1. Quantitative Genetics in Red Squirrels: mechanisms of adaptation Basics Red squirrel examples –Parturition date –Growth rate Genomics and the future Andrew McAdam University of California, Santa Cruz mcadam@biology.ucsc.edu

2. Quantitative Genetics Examines the genetics of continuously varying (quantitative) traits Understanding the genetic basis to quantitative traits allows us to predict future evolutionary responses to selection Traditional Quantitative Genetics estimates sources of trait variation by examining the phenotypic resemblance among known relatives.

3. R = h 2 S J. Merilä R. Rothman Schroeder

4. 1.Sources of variation Heritability Maternal effects 2.Selection 3.Response to selection Quantitative Genetics in Red Squirrels Spruce Cones 198819901992199419961998 2000 0 50 100 150 200 250 300 350

5. Parturition Date Increase in Temperature Increase in Food Abundance

6. Parturition Date - Heritability h 2 = 0.16 ± 0.03 Matrilineal Pedigree (1989-2001) 1059 breeding events 568 females 5 generations Paternity and Maternal Effects?? - Réale et al., 2003, Evolution

7. S = - 8.96 ± 2.56 Parturition Date - Selection Fitness: total number of offspring produced in lifetime. Considered females dead prior to 2000 (n=303) - Réale et al., 2003, Evolution

8. Response to Selection (R) R = h 2 S Predicted R = - 1.4 days/gen. Observed R = - 6.0 days/gen. Plasticity = - 23.1 days/cone index - Réale et al., 2003, Proc. Roy. Soc. L., B (1991-2001) n = 11 years

9. Parturition Date Questions 1.Does food supplementation result in the plastic advancement in breeding? 2.Are there differences in the heritability of parturition date between the experimental and control populations? 3.Does selection on parturition date differ between experimental and control populations? 4.Do these differences in selection result in experimental evolution of earlier breeding?

10. Widespread Strong in mammals Predicted to have important effects on evolutionary dynamics…if heritable Maternal Effects Occur when the phenotype of a mother causes phenotypic effects in her offspring www.sbgmath.com

11. ~25 Days Nestling Growth Rate (g/day) Cross-Foster

12. Percentage of variation in growth in body mass Genetic Maternal G x E Error 10% 81% 9%9%9%9% h 2 = 0.09 ± 0.04

13. Maternal Growth Rate Offspring Growth Rate Maternal Effects Litter Size Parturition Date h 2 = 0.09

14. Maternal Growth Rate Offspring Growth Rate Maternal Effects h 2 = 0.09 h 2 t = 0.31 + + - McAdam et al., 2002, Evolution

15. Food Effects on Growth 19992000Food Growth rate (g/day) 1.5 1.6 1.7 1.8 1.9 2.0 2.1 Cross-fostered n = 32 n = 176 n = 72 1989 - 2001 Slope = 0.23 g/day/log cones t-1 n = 13 years

16. Maternal cov (dir,mat) 1999 0.043 2000 0.079 Food- 0.005 Coefficient of Variation 0.00 0.05 0.10 0.15 0.20 0.25 Direct Genetic 19992000Food h 2 t = 0.52* (h 2 = 0.10)* h 2 t = 0.70 (h 2 = 0.12) h 2 t = 0.57 (h 2 = 0.57) - McAdam & Boutin, 2003, J. Evol. Biol.

17. Viability Selection on Growth - McAdam & Boutin 2003, Evolution Fitness: survival to potential breeding age Other variables in model: Litter size, parturition date, sex, year No spatial variation in selection

18. Components of Selection Birth Emergence Recruitment Breeding Spring temperature (-) Previous year’s cones (+)

19. Corrected Growth (t) Corrected Growth (t+1) Selection Maternal Effects h 2 Response

20. Maternal Effects and the Response to Selection 198919911993199519971999 Response (g/day) -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 Year * * * 1.Observed response greater than predicted by h 2 2.Response not independent of selection in the previous generation - McAdam & Boutin 2003, Proc. Roy. Soc. L., B

21. Growth Rate Questions 1.Does food supplementation increase nestling growth rates? 2.Does food supplementation eliminate maternal effects? 3.Does selection on growth rates differ between experimental and control populations? 4.Do these differences in selection result in experimental evolution of earlier breeding? 5.Do maternal effects contribute to evolution in the control population but not the food supplemented one?

22. Genetic Mechanisms of Adaptation It has recently become possible to use genetic markers to determine regions of the genome (loci?) that contribute to quantitative variation. Quantitative Trait Loci (QTL’s) QTL’s can be mapped for natural populations with extensive pedigrees and many molecular markers

23. Genetics of Speciation in Sticklebacks - Peichel et al., 2001, Nature

24. Ecological and Evolutionary Functional Genomics (EEFG) GenesGenotypePhenotypePhenotype’ Evolution Genomics Q. Genetics Development Selection

25. GenesGenotypePhenotypePhenotype’ Evolution