L567: From last time:
|
|
- Kerry Fox
- 6 years ago
- Views:
Transcription
1 L567: From last time: Fisher: in Fisher s original presentation, he considered female preference for male traits that were initially favored by natural selection. This could lead to a covariance between the mail trait and the female preference. If the covariance is strong enough, this covariance could lead to a runaway sexual selection, such that the male trait continues to be favored (due to female choice) even after it is no longer favored, or even disfavored, by Natural Selection. But, as we will see, Runaway Sexual Selection can lead to an interesting paradox. Kirkpatrick: Kirkpatrick showed (using a haploid model) that the male trait need not be initially favored by NS to generate linkage disequilibrium between female preference and the male trait. In fact, the male trait was initially selected against by NS. The model also showed that female preference would not increase, unless (1) D > 0, and (2) the male trait was increasing. Kirkpatrick s model also showed how drift and selection could interact to drive allopatric populations in different directions, with respect to female choice and the male trait. 1
2 New topic. How to choose a mate. Darwin considered two kinds of sexual selection (i.e., variation among individuals in mating success). 1. Intrasexual selection due to male-male combat (We won t cover this). And 2. Intersexual selection due to female choice But, does that mean that 1. Plants cannot have sexual selection? 2. Hermaphrodites cannot have sexual selection? See Delph and Ashman 2006 (posted on class web site) for a contrast of interactiondependent and interaction-independent sexual selection and the application to plants. 2
3 Why, in general is there female choice (and sometimes male choice)? 1. whims sensory exploitation This is assumed in Kirkpatrick s model 2. Males provide resources (nuptial gifts) or paternal care. 3. Males are selected for their good genes. a. Incest avoidance. b. genetic advantages to offspring. c. favorable combinations of paternal genes with maternal genes. Problems for the good-genes model. a. Natural selection and sexual selection for good genes erodes the additive genetic variance for the male trait. Hence, at some point in the future, there could be no effect of female choice. Why then be choosy? Possible solution to the problem (Hamilton and Zuk 1982). Conditiondependent choice for high-fitness males. a. The favored combination of genes (epistasis) changes over time. b. Good combinations of genes results in good condition c. Thus, condition may be a reliable indicator of good genes in the male. 3
4 But what causes the favored combination of genes to change over time? à Hamilton and Zuk (1982, Science) proposed that host-parasite coevolution could cause the favored combinations to change over time (The Red Queen again). As such, the variation underlying the male trait would be maintained by frequency-dependent selection. Question: Given that host-parasite coevolution is taking place, would female choice for good condition in males (Condition-Dependent (CD) choice) increase when rare, and go to fixation, in a population of randomly mating (RM) females? à An alternative: opposites attract (OA). What if instead of conditiondependent choice, the females could directly select males that had different genotypes from themselves, so as to increase the genetic diversity among their offspring? Would an OA female preference gene increase when rare in a population of random maters (RM)? Would an OA gene go to fixation? Would an OA female gene increase when rare in a population of females practicing condition-dependent (CD) choice of males? Would an OA gene go to fixation? 4
5 Introduction of Condition-Dependent (CD) or Opposites Attract (OA) alleles into Randomly Mating (RM) populations. Frequency Linkage Disequilibrium a c Condition-dependent choice Host genotype 11 choice allele b d Opposites attract Host genotype 11 choice allele Both forms of mate choice increase when rare in a RM population.!! CD choice goes to fixation, and increases the amplitude of oscillations.!! OA choice reduces the amplitude of oscillations. " CD choice increases linkage disequilibrium." " OA choice reduces linkage disequilibrium. " Generations Remember: linkage disequilbrium refers to a statistical association between alleles at two different loci. Here the loci are disease-resistance loci. Q: why does OA not go to fixation? Source: J. Evol. Biol. 16:
6 Top Left. OA increases against RM, but does not go to fixation. Two kinds of choice could coexist. Top Right. CD increases when rare against RM, and goes to fixation. Left. OA increases when rare against CD, but does not go to fixation. Two kinds of choice could coexist. 6 Source: BMC Evol. Biol. 2004, 4:48
7 Evidence for Opposites Attract 1. Mice and MHC. 2. Fish and MHC. 3. Humans and MHC: the T-shirt study (Wederkind et al Posted on web site.) But see this update from Fabio (class of 2013): for humans: and, for salmon see: Methods for the T-shirt study 1. Male (49) and female (44) Swiss college students typed for MHC genotype. 2. Men wore standard T-shirts for two nights (no showers, no wine, etc.) 3. Women were given T-shirts to smell in a small, unmarked box. 4. Women were asked to rate the odors for three men with similar MHC, as well as three men with dissimilar MHC. A score was given for pleasantness and intensity. Results: Odors of men having dissimilar MHC genotypes were preferred by women; and these odors were more likely to remind them of a boyfriend, at least by women not taking oral contraceptives. 7
8 Genetic correlation, indirect selection, sexual selection, and selfish genetic elements Featuring stalk-eyed flies Males compete for position on root hairs (nighttime roosts). Male with the longer eyestalk usually wins. Females mate with territory holders. Neither males nor females care for the offspring. 8
9 Genetic correlation. 1. Graphical version showing a genetic correlation (r) between the family means for daughters preference plotted against the mean for sons traits, for Stalk eyed flies. Correlation: r = cov(y,x) var(y) var(x) Note the difference between correlation and the slope of a regression line β y,x = cov(y,x) var(x) 9
