Exam Three Flashcards
Define sociobiology
the study of social behavior
Actor and Recipient both benefit
Cooperation
Actor benefits, Recipient is harmed
Selfishness
Actor is harmed, Recipient benefits
Altruism
Actor and Recipient are both harmed
Spite
Describe r
coefficient of relatedness (fraction of alleles shared by relative) or probability (average) of finding the same allele at any given gene in a relative
What is r for parent/child, full siblings, half siblings, first cousins, grandparent/child, and uncle/nephew
1/2, 1/2, 1/4, 1/8, 1/4, 1/4
Describe Hamilton’s Rule
If Br-C>0
Where B is benefit (increase to relative), C is cost (decrease to actor), and r is additive among relative benefited
Then alleles that cause altruistic behavior will increase in frequency by natural selection
What is the new definition of fitness
Inclusive fitness is direct fitness (personal reproduction) plus indirect fitness (reproduction by a relative due to altruistic behavior)
What is the yearling male dilemma in white-fronted bee eaters
Direct fitness-own nest
Indirect fitness-help at nest
What are the three requirements for eusociality?
Generations overlap (siblings raising siblings) Cooperative brood care Specialized non-reproductive individuals (defn of eu)
What is the r for female siblings in haplodiploidy?
3/4
Describe facultative eusocialily
Can bred or raise siblings
What explains the eusocial set-up of naked mole rats?
inbreeding
Queen is often related to male she is breeding with
Sibling r is between ½ and ¾
What are the two factors that determine if a red squirrel female will adopt a kit and when will that occur?
Cost of adoption and benefit to adoptee (Br)
Occurs when Br is greater than C
What is the weaning conflict?
Natural selection favors parent that weans at B/C=1
Natural selection favors child that weans at B/C=½
What is r for workers and their brothers in Hymenoptera?
1/4
Why is there siblicide?
Prevents futile investment of energy and resources in an offspring that will die anyway
Describe reciprocal alturism
Natural selection will favor alleles that cause altruistic (fitness decreasing) acts to nonkin if equally valuable (fitness increasing) favors are returned
What are the two conditions on reciprocal altruism?
B/C must be > 1
Cheaters cannot be continuously rewarded
What are the three factors for the environment in reciprocal altruism?
Repeated interactions with the same individuals
Many opportunities for altruism in a lifetime
Interactive relationships are symmetrical
What are the four over-all rules for the situations in which reciprocal altruism occurs?
Be social
Small group size
Long lived
By mutually dependent (not eusocial)
What is the order of highest to lowest reward in the Prisoner’s Dilemma and what does this represent?
It is best if you cheat and they don’t (T), then if you both cooperate(R), then if you both defect(P), then if you cooperate and they defect(S)
This represents reciprocal altruism
What is the best basic strategy to win in the long term of the Prisoner’s Dilemma?
Best strategy is to start by cooperating and then repeat opponents last decision (TFT) - Tit for Tat
When is a strategy evolutionary stable?
A behavior strategy is evolutionary stable if the population of individuals practicing it cannot be exploited by a rare form practicing another strategy
What strategy did humans use when playing the Prisoner’s Dilemma and what modification did they make?
If stuck in a defect - defect loop between 2 players using TFT
GTFT will cooperate to break the loop
What is the greenbeard effect?
Reciprocal altruism amplified with recognition
Imagine an allele with 3 effects on phenotype
Causes green beards
Recognizes green beards in others
Altruism toward anyone with a green beard
The frequency of that allele would increase rapidly
What is kind of selection is reciprocal altruism?
Average fitness of members higher than a group not practicing reciprocal altruism
Multilevel selection
What is group selection?
Group selection is when you lower your own fitness for the good of the species
Almost never happens
What three things is energy used for before and after maturity?
energy is used for growth, metabolism and repair, after maturity it is used for metabolism, repair, and reproduction
What kinds of things will cause an organism to undergo repair?
Damage by: parasites, pathogens, wounds, toxic substances (exogenous from nature or endogenous from metabolic by-products)
What time scale do organisms optimize their reproduction based on?
Lifetime
What is senescence?
Late life decline in fitness (probability of survival and rate of reproduction)
What is the rate of living hypothesis?
Finite amount of metabolism can occur in a lifetime Accumulation of: Errors in DNA replication Errors in gene expression Poisonous metabolic by-product
What two things disprove the rate of living hypothesis?
If this is true, then there should exist a constant total lifetime metabolic limit across species (kcal/g body weight/lifetime)
Even just looking at mammals (especially similar size), this is not true
If ROL is true, then natural selection should have already maximized lifespan
15 generations of selecting flies increases average longevity by a lot
What is the rate of cell division hypothesis?
Finite number of cell divisions are possible
Finite number of chromosome replications
Linear chromosomes become shorter with each generations
Taking red blood cells from mammals and making a graph with lifespan of red blood cells against maximum lifespan for species is a direct + correlation
What adds length to chromosomes?
Telomerase
What is the effect of telomerase in cell culture?
In cell culture
No telomerase activity=short lived
Moderate=long lived
High=immortal (cancers)
What is the evolutionary hypothesis for senescence?
