Midterm 1

Question 1

Evolution

Answer 1

• many definitions are available
• in a succinct way, it could be defined
as “descent with modification”
• more technically:
an outcome of evolutionary processes that
generate change (e.g. natural selection) and
evolutionary patterns that constrain that change
(e.g., phylogenetic history).

Question 2

Charles Darwin’s Theory of Evolution

by Natural Selection

Answer 2

The ideas of this person had a major influence on
biology and the evolutionary framework for the study
of animal behavior

Question 3

Concept of Evolution

Answer 3

All living things have descended from

common ancestors by a natural historical process of change and diversification.

Question 4

Evolutionary change occurs if three

conditions are met:

Answer 4

1. Variation
2. Heredity
   3) Differences in reproductive success

Question 5

Variation

Answer 5

• members of a species differ in some of their

characteristics

Question 6

Heredity -

Answer 6

parents are able to pass on some of their distinctive

characteristics to their offspring

Question 7

Differences in reproductive success

Answer 7

• some individuals have
  more surviving offspring than others in their population,
  thanks to distinctive characteristics

Question 8

Darwin’s Three Key Concepts

of Evolution:

Answer 8

• Adaptation
• Descent with Modification
• Natural Selection

Question 9

Adaptation

Answer 9

= a positive characteristic of an organism favored by the
process of natural selection, where
-favorable (heritable) traits produce more surviving offspring
than others in their population.
-Characteristics of a species are adapted to its ecological niche
Mimicry = look like your background or something other than what
you are.
• Mimicry as example:
Defensive mimicry - for the purpose of avoiding or escaping from your predators.

Question 10

Aggressive mimicry -*Adaption

Answer 10

for the purpose of capturing prey.

Question 11

Descent With Modification

Answer 11

Refers to the passing on of traits from parent
organisms to their offspring (aka, heredity)
• Any 2 species can be traced back ultimately to a common ancestor.
• Thus the more recent their common ancestor, the more similar two
species should be.
• Also, the more similar their history
of adaptations, the more
similar two species should be
Darwin’s Tree of Life 1837
• The differences between them are the result (in part) of adaptations

Question 12

Homology

Answer 12

-similarities due to recent common ancestry
-Homologous traits in different animals are similar because they are
derived from a common ancestor.

-Example of homology:
Bones of mammalian forelimbs are homologous
to forelimbs of human, horse, seal, bat, kangaroo,
mole etc.
The forelimb bones have different functions but
share a the same identifiable sequence and
arrangement of bones

Question 13

Analogy

Answer 13

= similarities due to similar function
-Analogous traits in different animals are similar because
they are adaptations to a similar ecological niche.
If you trace back to the common ancestor of the animals, it would not have that trait.
–Example of Analogous traits (analogy)
Body shape and flippers are analogous in seals and penguins.
Designed for locomotion through water, but underlying structures are very different.

Question 14

**Divergent vs. Convergent Evolution

DIVERGENCE

Answer 14

occurs when two evolving groups of recent common

ancestry become more dissimilar.

Question 15

Convergence

**Divergent vs. Convergent Evolution

Answer 15

occurs when two evolving groups of distant common

ancestry become more similar.

Question 16

Natural Selection (definition) -

Answer 16

Differential reproduction and survivorship
among individuals within a population. The
mechanism that results in adaptive evolution.

Question 17

Natural (direct) Selection

Answer 17

• Individuals vary within a species

• Variation is (in part) heritable
• If individuals vary on some trait related to
reproductive success, the better adapted
individuals will leave moreoffspring.
• Natural selection occurring over a long time
will lead to dramatic changes in a species
(evolution).

Question 18

Some qualifications of natural selection:

Answer 18

• If there is no genetic basis of variation in a trait,
then no natural selection of that trait will occur.
• Reproductive success (not survival) is the bottom line for
natural selection.
• Selection acts on individuals
- not species, groups, or populations
- traits are not present for the “good of the species”

However, many behaviors appear to benefit the group at the
cost to the individual: they are altruistic

Question 19

Altruism

Answer 19

an individual acts to further the reproductive success of
 another individual(s) at some reproductive cost to itself

Question 20

hypothesis

Answer 20

is simply a logical, testable
explanation for a specific set of observations
that serves as the basis for experimentation.

