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Conservation Genetics

Scope of EcologyEcology

The study of the interactions of organisms withother organisms, andThe physical environment

Habitat - Place where an organism lives

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gPopulation - All the individuals of a species within a particular spaceCommunity – Specified populations interacting with each otherEcosystem - Community interacting with environment

Density and Distribution of PopulationsPopulation Density - Number of individuals per unit area or volumePopulation Distribution - Pattern of dispersal of individuals within a space of interest

Ecologists analyze what causes the spatial and temporal “patchiness” of organisms

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p gLimiting factors are factors that predominantly determine whether a species lives in a habitat

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Carrying CapacityCarrying Capacity

The maximum number of individuals of a species the environment can continuously supportThe closer the population to the carrying capacity, the greater the environmental resistance

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Human Population GrowthHuman population has an exponential growth patternDoubling time currently estimated at 53 yearsPopulation Size

1800 1 Billion1930 2 Billion

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1960 3 Billion2000 6 Billion

Country DevelopmentMore-Developed Countries (MDCs)

Slow population growth

High standard of living

Completed Demographic TransitionNorth America and Europe

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North America and Europe

Less-Developed Countries (LDCs)Rapid population growth

Low standard of livingLatin America

Africa and Asia

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Environmental ImpactEnvironmental impact of a population is measured in terms of:

Population sizeResource consumption per capita Resultant pollution

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Community ConceptAn assemblage of populations interacting with one another within the same environment

Composition is a listing of various species in the

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various species in the communityDiversity includes both species richness and species diversity

Community StructureCompetition

When two species compete, the abundance of both species is negatively impactedPredation (or parasitism)

Expected to increase the abundance of the predator (or parasite)And reduce the abundance of the prey (or host)

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And reduce the abundance of the prey (or host)

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Habitat and Ecological NicheHabitat

The area an organism lives and reproduces in

Ecological niche

The role a species plays in its community

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Includes its habitat, and

Its interactions with other organisms

Fundamental niche - All conditions under which the organism can survive

Realized niche - Set of conditions under which it exists in nature

Feeding niches for Wading Birds

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Natural Selection and AdaptationIndividuals have heritable variationsMore individuals produced each generation than environment can supportSome individuals have adaptive characteristics

Enables increased survival and reproduction

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Increasing proportion of succeeding generations will have these characteristics

Populations become adapted to their local environment through change in individuals

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Artificial Selection of Animals

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Artificial Selection of Plants

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Predator-Prey InteractionsPredation

One living organism, the predator, feeds on another, the preyPredator is usually largerPredator has lower reproductive rate

Presence of predators can decrease prey densities, and vice-versa

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versa

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Prey DefensesPrey defenses

Mechanisms that thwart the possibility of being eaten by a predator

SpinesTough EpidermisPoisonous Chemicals

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Poisonous ChemicalsCamouflageBright ColorationFlocking Behavior

MimicryMimicry

One species resembles another speciesMimicked species possesses an overt antipredator defense

B t i Mi i Mi i l k Flower Fly Cucumber Beetle

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Batesian Mimicry - Mimic lacks defense of the organism it resemblesMüllerian Mimicry - Mimic shares same protective defense

Bumble Bee

Bald Faced HornetSaw Fly

Predation, Competition, and BiodiversityPredation by a particular species may reduce competition and increases diversity

Such predators are referred to as keystone predators

Exotic speciesMay lead to unbridled competition

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Resultant reduction in biodiversity

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Conservation Biologyand Biodiversity

Considers all aspects of biodiversityGeneral goal is conserving natural resources for this and future generationsPrimary goal is the management of biodiversity for sustainable use by humans

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Conservation Biology and BiodiversityConservation biology supports certain ethical principles

Biodiversity is desirable for the biosphereExtinctions due to human actions are undesirableEcosystem interactions supporting biodiversity are desirableBiodiversity brought about by evolutionary change has value in

d f i lf

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and of itself

BiodiversityAt its simplest level, biodiversity is the variety of species on Earth

