sex genetic correlation hypothesis.
Groth, J.G. 1992. Further information on the genetics of bill crossing in crossbills. Auk 109:383–385.
Genetic correlation - Wikipedia
Trade-offs between fitness related traits are expected to generate negative genetic covariances, unless genetic variance for resource acquisition exceeds that for resource allocation. For what concerns post-copulatory sexual selection, producing competitive ejaculates is costly, however, and it can be attained at the expenses of traits involved in mate acquisition and/or survival, because resources are limited. Alternatively, under a good‐sperm scenario, males that are better equipped for winning sperm competition should also show higher survival and, more generally, perform better than poor sperm competitors. In the guppy (Poecilia reticulata) the number of sperm inseminated is the most important determinant of male fertilization success, therefore to evaluate the evolutionary consequences of male investment in sperm production we performed a bidirectional artificial selection experiment for sperm production in guppies. Contrary to expectation, males selected for high sperm production not only transferred more sperm per copulation, but also grew faster, attained a larger body size, were more colourful, sexually more active and more attractive to females. Sperm velocity and morphology was not affected, but sperm viability increased with sperm number. All the other measured male and female fitness-related traits were unaffected by sperm production. These results suggest that, at least in lab conditions, some guppy genotypes perform better in most life-history traits, acquiring more resources than others.
N2 - There is ample empirical evidence that phenotypic diversification in an adaptive radiation is the outcome of divergent natural selection related to differential resource use. In contrast, the role of ecological forces in favoring and maintaining reproductive isolation in nature remains poorly understood. If the same forces driving phenotypic divergence are also responsible for speciation, one would predict a correlation between the extent of trophic specialization (reflecting variable intensity of divergent natural selection) and that of reproductive isolation being reached in a given environment. We tested this hypothesis by comparing the extent of morphological and genetic differentiation between sympatric dwarf and normal whitefish ecotypes (Coregonus sp.) from six lakes of the St. John River basin (eastern Canada and northern Maine). Eight meristic variables, 19 morphometric variables, and six microsatellite loci were used to quantify morphological and genetic differentiation, respectively. Dwarf and normal ecotypes in each lake differed primarily by traits related to trophic specialization, but the extent of differentiation varied among lakes. Significant but variable genetic divergence between ecotypes within lakes was also observed. A negative correlation was observed between the extent of gene flow between ecotypes within a lake and that of their morphological differentiation in trophic-related traits. The extent of reproductive isolation reached between dwarf and normal whitefish ecotypes appears to be driven by the potential for occupying distinct trophic niches and, thus, by the same selective forces driving tropic specialization in each lake. These results therefore support the hypothesis of ecological speciation.
Is There a Genetic Correlation Between General Factors …
The inherent genetic structure of populations can be assessed directly using a method developed by Pritchard et al. (2000) and implemented in the program . The program implements a model-based clustering method to infer population structure, assign individuals to populations and identify migrants and admixed individuals using multilocus genotype data independent of prior population information. The approach implemented in assumes a model in which there are populations (where may be unknown), each of which is characterized by a set of allele frequencies at each locus. Individuals in the sample are assigned probabilistically to populations or jointly to two or more populations if their genotypes indicate them to be admixed.
Genetic evidence provides high quality information about biological relationships. Our DNA is akin to an original record providing information about our ancestral lines. When it’s possible and applicable to a question, incorporating analysis of DNA data into our proof arguments provides increased confidence that our conclusions are accurate.
03/11/2014 · Correlation with reported ..
So even if we control for family background, IQ, education and all the like, the colorism hypothesis still predicts a relationship between skin color and wage (or education). This is because the color discrimination is all about physical appearance, and nothing more. It posits that because you look black, or because you have negroid traits, you are discriminated against. And this phenomenon occurs at every place, as colorism predicts. If the relationship persists after controlling for SES and IQ, that correlation won’t be enough to draw any conclusion about the arrow of causality however. Further information is needed. For example, the genetic hypothesis may argue that it is due to differences in racial admixture or other characteristics tied to skin color, and that skin color therefore is just a confounding factor. But if the correlation drops to zero, we cannot even begin to speak about causality.
As I argued , if the colorism prediction is correct, there must be a negative correlation between darker skin and social outcome, when economic background and/or IQ have been controlled. Controlling for SES is a genetic effect, to the extent that SES has a genetic component (Jensen, , pp. 116-117, 155-156).
The hypothesis that genetic diversity at ..
sex genetic correlation as a ..
Genetic Hypothesis of Idiopathic Schizophrenia: ..
Tests of each postulated genetic abnormality ..
Do you know the difference between Mantel test and Pearson correlation test
Positive genetic correlation between brain size and …
When analyzing the available data, it would be safe to state that the correlations between video games and the development of negative behaviours found in youths are minimal and have caused generalization.
for testing the neutral mutation hypothesis is ..
Genealogy Standards offers guidance on crafting effective research questions. The question “How is person A genetically related to person B?” is neither too broad nor too narrow. It allows us to impartially collect information from our sources without prejudgment. Consider a case where one source provides the information that A and B share 3587 centiMorgans (cM) of autosomal DNA (atDNA). Researchers use the centiMorgan—a measure of genetic linkage based on the probability of recombination—to predict a relationship between test takers. We consult a second source to learn that 3587 shared cM is predictive of a parent-child relationship. We combine those two pieces of evidence, yet we still do not know if person A is the parent or the child. We add a third item—documentary evidence on the ages of the individuals. This third evidentiary shard, when correlated with the other two, provides convincing evidence to answer the research question. We build a case and share our findings in writing.
The “Viking Hypothesis” – Genetic Ties to Hereditary ..
Design hypothesis. This diagramdepicts that 4-μm sections would cause the loss of genetic DNA,resulting in the detection error when performing FISH. FISH,fluorescence in situ hybridization.
Genetic Ties to Hereditary Hemochromatosis
In the gene analysis and chromosome 17amplification, FISH was performed using 4-μm paraffin sections(,–).FISH conducted with thin tissue sections leads to theunderestimation of the true chromosome copy number in various typesof cancer (). In this study itwas hypothesized that the 4-μm sections caused DNA loss resultingin detection bias (). In the4-μm serial breast cancer paraffin sections, the same nuclei weresectioned twice and appeared in two adjacent sections (). The disruption of nuclearintegrity may lead to an inaccurate estimate of gene copy numberswith thin tissue sections. Therefore, in the present study FISHwith intact nuclei was performed to test the detection bias usingthin tissue sections. In total, 109 cases of invasive breast cancerwere examined for the correlation between geneamplification, CEP17 polysomy and /CEP17 ratio.
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."