PSYC 327

Scientfic method

scientific observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses.

ethology

Study of animal behavior

The field of ethology

is integrative in the true sense of the word, in that it combines the insights of biologists, psychologists, anthropologists, and even mathematicians and economists.

Ethologists pose 4 distinct types of questions. Who outlined this and what are the 4 questions?

Niko Tinbergen

Mechanism

Developmental

Survival value

Evoltionary History

Mechanism-Questions asked towards

What stimuli elicit behavior? What sort of neurobiological and hormonal changes occur in response to, or in anticipation of, such stimuli?

Development- Questions asked towards

How does behavior change with the ontogeny, or development, of an organism?

How does developmental variation affect behavior later in life?

Survival Value-Questions asked towards

How does behavior affect survival and reproduction?

Evolutionary History-Questions asked towards

How does behavior vary as a result of the evolutionary history, or phylogeny?

When did a behavior first appear in the evolutionary history of the species under study?

Tinbergen’s Questions can be found in which kinds of analyses.

Proximate analysis

Ultimate analysis

Proximate analysis

focuses on immediate causes

Ultimate analysis

centers on evolutionary forces that have shaped a trait over time

Proximate analysis cover which of Tinbergen’s questions.

Mechanistic

Developmental

Ultimate analysis covers which of Tinbergen’s questions.

Survival Value

Evolutionary/Phylogenetics

What is behavior?

Many different definitions over the years. There is not one true definition, but according to the book behavior is the

What links animal behavior to all scientific endeavors

is a structured system for developing and testing falsifiable hypotheses and a bedrock set of foundations on which such hypotheses can be built.

Natrual Selection

the process whereby traits that confer the highest relative reproductive success on their bearers increase in frequency over generations.

What did Charles darwin argued? What is this in support of

Darwin argued that any trait that could be transmitted across generations (i.e., is heritable) and provided an animal with some sort of reproductive advantage over others in its population would be favored by natural selection.

Its in support of natural selection

Individual Learning

can alter the frequency of behaviors displayed within the lifetime of an organism.Animals learn about everything from food and shelter to predators and familial relationships.

If we are learning effects of behavior over a lifetime of an organisms

we are studying learning from a proximate perspective

If we study how natural selection affects the ability of animals to learn.

we are approaching learning from an ultimate perspective.

Cultural Transmission

process whereby a behavior is passed on from one generation to the next in a community. Allows traits to spread through populations at quick rates.

Social Learning

Learning by observing others

Mutations

the changing of the structure of a gene, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of single base units in DNA, or the deletion, insertion, or rearrangement of larger sections of genes or chromosomes

Zuk and Her team study the relationship between crickets and parasitic flies since 1991. What are some significant findings?

-over the years, they heard fewer singing males, such though in 2003 only one singing male was heard

-However, when they LOOKED, they found an abundance of these crickets

-male crickets had modified wings, likely due to mutations

-Male crickets with flat wings are at an advantage of not being partized by these files, however they are disadvantage when it comes to breeding

-research suggests that flatback crickets stay near singing crickets to secure a chance to breed with the ladies

Convergent Evolution

independent evolution of similar features in species of different periods or epochs in time

Xenophobia

a fear of strangers.

Resource scarcity and the evolution of xenophiobia. Take ways?

Tested on mole rats

-Male rats from arid temperatures and mesic temperatures were place together in a trial

-Results showed that mole rats from the arid temperatures areas were more agressive to outsiders than mesic mole rates

-When mole rats from arid areas were place with moles rats from the same area, the aggression went away.

-Natural selection favored stronger xenophobia responses in mole rats that had more limited resources

-sex is important as well

Dukas and bernays wanted to address the question of learning-related benefits directly. What was their study and their ultimate takeaways?

-Grasshoppers in the learning treatment ate a greater proportion of their food from the balanced diet dish than did the grasshoppers in the random treatment

- they learned to pair diet type with color and odor cues when the situation allowed for such learning

How is cultral transmission more complicated than indvidual learning?