Question 21

Scientific Method

Answer 21

observation, formulating a hypothesis, making
predictions, experimenting to test the predictions and
drawing conclusions.

Question 22

Prediction vs Hypothesis

Answer 22

“We hypothesized that, owing to its effects on the frontal lobe and hippocampus, alcohol consumption would impair long-term memory.”

“We predicted that subjects who drank 6 or more ounces of alcohol would recall significantly fewer”

Question 23

Application of Darwinian theory:

Answer 23

When trying to understand ultimate reasons for animal
behavior, biologists try to come up with a hypothesis that
is consistent with natural selection theory
-In some case certain traits (or behaviors) might not seem to increase an individual’s reproductive success (or do they?).
EXAMPLE: Monkey killing other babies to make their own video thing called infanticide

Question 24

Hanuman langur monkeys

Answer 24

Behavior
• They live in groups of 11-64, typically
 1 male:multi-female
• langurs spend up to 80 per cent of
 their time on the ground, although
 will some spend time in the trees.
• are diurnal and move quadrupedally. 
-Males fight to monopolize reproduction with
the females in the group
-When a new male takes over a troop, he
systematically kills all the infants sired by
the previous alpha male.

Question 25

1) Social pathology hypothesis for infanticide in Langur moneys

Answer 25

infanticide is an abnormal, pathological response to overcrowding in areas where they are fed by humans. Non-evolutionary If this hypothesis were true, then one would expect to see infanticide by males only in areas where langurs live in very high densities. Results don't support this.

Question 26

2) Quicker reproduction hypothesis for infanticide in Langur moneys

Answer 26

infanticide boosts reproductive success of new dominant male. When lactating infant is killed, its mother might resume her reproductive cycle sooner and thus become impregnated sooner by the new dominant male. Evolutionary – individual selection.

Question 27

Does evidence support Quicker reproduction hypothesis?

Answer 27

• Infanticide should occur soon after takeover • Females who have lost their infants will promptly resume cycling and become sexually receptive to the killer male. • Killer male will not kill any of his own young. • Infanticide is not dependent on group size or density. Evidence exists to support all of the above predictions.

Question 28

1) Cannibalism Hypothesis

Answer 28

- this hypothesis predicts that infanticide should occur soon after a take over when dominant male is energetically stressed and need to reproduce quickly - is there data to support this hypothesis? NO

Question 29

2) Population Regulation Hypothesis

Answer 29

- this hypothesis predicts that male langurs commit infanticide as means of population regulation. E.g., High density populations put stress on food supply resources. Infanticide would then prevent overpopulation Who benefits?? Group benefits but not the male killer! This is not Darwinian selection…..

Question 30

Darwinian selection

Answer 30

= based on differences among individuals | and their reproductive success

Question 31

Group selection

Answer 31

based on differences among groups and | their ability to survive.

Question 32

George Williams (1966)

Answer 32

challenged the concept of group selection in this book Adaptation and Natural Selection - Main point: Williams showed that survival of alternative alleles was much more likely to be determined by differences in the reproductive success of genetically different individuals than by survival differences among genetically different groups.

Question 33

Tinbergen's Levels of Analysis

Answer 33

• The causes of any behavior can be understood at | four levels of analysis

Question 34

“Ultimate” | *Level of analysis

Answer 34

phylogeny & function | -Evolutionary history

Question 35

“Proximate”: | *Level of anaysis

Answer 35

development & immediate causation | -Within the lifetime only

Question 36

Tinbergen's Four Questions (levels of Analysis)

Answer 36

1) What is its function? (Effects on lifetime reproductive success ) ***ULTIMATE 2) How has it evolved? (long term Qs) (evolutionary origins) 3) What causes it? (sensory-motor mechanisms/ hormone systems) **Proximate 4) How does it develop? (immediate) (genetic mechanism/ontogenetic processes)

Question 37

Tinbergen's four questions 1. What is the survival value or function of a behavior? 2. What is the cause(s) of a behavior? 3. What is the development of a behavior? 4. What is the evolutionary history of a behavior?

