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The quantitative genetics of sexual dimorphism
The quantitative genetics of sexual dimorphism

... the two sexual morphs (Lande, 1980, 1987; Reeve and Fairbairn, 1996, 1999, 2001; Fairbairn, 1997; Badyaev, 2002)? In some cases, the sexes can be so disparate as to be unrecognizable as the same species (Darwin, 1871) and yet these highly distinct phenotypes can arise from substantively identical ge ...
THE GENOMIC LOCATION OF SEXUALLY ANTAGONISTIC VARIATION: SOME CAUTIONARY COMMENTS
THE GENOMIC LOCATION OF SEXUALLY ANTAGONISTIC VARIATION: SOME CAUTIONARY COMMENTS

... which the allele that is beneficial in males but deleterious in females is recessive or partly recessive. In this case, when the malebeneficial allele is rare, X-linkage facilitates its maintenance in the population by exposing it to selection in hemizygous males. Conversely, when the dominant, fema ...
Embryonic growth and the evolution of the mammalian Y
Embryonic growth and the evolution of the mammalian Y

... the zygote. It is thus significant that, like these protooncogenes (and hence putative growth-related factors), Zfy (Kalikin et at., 1989), Ubely] and Sry (Hendriksen et a!., 1993) also have postmeiotic gene expression. As noted above, a Y-linked mutant that promoted early growth rate could potentia ...
presentation source
presentation source

... White = no sword Hatched = ambiguous ...
Evolution by Natural Selection
Evolution by Natural Selection

... 6. "Survival of the fittest" is a common expression. What do you think most people mean by this expression? How would you explain this expression to help someone understand how natural selection actually functions? Most people proably think the stronger the individual the greater chance they have t ...
Rock-Around-the-Clock PDF document
Rock-Around-the-Clock PDF document

Teaching and Learning Genetics with Drosophila 4. Pattern of
Teaching and Learning Genetics with Drosophila 4. Pattern of

... types of flies differ from both the parents and show new combinations for the three characters under analysis. In these six new varieties, one can see that the three mutant characters, namely thread arista, curled wing and striped thorax are separable from one another and they are not always found i ...
1 Human Inheritance - Northside Middle School
1 Human Inheritance - Northside Middle School

... forms of a gene that code for a single trait. Even though a gene may have multiple alleles, a person can carry only two of those alleles. This is because chromosomes exist in pairs. Each chromosome in a pair carries only one allele for each gene. Human blood type is controlled by a gene with multipl ...
Evolutionary Limits and Constraints
Evolutionary Limits and Constraints

... humans are often around 0.5 to 0.8), while they tend to be lower for behavioral and physiological traits; however, heritability estimates for natural populations of animals and plants can be quite variable, particularly for traits that are important in determining the ecological niche of species. Fo ...
Extensions of Mendel`s First Law. ppt
Extensions of Mendel`s First Law. ppt

... Sex-limited Traits • Traits that occur in only one of the two sexes • For example in humans – Breast development is normally limited to females – Beard growth is normally limited to males ...
Reprint
Reprint

... females with directional preferences the opportunity to obtain mates with higher than average viability (good genes). In both cases mutation not only introduces new genetic variation into the population, but it imparts a directional force on evolutionary change as well. In the case of the sexy son m ...
File
File

... (g) You cannot reject Joe's hypothesis, since chi square (3.125) is less than 11.070. Note that Joe’s hypothesis has no genetic basis in fact, but these data do not allow you to reject his hypothesis. 7. In Drosophila, pure breeding males with hairy legs were crossed to pure-breeding dumpy-bodied fe ...
Chapter 7 Beyond alleles: quantitative genetics and the
Chapter 7 Beyond alleles: quantitative genetics and the

... total phenotypic variance • Heritability is the proportion of phenotypic variance due to genetic differences • Broad sense heritability includes: ...
The genetic architecture of sexual dimorphism: the potential roles of
The genetic architecture of sexual dimorphism: the potential roles of

... 1987; and see Chapters 1, 16, and 18 in this volume). Sexual selection on male traits can cause correlated evolution in homologous female traits, displacing the female phenotype from the optimum for viability and fecundity. Likewise, viability and fecundity selection on female traits can constrain t ...
Pleiotropy and the Genomic Location of Sexually Selected Genes
Pleiotropy and the Genomic Location of Sexually Selected Genes

... genomic location of sexually selected genes. Models that do not incorporate pleiotropic effects often predict sex linkage. Conversely, sex linkage is not explicitly predicted by the condition-dependent model (which considers pleiotropic effects). Evidence largely based on reciprocal crosses supports ...
punnet squares, crosses, linked genes and pedigreesppt
punnet squares, crosses, linked genes and pedigreesppt