The information acquired via individual learning never makes it across generations. In contrast, with cultural transmission, if a single animal’s behavior is copied, it can affect individuals many generations down the road.

has both within- and between-generation effects

Cultural Transmission in relation to Rats

-when rats scavenge for food, it might come across as dangerous

-smelling other rat provides olfactory cues about what it has eaten

-this transfer of information from one rat to the other is a form of cultural transmission

Conceptual approaches

involve integrating formerly disparate and unconnected ideas and combining them in new, cohesive ways.

Benefits of conceptual advances

-generate new experimental work

Kin selection in relation to conceptual approaches

essentially natural selection favors behaviors that increase reproductive success of individuals expressing that behavior, but also favors behaviors that increase the reproductive success of those individuals’ close genetic kin

(by W.D hamition)

Hmailiton proposed fitness is composed of two parts, what are they?

Direct fitness and indirect fitness

How is direct fitness measured?

is measured by the number of viable offspring produced, plus any effects that individual 1 might have on the direct descendants of its own offspring:

How is indirect fitness measured?

measured by the increased reproductive success of individual 1’s genetic relatives—not including its offspring and any lineal descendants of offspring— that are due to individual 1’s behavior

Inclusive fitness

is the sum of its direct and indirect fitness

Theoretical Approach

to animal behavior often entails the generation of some sort of mathematical model of the world.Motly fouced on animial foraging behavior

Example of theorical apporach

Ethologist asked the question “which food items should an animal add to its diet, and under what conditions?”, to tackel this they used the mathematical model , OPTIMAILITY THEORY

Theoreticians are interested in

in condensing a difficult, complex topic to its barest ingredients in an attempt to make specific predictions

Emperical approaches

—either observational or experimental studies.

Observational work

involves gathering data on what animals do, without attempting to manipulate or control any ethological or environmental variable.

Artificial Selection

which is defined as the process of humans deliberately choosing certain varieties of an organism over others by implementing breeding programs that favor such varieties

Examples of Artificial selection with Darwin and his pigeons

-Morphological differences between tumbler pigeons and homing pideogons

-These morphological behaviors were the product of generation of breeding,

Domestication Syndrome

Why is it that so many domesticated species display a suite of traits like that include mottled coloration, floppy ears, curly tails, and more juvenile characteristics.

Dmitri Belyaev experiment and results in relation to artificial selection

-, has been systematically selecting the tamest, most docile foxes from an experimental population of foxes they have in Siberia

-this artificial selection program has produced foxes that not only can be held and petted by humans, but who seek out human contact

-Tame foxes have lower levels of stress hormones and their skull shape has been remodeled

Richard Wrangham, proposed that what is key to tameness

proposed that neural crest cells may be key in explaining how tameness is linked to the domestication syndrome (

If a trait varies and helps individuals survive and reporduce beter in their enviromnt than another variety then…

natural selection will operate to increase its frequency over time.

Phenotype

as the observable properties of an organism.

Genotype

genetic makeup

A fitness advatage of 1 percent per genenraton is

sufficient for one behavioral variant to replace another over evolutinary time.

Allele

a gene variant, one of two or more alternative forms of a gene

Over evolutionary time

small differences in fitness can accumulate into large changes in gene frequencies.

To understand natural selection we look at it like

Natural selection on a certain behavior, not of itself

The process of natural selection requires three prerequisites to be met

Varation in the trait

fitness consquenses of the trait

A mode of inhertiance

Mode of inheritance

—a means by which the trait is passed down to the next generation

Fitness consequence of a trait

different varieties of the trait must affect reproductive success and or longevity differently.

What causes variation?

can be caused by either environmental or genetic factors.

Genetic variation

is the presence of differences in sequences of genes between individual organisms of a species

Genetic variation in a population can be generated in Mutiple ways such as….

mutation

migration

Genetic recombination

Mutation

which is defined as any change in genetic structure—creates new variation in a population

Ways mutations can occur

addition and deletion point mutations.

base mutations-

Silent mutations-does not cause changes in ammino acid produced

Genetic Recombination

occurs when genetic material is exchanged between two different chromosomes or between different regions within the same chromosome.

Migration and how it can increase varation

can increase genetic diversity in a given population because individuals coming from other populations can introduce new trait variants

Fitness consequences of a train refers to

a trait refers to the effect of a trait on an individual’s lifetime reproductive success—for example, the difference in reproductive success associated with slow versus fast approach behavior.