Maximum lifetime reproductive potential
What are the two things that make up the evolutionary hypothesis for senescence?
Deleterious mutations with late life effect are not strongly selected against
Therefore they can accumulate with little cost to lifetime reproductive success and will shorten lifespan
There is positive selection for mutations that trade early reproduction for less repair with late life effect so they will accumulate, shortening lifespan
Describe transitional forms
Fossils or organisms that show the intermediate states between an ancestral form and that of its descendants (not linear, common ancestor)
What are vestigial organs?
Remnants of something previous
What two things does piloerection do in mammals?
Aggression or defense-look larger
Insulation from cold
Give an example of structural homology
Forearm in humans, moles, horses, bat, and dolphin all have humerus/radius/ulna/carpals/metacarpals/phalanges
Give an example of developmental homology
The common ancestor to all tetrapods (everything that first left the sea) had five digits in fore and hind feet, mammals retain this pattern
Horse has five fused
The evolutionary changes (mutation) that cause chickens to have 4 in wing and 3 in feet affect development after the embryonic appearance of the digits (appear, then go away)
Laryngeal nerve anatomy
Goes all the way down the giraffe neck then back up instead of a few inches across
This is because it first evolved in fish (with a direct route)
Give an example of molecular homology
We all have DNA that is set up the same We also have the same mechanisms of DNA replication Transcription Translation
The genes that control early development are the same
Mouse genes can go in flies to develop fly eyes
Same gene, very different results
What are Lack’s two assumptions?
Reproductive potential in one year does not affect reproductive potential in the next and Fitness of offspring does not depend on originating clutch size
Does evolution change the population or the individual?
Population
Does selection act on phenotype or genotype?
Phenotype
Does natural selection follow with or behind environment?
Behind
Does natural selection create new structures or adapt ones?
Adapt
Is selection towards complexity or fitness?
Fitness
Is selection/mutation random?
Only mutation
Refute: Perfection and complexity require instant creation.
Numerous graduations from a simple and imperfect system to one complex and perfect system have been shown to exist. Parts that make up a system have functions alone.
Refute: Evolution is not falsifiable by testing and makes no testable predictions.
Current evolution is falsifiable by testing, darwin’s postulates have been tested and found valid, r=h^2S, every experiment had a hypothesis, and predictions of fossil record findings are common.
Refute: The age of the earth is 6000 to 8000 years old.
Geology, physics, astronomy, and cosmology say that’s crap. Radiometric dating also says it’s crap.
Refute: Evolution defies the second law of thermodynamics.
The second law only applies in a closed system.
Refute: No one has ever observed speciation because it takes too long.
We may have observed speciation (or are about to). We observe millions of species for a short time and can reconstruct the events of evolution.
Discuss the three areas of observation at Darwin’s time that indicated to scientists that evolution was the origin of the diversity.
Age of the earth (Kelvin said 20m, Lyell said 100m, Darwin said older), change over time (fossil record shows relationship between fossils and extant organisms, principle of faunal succession, vestigial organs), and common ancestry (homology in structure, development, and molecular).
Name Darwin’s four postulates
Individuals within a species are variable, some of these generations are passed onto offspring, in every generation more offspring are produced than can survive, survival and reproduction are not random: the individuals that survive and go on to reproduce (or who reproduce the most) are those with the most favorable variations (they are naturally selected).
Describe how Darwin’s four postulates were tested
Beak depth is variable, beak depth is heritable, not all finches survive, drought causes birds with appropriate beaks to survive more (which is disruptive selection that causes population characteristics to change in the next generation).
Restate Darwin’s postulates in modern terms
Mutation creates new alleles and recombination produces new genetic combinations, so individuals vary in phenotype. Alleles are passed from parent to progeny unchanged. More offspring are produced than can survive. Individuals that survive, or reproduce the most, determine the new genotypic frequencies, and therefore the phenotypic characteristics of the next generation.
Refute: A perfect and complex biological organ or system requires an intelligent designer.
Numerous graduations from a simple and imperfect system to one complex and perfect system have been shown to exist. Parts that make up a system have functions alone.
Refute: Even evolutionary biologists have problems with evolution as evidenced by their disagreements.
Arguments are not about evolution, but the path it took. Quotes are taken out of context.
Refute: Evolution is just a theory.
It is a theory in the sense that evolutionary theory (natural selection) is a formulation of the underlying principles of natural selection and that formulation has been verified to an extreme degree. Evolution is a observable face, natural selection is the explanations that has been verified.
What is the significance of Epperson vs Arkansas?
Supreme court removed laws banning the teaching of evo
What is the significance of
Edwards vs Aguillard?
Supreme court said creation science was religion, illegal to teach
What is the significance of
Kitzmiller et al. vs Dover School District?
Intelligent design is creation science is religion, illegal to teach
Where did intelligent design come from?
Irreducible complexity
What is ontological naturalism?
Nothing exists outside the natural world, philosophy
What is methodological naturalism?
Physical evidence can only provide info about the natural world, science
Crystallin
Different lineages use different proteins for the eye, only need it to be flexible and clear