10 2. Using what we know from Quantitative Genetics, selection on the father s trait should produce a response to selection in the Daughter preference, as well as in the male trait in sons. How to test? Truncation selection on father s eyestalk should produce a response to selection in daughter s preference. 10
11 Thirteen-generation artificial selection experiment with Stalk-Eyed flies (Wilkinson and Reillo 1994). Prediction: selection on male eye-span length will produce a correlated response in the preference by females. 1. Control line: 10 males and 25 females picked at random every generation. 2. Long line: 10 males with longest eye span (relative to body size) picked each generation, along with 25 randomly selected females. **male and female eyespans increased. 3. Short line: 10 males with shortest eye span (relative to body size) picked each generation, along with 25 randomly selected females. **male and female eyespans decreased. The experiment ran for 13 generations, and then female choice was determined. Specifically, at generation 13, females were given a choice between two males, matched for body size, where one had a long-eye stalk and one had a short eyestalk). 11
12 Results. 1. Females from the Short line preferred to mate with males with short eyestalks. Why? 2. Females from the Control line preferred to mate with males with long eyestalks. What does that mean? 3. Females from the Long line preferred to mate with males with long eyestalks. But they did not prefer males with long eyestalks more than females from the control lines. Why? (ps: no evidence that long eye span was associated with good genes for development) 12
13 Curious result Stalk-eyed flies are female-biased in nature. But, the female bias became less extreme in the lines where males were selected for long stalks (i.e., sex ratio became closer to 1:1). And the sex ratio became more female-biased in the lines were males were selected for short eyestalks. Why? A surprising twist. Suppose we had two kinds of males: X d Y males and XY males, where the d refers to driving. At meiosis, the driving X chromosome, X d, kills Y-bearing sperm. This kind of drive is called meiotic drive. Normal X chromosomes do not kill the Y-bearing sperm. What happens to X d? 13
14 And what does this have to do with the stalk-eyed flies? Remember that the offspring of the lines selected for short-eye stalks had female-biased sex ratios. Perhaps short eyes are genetically associated (in linkage disequilibrium) with the driving X chromosome, X d. Why do females prefer long-stalk males in Nature? It would now appear that either: 1. Males with long eye-stalks are more likely to have a normal X (non driving) chromosome. Or, 2. that males with long eyestalks are more likely to have Y chromosomes that prevent the action of the driving X (Wilkinson et al. 1998). (Best supported at present?) 14
15 More on selfish DNA? Cytoplasmic Male Sterility (CMS) in plants (simplified). CMS is a mitochondrial gene that inhibits pollen production in hermaphroditic plants. (see page 164 in Burt and Trivers: Genes in conflict.) This was a chalk talk with hand-drawn figures. The main points were 1. CMS is a mitochondrial gene that inhibits pollen production. Resources are shifted to making ovules, which increases the transmission probability for cytoplasmic genes in general. CMS spreads when rare. 2. The population becomes female-allocation biased, but the CMS does not go to fixation. (show graph of CMS spread when rare.) 3. The female bias creates selection that favors allocation to pollen. This could result in increased allocation to male function in male-fertile hermaphrodites, and could lead eventually to the evolution of separate sexes, where female is determined by the CMS mutation. 4. But there is also selection favoring nuclear genes that restore male function in CMS plants. Basically, CMS causes a departure from the ESS sex ratio. Nuclear genes that move non-cms plants closer to the ESS sex ration are favored by selection. 15
16 Chase-away sexual selection (see page 516 in text, 4 th ed. Freeman&Heron). 1. A new male trait arises that increases the mating success of the males, but reduces the survivorship of females. 2. The male trait spreads in the population. 3. A female-expressed mutation arises that allows resistance to manipulation by the male trait. Resistant females become more common; males with the novel trait become less numerous. 4. A new mutation arises that is expressed in males, which again increases the mating success of males, with a cost to females. 5. The cycle continues. Genes expressed in males and genes expressed in females are engaged in a kind of antagonistic coevolution. Genomic conflict. Design an experiment But first, Bill Rice s experiment. 16
17 Rice s experiment. (see Rice s 1996 paper in Nature on web site.) 1. Experimental group. Males compete with each other for females. Females mate with multiple males. Sons were taken from this group to start the next generation. But the females for the next generation were taken from non responding stock population (meaning the females could not coevolve with the males). Males could evolve, females could not. 2. Control group. No competition for mates. 17
18 3. Results: males from experimental lines had higher fitness than control males. They were also more likely to re-mate with the same female, and they were more successful at defense (defense was measured as the relative number of offspring sired after the female was allowed to remate with a different male). 4. Results. Females mated to males from the experimental lines had significantly higher mortality rates, which apparently resulted from the toxic seminal fluid produced by males from the experimental lines. Design a new experiment.. 18
