BIOL 4100 Animal Physiology

1. BIOL 4100 Animal Physiology

2. Topics covered in Ch 1 The importance of physiology The central questions of physiology. Physiological approaches Mechanistic Evolutionary Comparative Environmental Homeostasis The 5 time frames in which physiology changes Physiology and the environment Evolutionary physiology

3. The importance of physiology Understand the fundamental biology of all animals. Provides insight into human health and disease. Provides a foundation for understanding the health and disease of animals. It is the most integrative discipline.

4. The integrative nature of Physiology anphys-fig-01-01-1.jpganphys-fig-01-01-1.jpg

5. Mechanism and origin Mechanism refers to how an organism functions or behaves. Origin refers to how a mechanism arose.

7. The question of mechanism in Physiology anphys-fig-01-02-1.jpg anphys-fig-01-02-1.jpg

8. Mechanisms occur on different levels

9. The question of mechanism in Physiology anphys-fig-01-02-2.jpganphys-fig-01-02-2.jpg

10. The question of mechanism in Physiology anphys-fig-01-02-3.jpganphys-fig-01-02-3.jpg

11. How to produce a flash of light

12. The adaptive function of light production Producing light can be used for different means luring prey, distracting predators, synchronizing biorhythms. Producing light is anaother means of communicataion do all light producing organisms use the same mechanism? Producing light can be used for different means luring prey, distracting predators, synchronizing biorhythms. Producing light is anaother means of communicataion do all light producing organisms use the same mechanism?

13. Origin arises from adaptive significance Natural selection is the increase in gene frequency for traits that confer a selective advantage. Adaptation is the trait produced by natural selection. Adaptive significance is why a trait is an asset. Understanding mechanism does not lead to an understanding of adaptive significance. Francoise Jacob asked whether evolution by natural selection more closely resembled engineering or tinkering. Understanding mechanism does not lead to an understanding of adaptive significance. Francoise Jacob asked whether evolution by natural selection more closely resembled engineering or tinkering.

14. Disciplines of physiology Mechanistic physiology—how animals perform life-sustaining functions Evolutionary physiology—explores adaptive significance of physiological mechanisms. Comparative physiology—explores variation physiological traits among animals. Environmental physiology—explores how organisms interact with the environment. Integrative physiology—explores the synthesis of features across levels of organization.

15. Cephalopod and fish eyes

16. Animal properties Animals are structurally dynamic. Atoms dynamically interchange with the environment. Animals are made up of organized systems that require energy to be maintained. The organization persists through time. Internal and external environment Time and size are significant properties. Rudolf Schoenheimer traced the composition of organisms through chemical isotopes. Example 56Fe and 58Fe Claude Bernard coined the term internal environment to refer to the internal conditions to which a cell is exposed.Rudolf Schoenheimer traced the composition of organisms through chemical isotopes. Example 56Fe and 58Fe Claude Bernard coined the term internal environment to refer to the internal conditions to which a cell is exposed.

17. Conformity and regulation anphys-fig-01-05-0.jpganphys-fig-01-05-0.jpg

18. Mixed conformity and regulation in a single species anphys-fig-01-06-0.jpganphys-fig-01-06-0.jpg

19. Homeostasis As defined by Walter Cannon, homeostasis is the existence of regulatory systems that automatically make adjustments to maintain internal constancy. Negative feedback systems Positive feedback systems

20. Physiology and time Changes in response to the external environment Acute changes Chronic changes Evolutionary changes Changes that are internally programmed Developmental changes Changes controlled by periodic biological clocks

21. Heat acclimation in humans anphys-fig-01-07-0.jpgYoung men walked 3.5 miles per hour in hot dry air (20% humidity, 49o C or 120o F).anphys-fig-01-07-0.jpgYoung men walked 3.5 miles per hour in hot dry air (20% humidity, 49o C or 120o F).

22. Phenotypic plasticity Defined as the ability of an organism to express more than one genetically controlled phenotype. Acclimation is the chronic response to a changed environment that varies in a few specific ways. Acclimatization is the chronic response to a new environment that differs in numerous ways.

23. Function of body size in mammals anphys-fig-01-08-0.jpganphys-fig-01-08-0.jpg

24. Animal environments The environment is the chemical, physical, and biotic components of an organism’s surroundings. Temperature O2 levels Water The Big 3 that set the stage for life. Temperature is a measure of the intensity of the random motion of atoms and molecules. O2 levels vary according to altitude and its ability to diffuse in both air and water. Water is a universal solvent and necessary for the function and chemistry of macromolecules. The Big 3 that set the stage for life. Temperature is a measure of the intensity of the random motion of atoms and molecules. O2 levels vary according to altitude and its ability to diffuse in both air and water. Water is a universal solvent and necessary for the function and chemistry of macromolecules.

25. Fish around Antarctica spend their entire lives at body temperatures near –1.9°C anphys-fig-01-09-0.jpganphys-fig-01-09-0.jpg

26. Adaptations to temperature Temperature conformers operate at the extremes of temperature. Arctic aquatic animals can function with tissue temperatures of -1.9oC. Insects can endure tissue temperatures of -60o to -70oC Lizards in the desert can function at tissue temperatures of 45o to 52oC Diversity of species declines at temperature extremes.

