1. Habitat Fragmentation 1. A reduction in total area 2. Creation of separate isolated patches from a larger continuous distribution 3. Leads to overall reduction in population size and reduced migration among patches. 1. A reduction in total area 2. Creation of separate isolated patches from a larger continuous distribution 3. Leads to overall reduction in population size and reduced migration among patches.

2. Population fragmentation Genetic diversity Genetic diversity inbreeding inbreeding Differentiation Differentiation Extinction Extinction These all depend on gene flow among fragments These all depend on gene flow among fragments Genetic diversity Genetic diversity inbreeding inbreeding Differentiation Differentiation Extinction Extinction These all depend on gene flow among fragments These all depend on gene flow among fragments

3. Population Fragmentation Number of fragments Number of fragments Distribution of population sizes in the fragments Distribution of population sizes in the fragments Geographic distribution or spatial pattern of populations Geographic distribution or spatial pattern of populations Dispersal ability of the species Dispersal ability of the species Migration rates between fragments Migration rates between fragments Time since fragmentation Time since fragmentation Number of fragments Number of fragments Distribution of population sizes in the fragments Distribution of population sizes in the fragments Geographic distribution or spatial pattern of populations Geographic distribution or spatial pattern of populations Dispersal ability of the species Dispersal ability of the species Migration rates between fragments Migration rates between fragments Time since fragmentation Time since fragmentation

4. Habitat Fragmentation

7. Population Fragmentation and H

8. Natural Disasters Hurricane Hugo in 89 wiped out 87% of the active nests in Francis Marion NF and killed 63% of the population. Through intensive management it has recovered by 33%. Hurricane Hugo in 89 wiped out 87% of the active nests in Francis Marion NF and killed 63% of the population. Through intensive management it has recovered by 33%.

9. Population Structure The genetic impacts of population fragmentation can go from insignificant to severe depending on the details of fragmentation. The genetic impacts of population fragmentation can go from insignificant to severe depending on the details of fragmentation.

10. Population structure 1. Totally isolated population fragments with no gene flow 2. Effectively single large – fragments where gene flow is sufficient to result in effectively a single large pop. 3. Island models where migration is equal among equally sized islands 4. Linear stepping stone models where only neighboring populations exchange migrants 5. Two-dimensional stepping-stone models where only surrounding populations exchange migrants 6. Mainland-Island 7. Metapopulations 1. Totally isolated population fragments with no gene flow 2. Effectively single large – fragments where gene flow is sufficient to result in effectively a single large pop. 3. Island models where migration is equal among equally sized islands 4. Linear stepping stone models where only neighboring populations exchange migrants 5. Two-dimensional stepping-stone models where only surrounding populations exchange migrants 6. Mainland-Island 7. Metapopulations

13. Fragmentation When a population is subdivided, individual alleles and genotypes are distributed among fragments. Fragments will be genetically differentiated from the beginning. When a population is subdivided, individual alleles and genotypes are distributed among fragments. Fragments will be genetically differentiated from the beginning. 1. Fragmentation resulting in an initial genetic sub-division of a population 2. Cumulative diversification, through genetic drift and inbreeding over time in each of the population fragments When a population is subdivided, individual alleles and genotypes are distributed among fragments. Fragments will be genetically differentiated from the beginning. When a population is subdivided, individual alleles and genotypes are distributed among fragments. Fragments will be genetically differentiated from the beginning. 1. Fragmentation resulting in an initial genetic sub-division of a population 2. Cumulative diversification, through genetic drift and inbreeding over time in each of the population fragments

14. Degree of Fragmentation A population of size N separated into f totally isolated equal sized fragments, the size of each fragment is N/f. A population of size N separated into f totally isolated equal sized fragments, the size of each fragment is N/f. Each frag will become inbred and lose genetic diversity at a rate dependant on N/f. Each frag will become inbred and lose genetic diversity at a rate dependant on N/f. A single pop. Of the same total size will become inbred and lose GD at a slower rate dependant on its size N. A single pop. Of the same total size will become inbred and lose GD at a slower rate dependant on its size N. A population of size N separated into f totally isolated equal sized fragments, the size of each fragment is N/f. A population of size N separated into f totally isolated equal sized fragments, the size of each fragment is N/f. Each frag will become inbred and lose genetic diversity at a rate dependant on N/f. Each frag will become inbred and lose genetic diversity at a rate dependant on N/f. A single pop. Of the same total size will become inbred and lose GD at a slower rate dependant on its size N. A single pop. Of the same total size will become inbred and lose GD at a slower rate dependant on its size N.

