biology: chapter21

• biodiversity can be measured at different levels - species diversity (number of species), genetic diversity (differences between individuals within a population) or ecosystem diversity (variety of habitats)
• biodiversity is the variety of life on Earth, including all living organisms.
• endemic species are found in only one location
• biogeography can be divided into three main fields - ecological (plants and animals), historical (fossils), and conservation (bringing back species)
• extinction is the species permanently removed from the Earth's surface
• habitat heterogeneity is the variation in the environment within a habitat or number of ecological niches
• secondary plant compounds are toxins used to protect the plant from insects and other animals
• importance of biodiversity - human health (medications and antibiotics), agriculture (thriving in soil), and wild food sources (humans obtaining food from outside)
• there are three great threats to biodiversity - habitat loss (destruction of the natural environment where organisms live), overharvesting (unsustainable exploration of natural resources), and exotic species (invasive species, introduced to an ecosystem in which it didn't evolve)
• tragedy of the commons is when a resource is not managed properly and is overused
• bush meat is meat from wild animals that are not domesticated or farmed (wild pigs, birds, and monkeys)
• endangered means at risk of becoming extinct due to low population numbers
• chytridiomycosis is a disease caused by the fungus Batrachochytrium dendrobatidis
• white-nose syndrome is a fungal disease that affects hibernating bats
• climate change is forcing range changes that may lead to extinction
• extinction rate is the number of species that become extinct over time
• species-area relationship is the relationship between the area of an island and the number of species on it
• biodiversity hotspot is an area of high biodiversity that is under threat
• global warming raises sea levels, in which it eliminates some islands and reduces area
• crop diversity is required for food security, and it is being lost
• habitat restoration has the potential to restore ecosystems to previous biodiversity levels before species become extinct
• zoos have an active role in conservation and useful in the role of education