On the quantitative genetics of mixture characters

Finite mixture models are helpful for uncovering heterogeneity due to hidden structure. Quantitative genetics issues of continuous characters having a finite mixture of Gaussian components as statistical distribution are explored in this article. The partition of variance in a mixture, the covariance between relatives under the supposition of an additive genetic model, and the offspring-parent regression are derived. Formulas for assessing the effect of mass selection operating on a mixture are given. Expressions for the genetic and phenotypic correlations between mixture and Gaussian traits and between two mixture traits are presented. It is found that, if there is heterogeneity in a population at the genetic or environmental level, then genetic parameters based on theory treating distributions as homogeneous can lead to misleading interpretations. Some peculiarities of mixture characters are: heritability depends on the mean values of the component distributions, the offspring-parent regression is nonlinear, and genetic or phenotypic correlations cannot be interpreted devoid of the mixture proportions and of the parameters of the distributions mixed.     

On the internal dynamics of Mendelian genetics

This paper offers a revisionist account of the development of Mendelian genetics, focusing on the 'problem of the gene', 1900-1930. I examine conflicting claims about the composition, location, and action of genes posed by Bateson, the Morgan group, and Goldschmidt. Their research programs focused on different phenotypes and were based on different assumptions about the nature of genes. The problem of the gene transcended such specific research programs, but their findings had to be taken into account to solve it. The need to resolve conflicting claims drove Mendelian geneticists to exploit the resources and invade the turf of other disciplines in their search for a sound characterization of the gene. The problem of reconciling conflicting views greatly influenced the development of genetics and provided the stimulus for many of the discoveries made by geneticists from 1900 to 1940.     

On the genetics of prelingual deafness.

In view of the many discordant findings in previous studies regarding the genetics of prelingual deafness, family data (133 nuclear families and 25 pedigrees) were gathered from India. Analysis of these data has revealed that the defect is primarily genetic, which is in agreement with earlier findings. Segregation analysis was performed to compare various autosomal diallelic one-locus and multilocus models. Our analysis revealed that the most parsimonious model for prelingual deafness is that it is controlled by recessive genes at a pair of unlinked diallelic autosomal loci. Individuals are affected if and only if they are recessive homozygous at both loci. The likelihood of the present data under this two-locus multiple recessive homozygosis model is at least 10(8) times higher than that of the one-locus models that were examined in previous studies. This model is also the best-fitting model among other plausible two-locus models.     

On the population genetics of the ceruloplasmin polymorphism

Summary The frequencies of Cp-variants in 3 European, 1 Asiatic and 3 African populations are reported. The most striking fact is the high incidence of the Cp^A-allele not only in the African but also in 2 European samples.

---

Zusammenfassung An 3 europäischen, 1 asiatischen und 3 afrikanischen Stichproben werden die populationsgenetischen Daten von Coeruloplasmin-Varianten erhoben. Der auffallendste Befund ist die erhöhte Cp^A-Frequenz nicht nur in den afrikanischen, sondern auch in 2 europäischen Stichproben.

---

---

Supported by the Deutsche Forschungsgemeinschaft.     

On the genetics of the Pi serum proteins

Summary The authors report family studies (51 families with 134 children) on the inheritance of the Pi phenotypes. Combining these data with a Norwegian family material (77 families with 323 children) published by Fagerhol and Gedde-Dahl (1969) a total of 128 families with 457 children is now available, which allows the following conclusion: The Pi phenotypes are inherited by a simple codominant mode of heredity and they are determined by a set of (at least nine) alleles. As up to now no exception to the role of inheritance has been observed, the application of the Pi system in cases of disputed paternity seems to be discussible. Some methodological problems in connection with this are shown.Supported by the Deutsche Forschungsgemeinschaft.     