15. Degree of Fragmentation H declines with the number of fragments compared to a large pop.

16. Fragments Single pop N=500 ind./Gen. Single pop N=500 ind./Gen. Over 50 generations this pop. loses 5% Over 50 generations this pop. loses 5% While 2 populations of 250 lose 10% each and 5 populations of 100 lose 22% each of their initial H. While 2 populations of 250 lose 10% each and 5 populations of 100 lose 22% each of their initial H. Single pop N=500 ind./Gen. Single pop N=500 ind./Gen. Over 50 generations this pop. loses 5% Over 50 generations this pop. loses 5% While 2 populations of 250 lose 10% each and 5 populations of 100 lose 22% each of their initial H. While 2 populations of 250 lose 10% each and 5 populations of 100 lose 22% each of their initial H.

17. Divergence of Allele frequencies Will vary due to random genetic drift Will vary due to random genetic drift Each fragment will fix of lose different alleles Each fragment will fix of lose different alleles Drift among fragmented populations reduces overall heterozygosity across all fragments to below the expected HW Drift among fragmented populations reduces overall heterozygosity across all fragments to below the expected HW Will vary due to random genetic drift Will vary due to random genetic drift Each fragment will fix of lose different alleles Each fragment will fix of lose different alleles Drift among fragmented populations reduces overall heterozygosity across all fragments to below the expected HW Drift among fragmented populations reduces overall heterozygosity across all fragments to below the expected HW

18. Impacts of pop structure on repro fitness In island and stepping-stone models migration and population size are key In island and stepping-stone models migration and population size are key – No migration then Ne of each frag. In Source-sink structures then the effective pop. size will depend on Ne of mainland, thus inbreeding and loss of fitness will be much higher in this type than a SL. In Source-sink structures then the effective pop. size will depend on Ne of mainland, thus inbreeding and loss of fitness will be much higher in this type than a SL. Metapopulations typically have Ne that are smaller than the number of breeding adults due to extinction and recolonization. Metapopulations typically have Ne that are smaller than the number of breeding adults due to extinction and recolonization. In island and stepping-stone models migration and population size are key In island and stepping-stone models migration and population size are key – No migration then Ne of each frag. In Source-sink structures then the effective pop. size will depend on Ne of mainland, thus inbreeding and loss of fitness will be much higher in this type than a SL. In Source-sink structures then the effective pop. size will depend on Ne of mainland, thus inbreeding and loss of fitness will be much higher in this type than a SL. Metapopulations typically have Ne that are smaller than the number of breeding adults due to extinction and recolonization. Metapopulations typically have Ne that are smaller than the number of breeding adults due to extinction and recolonization.

19. Metapopulations

20. Genetically Viable populations So how many do we need???? So how many do we need???? What is the minimum Ne to keep genetics healthy? What is the minimum Ne to keep genetics healthy? Minimum Viable Population Size Minimum Viable Population Size So how many do we need???? So how many do we need???? What is the minimum Ne to keep genetics healthy? What is the minimum Ne to keep genetics healthy? Minimum Viable Population Size Minimum Viable Population Size

21. How Big??

22. One Horned Rhino

23. 3 goals 1. Retaining reproductive fitness by avoiding inbreeding depression 2. Retaining the ability to evolve in response to changes in the environment 3. Avoiding accumulation of new deleterious mutations 1. Retaining reproductive fitness by avoiding inbreeding depression 2. Retaining the ability to evolve in response to changes in the environment 3. Avoiding accumulation of new deleterious mutations

24. Estimates of Ne

25. How large Generally the goal is 500 = Ne Generally the goal is 500 = Ne This means that there must be 5000 indivs. This means that there must be 5000 indivs. Maintain long term viability Maintain long term viability Generally the goal is 500 = Ne Generally the goal is 500 = Ne This means that there must be 5000 indivs. This means that there must be 5000 indivs. Maintain long term viability Maintain long term viability

26. How large are endangered species pop’s Generally population size is smaller then the recommended 500. Generally population size is smaller then the recommended 500. Not doomed for immediate extinction but they will suffer depletion of genetic resources Not doomed for immediate extinction but they will suffer depletion of genetic resources Generally population size is smaller then the recommended 500. Generally population size is smaller then the recommended 500. Not doomed for immediate extinction but they will suffer depletion of genetic resources Not doomed for immediate extinction but they will suffer depletion of genetic resources

28. GLT

29. Genetic goals in management The GLT goal is to retain 98% of the genetic diversity for 100 years. The GLT goal is to retain 98% of the genetic diversity for 100 years. 630 wild + 360 reintro. 630 wild + 360 reintro. The Ne/N ratio must be.31 for total or.5 for wild animals to meet the goal. The Ne/N ratio must be.31 for total or.5 for wild animals to meet the goal. The GLT goal is to retain 98% of the genetic diversity for 100 years. The GLT goal is to retain 98% of the genetic diversity for 100 years. 630 wild + 360 reintro. 630 wild + 360 reintro. The Ne/N ratio must be.31 for total or.5 for wild animals to meet the goal. The Ne/N ratio must be.31 for total or.5 for wild animals to meet the goal.

32. The fallacy of small surviving populations A few small populations are surviving but this is not the majority. A few small populations are surviving but this is not the majority.