Seizures are symptoms of a brain problem. They happen because of sudden, abnormal electrical activity in the brain. When people think of seizures, they often think of convulsions in which a person's body shakes rapidly and uncontrollably. Not all seizures cause convulsions. There are many types of seizures and some have mild symptoms. Seizures fall into two main groups. Focal seizures, also called partial seizures, happen in just one part of the brain. Generalized seizures are a result of abnormal activity on both sides of the brain. Read more on MedlinePlus.gov.
The purpose of the ESA is to protect and recover imperiled species and the ecosystems upon which they depend. It is administered by the U.S. Fish and Wildlife Service (Service) and the Commerce Department's National Marine Fisheries Service (NMFS).
Biodiversity is simply the variety of life on Earth, but its importance to global ecology has made it one of the most important concepts in modern science. Because biodiversity cuts across different levels of organization it is often useful to focus on a particular type of biological diversity. 1  Species diversity is a measure of how many different species are present in a given area. Most often when people think of biodiversity they think of species diversity. Genetic diversity measures the amount of inherited genetic variability contained within a populations of species.