lecture 11 notes 9/23/15
lecture 11 notes 9/23/15 EEOB 3310 - 200
Popular in Evolution
Popular in Ecology
verified elite notetaker
This 3 page Class Notes was uploaded by an elite notetaker on Wednesday September 23, 2015. The Class Notes belongs to EEOB 3310 - 200 at Ohio State University taught by Joan Herbers,Zakee Sabree in Summer 2015. Since its upload, it has received 18 views. For similar materials see Evolution in Ecology at Ohio State University.
Reviews for lecture 11 notes 9/23/15
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/23/15
92315 EEOB Lecture 11 Selfish Genes levels of selection and the evolution of secondary sexual traits Reading Chapter 17 Andersson Simmons 2006 How does selection operate Levels of selection Genes gt individuals gt kin gt groups gt species Range of levels on which selection acts It is important to think about the different levels when thinking about natural selection and traits that have been selected Selection acts on different levels more or less at the same time Not equally visible or important but acknowledgement of multiple levels is important Relationships between actors and recipients of an action Cooperation mutualism both participants benefit recipient and actor Altruism individual pays a fitness cost but others benefit warning calls recipient benefits actor is harmed Selfishness individual gains benefit at the cost of others actor benefits recipient is harmed Spiteful behavior both participants pay a fitness cost recipient and actor Kin Selection Hamilton 1964 coef cient of relatedness r relatedness and level of relatedness matters Brother is more important that cousin Half siblings r 1A1 Siblings r 12 Cousins r 18 Hamilton showed that altruism will spread if Br C gt 0 Introduces the concept of inclusive fitness direct fitness results from reproduction inclusive fitness results from the reproduction of close relatives who share some fraction of your genes As long as your alleles are being passed on in close relatives you are being helped also Natural selection on inclusive fitness is termed kin selection Best evidence comes from eusocial insects wasps bees etc Hymenoptera Unfertilized eggs are males fertilized eggs are females Alarm calling is very interesting One group that often performs alarm calls are prairie dogs Track prairie dogs to see how related they are to their social groups Males are always not as closely related once they reach reproductive age Marks males and females and put fake badgers out to act as predators Rate of calling had very much to do with whether kin was present or not Prairie dogs with parents of full siblings but no offspring versus prairie dogs with offspring were not very different there was quite a bit of calling in both groups Alarm calling changes as a function of age or stage of life Young call a lot don t always know when to call after moving to a breeding coterie they are selfish and do not call a lot While living in breeding coterie with offspring the calling goes up Once the old males are evicted from the breeding coterie the calling again goes down there is no kin nearby Reciprocal Altruism Vampire bats supply one of the best examples of reciprocal altruism Find big groups of sleeping animals Large incisors that do not hurt because of an anticoagulant Most bats do not fee on blood only 3 species so they are much evolved Live in social groups Young vampire bats fail I out of every 3 nights to feed and even adults fail I out of 5 nights none can survive more than three nights without food If one bat feeds and has a roost made that doesn t feed it will regurgitate part of its meal so it can eat After feeding the bats are very rotund it is obvious which have fed and which have not At first it was believed to be kin selection but after Wilkinson s research he found that it was not purely a function of kin selection More likely to regurgitate if they shared a roost than if they were siblings Association was more important than relatedness the animals were remembering how other animals had treated them in the past This is very interesting because it is very moral of these bats Maladaptive traits takes energy to grow ornamental things Large feathers more energy needed to y ight dynamics may be negative Tradeoffs How do these evolve Tend to evolve in species where there is a lot of variance in the reproductive success of males also occurs in females Birds are a good example there is a cost to having long tails but they get more mating opportunities and produce more offspring Sexual dimorphism a difference between males and female members of a species Ex Average difference of male height vs female height Strength of different sexes colorationornamentation etc Mating success vs reproductive success Every female can get at least one mate Males cannot many get zero The distribution of number of offspring is very different for males than it is for females A small amount of males are producing the majority of offspring male competition is driving evolution for secondary sexual characteristics Darwin on iguanas There is a strong correlation between the number of mates and the number of offspring for males but not for females Female iguana snouts are near optimal size while male iguana snouts were bigger than the optimal size there survival rates were way down and they were not able to persist for very long but year after year there were these super males Iguanas have a very unevolved mating system males push each other of rocks to claim their territories and the super males get the rocks that the female iguanas like to mate on The territories are not all equal Starting in 1960 s females began to enter the field and do research Women had different perspectives and one of the things was sexual selection we cannot only look at male evolution as a result of selection different traits in females are different Tradeoffsmaladaptive traits you must have good genes to survive even With your handicap Female choice eggs are costly take more energy there is a finite number Sperm is not costly and takes less energy unlimited Hanging ies Bittacus apicalis males have to capture a prey item and bring it to the female While female is eating the male copulates With her This is called a nuptial gift and the size of the gift corresponds With the length of copulation female Will take longer to eat larger gift longer copulation means more offspring Systems Where males exploit female behavior Fiddler crabs build these little structures on the beach because females like to copulate in cozy places Male beetles Will rub females With antennae and Whichever does it the best gets to copulate The females like it and because they like it that male gets to copulate It is in the female s best interest to have sons that are sexy Sexy son s theory Malemale competition is clearly important but so is female choice Evolution happening across multiple loci also important
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'