19 Remember parent-offspring conflict? Now for parent-parent conflict More on conflict between male and female parents: Zeh and Zeh Live birth (viviparity) offers the opportunity for conflict that is not possible in spawning species or egg laying species. Specifically, the womb (or similar structure) provides an arena for competing interests to play out. There may be a difference, for example, of the effects of natural selection on males and females. In the mother, selection should favor equal allocation to offspring within a brood, as they are all equally related to her. In addition, for interoparous species (species reproduce more than once), the mother may hold back resources for future broods. How does selection act on males in polyandrous species (where females mate with more than one male)? Males would be selected to manipulate the mother into investing more in their (the dad s) offspring, at the expense of the progeny sired by other males and at the expense of the mother s future reproductive success. How could they do this? 19
20 In mice embryos, the maternal allele for IGF2 is mostly turned off. IGF2 is insulin-like growth factor 2, which stimulates cell development, increases the growth rate of embryos, and effectively garners resources from the placenta. Why should a mother imprint her IGF2 alleles to reduce transcription of this gene in her offspring? Does she want to starve her offspring? In the same embryos, the paternal copy of the allele IGF2 is turned on. Why? In addition, the mother expresses another gene, IGF2-r, which codes for a receptor that mops up extra growth factor. Conversely, the male copy of the same gene is not expressed. Why? Who wins? 20
21 lgf2 on in sperm, off in eggs. lgf2r on in eggs, off in sperm. Top: transfer activity Bottom: suppression activity Figure 2. Left, Igf2 (insulin-like growth factor type 2) and Igf2r (insulin-like growth factor type 2 receptor) are reciprocally imprinted genes in eutherian mammals. In the developing embryo, gene expression occurs only from the paternally inherited (red) copy of the Igf2 locus and only from the maternally inherited (blue) copy of the Igf2r locus. The two loci function in opposition: insulin-like growth factor type 2 promotes resource transfer from the mother to the embryo but is degraded by the product of the Igf2r locus. With a number of loci contributing to the stimulation of resource transfer by the paternal genome and suppression by the maternal genome, maternal and paternal genomes are likely to vary in the extent to which they are genetically compatible (right). Since multiple paternity drives the evolution of more aggressive paternal genomes, such incompatibility is predicted to be greatest in crosses between populations which differ in level of polyandry. From Zeh&Zeh Bioessays paper (2000). 21
22 Figure 2. Functionally distinct roles played by maternally and paternally inherited genomes in mammalian development. Nuclear transplantation experiments have revealed that early development of the embryo proper is controlled largely by expression of the maternal genome, whereas paternally inherited genes control growth primarily of the trophoblast and placenta (McGrath & Solter 1984; Surani et al. 1984). Naturally formed conceptuses with two paternally inherited genomes and no maternal genome are known as complete hydatidiform moles (CHMs). CHMs closely resemble the androgenic embryos produced in the nuclear transplantation experiments. (From Zeh and Zeh 2008) 22
23 Additional points from the Zeh s paper (read for next time.) 1. Mammals develop post-zygotic isolating barriers much faster that frogs and birds. Why? 2. Viviparity creates a post-fertilization arena, allowing for the possibility of reallocation of resources within the arena, which indirectly aid the spread of cytoplasmic male killers. Why? 3. Polyandry drives conflict, which might drive greater degrees of polyandry, possibly resulting is a positive feedback situation. 23
Female Choice in Gray Tree Frogs. Female Choice in Gray Tree Frogs
Female Choice in Gray Tree Frogs Female Choice in Gray Tree Frogs Research by Gerhardt et al. (1996). Males call to attract females. Males call to attract females Ribbet! Figure 11.27 Tiny and super cute!
More informationApril 12: Reproduction III: Female choice. Female choice
April 12: Reproduction III: Female choice Female choice In general, females are expected to be choosier than males because they have more to lose by making bad mating decisions Costs and Benefits: Possible
More information3/26/ Sexual dimorphism is differences between males and females of a species. 2. Anisogamy. 1. Fecundity
Sexual Dimorphism 1. Sexual dimorphism is differences between males and females of a species. 2. Anisogamy A. sexual reproduction involving the fusion of two dissimilar gametes;individuals producing the
More informationNovember 4, 2009 Bioe 109 Fall 2009 Lecture 17 The evolution of mating systems. The evolution of sex ratio
November 4, 2009 Bioe 109 Fall 2009 Lecture 17 The evolution of mating systems The evolution of sex ratio - let us define sex ratio as the proportion of males to females. - in discussing the evolution
More informationGood resources. Why are females choosy? Good resources. Resources from males can tip the scales of relative investment
Why are females choosy? Good resources direct benefits Good genes indirect benefits Sexy son hypothesis (Fisher) Handicap hypothesis (Zahavi) Good genes for sons, daughters Good resources courtship feeding
More informationGood resources. Why are females choosy? Good resources. Good resources direct benefits Good genes indirect benefits
Why are females choosy? Good resources direct benefits Good genes indirect benefits Sexy son hypothesis (Fisher) Handicap hypothesis (Zahavi) Good genes for sons, daughters courtship feeding Good resources
More informationThe selfish gene. mitochondrium
The selfish gene selection acts mostly for the benefit of the individual sometimes selection may act for the benefit of relatives rarely, selection acts for the benefit of the group mitochondrium in asexual
More informationReproduction. Chapter 7
Reproduction Chapter 7 Sexual Selection Darwin's theory to explain traits that aren't obviously advantageous https://www.youtube.com/watch?v=ll30qttsz9u Bower Birds Bower Birds She builds the nest, cares
More informationWhat is sex? What about asexual reproduction? What is sexual reproduction?
