Nonevolutionary Responses to Environmental Change

1. Nonevolutionary Responses to Environmental Change Organisms can change to perform better in different conditions, without a change in population genetic makeup

2. Time scales, mechanisms, flexibility Regulatory Physiological/behavioral <<1 generation Reversible Acclimatory Physiological/behavioral <1 generation Reversible Developmental Developmental/behavioral ~1 generation Irreversible Evolutionary Genetic/ecological >1 generation Reversible

3. Regulatory Responses No morphological change required, involves physiology or behavior Modified activity to maintain favorable body conditions Examples: Sweating, panting, shivering, altered kidney filtration, altered heart rate, drinking, basking Objective: homeostasis-- buffer the internal environment of an individual, or to modify the immediate external environment.

4. Acclimatory Responses Change in physiology, behavior, or morphology, in response to environmental changes, especially seasonal changes Examples: Fur growth Color change Foliage loss Flowering Mating coloration Antler growth Mating rituals Feeding patterns Responses to environmental cues (e.g. change in day length)

5. Developmental Responses (Phenotypic Plasticity) Differences in body form or behavior depending on environmental conditions

6. Induced defenses and cyclomorphosis

7. Nonevolutionary responsesare not adaptations, but they are adaptive Response itself is done without genetic change, but the ABILITY to make the response has very likely evolved through adaptation (i.e. natural selection) Success of response Survival and Reproduction Establishment and Maintenance of population

8. Distributions Summarize the locations where a species has been successful Do not tell us about locations where they could be successful Do not tell us about places where a species has failed Understanding distributions relies on knowing what factors prevent species from occupying a particular location or region

9. Ranges Geographic-- set of places actually occupied Ecological-- set of places with suitable conditions C B A Ecological > Geographic Reasons why involve most topics of interest to ecologists

10. Explaining an Absence Species does not occur because: It can’t reach it It doesn’t choose to (habitat selection) Physical or chemical conditions not favorable Other organisms in the area prevent establishment (competition, predation, parasitism) or a key species (food, mutualist) is missing Chance

11. Transplant experiments Remove suspected dispersal barrier Success: transplanted populations grow Reject: physical/chemical factors Reject: species interactions Support: dispersal barrier Failure: transplanted populations dwindle Reject: dispersal barrier Consistent with species interactions or physical/ chemical factors Problem: ethical considerations of transplantation

12. Solutions: Compare occupied and unoccupied environments What major factors differ? --> hypotheses Duplicate differences in laboratory setting “Transplant” occurs in lab; hypotheses tested limitation: lab setting Conduct transplants in field under highly controlled conditions Catch species in the act of invasion

13. Lessons from Invasions and Introductions Chestnut Blight Starling Dutch Elm Disease Gypsy moth Hessian Fly Aedes albopictus Norway maple Rabbits to Australia Failed introductions: Fish stocking Seeds in wool

14. Become clearest when they are overcome and followed by successful invasions Dispersal Barriers European Starling:

15. Chestnut Blight

16. Gypsy Moth

17. Gypsy Moth, recent

18. Gypsy Moth

19. Antarctic Beech, Nothofagus

20. Antarctic Beech, Nothofagus

21. Dispersal Strategies

22. Water Striders

23. Desert Locusts

24. Niche

25. Tsetse Fly

26. Temperature and Aedes aegypti

27. Barnacle life cycle

28. Temperature and Barnacle dist.

29. Moisture

30. Composition of Calif. Forests

31. Other factors Fire

32. Currents

33. Oxygen

34. Light, or tolerance to shade

35. Interactions between factors Climographs

36. Hungarian Partridge: Climograph for home range and for two places where introductions were attempted. Interactions between factors

37. Interactions between factors Mediterranean Fruit Fly and Tel Aviv climates in Two years

38. Interactions between factors Mediterranean Fruit Fly and Tel Aviv climates in Two years Georgia climates (A: coastal plain; B: northern mountains)

39. Interactions between factors Climographs Mediterranean Fruit Fly and Tel Aviv climates in Two years Georgia climates (A: coastal plain; B: northern mountains)

40. Interspecific Interactionsand distribution • Restriction of a species’ distribution • Some areas may be unfavorable because of: • Predation in unoccupied areas • Food supply is inadequate in unoccupied sites • Competition with another species in unoccupied sites • Parasitism and disease in unoccupied areas • Commensalism (absence or shortage of host sp.) • Mutualism (absence or shortage of partner sp.)

41. Parasitoids Pupae of tachinid fly, just left their moth larva host Ichneumonid wasps and caterpillar host

42. Parasitoids Braconid wasp pupal cocoons on Tobacco Hornworm

43. Predation

44. Food Supply

45. Competition

46. Parasites, Mutualists

47. Niches Fundamental Niche: set of physical, chemical and resource conditions necessary for population maintenance Realized Niche: set of physical, chemical and resource conditions necessary after taking species interactions into account-- a smaller set and a subset of Fundamental Niche

48. Niche and Distribution Conditions Places

49. Niche and Distribution Conditions Places Fundamental Niche Ecological Range

50. Niche and Distribution Conditions Places Fundamental Niche Ecological Range Species Interactions Realized Niche