INTERACTIONS of FORCES and CONSERVATION GENETICS

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INTERACTIONS of FORCESand CONSERVATION GENETICS

• TOPICS
• You already know some examples
• One more interaction
• Putting it together . . .
• Neo-Darwinian Synthesis
• Interdeme Selection (Wrights Shifting Balance)
• Punctuated Equilibrium
• Conservation Genetics (Florida panther)

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EVOLUTIONARY FORCESINTERACTIONS

• Remember these?
• Drift-mutation F 1/(14Nu)
• Drift-migration F 1/(14Nm)
• Selection-mutation
• q(e) ? u/s
• q(e) ? (u/saa)1/2
• We could address others
• Drift-selection
• Selection-migration
• Etc.

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ONE-ISLAND MIGRATION MODEL WITH SELECTION
Freq(A1) ? p Freq(A2) ? q
Freq(A1) ? pm Freq(A2) ? qm
m
A1A1 A1A2 A2A2 1 1-s 1-2s
no selection on continent
CONTINENT (DONOR) POPULATION
ISLAND (RECIPIENT) POPULATION
It turns out that qe (2s)-1 (ms) ? (ms)2
- 4msqm 1/2 (Hedrick 2005, pp. 510-511)
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EVOLUTIONARY FORCESINTERACTIONS

• Neo-Darwinian Synthesis Prelude
• Darwin (1859)
• Mendel (1865)
• Rediscovery of Mendel (1900)
• Biometricians (1900 onward)
• Population genetics
• Hardy Weinberg (1908)
• Sir R.A. Fisher
• J.B.S. Haldane
• Sewall Wright

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EVOLUTIONARY FORCESINTERACTIONS

• Neo-Darwinian Synthesis (1940s - 50s)
• Who
• Theodosius Dobzhansky
• Sewall Wright
• Ernst Mayr
• Julian Huxley
• Ledyard Stebbins
• Others
• What a cohesive view of evolution
• 1. Mutation introduces genetic variation
• 2. Selection, drift, migration determine outcome
• 3. Mating system may affect rates of change

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NEO-DARWINIAN SYNTHESIS

• Something New in 1966
• Introduction of isoenzyme electrophoresis to
  population genetics (Lewontin and Hubby)
• Discovery unexpectedly high he
• Result years of controversy
• Selectionists heterozygote advantage and
  coadapted gene complexes responsible for genetic
  diversity
• Neutralists mutation-drift balance
  responsible for genetic diversity
• (Lewontin, R.C. and J.L. Hubby. 1966. A
  molecular approach to the study of genic
  heterozygosity in natural populations. II.
  Amount of variation and degree of heterozygosity
  in natural populations of Drosophila
  pseudoobscura. Genetics 54595-609.)

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NEO-DARWINIAN SYNTHESIS

• Wrights Shifting Balance Theory (1931)

3 Phases 1. Exploratory (involves drift) 2.
Mass selection 3. Interdeme selection
(involves group selection, migration)
(Image from V. Sork, accessed March 2004 at
http//www.umsl.edu/biology/Bio342/Lecture/Shifti
ngBalance/anchor11818682)
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NEO-DARWINIAN SYNTHESIS

• An Alternative Punctuated Equilibrium
• Observation Gaps in fossil record
• Hypothesis Evolution involves
• 1. Long periods of stasis
• 2. Short bursts of rapid change
• Eldridge, N. and S.J. Gould. 1972. Punctuated
  equilibria an alternative to phyletic
  gradualism. Pp. 82-115 in Schopf, T.J.M. (ed.)
  Models in Paleobiology. San Francisco Freeman,
  Cooper.