BIOL2007 EVOLUTION OF SEX AND SEXUAL SELECTION Kanchon Dasmahapatra EVOLUTIONARY QUESTIONS ABOUT SEX Today: A) The evolution of sex 1) What is the advantage of sex? B) Ev. of sexual dimorphism - sexual
More informationLab Activity 36. Principles of Heredity. Portland Community College BI 233
Lab Activity 36 Principles of Heredity Portland Community College BI 233 Terminology of Chromosomes Homologous chromosomes: A pair, of which you get one from mom, and one from dad. Example: the pair of
More informationAnti-predator behavior: Group defense - Many eyes - Selfish herd - Dilution effects - Tonic immobility. Dispersal:
Note: These are just the topics that have been covered since Exam 2. The exams are cumulative, so all the material that we have covered in this course can be included in the Final. However, there will
More informationSEX. Genetic Variation: The genetic substrate for natural selection. Sex: Sources of Genotypic Variation. Genetic Variation
Genetic Variation: The genetic substrate for natural selection Sex: Sources of Genotypic Variation Dr. Carol E. Lee, University of Wisconsin Genetic Variation If there is no genetic variation, neither
More informationAdaptation and Optimality Theory
Adaptation and Optimality Theory Prisoner s Dilemma game: An optimality model What is the optimal strategy when you are playing with different people of unknown reputation? Defect: We call this the evolutionarily
More informationSome observations. Some traits are difficult to view as adaptations, because they appear to provide a disadvantage to the organism
Some traits are difficult to view as adaptations, because they appear to provide a disadvantage to the organism Darwin asked: Can natural selection explain these differences? Structural traits: cumbersome
More informationThis question is taken directly from the list of second test study questions (#6) it should not be a surprise...
1. Female choice of males that have exaggerated characters has been explained by female choice of males that have better genes. Explain how female choice of higher quality males might lead to exaggerated
More informationGenetics Review. Alleles. The Punnett Square. Genotype and Phenotype. Codominance. Incomplete Dominance
Genetics Review Alleles These two different versions of gene A create a condition known as heterozygous. Only the dominant allele (A) will be expressed. When both chromosomes have identical copies of the
More informationSexual selection. 1) Sexual dimorphism. 2) Variation in mating success. 3) Sexual selection. 4) Female choice based on male ornaments
Sexual selection 1) Sexual dimorphism 2) Variation in mating success 3) Sexual selection 4) Female choice based on male ornaments 5) The evolution of female preference 1) Sexual dimorphism http://en.wikipedia.org/wiki/file:descent_of_man_-_figure_16.jpg
More informationUnit 1 Biological Diversity Topic 1.1 Examining Diversity. Text p. 3-15
Topic 1.1 Examining Diversity. Text p. 3-15 Variation to the MAX! Biologists have identified over species of animals and over species of plants. The most successful life form is What is Biodiversity? The
More information1.3 - Sexually Reproduction What is Sexual Reproduction?
1.3 - Sexually Reproduction What is Sexual Reproduction? Sexual Reproduction - Genetic information from two cells is combined to produce a new genetically unique organism. Sexual reproduction occurs when
More information11.1 Genetic Variation Within Population. KEY CONCEPT A population shares a common gene pool.
KEY CONCEPT A population shares a common gene pool. Genetic variation in a population increases the chance that some individuals will survive. Genetic variation leads to phenotypic variation. Phenotypic
More informationGenetic basis of inheritance and variation. Dr. Amjad Mahasneh. Jordan University of Science and Technology
Genetic basis of inheritance and variation Dr. Amjad Mahasneh Jordan University of Science and Technology Segment 1 Hello and welcome everyone. My name is Amjad Mahasneh. I teach molecular biology at Jordan
More informationQ: Do platypus have more functional genes on their Y s than other mammals?
One minute responses Q: Do platypus have more functional genes on their Y s than other mammals? A: I wasn t able to find out I did learn that the platypus X s and Y s are not homologous to normal mammal
More informationSexual selection and the evolution of sex differences
Sexual selection and the evolution of sex differences Males and females have the same genes. Why do the sexes often look and act so differently? Why is the male often insanely ornamented? (Or simply insane?)
More informationTEST NAME:review TEST ID: GRADE:07 Seventh Grade SUBJECT:Life and Physical Sciences TEST CATEGORY: My Classroom
TEST NAME:review TEST ID:1070005 GRADE:07 Seventh Grade SUBJECT:Life and Physical Sciences TEST CATEGORY: My Classroom review Page 1 of 18 Student: Class: Date: 1. There are four blood types: A, B, AB,
More informationThe sight of a feather in a peacock s tail, whenever I gaze at it, makes me sick. --Charles Darwin 1887
The sight of a feather in a peacock s tail, whenever I gaze at it, makes me sick. --Charles Darwin 1887 1 Outline causes sexual selection vs. natural selection sexual selection during courtship male-male
More informationEvolution of genetic systems
Evolution of genetic systems Joe Felsenstein GENOME 453, Autumn 2013 Evolution of genetic systems p.1/24 How well can we explain the genetic system? Very well Sex ratios of 1/2 (C. Dusing, " 1884, W. D.
