1. Chapter 1 Animals and Environments: Function on the Ecological Stage
Chapter 1 Animals and Environments: Function on the Ecological Stage
BIOLOGY 3408

2. Alvizo, Cyndi Cecilia Craft, Kyle Michael Dominguez, Kenisha Michelle Garza, Rene Ricardo Lozano, Savannah Lynn Martinez, Dionisio Paredez Mcelroy, Terri Marie McMillan, Alexander Joe Mendez, Erasmo Alejandro Vela, Angelina Marie Villarreal, Pete Villavicencio, Ivan Hertel, Brent John Nguyen, Morgan Marie Ramos, Amanda Serna, Justin Taylor, Jarred Joseph Valdez, Jeremiah Alexander
Alaniz, Jose Daniel Alaniz, Michelle Chavarria, Melissa N Escatiola, Emily Nicole Garza, Victoria R Gonzalez, Luis Amando Manigault, Erykah Cire' Newsome, Jacob D'Juan Rodriguez, Brenda Vega, Esmeralda

3. LAB MEETS THURSDAY!!

4. Review Question 1
What is physiology?

5. Physiology
Study of how organisms function
Internal or external traits to gain energy, grow, move, reproduce and interact with the environment.
Integrates knowledge at all levels of organization (atoms to organisms; physics to evolution)

6. Animals live in wide range of habitats and environments
Two broad categories of physiological responses to environmental changes
Conform
Regulate
Conform = the change/environment is “in control” – “go with the flow” vs. “take charge”, direct and control the parameters

7. Review Question 2
What is the difference between a physiological regulator and a physiological conformer? Give an example of each.

8. Review Question 3
What are the benefits and costs of being a conformer?

9. 1: Conformers (Fig 1.6a) Benefit: Change/Environment is “in control”
Do not expend energy to maintain internal conditions
“go with the flow”
inexpensive, but unable to maintain homeostasis for internal conditions

10. 1: Conformers
Costs:
enzymes typically perform best in specific conditions
If conditions change, some will not function optimally.

11. Review Questions 4 and 5
What are the benefits and costs of being a regulator?
What is the main the benefit of physiological regulation

12. 2: Regulators (Fig 1.6b)
internal environment kept within narrow limits, no matter what the environment
Benefit
Enzymes, etc. function optimally
Cost
Requires energy to direct and control parameters
Conform = the change/environment is “in control” – “go with the flow” vs. “take charge”, direct and control the parameters

13. Review Questions 6 and 7
Be able to draw a graph similar to Fig. 1.6 or 1.7 to illustrate conformity and/or regulation. Which graph represents homeostasis? Why?
What does Figure 1.7 indicate about salmon?

14. Figure 1.7 Mixed conformity and regulation in a single species
anphys-fig jpg

15. Homeostasis (Box 1.1)
pervades every aspect of the physiological mechanisms of life

16. Review Question 8
Who are Claude Bernard and Walter Cannon? What is their importance?

17. Claude Bernard (1813-1878) Walter Cannon (1871-1945):
“Constancy of the internal environment is the condition for free life”
Physiological processes function within relatively narrow ranges
Walter Cannon ( ):
introduced the term “homeostasis = coordinated physiological processes which maintain most of the constant states in the organism”.

18. Review Question 9
What is homeostasis? Why is it important?

19. Homeostasis
Body conditions are maintained independent of external environment
Requires
sensing internal and external conditions
responding to changes using biochemical, physiological, behavioral, and other mechanisms (generally there is a maximum ability to do this)

20. Review Questions 10 and 11
Why does homeostasis require negative feedback control?
Explain and give an example example of a negative feedback loop.

21. Homeostasis requires regulation via Negative Feedback control
The Positive System of Negative Feedback.
Mechanisms reestablish homeostasis when there is an imbalance by reestablishing a set point.
Homeostatic Regulation of Body Temperature through Negative Feedback

22. Review Questions 12 and 13
Explain and give an example example of a positive feedback loop.
In physiological systems, why are positive feedback loops of limited duration?.

