Describing Biodiversity Genetic Diversity: the number of different kinds of genes present in a population or a specles High genetic diversity -many different kinds of genes, individuals within the population having different structures and abilities Low genetic diversity -nearly all the individuals in the population having the same characteristics
Describing Biodiversity • Genetic Diversity: the number of different kinds of genes present in a population or a species. – High genetic diversity High genetic diversity – many different kinds of genes, individuals within the population having different structures and abilities. – Low genetic diversity Low genetic diversity – nearly all the individuals in the population having the same characteristics
Describing Biodiversity Several things influence the genetic diversity of a population Mutations are changes in the genetic information of an organism Migration of individuals of a species from one population to another alters the genetic diversity of a population Sexual reproduction generates new genetic combinations superior to those of other members of the population Population size is a very important factor related to genetic diversity Selective breeding eliminates undesirable characteristics and selects for desirable ones
Describing Biodiversity • Several things influence the genetic diversity of a population – Mutations Mutations are changes in the genetic information of an organism. – Migration Migration of individuals of a species from one population to another alters the genetic diversity of a population. – Sexual reproduction Sexual reproduction generates new genetic combinations superior to those of other members of the population. – Population size Population size is a very important factor related to genetic diversity. – Selective breeding Selective breeding eliminates undesirable characteristics and selects for desirable ones
Describing biodiversity Species Diversity-a measure of the number of different species present in an area Two kinds of species diversity Species richness: number of different kinds of species In an area Taxonomic richness: the number of different taxonomic categories of the species present in an area Species diversity is influenced by climatic events ntroduction of new species size of the area, and human activities
Describing Biodiversity • Species Diversity – a measure of the number of different species present in an area. – Two kinds of species diversity Species richness Species richness: number of different kinds of species in an area. Taxonomic richness Taxonomic richness: the number of different taxonomic categories of the species present in an area. – Species diversity is influenced by climatic events, introduction of new species, size of the area, and human activities
Numbers of Described Species by Taxonomic Group Taxonomic Group Approximate Number of Described Species Insects 751.000 Plants 248428 Noninsect Arthoropods(mites, spiders 123.151 crustaceans, etc.) Mollusks 50.000 46,983 Protozoa 30.800 Algae 26.900 Flat 12,200 Roundworms 12.000 Earthworms and related organisms 12.000 Birds 9.040 Jullyfish, corals, comb jellies 9.000 Reptiles 6300 Starfish, sea urchins, sand dollars, etc 6,100 Sponges 5000 Bacteria, blue-green algae 4.760 Amphibians 4.184 Mammals 4.000 Total 1380,902
Numbers of Described Species by Taxonomic Group Taxonomic Group Approximate Number of Described Species Approximate Number of Described Species Insects 751,000 Plants 248,428 Noninsect Arthoropods (mites, spiders, crustaceans, etc.) 123,151 Mollusks 50,000 Fungi 46,983 Protozoa 30,800 Algae 26,900 Fish 19,056 Flatworms 12,200 Roundworms 12,000 Earthworms and related organisms 12,000 Birds 9,040 Jullyfish, corals, comb jellies 9,000 Reptiles 6,300 Starfish, sea urchins, sand dollars, etc. 6,100 Sponges 5,000 Bacteria, blue-green algae 4,760 Amphibians 4,184 Mammals 4,000 Total 1,380,902 1,380,902
Describing biodiversity Ecosystem Diversity-a measure of the number of kinds of ecosystems present in an area Many regions of the world appear to be quite uniform in terms of the kinds of ecosystems present Desert with similarities of low rainfall, thorny woody plants, animals that can survive on little water Natural events such as hurricanes fires, floods or volcanic eruptions may have destroyed the original vegetation, resulting in patches of early successional stages ocal topographic conditions may create patches of the landscape that differ from the prevailing type
Describing Biodiversity • Ecosystem Diversity – a measure of the number of kinds of ecosystems present in an area. – Many regions of the world appear to be quite uniform uniform in terms of the kinds of ecosystems ecosystems present. Desert with similarities of low rainfall, thorny woody plants, animals that can survive on little water. – Natural events Natural events such as hurricanes, fires, floods, or volcanic eruptions may have destroyed the original vegetation, resulting in patches of early successional stages. – Local topographic conditions Local topographic conditions may create patches of the landscape that differ from the prevailing type