More informationCh 8 Practice Questions
Ch 8 Practice Questions Multiple Choice Identify the choice that best completes the statement or answers the question. 1. What fraction of offspring of the cross Aa Aa is homozygous for the dominant allele?
More informationAll discussion of mating strategies and sex differences begins with Darwin s theory of Sexual Selection
All discussion of mating strategies and sex differences begins with Darwin s theory of Sexual Selection Intrasexual Natural Selection Sexual Selection Survival Mating Success Parental Care Intrasexual
More informationLectures 7 & 8 Wednesday, October 12, 2011 & Friday, October 14, 2011
Lectures 7 & 8 Wednesday, October 12, 2011 & Friday, October 14, 2011 Recombination Diploid organisms: The first step in sexual reproduction is the production of gametes, each of which has half the chromosomes
More informationChapter 17 Genetics Crosses:
Chapter 17 Genetics Crosses: 2.5 Genetics Objectives 2.5.6 Genetic Inheritance 2.5.10.H Origin of the Science of genetics 2.5.11 H Law of segregation 2.5.12 H Law of independent assortment 2.5.13.H Dihybrid
More informationEffect of act on fitness of recipient
Kin selection (inclusive fitness) and social behavior These worker ants are sterile, and they differ greatly from their queens and males. Darwin was troubled by social-insect workers, because they have
More informationEvolution of gender Sex ratio how many males and females? Sex determination how did they get to be male/female? Some truly weird animals
1 Roadmap Finishing up inbreeding Evolution of gender Sex ratio how many males and females? Sex determination how did they get to be male/female? Some truly weird animals 2 Midterm Mean 72.6 Range 35-92
More information--- understanding its biological significance. -- appreciating how genetics was used to understand how it is determined.
Sex: --- understanding its biological significance -- appreciating how genetics was used to understand how it is determined. according to Jacob Bronowski in The Ascent of Man (1973) Mendel himself was
More informationSexual Selection. Male and female. Lukas Schärer. Evolutionary Biology Zoological Institute University of Basel
Sexual Selection Lukas Schärer! Evolutionary Biology Zoological Institute University of Basel 1 8.11.2017 Advanced-level Evolutionary Biology Male and female 2 Summary: Sexual Selection defining sexual
More informationA gene is a sequence of DNA that resides at a particular site on a chromosome the locus (plural loci). Genetic linkage of genes on a single
8.3 A gene is a sequence of DNA that resides at a particular site on a chromosome the locus (plural loci). Genetic linkage of genes on a single chromosome can alter their pattern of inheritance from those
More informationEVOLUTIONARY BIOLOGY BIOS EXAM #2 FALL 2017
EVOLUTIONARY BIOLOGY BIOS 30305 EXAM #2 FALL 2017 There are 3 parts to this exam. Use your time efficiently and be sure to put your name on the top of each page. Part I. True (T) or False (F) (2 points
More informationSEX AND REPRODUCTIVE SUCCESS
Chapter 15 SEX AND REPRODUCTIVE SUCCESS Genetic system refers to the way a species reproduces itself: sexually or asexually, self-fertilize or outcross, hermaphroditic or have separate sexes. THE EVOLUTION
More informationGenetic Variation Junior Science
2018 Version Genetic Variation Junior Science http://img.publishthis.com/images/bookmarkimages/2015/05/d/5/c/d5cf017fb4f7e46e1c21b874472ea7d1_bookmarkimage_620x480_xlarge_original_1.jpg Sexual Reproduction
More informationCh. 23 The Evolution of Populations
Ch. 23 The Evolution of Populations 1 Essential question: Do populations evolve? 2 Mutation and Sexual reproduction produce genetic variation that makes evolution possible What is the smallest unit of
More informationGenetics and Diversity Punnett Squares
Genetics and Diversity Punnett Squares 1 OUTCOME QUESTION(S): S1-1-12: How are the features of the parents inherited to create unique offspring? Vocabulary & Concepts Allele Dominant Recessive Genotype
More informationThe Evolution of Sex. Or, why do we even need males?
The Evolution of Sex Or, why do we even need males? Sexual VS Asexual reproduction Sexual Fewer offspring/individual Only half of genes passed on Good genotypes are lost Offspring are variable Asexual
More informationChapter 4 PEDIGREE ANALYSIS IN HUMAN GENETICS
Chapter 4 PEDIGREE ANALYSIS IN HUMAN GENETICS Chapter Summary In order to study the transmission of human genetic traits to the next generation, a different method of operation had to be adopted. Instead
More informationWill now consider in detail the effects of relaxing the assumption of infinite-population size.