23. Positive feedback systems
are rare, short duration, part of a larger negative feedback system (e.g. blood clotting, action potentials, oxytocin and childbirth)

24. Review Question 14
What are some of the ways an individual's phenotype can change?

25. Physiological traits are
Physiological traits are
Genetically determined
Environmentally determined
Combination of both

26. Proximate questions – How? mechanisms responsible for interactions
Two types of questions
Proximate questions – How?
mechanisms responsible for interactions
processes, mechanisms, “nuts and bolts”
Ultimate questions – Why?
how these interactions influence an individual's survival and reproduction.
evolutionary reasons, fitness consequences
Physiologists attempt to understand and account for diversity of animal body form and strategies that animals use to cope with their environments.

27. Review Question 15
Physiological responses can be categorized as being acute, chronic, or evolutionary. Define each, in terms of what is going on at the molecular (e.g., gene and/or protein) level, and explain why each is occurring.

28. Irreversible change in individual of the genotype Adaptation
Within population changes in physiology that are responses to changes in the external environment.
EVOLUTIONARY
Adjustment of physiology to environmental conditions in populations across generations
Irreversible change in individual of the genotype
Adaptation
modifications occurring within a species that increase ability to survive and reproduce in a particular environment (natural selection)

29. Rapid responses (e.g. within minutes) No change in gene expression,
Within individuals changes in physiology that are responses to changes in the external environment 1.
Short term or ACUTE
changes that individuals exhibit soon after their environments have changed.
Rapid responses (e.g. within minutes)
No change in gene expression,
Acute changes are reversible.

30. Change in how a gene is expressed Change in phenotype not genotype
Within individuals changes in physiology that are responses to changes in the external environment 2
Long term or CHRONIC
Changes that individuals display after they have been in new environments for days, weeks, or months
Change in how a gene is expressed
Change in phenotype not genotype
Tends to be reversible
Phenotypic plasticity (next slide)

31. Review Question 16
What is phenotypic plasticity?
What is the difference between a chronic and an evolutionary (adaptation) physiological response? Give an example of each in response to the same physiological challenge.

32. 2. Reversible Chronic Change
2. Reversible Chronic Change
Phenotypic plasticity:
The ability to express more than one genetically controlled phenotype
range of physiological responses in an individual during its lifetime in response to changes in the environment
For example, the salmon

33. Migrating Pacific salmon
Physiological changes are made to identify a home stream, swim hundreds of miles, and shift from freshwater to sea water and finally back to freshwater.
anphys-opener-01-0.jpg

34. E. Phenotypic Plasticity (cont.)
Acclimatization
change within an individual that results from the chronic exposure in its habitat to new naturally occurring environmental conditions
Acclimation
same process except it is initiated by the investigator either in the lab or in the wild.

35. Review Question 17
Is acclimation or acclimitization an acute, chronic, or evolutionary response? Explain why it is this type of response. Explain why it is not each of the other two physiological responses.

36. Review Question 18
Explain what is meant by the following two statements.
Tibetans have adapted to living in the Himalayan mountains at high elevations.
When I go to Tibet to see the Himalayas, I acclimate to living at high elevations.
???????????

37. Review Question 19
Fig What is the difference between a chronic and an acute response to environmental conditions? Give an example of each in response to the same physiological challenge.

38. Review Question 20
Figure 1.8 is an example of physiological responses of 24 men to heat and excercise over seven days.
What part of the graph represents the acute response?  Give some examples of acute responses that may have occured.
What part of the graph represents acclimation.  Is acclimation an example of an accute, chronic, or evolutionary response?  Justify your answer.
Give two examples of the physiological changes (biochemical/cellular) that took place during acclimation that are examples of phenotypic plasticity. At day 7 has an evolutionary response occurred? Explain why or why not.
In Figure 1.8, what part of the graph represents the chronic response?  The acute response?  What happened in terms of physiological response from day 1 to 6 and after day 6? Explain why Figure1.8 illustrates an example of phenotypic plasticity.
Give two examples of the physiological changes (biochemical/cellular) that took place from day 1 to day 7 that are examples of phenotypic plasticity

39. Figure 1.8 Heat acclimation in humans as measured by exercise endurance
Walk 3.5 miles at 49°C at 20% Humidity
Day 1: acute response
No change in gene expression
sweat a little, overheat a lot
0/24 walked for 100 mins.
24 fit humans without Heat experience
anphys-fig jpg

40. Day 6: chronic response is maximally achieved
Figure 1.8 Heat acclimation in humans as measured by exercise endurance
Days 2-6: aclimation
Day 6: chronic response is maximally achieved
23/24 walked 100 mins.
24 fit humans without Heat experience
anphys-fig jpg

