive and adhesive forces. The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive force...

A species is a group of organisms that interbreed and produce fertile offspring. Typically, individuals of the same species appear similar and share common characteristics due to their highly similar genomes. However, not all organisms that look alike are members of the same species. Various mechanisms keep most species discrete. While some mechanisms prevent reproductive behavior and fertilization (pre-zygotic isolation), others prevent the production of fertile offspring after mating has...

Reactive oxygen species are chemically active, oxygen-derived molecules capable of oxidizing other molecules. Because of their reactive nature, there are many deleterious effects associated with unchecked ROS production, including structural damage to DNA and other biological molecules. However, ROS can also be mediators of physiological signaling. There is accumulating evidence that ROS play significant roles in everything from activation of transcription factors to the mediation of...