On applications of landscape genetics

Recent assertions in the literature (e.g., Keller et al. 2015) suggest that landscape genetic research has been infrequently applied by practitioners. We were interested to test this assertion, which is difficult to assess, since applications may not be detectable through searches of peer-reviewed literature. Producing publications may not be a goal of practitioners. We developed a method to search the internet for evidence of research applications and evaluated 25 different research fields in the natural sciences. We found that fields with more publications also had more applications, but the field of landscape genetics was less applied than expected based on the number of peer-reviewed publications—only about 4 % of landscape genetics articles were applied. In fact, all research fields in genetics or evolutionary biology were under-applied compared to ‘whole organism’, ecological research fields. This result suggests the lack of applications in landscape genetics may be due to a systemic under-application of genetics research, perhaps related to a lack of understanding of genetics by practitioners. We did find some evidence of landscape genetic applications however, which we sorted into 5 categories: (1) identification of evolutionarily significant units for conservation, (2) managing pathogens and invasive species, (3) natural heritage systems planning, (4) assessing population status, and (5) restoration of populations.     

On the genetics of transplantation in the lizardCnemidophorus tigris

A total of 195 allografts were analyzed among 14 wild individuals of the whiptail lizardCnemidophorus tigris. The cumulative time for rejection of all allografts by each individual varied in a uniformly graded sequence ranging from 502 to 2263 days. One individual did not reject 9 of 13 allografts. A comparison of rejection rates revealed that the relative degree of antigenicity of a donor was more or less proportional to its immune response, i. e., the strongest rejectors tending to elicit the strongest immune response and the weakest rejectors the weakest response. Such a relationship as well as the graded sequence of rejection suggest that neither the many weak transplantation antigen hypothesis, nor the strong locus hypothesis adequately explain the present results. Probable genetic models are discussed and a summary of transplantation studies in lower vertebrates is presented.     

On genetics and criminal behavior

Crime and Human Nature: By J. Q. Wilson and R. J. Herrnstein. Simon and Schuster, Inc., New York, 1985.     

On the genetics of rosette pattern in guinea pigs

Summary New data on the heredity of rosette pattern in guinea pigs and a critical review of the data ofPictet andFerrero support the conclusions reached in 1916 on the genetics of the major variations of this character.The results ofPictet andFerrero fully confirm the existence of the primary pair of alleles R, r and are so treated by them in their more recent papers. There is strong evidence that the rough inhibiting factor M (of wild species ofCavia and of many guinea pigs) was present in their stock, in certain smooths which transmitted roughness (R-MM) and in the types described as lisses à crête and monorosettes (R-Mm) but was not recognized. This gene was clearly much less common than in my stocks.Their stocks on the other hand seem to have exhibited more variability in the high grades of roughness and to have reached somewhat higher grades than I have observed. They attribute these variations to two new pairs of genes G, g and D, d, the former said to distinguish two patterns on the trunk, the latter, grades of roughness of the head. The data as presented, contain contradictions in both cases. Nevertheless they indicate segregation in their stock of a pair of alleles distinguishing the highest grade of fancier's rough (RRmmGG), from ordinary high grades (RRmmgg). The contradictions may perhaps be due to overlap. No judgment of the validity of genes D, d can be reached without presentation of data showing the breeding results for trunk and head rosettes simultaneously.     

On the genetics of tetraploid plants in Primula sinensis

Ohne Zusammenfassung     

On the population genetics of beta2-glycoprotein I.

Beta2-glycoprotein I typings on 152 healthy Germans and 150 patients with atopic diseases did not show any differences in the serum protein concentrations or in the phenotype and gene frequencies. Compared to these German samples, Philippinos (n = 88) as well as healthy Negroes from South Africa (n = 192) revealed statistically significant lower concentrations of this serum protein. They differ also from the Germans with regard to phenotype and gene frequencies. A most striking result was found in the comparison of healthy and leprous Negroes (n = 250) from South Africa. In these, quite different and statistically significant beta 2-Glycoprotein I concentrations, respectively, phenotype and gene frequencies were seen, which may be due to this disease. The possible reasons for these observations as well as for the observed population differences are discussed.