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Professor: Dr. Theodore Garland, Jr.
Department of Biology
Office: 2366 Spieth Hall
Phone 827-3524 - better for long questions tgarland@ucr.edu
Office Hours: Tuesday 8:30-9:30 and
Wednesday 10:30-11:30 A.M.
in 2366 Spieth, or by appt.

Lecture: Tuesday and Thursday
2:10 - 3:30 A.M. in 2200 Spieth Hall
Lectures will be posted on the
"Blackboard" website ilearn.ucr.edu
after the lecture is finished.
Discussion: All are on Wed.
12:10-1:00, 1:10-2:00, 4:10-5:00, 5:10-6:00 PM
Syllabus: Both Lecture and Discussion are posted on the course website.
T.A. will go over with you.
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Teaching Assistant:
Mr. Jarren Kay
Ph.D. candidate
Department of Biology jkay001@ucr.edu
Office Hours:
Monday 10:30-11:30 PM
Thursday 11-12 PM in 2378 Spieth Hall, or by appointment
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Catalog Description: Interactions between organisms and their environments, emphasizing coadaptation of physiological, morphological, and behavioral phenotypes.
Topics include: allometry and scaling, metabolism and locomotion, heat and water exchange, evolution of endothermy, artificial selection experiments, and phylogenetically based statistical methods.

"Animal Physiology"
(BIOL 175)
"Comparative Biomechanics"
(BIOL 176)
"Hormones and Behavior"
(BIOL 178)
"Animal Behavior"
(BIOL 160)
"Functional Anatomy of the Vertebrates"
(BIOL 161 A, B)
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Required Text: Readings posted on the
"Blackboard" website ilearn.ucr.edu
Don’t get behind on the reading!
Exams will take some material directly from the reading, even if we have not discussed it in class!
A copy of the first exam from a previous year is posted on the Blackboard website. Warning:
Material covered will not be identical !!!
Format may differ !!!
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Grading
Item Points % of Total
--------------------------------------------------------------------------------------------------
Pre-Course Survey (5 Jan)
Midterm Exam 1 (28 Jan)
Midterm Exam 2 (25 Feb)
Final Exam 3 (14 Mar)
20
40
40
60
8.9
17.8
17.8
26.7
Discussion Section
Attendance
Participation
3 Quizzes
(6 Jan, 3 Feb, 2 Mar)
10
10
15
(5 pts each)
Paper Critique (20 Jan) 10
Heritability Exercise (9 Mar) 20
4.4
4.4
6.7
4.4
8.9
-------------------------------------------------------------------------------------------------
Total Points 225 100
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How grades are determined (of total points):
> 90% = A
> 80% = B
+ or - may also be used
> 70% = C
> 60% = D
< 60% = F
Scale may be moved down ("curved"), depending on distribution of total points at end of course.
I cannot tell you in advance if this will happen or by how much.
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Regrades: only within one week of when you get it back. We will regrade the whole thing, and points on ANY question may go up or down.
Missed assignments: no make-ups are allowed, except for ...
Valid excuses, absences: tell us when it
happens, or before. Do not wait until the end of the quarter! For medical absences, we need a note from your healthcare provider.
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Edited 1950 volume, in which he outlined a broad agenda for comparative physiology :
Prosser, C. L., ed. 1950. Comparative animal
physiology. W. B. Saunders Co.,
Philadelphia. ix + 888 pp.

Five Big Goals:
1. Simply to describe how different kinds of animals meet their needs.
= cataloging biological diversity
"Biodiversity" often = how many species
But perhaps equally important is how variable are those species, morphologically, physiologically, behaviorally? In other words, functional diversity .
Recently, some have criticized this as "stamp collecting" and said that we must now move beyond that phase of simple description.
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2. Use physiological information to reconstruct phylogenetic relationships of organisms.
In principle, we could use physiological information just like we use morphological information or DNA sequences.
In practice, has rarely been done, for 4 reasons: a. physiology doesn't leave many fossil cues b. it can't be measured on museum specimens c. it is difficult to measure as compared with morphology or DNA sequences d. more likely to be adaptive than DNA, so subject to parallel and convergent evolution, which confuses phylogenetic reconstruction.
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3. To elucidate how physiology mediates interactions between organisms and their environments.
= physiological ecology or ecological physiology
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4. To identify "model systems" for studying particular physiological functions.
= comparative physiology
Examples: a. squid giant axons for nerve transmission b. rattlesnake tail shaker muscles because whole animal can be put in an NMR to measure
in vivo changes in metabolites
Conley, K. E., and S. L. Lindstedt. 1996. Rattlesnake tail-shaking: minimal cost per twitch in striated muscle. Nature 383:71-73.
17 c. ectothermic poikilotherms in general to study effects of temperature on physiology d. lizards to study effects of fever