FINITE POPULATION SIZE: GENETIC DRIFT READING: Nielsen & Slatkin pp. 21-27 Will now consider in detail the effects of relaxing the assumption of infinite-population size. Start with an extreme case: a
More informationThe behavioral ecology of animal reproduction
The behavioral ecology of animal reproduction I. Introduction to Behavioral Ecology Behavioral ecologists test hypotheses about the adaptive function of a behavior Behavioral Ecology Behavioral ecologists
More informationASSOCIATION BETWEEN SEX RATIO DISTORTION AND SEXUALLY ANTAGONISTIC FITNESS CONSEQUENCES OF FEMALE CHOICE
doi:10.1111/j.1558-5646.2009.00692.x ASSOCIATION BETWEEN SEX RATIO DISTORTION AND SEXUALLY ANTAGONISTIC FITNESS CONSEQUENCES OF FEMALE CHOICE Tim Connallon 1,2 and Erin Jakubowski 1 1 Department of Ecology
More informationEvolution of Mating Systems. Chapter 8
Evolution of Mating Systems Chapter 8 Mating Systems-Chapter 8 1 Monogamy 2 Polyandry 3 Polygyny And the many combinations within! Why should a male be monogamous? 1 extension of guarding, little chance
More informationUnit 4 - Reproduction
Living Environment Practice Exam- Parts A and B-1 1. Which cell process occurs only in organisms that reproduce sexually? A) mutation B) replication C) meiosis D) mitosis 2. Which sequence represents the
More informationEOG Practice:,Evolution & Genetics [126663]
EOG Practice:,Evolution & Genetics [126663] Student Class Date 1. A particular peach tree produces peaches that are more resistant to disease than other peaches. What method would reproduce these EXACT
More informationChapter 11: Fornications of Kings. Kirsten and Sam
Chapter 11: Fornications of Kings Kirsten and Sam Good Morning! Who s ready to learn about some incest? Discussion: Social reactions to incest vs. animal world incest- talk away! - Zoos - Dog breeds -
More informationSexual Reproduction. For most diploid eukaryotes, sexual reproduction is the only mechanism resulting in new members of a species.
Sex Determination Sexual Reproduction For most diploid eukaryotes, sexual reproduction is the only mechanism resulting in new members of a species. Meiosis in the sexual organs of parents produces haploid
More informationSexual Reproduction. Chapter 3 Sexual Reproduction BC Science Probe 9 pages
Sexual Reproduction Chapter 3 Sexual Reproduction BC Science Probe 9 pages 72-105 Why Sex? Textbook Read pages 74 77 Sexual Reproduction Is reproduction involving two parents Each parent contributes equal
More informationNormal enzyme makes melanin (dark pigment in skin and hair) Defective enzyme does not make melanin
Genetics Supplement (These supplementary modules, a Genetics Student Handout, and Teacher Preparation Notes with suggestions for implementation are available at http://serendip.brynmawr.edu/sci_edu/waldron/#genetics.
More informationB. male gametes that may be carried by the wind
1. Which characteristic of sexual reproduction has specifically favored the survival of animals that live on land? A. fusion of gametes in the outside environment B. male gametes that may be carried by
More informationSexual selection. Intrasexual selection mating success determined by within-sex interactions e.g., male-male combat
Sexual dimorphism Sexual selection Is sexual selection different from natural selection? Darwin saw them as distinct - only sexual selection could produce traits that compromise survival The basic principle
More informationr = intrinsic rate of natural increase = the instantaneous rate of change in population size (per individual). If r > 0, then increasing
Zoology 357 - Evolutionary Ecology - First Exam 1. (6 points) List three types of natural selection and show how the population changes over time (graph the initial phenotype frequency distribution and
More informationarxiv: v1 [q-bio.pe] 9 Sep 2016
Puzzles in modern biology. I. Male sterility, failure reveals design Steven A. Frank 1 1 Department of Ecology and Evolutionary Biology, University of California, Irvine, CA 92697 2525 USA, safrank@uci.edu
More informationReproduction. Asexual vs Sexual
Reproduction Asexual vs Sexual Why is Reproduction Important? The means by which an organism produces offspring Biologically and evolutionarily speaking, reproduction is what has made the continuation
More informationDRAGON GENETICS Understanding Inheritance 1
DRAGON GENETICS Understanding Inheritance 1 INTRODUCTION In this activity, you and a partner will work together to produce a baby dragon. You will simulate meiosis and fertilization, the biological processes
More informationThe Chromosomal Basis of Inheritance
The Chromosomal Basis of Inheritance Factors and Genes Mendel s model of inheritance was based on the idea of factors that were independently assorted and segregated into gametes We now know that these
More informationMastery. Sexual Reproduction and Meiosis. Chapter Content CHAPTER 3 LESSON 1. Directions: Study the diagram. Then answer the following questions.
Chapter Content Mastery Sexual Reproduction and Meiosis Directions: Study the diagram. Then answer the following questions. LESSON 1 Interphase Prophase I Metaphase I Anaphase I Telophase I Meiosis II
More informationHow do living things Sexually Reproduce?