... physically close to each other on the same chromosome • less likely to be independently assorted (separated from each other) during crossing over in meiosis ...
Muller Am. Nat. 66:703 1932
Muller Am. Nat. 66:703 1932

... have been inheritedby animals and higher plants alike. The essence of sexuality,then,is Mendelian recombination. Not increased variation in the sense of more change in the hereditaryunits or genes, now that we know there are these units, but the making and the testing out of all sorts of combination ...
Genetics to Genomics (From Basics to Buzzwords)
Genetics to Genomics (From Basics to Buzzwords)

... Are mutations always either beneficial or detrimental?  As we saw earlier, that depends on what phenotype one is examining  Even more insidious, that depends on population size and population structure  In small populations, it takes a mighty big change in fitness (either positive or negative) to ...
Metaphors and the role of genes in development
Metaphors and the role of genes in development

... The intrinsic (or extra-genetic) regulation of metabcharacter is changed in consequence of mutation at a olism is usually regarded as a ‘housekeeping’ function, single genetic locus we can eventually use this inforinvolving the products of so-called housekeeping genes mation to pinpoint the time an ...
Sex Linkage and Recombination
Sex Linkage and Recombination

... are carriers for the trait in that they may pass it on to their offspring. Males only need one recessive allele in their sole X chromosome for the trait to be expressed. Explain what happens to the expression patterns if the trait is X-linked and dominant. Use Table 2 as guide. Give the definition o ...
Sex Linkage and Recombination
Sex Linkage and Recombination

... are carriers for the trait in that they may pass it on to their offspring. Males only need one recessive allele in their sole X chromosome for the trait to be expressed. Explain what happens to the expression patterns if the trait is X-linked and dominant. Use Table 2 as guide. Give the definition o ...
The evolutionary causes and consequences of sex
The evolutionary causes and consequences of sex

... sex bias is not a fixed property but can vary among tissues or change over the course of development 15,34,35. Thus, it is possible that the rapid evolution of sex-biased genes is not necessarily a result of their sex-biased expression but may be a result of another correlated feature, such as expre ...
Principles of Evolution
Principles of Evolution

... – Intra-sexual selection: competition among males – Inter-sexual selection: males display certain traits to females ...
EVOLUTIONARY ECOLOGY SOME USEFUL DEFINITIONS
EVOLUTIONARY ECOLOGY SOME USEFUL DEFINITIONS

... Evolution; however, it’s not! - Evolution refers to temporal changes, whereas natural selection specifies one particular way in which these changes are brought about - Evolution more specifically refers to a change in gene frequencies or descent with modification ...
Sex-linked single-gene inheritance patterns
Sex-linked single-gene inheritance patterns

... genotype BB --- bald in both sexes genotype BB’ --- bald in males, nonbald in females genotype B’B’ -- nonbald in both sexes There are also traits that are sex-influenced, which means that their expression is influenced by the individual's sex. This does not imply that the gene is sex-linked. A huma ...
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Sex-limited genes

Sex-limited genes are genes that are present in both sexes of sexually reproducing species but are expressed in only one sex and remain 'turned off' in the other. In other words, sex-limited genes cause the two sexes to show different traits or phenotypes, despite having the same genotype. This term is restricted to autosomal traits, and should not be confused with sex-linked characteristics, which have to do with genetic differences on the sex chromosomes (see sex-determination system). Sex-limited genes are also distinguished from sex-influenced genes, where the same gene will show differential expression in each sex. Sex-influenced genes commonly show a dominant/recessive relationship, where the same gene will have a dominant effect in one sex and a recessive effect in the other (for example, male pattern baldness).Sex-limited genes are responsible for sexual dimorphism, which is a phenotypic (directly observable) difference between males and females of the same species. These differences can be reflected in size, color, behavior (ex: levels of aggression), and morphology. An example of sex-limited genes are genes which instruct the male elephant seals to grow big and fight, at the same time instructing female seals to grow small and avoid fights. These genes are also responsible for some female beetles' inability to grow exaggerated mandibles, research that is discussed in detail later in this article.The overall point of sex-limited genes is to resolve intralocus sexual conflict. In other words, these genes try to resolve the ""push-pull"" between males and females over trait values for optimal phenotype. Without these genes, organisms would be forced to settle on an average trait value, incurring costs on both sexes. With these genes, it is possible to 'turn off' the genes in one sex, allowing both sexes to attain (or at least, approach very closely) their optimal phenotypes.
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