5. Vague ... but indicates that "kind of animal" can be used as a sort of "experimental variable."
Scientists routinely conduct experiments to test hypotheses.
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Nature conducts " natural experiments ," e.g., putting animals in a desert, and we can use the results of these past experiments to understand how evolution occurs.

Noun conveys the main focus of the subdiscipline, adjective conveys the particular flavor.
Comparative physiology tends to focus on physiology and how it varies among different organisms.
Biomedical physiologists may see
"comparative" as anything other than human beings or "the rat."
Physiological ecology focuses on ecology, and how physiology affects interactions between organisms and their environment.
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Physiological ecology has always had an evolutionary component .
Calow, P., ed. 1987. Evolutionary physiological ecology. Cambridge
University Press, Cambridge. 239 pp., back cover:
"Physiological ecology is concerned with the way that physiological traits fit organisms for the ecological circumstances in which they live, so there is always, by definition, an implicit evolutionary component to it."
Bennett, A. F., and R. B. Huey. 1990. Studying the evolution of physiological performance. Pages 251-284 in D. J. Futuyma and
J. Antonovics, eds. Oxford surveys in evolutionary biology. Vol. 7.
Oxford Univ. Press, Oxford., p. 251:
"The field of physiological ecology ... is ... fundamentally evolutionary to the extent that it considers how organisms came to be the way they are and how they might change in the future."
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Although Comparative Physiology and
Physiological Ecology have always had evolutionary components, they were often an afterthought .
Typical mode of operation: make whatever physiological measurement they specialized in on some new, exotic or unusual organism ...
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… then tack on a paragraph about the adaptive
(evolutionary) significance of whatever they found.
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For Example: compare a temperate and an arctic-inhabiting bird.
Any difference that was found would be attributed to the past effects of natural selecting
(i.e., an evolutionary adaptation ).
Possibilities of phylogenetic inheritance or random genetic drift were not considered.
Often, a priori hypotheses were not tested.
Or, if they were tested, it was not with the rigor that would be found in evolutionary biology
(e.g., only two species might be compared).
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http://en.wikipedia.org/wiki/Just_So_Stories
First published in 1902, these are origin stories, fantastic accounts of how various phenomena came about.
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HOW THE ELEPHANT GOT ITS TRUNK
HOW THE WHALE GOT HIS THROAT
HOW THE CAMEL GOT HIS HUMP
HOW THE RHINOCEROS GOT HIS SKIN
HOW THE LEOPARD GOT HIS SPOTS
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So, the standards of evidence and interpretation used by evolutionary biologists were not being employed by most physiologists who wished to say something about the evolution of their favorite physiological system or organism.
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In short, many physiologists were practicing evolutionary biology without a license .

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Evolutionary physiology is a new subdiscipline that incorporates much of Prosser's (1950) five objectives, but with more rigorous evolutionary tools and definitions .
This course will emphasize the methods of ecological and evolutionary physiology and their conceptual background , rather than providing lots of empirical facts concerning how different kinds of organisms make their living or have evolved physiologically.
Also, I will show lots of examples . Try to remember the general point of these examples.
And we will need some definitions …

For example, the word " adaptation" has several meanings, with two being common in biology:
1. the genetic, evolutionary process of traits that change across generations because of natural selection and consequent changes in gene frequencies
(a property of populations );
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Bennett, A. F. 1997. Adaptation and the evolution of physiological characters.
Pages 3-16 in W. H. Dantzler, ed. Handbook of physiology.
Section 13: comparative physiology. Vol. I. Oxford Univ. Press, New York.

2. within-individual changes in response to environmental perturbations
= phenotypic plasticity (these changes are not passed on to offspring) a. Acclimatization = in the field b. Acclimation = in the lab
Often these changes are reversible (phenotypic flexibility)
May occur at any point in the lifecycle, but those occurring early, during "critical periods," may be less reversible ...
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Piersma, T., and J. A. van Gils. 2011. The flexible phenotype: a body-centred integration of ecology, physiology, and behaviour.
Oxford Univ. Press, Oxford, U.K. ix + 238 pp.

