Science 9 Unit A – Science 9 Unit A – Biological DiversityBiological Diversity

1.0 – Biological Diversity and 1.0 – Biological Diversity and the Variety of Life on Earththe Variety of Life on Earth

Goals of this Section:Goals of this Section:1.1. Describe the abundance of species on Describe the abundance of species on

Earth and in different environments.Earth and in different environments.2.2. Explain the role that variation plays in Explain the role that variation plays in

survival.survival.3.3. Identify examples of niches and how Identify examples of niches and how

closely related living things can closely related living things can survive in an ecosystem.survive in an ecosystem.

4.4. Explain how the survival of one Explain how the survival of one species depends on other species.species depends on other species.

5.5. Identify examples of natural selectionIdentify examples of natural selection

1.1 – Examining Diversity1.1 – Examining Diversity

Biological Diversity: All of the Biological Diversity: All of the different types of organisms on Earthdifferent types of organisms on Earth

Scientists, of course, rarely study all Scientists, of course, rarely study all of the Earth’s creatures togetherof the Earth’s creatures together

Rather, they focus on smaller Rather, they focus on smaller groupingsgroupings

Divisions in EcosystemsDivisions in Ecosystems

DiversityDiversity

Each ecosystem is differentEach ecosystem is different This is because they contain different This is because they contain different

biotic and abiotic componentsbiotic and abiotic components These components dictate which These components dictate which

organisms can be found living in a organisms can be found living in a particular ecosystemparticular ecosystem

Genetic VariationGenetic Variation

This term refers to the variation This term refers to the variation between individuals of the same between individuals of the same speciesspecies

These variations are typically due to These variations are typically due to small differences at the cellular levelsmall differences at the cellular level

Some of these variations may not Some of these variations may not even be visibleeven be visible

DistributionDistribution

Species are not Species are not evenly distributedevenly distributed

Regions near the Regions near the equator typically equator typically have a far greater have a far greater number of species number of species than those regions than those regions near to the polesnear to the poles

ClassificationClassification

Carolus Linnaeus developed a Carolus Linnaeus developed a system for naming and classifying system for naming and classifying organisms in the 18organisms in the 18thth century century

The purpose of this system was to The purpose of this system was to establish common scientific names establish common scientific names rather than using names that varied rather than using names that varied from language to languagefrom language to language

Binomial NomenclatureBinomial Nomenclature

Under the Linnean system, all Under the Linnean system, all organisms have two names – their organisms have two names – their genus and their speciesgenus and their species

For example, a wolf is known as For example, a wolf is known as Canis lupus Canis lupus

CanisCanis represents the genus and represents the genus and lupuslupus identifies the species identifies the species

The Five-Kingdom The Five-Kingdom Classification SystemClassification System

KingdoKingdomm

PlantaePlantae AnimaliaAnimalia

PhylumPhylum coniferophytconiferophytaa

ChordataChordata

ClassClass pinopsidapinopsida OsteichthyesOsteichthyes

OrderOrder pinalespinales SalmoniformSalmoniformeses

FamilyFamily pinaceaepinaceae SalmonidaeSalmonidae

GenusGenus PiceaPicea SalvelinusSalvelinus

SpeciesSpecies glaucaglauca confluentusconfluentus

White spruce

BullTrout

Diversity Under the SeaDiversity Under the Sea

Some regions, such as coral reefs Some regions, such as coral reefs have very high levels of biodiversityhave very high levels of biodiversity

The coral itself is a living thing, and it The coral itself is a living thing, and it also houses thousands of different also houses thousands of different species of life species of life

1.2 - Interdependence1.2 - Interdependence

No one species lives aloneNo one species lives alone All species are reliant on other All species are reliant on other

species for some aspect of their daily species for some aspect of their daily lives lives

Food chains and food webs show the Food chains and food webs show the relationship between predator and relationship between predator and prey prey

Even prey Even prey benefit from benefit from the predator-the predator-prey prey relationshiprelationship

SymbiosisSymbiosis

Sym-togetherSym-together Bios-lifeBios-life This is the association between two This is the association between two

different species that live close different species that live close togethertogether

There are different types of symbiosis There are different types of symbiosis depending on the benefit or harm to depending on the benefit or harm to each participant each participant

CommensalismCommensalism

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

MutualismMutualism

both are benefited both are benefited

ParasitismParasitism

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

NichesNiches

The role of an organism within an The role of an organism within an ecosystem ecosystem

Interspecies competition occurs Interspecies competition occurs when two different species are when two different species are competing for the same nichecompeting for the same niche

Resource PartitioningResource Partitioning

For similar species to coexist in an For similar species to coexist in an area, they must share resourcesarea, they must share resources

This can be accomplished by each This can be accomplished by each species changing their niche slightly, species changing their niche slightly, so there is no direct competitionso there is no direct competition

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

1.3 – Variation Within 1.3 – Variation Within SpeciesSpecies

Just as there is variation between Just as there is variation between species, there is variation within species, there is variation within species as wellspecies as well

Variation within a species is known Variation within a species is known as variabilityas variability

Variability and SurvivalVariability and Survival

Sometimes environments changeSometimes environments change In these cases, variability in a In these cases, variability in a

species will increase the chance of species will increase the chance of some of the individuals surviving that some of the individuals surviving that changechange

Antibiotic ResistanceAntibiotic Resistance Some bacteria are Some bacteria are

naturally resistant naturally resistant to antibioticsto antibiotics

When a bacterial When a bacterial population comes population comes into contact with into contact with these drugs, the these drugs, the naturally resistant naturally resistant ones will survive ones will survive and reproduceand reproduce

Natural SelectionNatural Selection

Natural selection occurs when the Natural selection occurs when the environment “selects” which environment “selects” which individuals survive long enough to individuals survive long enough to reproducereproduce

The survivors usually have adaptations The survivors usually have adaptations that make them more suited to the that make them more suited to the environment, and the adaptations are environment, and the adaptations are passed on to their offspringpassed on to their offspring