How do living things Sexually Reproduce? Besides animals, what other things reproduce sexually? Think of a family that has both biological parents and has 2 or more children #1 Consider what the parents
More informationReproduction Review YOU ARE EXPECTED TO KNOW THE MEANING OF ALL THE FOLLOWING TERMS:
Reproduction Review YOU ARE EXPECTED TO KNOW THE MEANING OF ALL THE FOLLOWING TERMS: CHROMOSOME GENE DNA TRAIT HEREDITY INTERPHASE MITOSIS CYTOKINESIS ASEXUAL BINARY FISSION CELL CYCLE GENETIC DIVERSITY
More informationSection 4 Genetics and heredity
1 Section 4 Genetics and heredity Chapter 21 Cell division, chromosomes and genes Page 182 1. a Gametes are reproductive cells. (i) Plants. The male gametes are the pollen nuclei and are produced in the
More informationThe bases on complementary strands of DNA bond with each other in a specific way A-T and G-C
1 Bio 1101 Lecture 6 (Guided Notes) Ch. 8: Cellular Basis of Reproduction 2 3 4 5 6 Cellular Basis of Reproduction & Inheritance In order for an organism to replace dead cells or to grow and produce new
More informationThe Evolution of Darwin s Theory Pt 2. Chapter 16-17
The Evolution of Darwin s Theory Pt 2 { Chapter 16-17 Natural Selection If an individual has an allele that allows them to survive better in an environment than another allele, they will have a better
More informationThe Chromosomal Basis Of Inheritance
The Chromosomal Basis Of Inheritance Chapter 15 Objectives Explain the chromosomal theory of inheritance and its discovery. Explain why sex-linked diseases are more common in human males than females.
More informationSelection at one locus with many alleles, fertility selection, and sexual selection
Selection at one locus with many alleles, fertility selection, and sexual selection Introduction It s easy to extend the Hardy-Weinberg principle to multiple alleles at a single locus. In fact, we already
More informationMendelian Genetics. 7.3 Gene Linkage and Mapping Genes can be mapped to specific locations on chromosomes.
7 Extending CHAPTER Mendelian Genetics GETTING READY TO LEARN Preview Key Concepts 7.1 Chromosomes and Phenotype The chromosomes on which genes are located can affect the expression of traits. 7.2 Complex
More informationCh. 15 The Chromosomal Basis of Inheritance
Ch. 15 The Chromosomal Basis of Inheritance Nov 12 12:58 PM 1 Essential Question: Are chromosomes the basis of inheritance? Nov 12 1:00 PM 2 1902 Walter S. Sutton, Theodor Boveri, et al Chromosome Theory
More informationComplex Traits Activity INSTRUCTION MANUAL. ANT 2110 Introduction to Physical Anthropology Professor Julie J. Lesnik
Complex Traits Activity INSTRUCTION MANUAL ANT 2110 Introduction to Physical Anthropology Professor Julie J. Lesnik Introduction Human variation is complex. The simplest form of variation in a population
More informationPage 1. Name:
Name: 4734-1 - Page 1 Warts result when certain viruses cause skin cells to reproduce at a high rate. This rapid reproduction of skin cells is due to the viruses stimulating cellular digestion mitotic
More informationGENETICS - NOTES-
GENETICS - NOTES- Warm Up Exercise Using your previous knowledge of genetics, determine what maternal genotype would most likely yield offspring with such characteristics. Use the genotype that you came
More informationTest Bank. Chapter 2. Abrams, Sexuality and Its Disorders SAGE Publishing, 2017
Test Bank Chapter 2 1. Is the male female dichotomy an appropriate mode of defining gender? Why, or why not? Ans: The male female dichotomy is strongly embodied in most of cultures, religions, and even
More informationToday. Genomic Imprinting & X-Inactivation
Today 1. Quiz (~12 min) 2. Genomic imprinting in mammals 3. X-chromosome inactivation in mammals Note that readings on Dosage Compensation and Genomic Imprinting in Mammals are on our web site. Genomic
More informationBy Mir Mohammed Abbas II PCMB 'A' CHAPTER CONCEPT NOTES
Chapter Notes- Genetics By Mir Mohammed Abbas II PCMB 'A' 1 CHAPTER CONCEPT NOTES Relationship between genes and chromosome of diploid organism and the terms used to describe them Know the terms Terms
More informationGenetics - Problem Drill 06: Pedigree and Sex Determination
Genetics - Problem Drill 06: Pedigree and Sex Determination No. 1 of 10 1. The following is a pedigree of a human trait. Determine which trait this is. (A) Y-linked Trait (B) X-linked Dominant Trait (C)
More informationSexual selection Introduction. Sexual selection Introduction. Sexual selection Introduction. Sexual selection Classification
Introduction 1 Introduction 2 Individuals rarely mate at random for a number of reasons: Dispersal may be limited Individuals may or may not be able to self Individuals may reproduce asexually Individuals
More informationThe Chromosomal Basis of Inheritance
Chapter 15 The Chromosomal Basis of Inheritance PowerPoint Lectures for Biology, Seventh Edition Neil Campbell and Jane Reece Lectures by Chris Romero Overview: Locating Genes on Chromosomes A century
More informationChromosomes, Mapping, and the Meiosis-Inheritance Connection. Chapter 13
Chromosomes, Mapping, and the Meiosis-Inheritance Connection Chapter 13 Chromosome Theory Chromosomal theory of inheritance - developed in 1902 by Walter Sutton - proposed that genes are present on chromosomes
More informationSexual Selection and Altruism
Sexual Selection and Altruism Sex in Humans: XX and XY Sex in Humans: XX and XY Y = just a trigger for stuff on X Sexual Selection "Thus it is, as I believe, that when the males and females of any animal
More information3.1 Meiosis
3.1 Meiosis Chromosome Number Individuals of the same species have the same number of chromosomes. Meiosis is used to half the number of chromosomes passed to the offspring. What is meiosis Meiosis happens
More informationSo what is a species?