Answer 37

Four answers to the question 1. To attract mates to breed. 2. Increasing day-length changes hormone levels 3. Birds have learned to sing from their neighbors 4. Bird song has evolved from simpler songs in ancestral bird species.

Question 38

Classical Roots of Ethology

Answer 38

Animal behavior interests date back to | prehistoric times

Question 39

Aristotle (384-322 B.C.)

Answer 39

• often considered to be the father of biology & psychology • classified > 540 species of animals; segregated as vertebrates (“enaima”) or invertebrates (“anaima”) based on the presence or absence of blood. • produce the first systematic account of animal behavior (Historia Animalium) • proposed the concept of scala naturae (“natural ladder”) to explain a gradual transition from inanimate to plants, animals, and humans.

Question 40

Historia Animalium

Answer 40

• Species’ habitats • Animal behaviors (e.g., foraging & social behavior of bees, migratory behavior of cranes & pelicans, electric discharge of electric rays, brood parasitism by European cuckoos) • Relative grades of animal intelligence

Question 41

scala naturae

Answer 41

``` Aristotle’s concept of scala naturae became closely intertwined with our view of God and religion. (compatible with the Biblical view) Scala naturae was seen as logically ending with God as the ultimate expression of perfection. ```

Question 42

The Great Chain of Being

Answer 42

``` Medieval Concept of God’s strict & hierarchical structure of the universe Ranked animals by level of development Lowest forms at bottom Humans near the top ```

Question 43

* *Pre-Darwinian Roots 17th and 18th century | 1. Aristotelians

Answer 43

- distinguished human soul (vs. animals which do not have souls) - Humans are rational and use logical reasoning - Animals are guided by sensory perception

Question 44

* *Pre-Darwinian Roots 17th and 18th century | 2. Cartesians (Based on Descartes)

Answer 44

• Shared Descartes concept of Mind-body Dualism - maintained that humans are unique from animals because of their ability for mental experience (mind). • Subscribed to Descartes’ mechanical theory of Animal Behavior (inspired by moving statues in the gardens of the Saint Germain palace).

Question 45

Descartes concept of Mind-body | Dualism

Answer 45

- maintained that humans are unique from animals because of their ability for mental experience (mind).

Question 46

Descartes’ mechanical theory of Animal | Behavior

Answer 46

(inspired by moving statues in the gardens of the Saint Germain palace). -Descartes conceived animals as complex “moving statues” equipped with finer tubes and faster & lighter fluids called “animal sprits” -• Thus, they maintained that animals (w/ no soul or free-will) operated as mere machines or brutes and followed the rules of physics

Question 47

3. Sensationalists

Answer 47

Major Influence from John Locke (1600’s) - tabula rasa - “blank or erased tablet” Born with blank slates and everything in life is learnt -“All ideas come from sensation or reflection.” - believed animals and humans were born with a tabula rasa - it is the learning process that determines what is “on the tablet” Humans knowing draw from same resources as those available to animals Stressed the role of environment & experience