41. Heat Acclimatization Change in Gene Expression
expanded plasma volume
increased sodium chloride retention
reduced heart rate
Increased cardiac output to skin capillary beds and active muscle.
increased sweat rate, earlier onset of sweat production
Reversible: will revert to acute

42. Body size influences biochemical and physical patterns
Body Size and Scaling
Body size influences biochemical and physical patterns

43. Living organisms: huge differences in size
length
Mass
Mycoplasma
0,2 µm
210-5 cm
< 0,1 pg
< g
bacterium
(on average)
20 µm
210-3 cm
0,1 ng
10-10 g
ciliate (Tetrahymena)
0,2 mm
210-2 cm
0,1 µg
10-7 g
large amoeboïd eukaryont
2 mm
210-1 cm
0,1 mg
10-4 g
honey bee
2 cm
2100 cm
100 mg
10-1 g
hamster
20 cm
2101 cm
100 g
102 g
human (Homo sapiens)
2 m
2102 cm
100 kg
105 g
blue whale
20 m
2103 cm
100 ton
108 g
Sequoia, Eucalyptus
100 m
1104 cm
1000 ton
> 109 g
109
1022
Bouw & Functie 2: Digestiestelsel

44. Review Questions 21, 22, 23
Why were log scales used in figure 1.9 (gestation period versus body mass)?
From the data on this graph, compare actual versus expected gestation period for several species.  Which of these would you find interesting to investigate?  Why?
Calculate the slope of the equation line in Fig. 1.9.  What is the Y intercept for this line?  What is the equation for this line?

45. HWA Appendix D-F Fitting lines to data Least squares regression
Fig 1.9 Length of gestation scales as a regular function of body size in mammals
HWA Appendix D-F Fitting lines to data
Least squares regression
What does this show about the reedbuck (and others)
Why?
???
anphys-fig jpg

46. Review Question 24
What is the difference between an isometric and an allometric relationship between physiological variables?

47. Isometric Growth Proportional growth. Shape is not changed
each dimension is scaled up or down regardless of the disproportionate change in such parameters as surface area and volume
isometric – proportional growth – follows a predictable formula as in equiangular spiral growth

48. Isometric growth (cont.)
If x doubles in length, then so does y.
Proportions remain constant and do not change with a change in size.

49. Isometric Growth (cont.)
Can also follow a predictable formula such as as in equiangular spiral growth
Left: ram’s horn
Right: Nautilus
isometric – proportional growth – follows a predictable formula as in equiangular spiral growth

50. Allometric Growth
Changes in body proportions accompany changes in body size

51. Allometric Growth
Different rates of growth of different parts at different stages
Important in physiology.
Proportions of an organism adjust to the different rates at which surface area, volume, and other physical parameters change with differing sizes

52. Body Size Profoundly Influences Physiology
Gravity
Circulation
Movement and Locomotion

53. Review Question 25
Why are there allometric changes in the proportions of the limb bones of a mouse and an elephant?

54. Bone shape changes with increasing body size.
Need a proportionately
thicker limb bone to
support the increased mass
Galileo Galilei, 1637 human versus elephant bone

55. Review Question 26
Why is the surface area to volume ratio important for physiology?  What happens to surface area as volume of a cube or sphere increases?

56. Size in the Life of Animals
Surface area to volume
SA/V α r2/3
is very important in the effects of body size on body structure and physiology

57. Surface to volume ratio
Surface to volume ratio
affects temperature regulation
water balance
bone and muscle structure
relative strength (ants)
structural integrity (throw an ant and an elephant out of a 3 story window)

58. Review Question 27
Explain the significance of the four terms in the equation Y = aMb

59. Y = aXb (a power function)
Allometric Equation
Y = aXb (a power function)
Y = variable being measured in relationship to the size of the organism
X = measure of size used for basis of comparison
usually a measure of whole body size

60. Total MR = * Mb0.75

61. Allometry
Allometric data can also be expressed as linear functions of Log-Transformed Data
Y = aXb
log Y = log a + b log X

62. Allometric Equation: Y = aXb
a is a coefficient; constant (typical for the organism and trait measured)
a = initial growth index
size of Y when X = 1 (b = 0)
b is the allometry exponent or scaling exponent,
proportional change in Y per unit X
b is not equal to 1 (if b =1, then growth is isometric)

63. Allometric Equation: Y = aXb
a is a coefficient;
b is the allometry or scaling exponent,
proportional change in Y per unit X
b is not equal to 1 (if b =1, and variables are equidimensional, then growth is isometric)

64. For many physiological properties Y = aMb
ALLOMETRY
For many physiological properties
Y = aMb
M is size, often measured as mass
measures the rate at which feature Y changes with body size.