27. Temperature effects on Butterfly biogeography anphys-fig-01-10-0.jpganphys-fig-01-10-0.jpg

28. Oxygen is necessary for metabolism O2 is necessary to combine with H+ that is released from biochemical reactions. O2 is abundant at low and moderate altitudes. O2 less abundant at higher altitudes and in water. O2 availability in water depends on density and temperature. Increases in salinity increase density

29. Adaptations to O2 availability In tropical hypoxic waters animals adapt by becoming air breathing. Absorb O2 across lining of mouth, stomach, or intestines Lunglike structures Adapt a biochemistry that allows H+ bind to another molecule rather than O2. Adapt tissues that can function with less O2 Intestinal parasites can live in O2 free environments.

30. Density layering and oxygen supply anphys-fig-01-13-0.jpgO2 enters in lake through photosynthesis or aeration of water at the surface Sunheated surface of the water tends to float on top of the deeper water The thermocline is the transition layer where temperatures change rapidly with depth Lack of mixing with surface waters leads to O2 depletion in the depths.anphys-fig-01-13-0.jpgO2 enters in lake through photosynthesis or aeration of water at the surface Sunheated surface of the water tends to float on top of the deeper water The thermocline is the transition layer where temperatures change rapidly with depth Lack of mixing with surface waters leads to O2 depletion in the depths.

31. Water: the primordial environment Animals living in salt water have blood with a similar composition to the sea. Freshwater animals had to adapt mechanisms that reduced taking on water osmotically. Animals in salt water that have lower salt concentration in blood develop mechanisms to distill water. Terrestrial animals had to develop an integument to prevent evaporation of water. Water is important to life—universal solvent, required for proper composition of the blood and is important in maintaining the shape of macromolecules. Animals living in salt water have blood with a similar composition to the sea. Freshwater animals had to adapt mechanisms that reduced taking on water osmotically. Terrestrial animals had to develop an integument to prevent evaporation of water. Integumentary lipids Develop tolerance to dehydration Animals in salt water that have lower salt concentration in blood develop mechanisms to distill water. Water is important to life—universal solvent, required for proper composition of the blood and is important in maintaining the shape of macromolecules. Animals living in salt water have blood with a similar composition to the sea. Freshwater animals had to adapt mechanisms that reduced taking on water osmotically. Terrestrial animals had to develop an integument to prevent evaporation of water. Integumentary lipids Develop tolerance to dehydration Animals in salt water that have lower salt concentration in blood develop mechanisms to distill water.

32. Microenvironments and microclimes Microenvironments are the variations in a larger environment Microclimates are the temperature, humidity, windspeed of a microenvironment. The two can affect O2 levels and water levels. Animals can modify their environments. Migration Animals can alter the temperature and O2 levels in their environment.

33. Microenvironments in a desert anphys-fig-01-15-0.jpg Microenvironments—small places can provide significantly different environments. This is more true for smaller animals than larger animals, which tend to respond to the average of conditions. Qualities of a microenvironment consist of temp, humidity, and wind temp. Desert rodents can reside in an area that is between 15 and 32 degrees C throughout the year.anphys-fig-01-15-0.jpg Microenvironments—small places can provide significantly different environments. This is more true for smaller animals than larger animals, which tend to respond to the average of conditions. Qualities of a microenvironment consist of temp, humidity, and wind temp. Desert rodents can reside in an area that is between 15 and 32 degrees C throughout the year.

34. Winter microenvironments anphys-fig-01-16-0.jpgSanphys-fig-01-16-0.jpgS

35. Evolutionary processes Evolution is defined as the change of gene frequencies over time of a population of organisms. Natural selection is the match between an organism and its environment. Evolution is not always adaptive—the optimum traits may not be available in the genetic pool. Genetic drift

36. Nonadaptive evolution Genetic drift is when gene frequencies shift Bottleneck effect Founder’s effect Genes affected by drift can sometimes confer no fitness benefit. Pleiotropy is the control by a gene of traits that appear unrelated. Adapted traits in one environment may not be useful in another environment.

37. Not all traits are adaptive Gould and Lewontin claimed natural selection is one of many processes that give rise to traits. An adaptive trait is hypothesized and must be experimentally tested.

38. Adaptation is empirical Can observe evolution. Can use comparative method Compare how particular functions are carried out in different organisms Invagination and evagination of breathing structures. Studies of laboratory populations over generations Single-generation studies of individual variation. Create variation in organism for study. Study genetic structure of natural populations. Phylogenetic reconstruction

39. The comparative method anphys-fig-01-17-0.jpganphys-fig-01-17-0.jpg

40. Physiological variation among individuals of a species anphys-fig-01-18-0.jpganphys-fig-01-18-0.jpg

41. The effects of genetic diversity on evolutionary potential anphys-fig-01-19-0.jpganphys-fig-01-19-0.jpg

42. Evolutionary potential Depends on genetic variation No evolution when there are fixed alleles