So what is a species? Evolutionary Forces New Groups Biological species concept defined by Ernst Mayr population whose members can interbreed & produce viable, fertile offspring reproductively compatible
More informationFor a long time, people have observed that offspring look like their parents.
Chapter 10 For a long time, people have observed that offspring look like their parents. Even before we knew about genes, people were breeding livestock to get certain traits in the offspring. They knew
More informationAll discussion of mating strategies and sex differences begins with Darwin s theory of Sexual Selection
All discussion of mating strategies and sex differences begins with Darwin s theory of Sexual Selection Natural Selection Survival Mating Success Parental Care Intrasexual Selection: Weapons that are used
More informationDarwin s Puzzle: Why are Males and Females Different? Darwin, C The Descent of Man and Selection in Relation to Sex. 1st ed., Murray, London.
Darwin s Puzzle: Why are Males and Females Different? Darwin, C. 1871. The Descent of Man and Selection in Relation to Sex. 1st ed., Murray, London. Parental Investment and Sexual Selection Trivers 1972
More informationBiology 352, Spring 2018 Exam Number KEY Second midterm exam Part 1 (short answer worth 21 % of grade)
Part 1 (short answer worth 21 % of grade) 1-1) Match the following terms used in behavioral ecology with the appropriate topics of behavioral study listed to the right (you may apply more than one topic
More informationThe bases on complementary strands of DNA bond with each other in a specific way A-T and G-C
1 Bio 1101 Lecture 6 Ch. 8: Cellular Basis of Reproduction 2 3 4 5 6 Cellular Basis of Reproduction & Inheritance In order for an organism to replace dead cells or to grow and produce new cells, existing
More informationLab 5: Testing Hypotheses about Patterns of Inheritance
Lab 5: Testing Hypotheses about Patterns of Inheritance How do we talk about genetic information? Each cell in living organisms contains DNA. DNA is made of nucleotide subunits arranged in very long strands.
More informationTypes of behaviors that are elicited in response to simple stimuli
Lecture 19: Animal Behavior I. Background A. Animal behavior reflects and arises from biological properties 1. Exhibited behavior defends on the physiological systems and processes unique to a given organism
More informationBio 1M: Evolutionary processes
Bio 1M: Evolutionary processes Evolution by natural selection Is something missing from the story I told last chapter? Heritable variation in traits Selection (i.e., differential reproductive success)
More informationMeiosis and Introduction to Inheritance
Meiosis and Introduction to Inheritance Instructions Activity 1. Getting Started: Build a Pair of Bead Chromosomes Materials bag labeled diploid human genome (male) bag labeled diploid human genome (female)
More informationChapter 15 Notes 15.1: Mendelian inheritance chromosome theory of inheritance wild type 15.2: Sex-linked genes
Chapter 15 Notes The Chromosomal Basis of Inheritance Mendel s hereditary factors were genes, though this wasn t known at the time Now we know that genes are located on The location of a particular gene
More informationLecture Outline. Darwin s Theory of Natural Selection. Modern Theory of Natural Selection. Changes in frequencies of alleles
1. Basics of Natural Selection Lecture Outline 2. How to test for the key components of natural selection a. Variation b. Heritability c. Can the trait respond to selection? d. What are the selective forces?
More information1042SCG Genetics & Evolutionary Biology Semester Summary
1042SCG Genetics & Evolutionary Biology Semester Summary Griffith University, Nathan Campus Semester 1, 2014 Topics include: - Mendelian Genetics - Eukaryotic & Prokaryotic Genes - Sex Chromosomes - Variations
More informationEvolution of Sex. No area of evolutionary biology. mixture of strange phenomena than the evolution of sex. (Stearns, 1987)
Evolution of Sex No area of evolutionary biology offers a more fascinating mixture of strange phenomena than the evolution of sex (Stearns, 1987) Sex Refers to union (SYNGAMY( SYNGAMY) ) of two genomes
More informationTHE CHROMOSOMAL BASIS OF INHERITANCE CHAPTER 15
THE CHROMOSOMAL BASIS OF INHERITANCE CHAPTER 15 What you must know: Inheritance in sex-linked genes. Inheritance of linked genes and chromosomal mapping. How alteration of chromosome number or structurally
More informationDownloaded from
Chapter-5 Principles of Inheritance and Variations Chapter No. Chapter Name Concepts Degree of imp. Ref. NCERT text book.: page nos Common errors 5 Principles of inheritance and variations 1. Mendel s
More informationA. Incorrect! Cells contain the units of genetic they are not the unit of heredity.
MCAT Biology Problem Drill PS07: Mendelian Genetics Question No. 1 of 10 Question 1. The smallest unit of heredity is. Question #01 (A) Cell (B) Gene (C) Chromosome (D) Allele Cells contain the units of
More informationPedigree Construction Notes
Name Date Pedigree Construction Notes GO TO à Mendelian Inheritance (http://www.uic.edu/classes/bms/bms655/lesson3.html) When human geneticists first began to publish family studies, they used a variety
More informationBird Mating Systems/Sexual Selection
Bird Mating Systems/Sexual Selection Why study mating systems? What are the ecological conditions under which different mating systems arise? Implications for evolution mating is where genes are passed
More information