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EVOLUTION
Darwinian? Punctuated Equilibrium? Both?
Character State
Darwinian
Punctuated Equilibrium
Time
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Conservation Genetics
Thanks to Josh Brown! The following slides are
his, except for minor modifications
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CONSERVATIONGENETICS

• Biodiversity exists at many levels
• Landscape
• Community
• Species
• Population
• Genetic variation exists
• Among species
• Within species

We will be addressing this type of genetic
variation
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CONSERVATIONGENETICS

• Extinction is natural but . . .
• Current rate of extinction is unnatural
• 6th mass extinction is in progress
• Genetic diversity necessary for future adaptation
• Environments will change
• Human desires will change

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CONSERVATIONGENETICS

• http//gslc.genetics.utah.edu/units/basics/conserv
  ation/

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FLORIDA PANTHER (Puma concolor coryi)

• N
• Several unusual characteristics
• low genetic variability (but this applies to all
  N. Am. subspecies)
• enlarged nasal canal, flat skull
• cowlick
• kinked tails
• high levels of chryptorchidism
• Strategy introduce Texas cougars to restore
  genetic diversity
• (Belden 1986 OBrien et al. 1990 Seal 1994)

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TEXAS COUGAR INTRODUCTION BENEFICIAL?

• 8 female Texas cougars released in Florida (1996
  m 0.2)
• Thereafter, 1 Texas animal released in Florida
  per generation (m 0.025)
• Can fitness be increased while retaining genetic
  integrity of Florida panther?
• Should genetic considerations outweigh
  demographics?
• (Seal 1994 Maehr and Lacy 2002)

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TEXAS COUGAR INTRODUCTION BENEFICIAL?

• Controversial, but . . .
• Popgen theory (migration-selection interaction)
  predicts success possible

• (Hedrick 2005 Maehr and Lacy 2002)

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TEXAS COUGAR INTRODUCTION BENEFICIAL?
(Hedrick 1995 Hedrick 2005, pp. 512-513)
A1 (Texas allele) adaptive in Florida Genotype A1A
1 A1A2 A2A2 Fitness 1 1 0.5

• A2 (Florida allele) adaptive in Florida
• Genotype A1A1 A1A2 A2A2
• Fitness 1 1.2 1.2

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TEXAS COUGAR INTRODUCTION BENEFICIAL?

• Popgen theory predicts success possible
• 15 kittens born to 8 Texas females by 1999
• Kinked tail less frequent
• Cowlick less frequent
• Chryptorchidism less frequent
• N 78 (March 2002)
• Carrying capacity?
• Behavioral changes appearing in FL
• (Hedrick 2005 Maehr and Lacy 2002)

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SOURCES

• Belden, R.C. 1986. Florida panther recovery
  plan implementation A 1983 progress report.
  Pp. 159-172 in Miller, S.D. and D.D. Everett
  (eds.) Cats of the world biology, conservation
  and management. Caesar Kleberg Wildlife Research
  Institute, Kingsville, TX.
• Hedrick, P.W. 1995. Gene flow and genetic
  restoration the Florida panther as a case
  study. Conservation Biology 9996-1007.
• Hedrick, P.W. 2005. pp. 509-515 in Genetics of
  populations (3rd edition). Jones and Bartlett
  Publishers, Sudbury, MA. 737 pp.
• Maehr, D.S. and R.C. Lacy. 2002. Avoiding the
  lurking pitfalls in Florida panther recovery.
  Wildlife Society Bulletin 30971-978.
• O'Brien, S.J., M.E. Roelke, N. Yuhki, K.W.
  Richards, W.E. Johnson, W.L. Franklin, A.E.
  Anderson, O.L. Bass Jr., R.C. Belden and J.S.
  Martenson. 1990. Genetic introgression within
  the Florida panther Felis concolor coryi.
  National Geographic Research 6485-494.
• Seal, U.S. (ed.) 1994. A plan for genetic
  restoration and management of the Florida panther
  (Felis concolor coryi). Report to the Fla. Game
  and Freshwater Fish Commission. Conservation
  Breeding Specialist Group, Apple Valley, MN. 22
  pp.

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If interested in more ...

• Graduate School
• http//www.carnivoreconservation.org
• http//www.bearbiology.com
• http//www.wildlife.org

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• (Stay in school!)
• THANKS for being a great class!