Question 48

Summary of Contrasts between Aristotelians/Cartesians | and Sensationalists

Answer 48

``` Aristotelians/Cartesians 1. Dichotomy* between humans as reasoning beings with souls and animals as automata. 2. Complex behavior explained by instincts instilled by God. 3. Innate tendency of species type ``` VS. ``` Sensationalists 1. Humans respond to environment like animals 2. Downplayed instincts, emphasized acquired knowledge 3. Agnostics/atheists 4. Environmental effects on individual ```

Question 49

Cartesian Dilemma

Answer 49

It was clear that the ‘beast machine’ image of animals was not correct because animals clearly could perceive, feel, and act intelligently as no machine could • Led to new dichotomies...

Question 50

Dichotomies

Answer 50

Humans as rational beings vs. Animals as beast-machines Instinct or Nature vs nurture vs. Learning

Question 51

Darwin’s Evolutionary Framework

Answer 51

-The Origin of Species (1859) – general theory of evolution by natural selection. -Natural Selection -Darwin suggested that: • all organisms were inter-related • different organisms (including humans!!) were derived or evolved from common ancestors

Question 52

Natural Selection =

Answer 52

process of differential reproduction and survivorship among individuals within a population that lead to the adaptive evolution of traits (behaviors).

Question 53

Darwin’s theory

Answer 53

marked the split between biology & religion Interests shifted from cataloging biological diversity for the clarification of God’s plan to the questioning of how biological diversity arose

Question 54

Darwin's Origin of Species

Answer 54

did not focus not on animal behavior, but provides conceptual framework for the field of animal behavior

Question 55

Later in life Darwin...

Answer 55

Later publishes two books which apply his evolutionary theory to behavior: The Descent of Man and Selection in Relation to Sex (1871) and Expression of the Emotions in Man and Animals (1872) -Placed humans on the same mental continuum as animals

Question 56

Darwin’s principle of antithesis

Answer 56

Darwin was first to observe that instincts could | often be grouped as pairs of opposites

Question 57

Antithesis Principle

Answer 57

signals with opposite meanings (aggression vs. submission) | should have opposite or contrasting form to make meaning clear

Question 58

Darwin on Instinct

Answer 58

Both innate and acquired -Instincts congenitally expressed (When fully developed, chick pecks/cracks egg shell to escape) -Instincts change little through life of organism -Tongue-flick behavior of chameleon doesn’t change

Question 59

Roots of Comparative Psychology | George John Romanes (1848-1894)

Answer 59

• 19th century naturalist • a protégé of Darwin • coined the term and laid the foundation of “comparative psychology” • He also postulated that Primary instincts arose through natural selection and Secondary instincts were derived from learned behavior • further developed the idea of mental continuum and postulated a similarity of cognitive processes and mechanisms between humans and animals -Based on subjective observations -the evolutionary appearance of emotions in animals

Question 60

C. Lloyd Morgan

Answer 60

-British psychologist - author of the first textbook on Comparative Psychology (1894) - best remembered for his experimental approach to animal psychology now known as “Morgan's Canon” (special form of Occam’s Razor)

Question 61

“Morgan's Canon”

Answer 61

-helped stop the anecdotal tradition, thereby helping comparative psychology to become the objective science that is today -when two explanations for a behavior appear equally valid, the simpler one is preferred.

Question 62

20th Century: The development of two approaches to the study of animal behavior -1) Classical Ethology Approach:

Answer 62

``` - focused on the evolution and function of inherited and innate behaviors - European school of animal behavior - was descriptive and field-oriented - gave rise to the establishment of ethology as a new and independent discipline (between the 1930s and 1950s) by the two founding fathers of ethology: ```

Question 63

Konrad Lorenz (1903-1989)

Answer 63

Austrian animal behaviorist • An early interest in natural history and evolution • Medical training: comparative anatomy & embryology • Oskar Heinroth (comparative studies of the behavior of ducks) First to introduce the term “ethology” (from Greek word ethos meaning “manner" or “behavior”) to describe the analysis of natural behavior. • considered to be one of the co-founders of ethology • studied instinctive behavior in animals, especially in greylag geese and jackdaws • recognized behavior as an inherited trait, used for taxonomy and phylogenetic analysis.

Question 64

Social imprinting in Geese

Answer 64

Konrad working with geese, he rediscovered the principle of imprinting (originally reported by Douglas Spalding in the 19th century) Best known form is filial imprinting - young animal learns the characteristics of its parent Imprinting = any kind of phase-sensitive learning that is rapid and apparently independent of the consequences of behavior.