65. Review Questions 28 and 29
In the equation Y = aMb, what is occurring if b<1, b=1, and b>1.
For values of b< or >1, what is the advantage of plotting variables on log scales for both X and Y?

66. The Scaling Exponent (b) Defines the Type of Scaling Relationship
Y = aXb
If b = 1, isometry (geometric similarity)
If b < 1, negative allometry
If b > 1, positive allometry
The Catch:
Above is true only when we compare like dimensions (e.g. length to length, mass to mass).

67. Review Question 30
Why are there allometric changes in structures for different sized organisms?

68. ISOMETRY (geometric similarity)
If b = 1, there is no differential growth
the relative size of Y (wing length) to X (thorax length) is the same at all values of X
Shingleton Mirth Bates 2008 Proceedings Royal Soc B. Developmental model of static allometry in holometabolous insects. Isometry, hypoallometry and hyperallometry. The relationship between wing area and body area (thorax length2) in wild-type Drosophila melanogaster is linear and isometric (α=1.0) (a). Example of a (hypothetical) hypoallometric (b) and hyperallometric (c) relationship between wing and body size. Illustrations show example flies for each allometric relationship

69. Negative Allometry
If b < 1, Y increases at a slower rate than X
as X (thorax length) increases, Y (wing length) becomes relatively smaller

70. Positive Allometry
If b > 1, Y increases at a faster rate than X
as X (thorax length) increases, Y (wing length) becomes relatively larger

71. Isometry for Different Dimensions
Example: Head Length vs. Body Length
Linear dimension (m1) vs. linear dimension (m1)
Isometry: m1/m1, b = 1/1 = 1.0
Example: Head Length vs. Body Mass
Linear Dimension (m1) vs. Cubic Dimension (m3)
Isometry: m1/m3, b = 1/3 = 0.33
Example: Surface Area vs. Body Mass
Square Dimension (m2) vs. Cubic Dimension (m3)
Isometry: m2/m3, b = 2/3 = 0.67

72. Review Questions 31, 32, and 33
When comparing length to mass with an allometric equation, what is the exponent for isometry?  Explain why.
When comparing area to mass with an allometric equation, what is the exponent for isometry?  Explain why.
When comparing volume to mass with an allometric equation, what is the exponent for isometry?  Explain why

73. Isometry for Different Dimensions
Example: Head Length vs. Body Length
Linear dimension (m1) vs. linear dimension (m1)
Isometry: m1/m1, b = 1/1 = 1.0
Example: Head Length vs. Body Mass
Linear Dimension (m1) vs. Cubic Dimension (m3)
Isometry: m1/m3, b = 1/3 = 0.33
Example: Surface Area vs. Body Mass
Square Dimension (m2) vs. Cubic Dimension (m3)

74. Isometry for Different Dimensions
Example: Head Length vs. Body Length
Linear dimension (m1) vs. linear dimension (m1)
Isometry: m1/m1, b = 1/1 = 1.0
Example: Head Length vs. Body Mass
Linear Dimension (m1) vs. Cubic Dimension (m3)
Isometry: m1/m3, b = 1/3 = 0.33
Example: Surface Area vs. Body Mass
Square Dimension (m2) vs. Cubic Dimension (m3)
Isometry: m2/m3, b = 2/3 = 0.67

75. Review Question 34
Why is the relationship of the surface area and volume of different size cubes or spheres isometric, even though surface area to volume scales to the 2/3 power for length or radius? Compare the surface area, volume, and the ratio between the two of different sized cubes.

