PARALLEL EFFECTS OF LAND-USE HISTORY ON PARALLEL EFFECTS OF LAND-USE HISTORY ON SPECIES DIVERSITY AND GENETIC DIVERSITY OF SPECIES DIVERSITY AND GENETIC DIVERSITY OF FOREST HERBSFOREST HERBS

Colin McInnesColin McInnes

Ecology, 2004Mark Vellend

Species andSpecies and Genetic DiversityGenetic Diversity

What is Species Diversity?What is Species Diversity?

What is What is Genetic Diversity?Genetic Diversity?

What is What is the the Difference?Difference?

What is What is Divergence?Divergence?

What Forces Could be Acting?What Forces Could be Acting?

Local Characteristic

MigrationDriftSelectionMutation

MigrationDriftSelectionMutation

Species

Diversity

Genetic Diversity

MigrationMigration

DriftDrift

SelectionSelection

MutationMutation

Primary vs. Secondary StandsPrimary vs. Secondary Stands

BottlenecksBottlenecks

Founder EffectsFounder Effects

QuestionsQuestions

1. Is Spp’s and Genetic 1. Is Spp’s and Genetic diversitydiversity higher in primary higher in primary standsstands

2. Is Spp’s and Genetic 2. Is Spp’s and Genetic divergencedivergence higher in primary higher in primary standsstands

……Predictions?Predictions?

Materials & MethodsMaterials & Methods

TrilliumTrillium

Materials & MethodsMaterials & Methods Spring & Summer (2000 - 2003)Spring & Summer (2000 - 2003) 27 Stands27 Stands ObservationalObservational Genetic AnalysisGenetic Analysis

AllozymesAllozymes Chloroplast DNAChloroplast DNA MicrosatellitesMicrosatellites

Materials & MethodsMaterials & Methods

What was measured?

Materials & MethodsMaterials & Methods

Fst:measure of difference between population

Population 1

Population 2

Population 3

AA AA AA AA AB AAAB AA AA

BB AB BB BB BB BBAB BB BB

AA AA BB AA AA AAAB AA AA

ResultsResults

Both Species Both Species & Genetic & Genetic Diversity Diversity IncreaseIncrease

ResultsResults

ResultsResults

• A. Presence-absence Divergence•1 > 2•Selection on Types

•B. Frequency based Divergence (species)

•2 > 1•More variance within ‘types’

•C. Frequency based Divergence (genes)

•2 > 1

ResultsResults

• geographic distance decreased migration

Population 1

Population 2Population 3

AA AA AA AA AB AAAB AA AA

BB AB BB BB BB BBAB BB BB

AA AA BB AA AA AAAB AA AA

DiscussionDiscussion

Local

Characteristic

MigrationDriftSelectionMutation

MigrationDriftSelectionMutation

Species

Diversity

Genetic Diversity

•These results are primarily governed by Drift!

DiversiDiversityty

DivergenDivergencece

PrimaryPrimary HighHigh LowLow

SecondarSecondaryy

LowLow HighHigh

DiscussionDiscussion

Implications:

Future Studies:

•Uncertainty behind agricultural diversity

•Drift is a Force!

•The case in other systems?…Animals?

•Do species and genetic diversity recover at the same rate?

QuestionsQuestions