What is the difference between cooperation and reciprocal altruism?
- Cooperation is living together and each individual benefits (mutualism). Reciprocal altruism is when there is a cost to you today and a benefit to the other, but in the future there is a benefit to you and a cost to the other. This results in both individuals benefiting from the relationship.
Know which of the major behaviors is a cost to “you” and a cost to “them.”
- Selfishness= you benefit and the other is harmed or does not benefit
Altruism= you have a cost and the other has a benefit
Cooperation=both individuals benefit
Spite=both individuals face a cost
What does YOU and THEM really mean in terms of evolutionary behavior?
- YOU= yourself (direct fitness) and your relatives (indirect fitness) THEM=the individuals that you are not related to
What is the difference between group and individual selection?
- Individual selection is when alleles that cause particular individuals within a population to perform well relative to other individuals are favored and spread. Group selection favors alleles that contribute to the performance of the group so that groups containing those alleles are far better than groups lacking them.
There will most certainly be a few questions on game theory and associated examples
- Game theory is a mathematical approach to studying behavior that solves for the optimal decision in strategic situations (games) where the payoff to a particular choice depends on the choices of others. For example, the side-blotched lizard population oscillates in the relative frequencies of the three male forms. When orange males are rare, they are successful at ousting blue males from their single female so the orange can mate with many females. As the number of orange males grows, the number of yellow sneaker males increase because they are better able to mate with more females. As the yellow sneakers become the most successful, the orange males become rarer. When the orange males become rare, the blue males increase in the population, causing less opportunity for yellow males to mate, decreasing their population.
What are the costs and benefits to being social?
- Benefits of sociality=increased vigilance, dilution effect, enhanced defense capability, cooperative foraging/hunting and improved defense of critical resources.
Costs of sociality=increased conspicuousness to redators, increased competition for food, increased competition for mates, decreased certainty for maternity/paternity, increased transmission for disease/parasites
Why is to coefficient of relatedness evolutionarily important?
- The coefficient of relatedness is the probability that homologous alleles in 2 individuals are identical by descent. A lower r value means less relation. This is important to evolution because individuals with higher relatedness coefficients to each other are more likely to support each other in raising young and reproduction to increase their inclusive fitness (kin selection)
what is hamilton’s rule
- Hamilton’s rule= an allele for altruism (=kin selection) will spread if Benefit to recipient>Cost and will not occur if Benefit to recipient
Why is being a helper at the nest the best of a bad situation?
- Being a helper at a nest is the best of a bad situation because an individual is helping to increase its inclusive fitness if it cannot reproduce itself. Additionally, the individual may benefit by receiving the territory once the inhabitants die off so it can reproduce in the future.
Why is being a helper at the nest the best of a bad situation?
- Making the best of a bad situation is important evolutionarily because it generally occurs when resources are scarce so it is not beneficial to have large amounts of offspring. By supporting relatives in raising their young, you are increasing their chance of survival, thus increasing your inclusive fitness.
Why is making the best of a bad situation an evolutionarily important concept?
- Helpers in the nest can evolve through learning. It has been determined as helpers gain more experience they are able to relate sights and sounds to certain situations. The gene for intelligence can then be passed down to their future offspring. Although the offspring are smarter and better able to recognize things, it has been found there may be a cost such as a shorter lifespan
What are the conditions needed for reciprocal altruism to occur?
- Each individual repeatedly interacts with the same set of individuals in a group. Many opportunities for altruism occur in an individual’s lifetime. Individuals have good memory (typically very intelligent). Potential exists for altruistic interactions in symmetrical situations.
What are the conditions for eusociality?
- Conditions for eusociality are an overlap in generations, cooperative brood care and specialized castes of non-reproductive individuals.
What is halplodiploidy? What are its conditions and what does this lead to?
Haplodiploidy is a mechanism of sex determination where the sex is determined by the number of copies of each chromosome that an individual receives. Offspring formed from the fertilization of an egg by sperm are female (diploid) while those formed from unfertilized eggs (haploids) are males. This results in sisters having a higher relatedness (r=3/4) to each other than their offspring (r=1/2). Therefore it is better for a worker to care for a mother to produce many sisters than to produce many offspring
Why and how are naked mole rats eusocial without being haplodiploid?
- All individuals are normal diploid and able to reproduce, but each colony has one reproductive queen who tends to be larger than the others. There are also 2-3 reproductive males. The queen prevents the others from mating via intimiation. It was found nonrelatives were pushed/shoved most often by the queen so they don’t reproduce due to stress. As the relatedness of an individual to the queen increases, less pushing/shoving occurs.
What is Ediacaran fauna?
- The edicaran fauna is a group of animal species that eisted between 575 and 535 mya. They were multicellular organisms that dominated the world’s oceans. Some of them gave rise to living lineages of animals. Many of the fossils found were highly diverse and had unique body plans, but some share characteristics of current life. For example kimberella had a rasp-shaped feeding structure found today in mollusks.
What is an adaptive radiation? What triggers adaptive radiations?
- Adaptive radiations are evolutionary lineages that have undergone exceptionally rapid diversification into a variety of lifestyles or ecological niches. Ecological opportunity functions as an AR trigger (increase in o2 levels and predation in Cambrian) morphological innovation also functions as an AR trigger (jointed legs of Cambrian arthropods.
Why is the Burgess Shale fauna significant?
The burgess shale area had many fossils along with soft tissue fossils. the soft tissue aspect of the fossils allowed scientists to determine how species grew/developed with age and changed overtime
What is stasis and what are examples?
Stasis is when an organism does not evolve over an extended period of time. An example of this is the white tail deer that has not evolved in over 20 million years and stromatolites
what is the difference between stasis and gradualism?
- Stasis means a species is not evolving to any extent. Gradualism is when a species evolves slowly over a long period of time.
Why does stasis occur?
stasis occurs because the species is successful with respect to the environment it lives in. Furthermore, if there is not new niche that needs to be filled, species will not evolve.
What is the relationship between adaptive radiations and mass extinction?
- When a mass extinction occurs (60% of all species go extinct in a 1 million yr period), there are many niches that need to be filled. Adaptive radiation occurs to fill these empty niches.
What are background extinctions?
Background extinctions are extinctions that are not part of mass extinction events. They are thought to be due to typical types and rates of environmental changes or species interactions as opposed to the extraordinary environmental changes that occur during a mass extinction
When did the 5 mass extinctions occur?
1. The Ordovician event-4.43 mya The devoian event-359 mya The Permian event=252 mya The triasic event-200 mya The cretaceous event-65 mya