Example with Laboratory House Mice:
Mohammed A. Al-kahtani. 2003.
Ph.D. in Zoology at the Univ. of Wisconsin - Madison.
"Evolutionary and Phenotypic Plasticity of Mammalian
Kidney: Using the Laboratory House Mouse as a Model."
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Currently faculty at
King Faisal University,
Saudi Arabia.

Three Goals:
Determine how mice "adapt" ontogenetically to reduced water availability.
Create a "model" for studying kidney function.
Create a "model" for studying desert rodents or other desert mammals.
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Eventually apply to "conservation physiology" in the context of captive breeding progams for endangered gazelle.

Two groups, starting at weaning (21 days of age)
FW-J = Free Water-Juveniles
WR-J = Water Restricted-Juveniles
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Method for Restricting Water
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Daily water consumption in both juvenile groups
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
10.0
9.5
9.0
8.5
8.0
7.5
7.0
6.5
6.0
20 25
Fig. 3-4
30 35 40 45
FW-J WR-J
Values are means + standard deviations
50 55
Age (days)
60 65 70 75 80 85 90

Food intake significantly decreased in water-restricted group.
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Fig. 3-5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
20 25 30 35 40 45
WR-J FW-J
50 55
Age (days)
60 65 70 75 80 85 90

Water restriction stunted the growth of water-restricted group.
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Fig. 3-2
40
38
36
34
32
30
28
26
24
22
20
18
16
14
12
10
20 25 30 35 40
WR-J FW-J
45 50 55
Age (days)
60 65 70 75 80 85 90

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Reversal
Experiment
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Control
Groups
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"Water-Restricted, then Free Water" group drank copiously when reversed to free water and remained significantly higher than Free Water group.
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Water-Retsricted, then Free Water
Water-Restricted
Free Water, then Water-Restricted
Free Water
Fig. 4-5
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15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
20 30 40 50 60 70 80 90
Age (days)
100 110 120 130 140 150 160

Food intake is intimately linked with water consumption in house mice.
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Water-Restricted, then Free Water
Water-Restricted
Free Water, then Water-Restricted
Free Water
5.5
Fig. 4-7
5.0
3.5
3.0
4.5
4.0
2.5
2.0
1.5
1.0
20 30 40 50 60 70 100 150 80 90
Age (day)
110 120 130 140

The effects of early-life water restriction are not completely reversible.
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Fig. 4-2
Water-Restricted, then Free Water
Water-Restricted
Free Water, then Water-Restricted
Free Water
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40
35
30
25
20
15
10
20 30 40 50 60 70 80 90
Age (days)
100 110 120 130 140 150

The kidneys became larger (relative to body mass) in the water-restricted juvenile group.
Fig. 3-7
WR-J FW-J
-0.10
-0.15
-0.20
-0.25
-0.30
-0.35
-0.40
-0.45
Note that if you did not account for the difference in body mass, you would conclude that the kidneys of the waterrestricted group became smaller!
-0.50
1.10
1.15
1.20
1.25
1.30
1.35
1.40
Log
10
Body Mass, g
1.45
1.50
1.55
1.60
1.65
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The urine was much more concentrated in the water-restricted juvenile group.
Fig. 3-19
WR-J FW-J
5500
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
20 25 n = 12 n = 12
30 35 40 45 n = 16 n = 15
50 55
Age (days)
60 n = 11 n = 15 n = 10 n = 11
65 70 75 80 85 90
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The heart became smaller (relative to body mass) in the water-restricted juvenile group.
-0.85
-0.90
-0.95
-1.00
-1.05
-1.10
1.10
-0.60
-0.65
-0.70
-0.75
-0.80
Fig. 3-11
1.15
1.20
WR-J FW-J
1.25
1.30
1.35
1.40
Log
10
Body Mass, g
1.45
1.50
1.55
1.60
1.65
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• This would be a good topic for future research
• Any evidence for epigenetic inheritance?
• Epigenetic processes:
– changes caused by modification of gene expression rather than alteration of the genetic code itself
– heritable changes in gene expression that do not involve changes to the underlying DNA sequence
• e.g., by DNA methylation
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Stopped here 6 Jan. 2015

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Modern evolutionary physiology arose in the late
1970s and early 1980s.
Three main contributing factors:
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1.
Debates concerning the metabolic and thermoregulatory status of dinosaurs and mammal-like reptiles. Were dinosaurs warm blooded?

