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Evolutionary physiology topics

Evolutionary physiology topics. 1. Patterns. 2. Processes. Evolutionary physiology topics. 1. Patterns. How and why of particular transitions. How and why did endothermic vertebrates evolve from ectothermic ancestors?. Endothermy versus ectothermy. scala naturae.

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Evolutionary physiology topics

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  1. Evolutionary physiology topics 1. Patterns 2. Processes

  2. Evolutionary physiology topics 1. Patterns • How and why of particular transitions How and why did endothermic vertebrates evolve from ectothermic ancestors?

  3. Endothermy versus ectothermy scala naturae

  4. Endothermy versus ectothermy

  5. Endothermy versus ectothermy Advantages of endothermy: • Independent of environment • Stenothermy • Aerobic metabolism

  6. Endothermy versus ectothermy Advantages of ectothermy: • Low energetic requirements

  7. mammals Passerine birds reptiles metabolism (Wg-1day-1) 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 0.1g 10g 1kg 100kg 1000kg

  8. Endothermy versus ectothermy Advantages of ectothermy: • Low energy requirements • Low food habitats

  9. Endothermy versus ectothermy Advantages of ectothermy: • Low energy requirements • Low food habitats • Fluctuating food habitats

  10. Flinders Island Mt Chappell Island Cape Barren Island

  11. Chappell Island tiger snake (Notechis ater serventyi) Short-tailed shearwater (Puffinus tenuirostris)

  12. Gila monster (Heloderma suspectum)

  13. Western banded gecko (Coleonyx variegatus)

  14. Endothermy versus ectothermy Advantages of ectothermy: • Low energy requirements • Low food habitats • Fluctuating food habitats • Small body dimensions

  15. body length surface/volume

  16. mammals: >20 g lizards: 8% spp. < 1 g 80% spp. < 20 g salamanders: 20% spp. < 1 g 90% spp. < 20 g

  17. Dwarf chameleon Monte Iberia Eleuth Dwarf gecko

  18. Kitti’s hog-nosed bat L: 29-33 mm Etruscan shrew W: 1.5-2.5 g FR: 4xW/day HR: 835 b/min RR: 661 p/min

  19. Endothermy versus ectothermy Advantages of ectothermy: • Low energy requirements • Low food habitats • Fluctuating food habitats • Small body dimensions • Elongate body forms

  20. surface/volume diameter height height/diameter

  21. wood rat (Neotoma sp.) weasel (Mustela nivalis) energy loss: x2

  22. Afrocaecilia taitana Desmognathus ochrophaeus Bipes bipes Anguis fragilis

  23. Opheodrys aestivus

  24. Endothermy versus ectothermy Advantages of ectothermy: • Low energy requirements • Low food habitats • Fluctuating food habitats • Small body dimensions • Elongate body forms • Low water habitats

  25. Sauromalus obesus Scaphiopus couchii

  26. Endothermy versus ectothermy Advantages of ectothermy: • Low energy requirements • Low food habitats • Fluctuating food habitats • Small body dimensions • Elongate body forms • Low water habitats • Low oxygen habitats

  27. Iguana iguana Amblyrhynchus cristatus

  28. Neoseps reynoldsi

  29. Scincus mitranus

  30. Dilong paradoxus Xu et al. 2004. Nature 431: 680-684.

  31. Synapsida (mammal-like reptiles) Dimetrodon (Pelycosauria) Moschops (Therapsida)

  32. Endothermy in Mammalia: RM x5 Tb > Ta, 28°C < Tb < 40°C DTcore < 1-2°C Maerox5

  33. increase in size (30-100 kg) become inertial homeotherms Tb constant, physiological benefits evolve insulation decrease in size increased metabolism improved insulation • Thermoregulation first • physiological version Synapsida evolve from small ectotherms McNab 1978. Am. Nat. 112: 1-21.

  34. increase in size (30-100 kg) becomeinertial homeotherms evolve larger, more complex brains Tb constant, physiological benefits evolve insulation • Thermoregulation first • brain version Synapsida evolve from small ectotherms Hulbert 1980.

  35. increase in size (30-100 kg) becomeinertial homeotherms evolve nocturnal habits Tb constant, physiological advantages evolve insulation • Thermoregulation first • ecological version Synapsida evolve from small ectotherms Crompton et al. 1978. Nature 272: 333-336.

  36. Aerobic capacity first • sustained ativity version small change in basal metabolic rate minimal effect on thermoregulatory capacity large effect on maximal aerobic metabolic rate Ruben 1995 Ann. Rev. Physiol. 57: 69-95.

  37. Aerobic capacity first • parental care version small change in basal metabolic rate minieme verandering in thermoregulatie-capaciteit large effect on maximal aerobic metabolic rate necessary for locomotor costs related to parental care Koteja 2000 Proc. R. Soc. Lond. 267: 479-484

  38. Evolutionary physiology topics 1. Patterns • How and why of particular transitions • Testing a-priori-hypotheses • plastic responses are adaptive

  39. Dicerandra linearifolia • leaf length • leaf thickness • density of stomata Winn A.A. 1999. J. Evol. Biol. 12: 306-313.

  40. Winn A.A. 1999. J. Evol. Biol. 12: 306-313.

  41. Winn A.A. 1999. J. Evol. Biol. 12: 306-313.

  42. Beneficial acclimation hypothesis

  43. Beneficial acclimation hypothesis Colder is better Hotter is better

  44. Beneficial acclimation hypothesis Deleterious acclimation hypothesis

  45. Beneficial acclimation hypothesis Escherichia coli Leroi et al. 1994.Proc. Natl. Acad. Sci. USA 91: 1917-1921.

  46. 32° 32° 32° 37° 41.5° 41.5° 41.5° competition acclimation Beneficial acclimation hypothesis > Escherichia coli > Leroi et al. 1994.Proc. Natl. Acad. Sci. USA 91: 1917-1921.

  47. Beneficial acclimation hypothesis Bicyclus anynana Geister T.L. & Fischer 2007. Behav. Ecol. 18: 658-664.

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