76. Isometric scaling.
When a cube’s edge is increased k times, then every surface on that cube increased by k2, and its volume by k3.
edge length: L2 = k  L1
surface area: 6L22 = k2  6L12
volume: L23 = k3  L13
SA/V = 6L2/3 L1 L2

77. Isometric scaling. Linear relations: Length vs. length
length (L1)
width (L2) L2 L3 L1

78. Isometric scaling. Non-linear relations: Surface area, volume vs
Isometric scaling. Non-linear relations: Surface area, volume vs. length
volume (cm3)
length (L1) (cm)
length (L1) (cm)
total surface area (cm2) L2 L3 L1

80. Metabolic rate versus body mass
Allometry
Metabolic rate versus body mass
anphys-fig jpg
What can you infer about the exponent?

81. Figure 2 Allometric relationships of the full-term placenta
Figure 2 Allometric relationships of the full-term placenta. Total surface area S , in m 2 ) in various species as a function of the total fetal Mass in kg).
P. Vogel Placenta Volume 26, Issues 8? – 596; S
The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution
exchange surfaces (in m2 and kg) allometry of y = 3.2x0.80 .
fetal Mass

82. Determine if the scales are arithmetic or logarithmic
If logarithmic, are the X and Y values already logs.
If not, convert them to logs (e.g., 100 =2)
Pick two points as far apart as possible (x1 and x2).
Determine the slope (b) = rise/ run = (y2-y1)/(x2-x1)
Determine the log of the Y intercept
Determine the equation

83. S Determine if the scales are arithmetic or logarithmic
If logarithmic, are the X and Y values already logs.
If not, convert them to log values (e.g., 100 = 2) 2 1 -1 -2
Note: X axis change from g to kg!!! S
The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution
exchange surfaces (in m2 and kg) allometry of y = 3.2x0.80 .
fetal Mass kg

84. S Pick two points as far apart as possible (x2 and x1).
Determine y2 and y1
Slope (b) = rise/ run = (y2-y1)/(x2-x1) 2 1 -1 -2 S
The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution
exchange surfaces (in m2 and kg) allometry of y = 3.2x0.80 .
fetal Mass kg

85. S b = rise/ run = (y2-y1)/(x2-x1)
Determine the log of the Y intercept (the value when log X = 0 2 1 -1 -2
2.3 – -1 = 3.3 = 0.83 = b S
NOT
200 – 0.09
The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution
exchange surfaces (in m2 and kg) allometry of y = 3.2x0.80 .
fetal Mass kg

86. S (y2-log a)/(x2-0) =b What is the equation for the line in the form
Log Y = log a + b log X
2.3 – log a = 0.83
2 – 0
Log a = 2.3 – 1.7
Log a = 0.6
a = 3.2 2 1 -1 -2 S
Log S = log M
The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution
exchange surfaces (in m2 and kg) allometry of y = 3.2x0.80 .
fetal Mass kg

87. S = 3.28m0.83 . What is the equation in the form Y = aXb S1 -1 -2
Positive allometry?
Isometry? or
Negative allometry S
The current molecular phylogeny of Eutherian mammals challenges previous interpretations of placental evolution
exchange surfaces (in m2 and kg) allometry of y = 3.2x0.80 .
S = 3.28m0.83 .
fetal Mass kg

89. end

90. Environments

91. When one aspect of an organism’s physiology conforms to its environment, it is
Maintaining homeostasis
An environmental regulator
Undergoing negative feedback
Using less energy.
Undergoing positive feedback 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

92. Exponential Equations
Amount of change in Y per unit of X is constant
E.g. green line reaction rate doubles every 10 degrees of increase
Blue 1.73 increase
Red 50% decrease
Equation F.1
Y = m . 10n X
Log Y = log (m) + n X

93. ISOMETRY (geometric similarity)
If b = 1, there is no differential growth
the relative size of Y to X is the same at all values of X

94. If b < 1, Y increases at a slower rate than X
Negative Allometry
If b < 1, Y increases at a slower rate than X
as X increases, Y becomes relatively smaller
Head Length (cm)

95. Positive Allometry
If b > 1, Y increases at a faster rate than X
as X increases, Y becomes relatively larger

97. Which of the following is an example of allometric scaling?
The ability of an organism to regulate body size in order to meet the demands of its ecological niche.
The quantitative relationship between polyphenism and population size within a given geographic area.
The ability of an organism to regulate homeostasis in response to environmental stress.
The quantitative relationship between body mass and metabolic rate.

98. The so-called mouse elephant diagram has the exponent 7/6.