2. attempts to integrate quantitative genetic perspectives into evolutionary biology and behavioral ecology: a. focus on individual variation as raw material for natural selection, not just "noise" b. attempts to estimate heritability of traits c. attempts to measure selection acting in nature
Bumpus, H. C. 1899. The elimination of the unfit as illustrated by the introduced sparrow, Passer domesticus .
Mar. Biol. Lab., Biol. Lect. (Woods
Hole, 1898), pp. 209-226.
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3. attempts to integrate phylogenetic perspectives into comparative biology:
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Stopped here 8 Jan. 2013 & 9 Jan. 2014
Close
Relatives
Tend to
Resemble
Each Other
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recurring themes in ecological and evolutionary physiology
1. How do Different Kinds of Organisms Work?
a. Discover general principles of organismal function, such as homeostasis or the scaling of metabolic rate with body mass.
b. Find exceptions to the rules, species that are
"outliers" from the general trend.
c. Determine whether there exist multiple solutions to a given adaptive problem.
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Because all organisms on this planet are descended from common ancestors - and probably from a single common ancestor general biological principles are likely to occur in a strongly hierarchical
(phylogenetic) pattern .
Related organisms tend to resemble each other in terms of how they are built and how they do things; for example, use of DNA as a genetic material, structure of eukaryotic cell membranes, responses to changes in ambient temperature by mammals.
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recurring themes in ecological and evolutionary physiology
1. How do Different Kinds of Organisms Work?
a. Discover general principles of organismal function, such as homeostasis or the scaling of metabolic rate with body mass.
b. Find exceptions to the rules, species that are
"outliers" from the general trend.
c. Determine whether there exist multiple solutions to a given adaptive problem.
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c. Determine whether there exist multiple solutions to a given adaptive problem.
What are some of the "solutions" that animals use to live in hot, dry deserts?
Are these evolved differences or phenotypic plasticity?
What about plants?
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2. Extremes of Adaptation, "Model" Species, and
The August Krogh Principle a. Identification of similarities among species allows the possibility that certain species may be able to serve as "model systems" for studying basic physiological processes.
b. August Krogh noted that for any physiological principle there exists an organism especially well suited for its study
(e.g, giant axons of squid).
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Squid can contract the muscles of the mantle simultaneously, thus forcing sea water through the mantle aperture and causing the body to move forward.
An important part of this system is a big ganglion from which departs a giant axon.
The axon sends signals to all muscles involved in the process, and is much thicker than any axon of other animals.
Accordingly, it has been used in many studies of nerve signalling, e.g.:
Hodgkin A.L. & Huxley A.F. 1952.
Propagation of electrical signals along giant nerve fibers. Proc. R. Soc. Lond.,
B Biol. Sci. 140:177-183.
Giant squid ( Architeuthis ) are enormous molluscs from the deep sea. The maximal length (from the dorsal fin to the end of a tentacle) is estimated to be 13 m in females and 10 m in males. These animals have a highly sophisticated nervous system, highly developed brains and excellent eyes.
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c. Similarly, organisms living in extreme environments are especially likely to exhibit clear examples of evolutionary adaptation, because of the presumably intense past selection.
They can also serve to illustrate the range of evolutionary possibilities .
But we must remember that the organisms alive today -- and hence available for physiological study -- are but a small fraction of what has existed .
We have no guarantee that we can observe the range of possibilities even among the most extreme of living species.
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Example:
Dinosaurs, such as
Spinosaurus http://www.biology.ucr.edu/people/faculty/Garland/Spinosaurus_30_Theo_29_Sep_2004.jpg
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Example: the largest terrestrial mammal ever
(Indricotherium
[formerly Baluchitherium ]
) was much larger than living elephants, mammoths or mastodons.
An extinct hornless rhinoceros that lived in the Oligocene epoch (30-
20 million years ago). Fossilized remains found in central Asia show that it was over 5 m high, with a heavy giraffe-like body.
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Giant birds (both flying and flightless) once existed, giant dragonflies.
And then there were plesiosaurs, ichthyosaurs, etc.
Many transitional forms are now extinct.
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Environmental conditions differed as well, e.g., temperature and atmospheric oxygen and carbon dioxide.