Without a mode of inheritance,

any fitness differences that exist within one generation are washed away, and natural selection cannot act.

one way to measure genetic transmission is through heritability which is a

a measure of the proportion of variance in a trait that is due to what is known as additive genetic variance.

many traits— ranging from morphological to behavioral

show low (0.0 to 0.1) to moderate (0.1 to 0.4) heritability

Ways to measure narrow sense hertaiblity

parent-offspring regression

truncation selection method

Parent-offspring regression

Parents pass on genes to their offspring, so when narrow-sense heritability is high, the behavioral variation in the offspring should map onto the behavioral variation observed in parents.

Cross-fostering experiment and its implications

An experiment measuring the relative contributions of genetic and environmental variation on the expression of behavioral traits. Often involves removing young individuals from their parent(s), and having them raised by adults that are not their genetic relatives

Young displays the same group-size preference as their genetic parents.

sociobiology

is the study of the evolution of social behavior

Selfish genes

a gene considered primarily as an element that tends to replicate itself in a population, whether or not it has a direct effect on the organism that carries it.

Adaptations

traits that natural selection molds, and that often match organism to environment so exquisitely.

also defined as traits associated with the highest relative fitness in a given environment.

Important case studies dealing with adaptations

1) antipredator behavior in guppies, and

(2) cooperative behavior in naked mole rats.

Guppies and high/low predation

guppies from high-predation sites mature faster, produce more broods of smaller offspring, and tend to channel more resources to reproduction when compared to guppies from low-predation sites

low-predation sites mature slower, are bigger but fewer offspring.

guppies from high-predation sites inspect a predator more cautiously, but more often, than their low-predation counterparts

Predator inspection

refers to the tendency for individuals to move toward a predator to ascertain various types of information about this presumptive danger.

eusociality

An extreme form of sociality in which there is cooperative brood care, division of labor, and overlapping generations.

Naked mole rats ancd their exteme form of sociality

• A reproductive division of labor in which individuals in certain castes reproduce and individuals in other castes do not.

• Overlapping generations, such that individuals of different generations are alive at the same time.

• Communal care of young

Kinship theory

suggests that the more genetically related individuals are, the more cooperation they will show with each other

DNA fingerprint

A molecular genetic technique used to examine the genetic relatedness among individuals.

How does the mole rats prove kinship theory

from the DNA fingerprinting, we ve determined that the mole rats are very genetically similarly to each other, an average relatedness of 0,81. This marks them as having the genetic variability closer to identical twins then siblings.So they have these unusual interactions due to the nature of their genetics

Phylogeny

the evolutionary development and diversification of a species or group of organisms, or of a particular feature of an organism.

Nodes

represent common ancestors to the groups that come after the splitting or branching point.

root on the phylogenetic tree

—the common lineage from which all species indicated on a tree are derived.

Traits can be

Structural

developmental

molecular

behavioral

Homology

is a trait shared by two or more species because they share a common ancestor.

Homoplasy

is a trait that is shared between two or more species, not because they share a common ancestor, but natural selection has acted independently on each species

Analogous traits

—the result of shared natural selection pressure

same as homoplasy

Converget evolution

The process whereby different populations or species converge on the same phenotypic characteristics as a result of similar natural selection pressures

Polarity

the direction of historical change in a trait. This is necessary when determining which variety of a trait appeared first.

parsimony analysis

what is ockams razor and its meaning in evolutionary biology?

“entities are not to be multiplied beyond necessity.”

the phylogenetic tree that requires the least number of evolutionary changes is the most likely to be correct

parental care behavior and levels

no parental care, maternal care, paternal care, and biparental (maternal and paternal) care

broad sense heritability

-The proportion of phenotypic variance attributable to genetic causes

-Narrow-sense heritability

The proportion of variance in a trait that is due to additive genetic variance

additive genetic effects

occur when two or more genes contribute to the final phenotype

endocrine system

is a communication network that influences many aspects of animal behavior.

the network in the edocrine system is composed of

a group of ductless glands that secrete hormones directly into the bloodstream (in vertebrates) or into fluid surrounding tissue (in invertebrates)

In verterbraates major glands producing hormones

the adrenal gland,

pituitary gland,

thyroid gland,

pancreas,

the gonads,

hypothalamus