Biodiversity

Section #1:What is Biodiversity?

Biodiversity

•short for biological diversity•the number & variety of

different species in a given area

•some areas are rich with biodiversity (like tropical rainforests)

Unknown Diversity

•scientists are trying to identify & catalog all the species that exist on Earth

•the actual number is unknown – there are records of 1.7 million known species (mostly insects)

Number of Species on Earth?

•scientists estimate greater than 10 million species

•unknown species could exist in remote wildernesses, deep in the ocean, even in cities

•more is known about trees & animals, less about fungi & insects

Number of Species on Earth

New Species

•scientists continue to find & describe new species

•specimens can stored in collections with small tags that explain when & where the specimen was located

Species Collections

Levels of Biodiversity

• species diversity = all the differences between populations of species (& between different species)

• ecosystem diversity = the variety of habitats, communities, & ecological processes within & between ecosystems

• genetic diversity = all the different genes contained within all members of a population

Species Connected to Ecosystem

• healthy ecosystems depend on the balance of energy & nutrients and species are a part of these cycles

• as scientists study species, they notice that each species plays an important (& often unknown) role in an ecosystem

• every species is either dependent on or depended upon by some other species

Keystone Species

• a species that plays a critical role in the functioning of an ecosystem

• Example = sea otters (Pacific coast)– sea otters were hunted for fur &

disappeared from the Pacific coast– sea urchins who now have no predators

multiply & consume lots of kelp– kelp beds begin to disappear– sea otters are protected & their

population grows– sea urchins are hunted again– kelp beds begin regeneration

Population Survival

•the level of genetic diversity within populations is a critical factor in species survival

•genetic variation increases the chances that some members of a population may survive environmental pressures or changes

Population Survival

•isolated populations are less likely to survive environmental pressures

•as the population shrinks, its genetic diversity decreases, leading to inbreeding & an increase in the chance of inheriting genetic diseases

Genetic Bottleneck

Undiscovered Species

•represent a source of potential products for medical, industrial, & agricultural purposes

•lots of drugs are derived from plants & almost all antibiotics are derived from chemicals found in fungi

Crops

•most new crop varieties are hybrids (crops that are developed by combining genetic material from other populations)

•most of the crops that the world eats originated in a few areas of high biodiversity

•its dangerous for a population to depend on too few plants for food

•these plants could be wiped out by disease & a famine results

Preserving Species

•for ethical & aesthetic reasons + for ecotourism

•some people believe that we should preserve biodiversity

•each organism on Earth is a gift with a higher purpose & have a right to exist