Environmental conditions differed as well, e.g., atmospheric oxygen.
64 http://geology.com/usgs/amber/oxygen-level-chart.gif

Environmental conditions differed as well, e.g., temperature & atmospheric carbon dioxide.
65 http://deforestation.geologist-1011.net/PhanerozoicCO2-Temperatures.png

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Some extinct forms are rather different from living organisms, or seem sort of like "hybrid" models.

A recently-extinct species that demonstrated convergent evolution with placental wolves.
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Plate 8.2 The last living
Tasmanian tiger, Hobart Zoo, 1933.
Plate 9.1 Rear view of the last living Tasmanian tiger,
Hobart Zoo, 1933.
Died night of 7
September 1936
Stopped here 7 Jan. 2016
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3. Are Species Differences in Physiology
Adaptive?
The neo-Darwinian synthesis, with its emphasis on natural selection as the major driving force in evolution, led to the view that virtually all features of organisms are adaptive.
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Comparative physiologists have routinely viewed any differences among species as adaptations to their different life styles.
And, of course, many examples clearly do represent strong evidence for adaptation.

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Nonetheless, not all features of organisms represent adaptations to current environmental conditions.
Some represent simple inheritance from ancestors.
"Four legs may be optimal, but [tetrapods] have them by conservative inheritance, not selected design." (S. J. Gould, 1980, p. 44)
A similar statement could be made about insects
(6 legs) or spiders (8 legs).
Genetic variation for leg number is virtually absent in extant populations, so natural selection cannot change it. A sort of "phylogenetic constraint."

"Darwin pointed out in The Origin of Species that the sutures in the skull of young mammals
'have been advanced as a beautiful adaptation for aiding parturition, and no doubt they facilitate, or may be indispensable for this act;
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"Darwin pointed out in The Origin of Species that the sutures in the skull of young mammals
'have been advanced as a beautiful adaptation for aiding parturition, and no doubt they facilitate, or may be indispensable for this act; but as sutures occur in the skulls of young birds and reptiles, which have only to escape from a broken egg, we may infer that this structure has arisen from the laws of growth, and has been taken advantage of in the parturition of the higher animals.'
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Gould and Vrba (1982) have offered the term exaptation to describe features that now enhance fitness, but were not built by natural selection for their current role." (Futuyma, 1986, p. 257)
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4. Are Organisms Optimally Designed?
In addition to presuming that most features of organisms are adaptations, a common perspective in comparative physiology is to view organisms as optimally designed, i.e., more-or-less perfectly adapted in some sense.
"We do not think a functional explanation complete until we can show that a structure or movement is optimal (by some plausible criterion) for the proposed function."
(Alexander, 1988, p. 237)
"Evolution by natural selection is a process of optimization." (Alexander, 1996, p. 2)

This is a controversial view (more later in course), and many workers have a very different expectation about "how good" organisms are, e.g.,
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"Natural selection increases fitness but it produces systems that function no better than they must. It yields adequacy of adaptation rather than perfection."
(Bartholomew, 1987, p. 14)
Natural selection involves relative fitness, not absolute fitness.
If a tiger is chasing you, you only have to be able to run faster than the guy next to you …

5. What is the Origin of Allometric Relationships?
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Allometry = how and why properties of organisms change in regular ways in relation to body size.
Scaling = essentially a synonymous term in biology, but used in other ways in engineering, image processing, computer science.
Example: does "smartness" vary with body size or among evolutionary lineages?

log-log axes
Slope = 1.00
Largeer
Slope = 0.67
animals have relatively smaller brains.
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log-log axes
Vertical deviations from "line of best fit"
(residuals) indicate deviation from general effect of body size.
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Add something on: learning outcomes the scientific method levels of analysis
MPBF proximate vs. ultimate causation
4 ways to study evolution:
CM
Biology of Natural Populations
Selection Experiments
Theoretical Models
Plasticity? Epigenetics?
https://www.msu.edu/.../Methods& Levels .
ppt from ZOL 313 May 14, 2008
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1. Phylogenetic Comparisons of Species
(or populations)
Shows what has happened in past evolution
2. Biology of Natural Populations: extent of individual variation (repeatability) heritability and genetic correlations natural and sexual selection field manipulations and introductions
Shows present evolution in action
3. Selection Experiments
Shows, experimentally, what might happen during future evolution
4. Compare Real Organisms with Theoretical Models
Shows how close selection can get to producing optimal solutions

