Threatened, Endangered, and Extinct Species Chapter 7 Lesson 7.1

Threatened, Endangered, Threatened, Endangered, and Extinct Speciesand Extinct Species

Chapter 7Chapter 7Lesson 7.1Lesson 7.1

PA Academic Standards for PA Academic Standards for Environment & EcologyEnvironment & Ecology

Standard 4.7.10.AStandard 4.7.10.A Explain the significance of diversity in Explain the significance of diversity in

ecosystems.ecosystems. Explain the role that specific organisms have Explain the role that specific organisms have

in their ecosystem.in their ecosystem.• Identify a species and explain what effects its Identify a species and explain what effects its

increase or decline might have on the ecosystem. increase or decline might have on the ecosystem. • Identify a species and explain how its adaptations Identify a species and explain how its adaptations

are related to its niche in the environment.are related to its niche in the environment.

Learning ObjectivesLearning Objectives

• Students will explain the role that specific organisms have Students will explain the role that specific organisms have in their ecosystems.in their ecosystems.

• Students will identify a species and explain what effects Students will identify a species and explain what effects an increase or decline in its numbers might have on the an increase or decline in its numbers might have on the ecosystem.ecosystem.

Theme OutlineTheme Outline

Lesson 7.1Lesson 7.1 BiodiversityBiodiversity Interactions Among Organisms in an Interactions Among Organisms in an

EcosystemEcosystem

BiodiversityBiodiversity

• Scientists have discovered about 1.75 million Scientists have discovered about 1.75 million species on Earth.species on Earth.

• Scientists estimate that there may be as many as Scientists estimate that there may be as many as 100 million species, yet to be discovered and 100 million species, yet to be discovered and catalogued.catalogued.

• The number of species on Earth is constantly The number of species on Earth is constantly changing, as new species are found and known changing, as new species are found and known species disappear without notice.species disappear without notice.

ExtinctExtinct• DefinitionDefinition: species that no longer exists: species that no longer exists

• Scientists estimate that as Scientists estimate that as many as 99.9% of all species many as 99.9% of all species that ever lived on Earth are that ever lived on Earth are now extinct. now extinct.

• Extinction is a natural Extinction is a natural process.process.

• Extinction rates have Extinction rates have accelerated because of accelerated because of human activities, with human activities, with ecosystems affects yet to be ecosystems affects yet to be observed.observed.

BiodiversityBiodiversity• DefinitionDefinition: variety of living organisms on Earth: variety of living organisms on Earth

• Diversity occurs on a variety of levelsDiversity occurs on a variety of levels GeneticGenetic SpeciesSpecies EcosystemEcosystem

Biodiversity: Biodiversity: Vascular Plants Species as an IndexVascular Plants Species as an Index

Biodiversity:Genetic DiversityGenetic Diversity

Living organisms contain a "history" of specific genes from their ancestry line, which makes individual living organisms of the same species different from one another in some genetic ways. In fact, there are no exact duplicates of any (naturally created) living organism. One thing that all living organisms share in similarity is that they can all reproduce. If an entire species could not reproduce, it would become extinct.Genetic diversity gives species the ability to adapt to changing environments, including new pests and diseases and new climatic conditions.

Biodiversity:Species DiversitySpecies Diversity

Species Diversity

An assessment of the number of species present, their relative abundance in an area, and the distribution of individuals among the species.

Biodiversity:Biodiversity:Ecosystem Ecosystem DiversityDiversity

Ecosystem A functional unit consisting of all the living organisms (plants, animals, and microbes) in a given area, and all the non-living physical and chemical factors of their environment, linked together through nutrient cycling and energy flow. An ecosystem can be of any size – a log, pond, field, forest, or the earth’s biosphere – but it always functions as a whole unit. Ecosystems are commonly described according to the major type of vegetation.

Biodiversity in Pennsylvania

What does biodiversity look like in Pennsylvania What does biodiversity look like in Pennsylvania ecosystems?ecosystems? 45.8% Insects45.8% Insects 23.5% Plants and Algae23.5% Plants and Algae 16.5% Fungi and Lichens16.5% Fungi and Lichens 3.2% Vertebrates3.2% Vertebrates 3.6% Protists3.6% Protists 7.4% Non-Insect Invertebrates7.4% Non-Insect Invertebrates

Interactions Among Organisms in an Ecosystem

Predator – PreyPredator – Prey

Symbiotic RelationshipsSymbiotic Relationships

ParasitismParasitism

MutualismMutualism

CommensalismCommensalism

Predator-Prey InteractionsPredator-Prey Interactions An organism of one species (the predator) eats a An organism of one species (the predator) eats a

living organism of another species (the prey).living organism of another species (the prey).

Other ecosystem relationships…Other ecosystem relationships…

SymbiosisSymbiosis• ParasitismParasitism• MutualismMutualism• CommensalismCommensalism

SymbiosisSymbiosisDefinition: relationship in which organisms live Definition: relationship in which organisms live

closely together over a long period of timeclosely together over a long period of time



ParasitismParasitismDefinition:Definition: relationship in which one species, the parasite, relationship in which one species, the parasite,

feeds on a second organism, the hostfeeds on a second organism, the host



MutualismMutualismDefinitionDefinition: : symbiotic relationship in which both symbiotic relationship in which both

species benefitspecies benefitExample: pollination between an insect and flowerExample: pollination between an insect and flower

MutualismMutualism: Lichens: Lichens

What is a lichen?What is a lichen? It is an alga and a fungus the grow together.It is an alga and a fungus the grow together.

• Role: Alga undergo photosynthesis and produce food for Role: Alga undergo photosynthesis and produce food for the lichen.the lichen.

• Role: Fungus collect minerals and water for the Role: Fungus collect minerals and water for the

lichen.lichen.

http://www.grandcolombier.com/2003-galleries/album/images-album/lichen.gif



CommensalismCommensalismDefinitionDefinition: : relationship in which one organism relationship in which one organism

benefits while the other is not affectedbenefits while the other is not affected• Example: Remoras in marine ecosystemsExample: Remoras in marine ecosystems• Example: Oxpecker in terrestrial ecosystemsExample: Oxpecker in terrestrial ecosystems

Summary of Summary of Symbiotic RelationshipsSymbiotic Relationships

ParasitismParasitism ++ --

MutualismMutualism ++ ++

CommensalismCommensalism ++ OO

Coding: “+” is a benefit or advantage

“-” is not beneficial or a disadvantage

“o” is a neutral. Neither positive or negative

Summary of Summary of Ecosystem RelationshipsEcosystem Relationships

ParasitismParasitism ++ --

MutualismMutualism ++ ++

CommensalismCommensalism ++ OO

CompetitionCompetition -- --

PredationPredation ++ --Coding: “+” is a benefit or advantage

“-” is not beneficial or a disadvantage

“o” is a neutral. Neither positive or negative

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Threatened, Endangered, and Extinct Species Chapter 7 Lesson 7.1