Science 9 Unit A – Biological Diversity 1.0 – Biological Diversity and the Variety of Life on Earth

Goals of this Section: 1. Describe the abundance of species on Earth and in different environments. 2. Explain the role that variation plays in survival. 3. Identify examples of niches and how closely related living things can survive in an ecosystem. 4. Explain how the survival of one species depends on other species. 5. Identify examples of natural selection

1.1 – Examining Diversity Biological Diversity: All of the different types of organisms on Earth Biological Diversity: All of the different types of organisms on Earth Scientists, of course, rarely study all of the Earth’s creatures together Scientists, of course, rarely study all of the Earth’s creatures together Rather, they focus on smaller groupings Rather, they focus on smaller groupings

Divisions in Ecosystems

Diversity Each ecosystem is different Each ecosystem is different This is because they contain different biotic and abiotic components This is because they contain different biotic and abiotic components These components dictate which organisms can be found living in a particular ecosystem These components dictate which organisms can be found living in a particular ecosystem

Genetic Variation This term refers to the variation between individuals of the same species This term refers to the variation between individuals of the same species These variations are typically due to small differences at the cellular level These variations are typically due to small differences at the cellular level Some of these variations may not even be visible Some of these variations may not even be visible

Distribution Species are not evenly distributed Species are not evenly distributed Regions near the equator typically have a far greater number of species than those regions near to the poles Regions near the equator typically have a far greater number of species than those regions near to the poles

Classification Carolus Linnaeus developed a system for naming and classifying organisms in the 18 th century Carolus Linnaeus developed a system for naming and classifying organisms in the 18 th century The purpose of this system was to establish common scientific names rather than using names that varied from language to language The purpose of this system was to establish common scientific names rather than using names that varied from language to language

Binomial Nomenclature Under the Linnean system, all organisms have two names – their genus and their species Under the Linnean system, all organisms have two names – their genus and their species For example, a wolf is known as Canis lupus For example, a wolf is known as Canis lupus Canis represents the genus and lupus identifies the species Canis represents the genus and lupus identifies the species

The Five-Kingdom Classification System KingdomPlantaeAnimalia PhylumconiferophytaChordata ClasspinopsidaOsteichthyes OrderpinalesSalmoniformes FamilypinaceaeSalmonidae GenusPiceaSalvelinus Speciesglaucaconfluentus White spruce Bull Trout

Diversity Under the Sea Some regions, such as coral reefs have very high levels of biodiversity Some regions, such as coral reefs have very high levels of biodiversity The coral itself is a living thing, and it also houses thousands of different species of life The coral itself is a living thing, and it also houses thousands of different species of life

1.2 - Interdependence No one species lives alone No one species lives alone All species are reliant on other species for some aspect of their daily lives All species are reliant on other species for some aspect of their daily lives Food chains and food webs show the relationship between predator and prey Food chains and food webs show the relationship between predator and prey

Even prey benefit from the predator-prey relationship Even prey benefit from the predator-prey relationship

Symbiosis Sym-together Sym-together Bios-life Bios-life This is the association between two different species that live close together This is the association between two different species that live close together There are different types of symbiosis depending on the benefit or harm to each participant There are different types of symbiosis depending on the benefit or harm to each participant

Commensalism one benefits the other is neither harmed nor helped one benefits the other is neither harmed nor helped

Mutualism both are benefited both are benefited

Parasitism one benefits and the other is harmed one benefits and the other is harmed

Niches The role of an organism within an ecosystem The role of an organism within an ecosystem Interspecies competition occurs when two different species are competing for the same niche Interspecies competition occurs when two different species are competing for the same niche

Resource Partitioning For similar species to coexist in an area, they must share resources For similar species to coexist in an area, they must share resources This can be accomplished by each species changing their niche slightly, so there is no direct competition This can be accomplished by each species changing their niche slightly, so there is no direct competition

This figure shows resource partitioning between three warbler species in a single tree This figure shows resource partitioning between three warbler species in a single tree

1.3 – Variation Within Species Just as there is variation between species, there is variation within species as well Just as there is variation between species, there is variation within species as well Variation within a species is known as variability Variation within a species is known as variability

Variability and Survival Sometimes environments change Sometimes environments change In these cases, variability in a species will increase the chance of some of the individuals surviving that change In these cases, variability in a species will increase the chance of some of the individuals surviving that change

Antibiotic Resistance Some bacteria are naturally resistant to antibiotics Some bacteria are naturally resistant to antibiotics When a bacterial population comes into contact with these drugs, the naturally resistant ones will survive and reproduce When a bacterial population comes into contact with these drugs, the naturally resistant ones will survive and reproduce

Natural Selection Natural selection occurs when the environment “selects” which individuals survive long enough to reproduce Natural selection occurs when the environment “selects” which individuals survive long enough to reproduce The survivors usually have adaptations that make them more suited to the environment, and the adaptations are passed on to their offspring The survivors usually have adaptations that make them more suited to the environment, and the adaptations are passed on to their offspring