Estimated that between 5 and 15 million species currently exist

Genetic diversity refers to variations among the members of a population

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Community diversity increases biodiversityLandscape diversity involves a group of interacting ecosystems

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Value of BiodiversityDirect Value

Medicinal ValueAgricultural Value

CropsBiological Pest Controls

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Consumptive Use ValueWoodSkins

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Pollinators

Value of BiodiversityIndirect Value

Biogeochemical CyclesWaste DisposalProvision of Fresh WaterPrevention of Soil Erosion

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Regulation of ClimateEcotourism

Causes of Extinction

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Causes of ExtinctionHabitat Loss

Occurs in all ecosystemsRecent concern focused on tropical rain forests and coral reefs

Habitat Fragmentation

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Alien SpeciesNonnative species that move, or are moved, into a new ecosystem

Often have competitive edge against native speciesAvenues of Human Introduction

ColonizationH ti lt d A i lt

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Horticulture and AgricultureAccidental Transport

PollutionAny environmental change that adversely affects living things

Acid DepositionEutrophicationOzone Depletion

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Organic ChemicalsGlobal Warming

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OverexploitationWhen the harvest is so great that the population becomes severely reduced in numbersThe market forces driving the harvest:

Exotic PetsHunting / Poaching

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Over-Harvesting Fisheries

Conservation TechniquesHabitat Preservation

Keystone Species

MetapopulationsSmall populations isolated because of habitat fragmentation

Source Populations

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Sink Populations

Landscape PreservationLandscape protection for one species benefits other wildlife in the same space

Conservation TechniquesHabitat Restoration - Three Principles

Begin as soon as possible before remaining fragments are lostOnce natural history is understood, use biological techniques to mimic natural processesGoal is sustainable usage

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Every species ever examined has revealed considerable genetic variation (polymorphism), both within and between populations. p p

Conservation GeneticsMaintenance, Loss, and restoration of biodiversity

Prevent genetic erosion

To conserve biodiversity, Genetic DiversitySpecies Diversity Ecosystem Diversity

Who needs protectionAll types of organisms need protection

Plant WildDomestic

AnimalWildWildDomestic

Prevent genetic erosion

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Groups beyond a speciesBreed/cultivar- a domestic subspecies, based on morphologyVariety- a group of individuals that are unique in colorLine-a group of related organisms that share a specific traitLandrace-a group of organisms that contain heterozygosity

FAOFood and Agriculture Organization of the United NationsKeith Hammond

Senior Officer of FAO's Animal Genetic Resources Group

The Problem• "In the past 100 years we have already lost about 1,000 breeds.

Our new findings show that domestic animal breeds continue to be in danger: one third are currently at risk of being extinct," said Keith Hammond, Senior Officer of FAO's Animal Genetic Resources Group.

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Genetic ErosionFAO has helped collect data from some 170 countries

6,379 breeds of 30 mammalian and bird speciesBird species in more trouble than mammals

Population size data is available for 4,183 breeds740 breeds extinct1 335 close to extinction

6,379- 740-1,335-2,2552 049 left1,335 close to extinction

80 country reports show that the number of breeds threatened by extinction is increasing

Two breeds lost per week2,255 more breeds could be lost in next 20 years

2,049 left

ImportanceDomestic animal diversity is unique and cannot be replaced"As much as novel biotechnology may attempt to improve breeds, it is not possible to replace lost diversity. Loss of diversity is forever. Biotechnology will not be able to

d f l " regenerate diversity if it is lost." Keith Hammond

Greatest ThreatExport of animals from developed to developing countries,

crossbreeding replacement of local breeds

These animals are mainly suited to the conditions of the country they come from and they have difficulty coping with the often harsh environment of developing countries the often harsh environment of developing countries.

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RegionsSub-Saharan Africa

total 738 breeds19% mammals, 34% birds endangered/extinct

Asia and the Pacific region1,251 breeds

14% mammals, 37% birds endangered/extinct14% mammals, 37% birds endangered/extinct

Europe2,576 breeds

49% mammals, 76% birds endangered/extinct

America (USA)259 breeds

35% endangered/extinct

Conservation Genetics