Animal Behavior Exam 1 Book Pages Main ideas

The logic of natural selection is such that evolutionary change is

inevitable if just three conditions are met:

1. Variation, with members of a population differing in a particular characteristic.

2. Differential reproductive success, with some individuals with particular

characteristics having more offspring than others.

3. Heredity, with parents able to pass on those characteristics to their offspring

fitness

how successful an individual is at passing down its traits; depends on both survival and reproduction

adaptations

traits associated with successful survival and reproduction

It is critical to recognize three points about this so-called gene-centered, or gene’s eye, view of evolution by natural selection:

1. Only genes replicate themselves; organisms do not.

2. Evolution is not natural selection. Evolution is gene frequency change within a population. Natural selection is one of several causes of evolution, as are mutation, migration, and genetic drift.

3. Natural selection is not guided by anything or anyone. Selection is not

“trying” to do anything. Instead, it is the individuals that reproduce more

that cause a population or species to evolve over time, a process that Darwin called descent with modification.

Sarah Hrdy Infanticide Study

killer monkeys killed the young because the females who nurse their infants stop ovulating so by killing their infants they can resume ovulating and the dominant male can start producing his own offspring

white crowned sparrow research Marler

• different birds sing different songs in different areas that are geographically close to each other

• not genetically different

• acoustic stimulus hypothesis (hear adult males sing different dialects and learn them, was correct the birds learned the dialect that was played for them when they grew up in a lab)

galahs adopted by cockatoos

• they sing songs like the cockatoos and galahs showing gene and environment interaction

Bautista addition to Marler study social interaction hypothesis

• social interaction with strawberry finches and white crowned sparrows

• when they could interact with strawberry finches learned their song

nuclei

anatomically distinct clusters of neurons connected by neural circuit

avian control sound system

HVC→ RA→nXIIts→syrinx

what part of sound control system is larger in males than in females

RA

environmental hypothesis in song learning

a young male learns his song and adapts it to fit his particular environment

nutritional stress hypothesis

birds having song learning machinary is costly but the benefits outweigh the costs because it allows them to reproduce more effectively and communicate with others

recognition hypothesis

vocal learning allows vocal signals to become recognizable and thereby promotes identification of neighbors and social cohesion within groups; also signifying rivalry between male birds

information sharing hypothesis

vocal learning enables expansion of the vocal repertoire in system were living with kin favors greater information sharing

sexual selection hypothesis

sings type match is really aggressive to other male bird, repertoire match semi aggressive and unshared song non aggressive

it is favorable to increase song knowledge in male male competition or female preference

geographic matching hypothesis

vocal learning evolves to promote geographic variation in vocal signals, which in turn allows assortative mating by site of origin and hence promotes local adaptation

migratory restlessness

movement at night in season with the time that they usually migrate

found that it was largely genetic

burrowing is largely ___ and is associated with the gene _____ and….

genetic!; avp which codes for vasopressin and high nesting behavior is associated with low levels of vasopressin

evo devo approach

figure out how a trait or development came to be that way through ancestry and evolution

monogamous vs. polygamous voles Larry Young

studied V1a receptor; prarie voles form pair bonds and have a lot of V1a vasopressin receptors in the ventral palladium and they are less numerous in mountain voles which are polygamous (but more numerous in the lateral septum

avpr1a

gene that codes for vasopressin, important in social behavior for voles

males with longer avpr1a alleles are likely to ______ and have fewer _____ because of greater ____

produce more offspring, V1a receptors, extra pair paternity particularly at higher population density

phenotypic plasticity

when different phenotypes arise as a result of differences in environment

polyphenisms

phenotypic plasticity that arises from a single genotype

tiger salamanders and dung beetles

tiger salamanders as larva can either become cannibals or non cannibals based on the food sources available to them

dung beetle males with a lot of food grow to produce horns and those without do not grow horns

irreversible vs reversible plasticity

irreversible is early development and cant change and reversible is later in life and can change

reversible plasticity example (ciclid)

either fiercly competetive for territory or not to conserve energy and has to do with genes in their brain GnRH is activated for competetive males produced by egr-1 which also enlarges the testes; androgen receptor ARA for competetive males is important