http://www.google.com/search?hl=en&lr=&oi=defmore&defl=en&q=define:allometry
17 Jan. 2006
Definitions of allometry on the Web:
Generally, the effect of size on shape. Specifically, any relationship of anatomical variables that fits the equation Y = AX k (A is a constant, the exponent k the coefficient of allometry).
www.modernhumanorigins.com/a.html
Change in a measurable aspect of an organism (such as shape) with increase or decrease in size.
www.csupomona.edu/~jcclark/classes/bio406/glossary.html
A disproportionate relationship between size of a body part and size of the whole body.
www.intuitive.com/coolsites/examples/ch5-1.html
The relationships between various aspects of a tree's size and shape. See the allometry topic for more.
www.sortie-nd.org/help/manuals/help/more_info/glossary.html
The study of the change in proportion of various body parts as a consequence of their growth at different rates.
highered.mcgraw-hill.com/sites/0767430220/student_view0/glossary.html
The study of the relative growth of a part of an organism in relation to the growth of the whole wordnet.princeton.edu/perl/webwn
Allometry is the science studying the differential growth rates of the parts of a living organism's body part or process. en.wikipedia.org/wiki/Allometry
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http://www.google.com/search?hl=en&lr=&oi=defmore&defl=en&q=define:scaling
17 Jan. 2006
Definitions of scaling on the Web:
The act of arranging in a graduated series act of measuring or arranging or adjusting according to a scale ascent by or as if by a ladder wordnet.princeton.edu/perl/webwn
In Euclidean geometry, scaling is an affine, linear transformation that can enlarge or diminish an object by certain factors. See also homothety. en.wikipedia.org/wiki/Scaling_(geometry)
In computer networking, scaling is the ability for a network to continue to function with limited or no degredation in performance as the number of users on the network increases. en.wikipedia.org/wiki/Scaling_(computer_network)
The measuring of lengths and diameters of logs and calculating deductions for defect to determine volume.
www.woodlot.bc.ca/swp/myw/html/21_Glossary.htm
A means of calculating the amount of enlargement or reduction necessary to accommodate a photograph within the area of a design.
www.purdue.edu/printingservices/support/glossary/glossrtoz.htm
The enlargement or reduction of an image or copy to fit a specific area.
www.millerbrosengraving.com/resources/glossary.html
Determining the proper size of an image to be produced (or reduced/enlarged). It is important that both directions be scaled in order to ensure proper fit in the final reproduction.
www.relyprint.com/help_dictionary.html
Reduction or enlargement of artwork, which can be proportional (most frequently used) or disproportional.
In desktop publishing, optimal scaling of bitmaps is reduction or enlargement that will avoid or reduce moiré patterns.
www.printingyoucantrust.com/glossary.cfm
Determining the proper size of an image to be reduced or enlarged to fit an area.
www.careydigital.com/support/glossaryr-s.html
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… then tack on a paragraph about the adaptive
(evolutionary) significance of whatever they found.
For example, consider the last paragraph of a study that compared goats with dogs:
"In conclusion, we show that highly aerobic mammals like dogs possess an “aerobic albumin” with elevated fatty acid binding capacity. This adaptation allows them to support much higher rates of circulatory fatty acid transport than sedentary goats, but further research is needed to determine whether all endurance-adapted species have evolved such albumin."
84

… then tack on a paragraph about the adaptive
(evolutionary) significance of whatever they found.
For example, consider the last paragraph of a study that compared goats with dogs:
"In conclusion, we show that highly aerobic mammals like dogs possess an “aerobic albumin” with elevated fatty acid binding capacity. This adaptation allows them to support much higher rates of circulatory fatty acid transport than sedentary goats, but further research is needed to determine whether all endurance-adapted species have evolved such albumin."
How do we know dogs are endurance adapted?
85

… then tack on a paragraph about the adaptive
(evolutionary) significance of whatever they found.
For example, consider the last paragraph of a study that compared goats with dogs:
"In conclusion, we show that highly aerobic mammals like dogs possess an “aerobic albumin” with elevated fatty acid binding capacity. This adaptation allows them to support much higher rates of circulatory fatty acid transport than sedentary goats, but further research is needed to determine whether all endurance-adapted species have evolved such albumin."
But what else differs between dogs and goats?
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