A Simple Exposition of Jensen’s Error

1978 ◽  
Vol 3 (3) ◽  
pp. 203-208
Author(s):  
Roger Milkman
Keyword(s):  
Genetic Basis ◽  
High Heritability ◽  
Two Populations ◽  
Simple Exposition

Jensen (1969 , 1973) has used within-population heritability data to support his contention that IQ differences between races have a considerable genetic basis. Criticism of this reasoning has been frequent, but perhaps never categorical. A method is now described for illustrating the error simply and quantitatively. An example shows that high heritability of a property within each of two populations is consistent with a vanishingly small heritability in the combined population.

scholarly journals Genetic analysis of three maize husk traits by QTL mapping in a maize-teosinte population

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaolei Zhang ◽  
Ming Lu ◽  
Aiai Xia ◽  
Tao Xu ◽  
Zhenhai Cui ◽  
...  
Keyword(s):  
Phenotypic Variation ◽  
Genetic Basis ◽  
Molecular Breeding ◽  
Best Linear Unbiased Predictor ◽  
Maize Line ◽  
Maize Varieties ◽  
Outer Covering ◽  
High Heritability ◽  
Best Linear Unbiased ◽  
Variation Explained

Abstract Background The maize husk consists of numerous leafy layers and plays vital roles in protecting the ear from pathogen infection and dehydration. Teosinte, the wild ancestor of maize, has about three layers of small husk outer covering the ear. Although several quantitative trait loci (QTL) underlying husk morphology variation have been reported, the genetic basis of husk traits between teosinte and maize remains unclear. Results A linkage population including 191 BC2F8 inbred lines generated from the maize line Mo17 and the teosinte line X26–4 was used to identify QTL associated with three husk traits: i.e., husk length (HL), husk width (HW) and the number of husk layers (HN). The best linear unbiased predictor (BLUP) depicted wide phenotypic variation and high heritability of all three traits. The HL exhibited greater correlation with HW than HN. A total of 4 QTLs were identified including 1, 1, 2, which are associated with HL, HW and HN, respectively. The proportion of phenotypic variation explained by these QTLs was 9.6, 8.9 and 8.1% for HL, HN and HW, respectively. Conclusions The QTLs identified in this study will pave a path to explore candidate genes regulating husk growth and development, and benefit the molecular breeding program based on molecular marker-assisted selection to cultivate maize varieties with an ideal husk morphology.

scholarly journals Major QTL controls adaptation to serpentine soils in Mimulus guttatus

2018 ◽  
Author(s):  
Jessica P. Selby ◽  
John H. Willis
Keyword(s):  
Genetic Basis ◽  
Common Garden ◽  
Serpentine Soils ◽  
Mimulus Guttatus ◽  
Fitness Effects ◽  
Spatially Varying ◽  
Spatially Varying Selection ◽  
Physical Challenges ◽  
Two Populations ◽  
Major Qtl

ABSTRACTSpatially varying selection is a critical driver of adaptive differentiation. Yet, there are few examples where the fitness effects of naturally segregating variants that contribute to local adaptation have been measured in the field. This project investigates the genetic basis of adaption to serpentine soils in Mimulus guttatus. Reciprocal transplant studies show that serpentine and non-serpentine populations of M. guttatus are genetically differentiated in their ability to survive on serpentine soils. We mapped serpentine tolerance by performing a bulk segregant analysis on F2 survivors from a field transplant study and identify a single QTL where individuals that are homozygous for the non-serpentine allele do not survive on serpentine soils. This same QTL controls serpentine tolerance in a second, geographically distant population. A common garden study where the two serpentine populations were grown on each other′s soil finds that one of the populations has significantly lower survival on this “foreign” serpentine soil compared to its home soil. So, while these two populations share a major QTL they either differ at other loci involved in serpentine adaptation or have different causal alleles at this QTL. This raises the possibility that serpentine populations may not be broadly tolerant to serpentine soils but may instead be locally adapted to their particular patch. Nevertheless, despite the myriad chemical and physical challenges that plants face in serpentine habitats, adaptation to these soils in M. guttatus has a simple genetic basis.

scholarly journals Variance Components and Estimates of Broad-sense Heritability of Nut and Kernel Traits in Hazelnut

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 494D-494
Author(s):  
Qiang Yao ◽  
Shawn A. Mehlenbacher
Keyword(s):  
Genetic Variation ◽  
Phenotypic Variation ◽  
Variance Components ◽  
Genetic Basis ◽  
Corylus Avellana ◽  
Broad Sense ◽  
Broad Sense Heritability ◽  
Narrow Sense ◽  
High Heritability ◽  
Kernel Traits

Seventy-seven trees representing 41 hazelnut (Corylus avellana L.) genotypes were to evaluate variance components and broad-sense heritability for 10 nut and kernel traits from 1994 to 1996. All effects in the models were assumed to be random. All traits had extremely high heritability. This indicated that nearly all of the phenotypic variation had a genetic basis. Knowledge of variance components may help us efficiently allocate resources. Broad-sense heritability estimates were larger than those in narrow sense, suggesting the presence of nonadditive genetic variation in the population.

scholarly journals Transcriptomic and genomic variants between koala populations reveals underlying genetic components to disorders in a bottlenecked population

2021 ◽  
Author(s):  
R. E. Tarlinton ◽  
J. Fabijan ◽  
F. Hemmatzadeh ◽  
J. Meers ◽  
H. Owen ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Genetic Disorders ◽  
South Australia ◽  
Differentially Expressed ◽  
Brain Diseases ◽  
Fixation Index ◽  
Testicular Development ◽  
Genetic Components ◽  
Anion Transporter ◽  
Two Populations

AbstractHistorical hunting pressures on koalas in the southern part of their range in Australia have led to a marked genetic bottleneck when compared with their northern counterparts. There are a range of suspected genetic disorders such as testicular abnormalities, oxalate nephrosis and microcephaly reported at higher prevalence in these genetically restricted southern animals. This paper reports analysis of differential expression of genes from RNAseq of lymph nodes, SNPs present in genes and the fixation index (population differentiation due to genetic structure) of these SNPs from two populations, one in south east Queensland, representative of the northern genotype and one in the Mount Lofty Ranges South Australia, representative of the southern genotype. SNPs that differ between these two populations were significantly enriched in genes associated with brain diseases. Genes which were differentially expressed between the two populations included many associated with brain development or disease, and in addition a number associated with testicular development, including the androgen receptor. Finally, one of the 8 genes both differentially expressed and with a statistical difference in SNP frequency between populations was SLC26A6 (solute carrier family 26 member 6), an anion transporter that was upregulated in SA koalas and is associated with oxalate transport and calcium oxalate uroliths in humans. Together the differences in SNPs and gene expression described in this paper suggest an underlying genetic basis for several disorders commonly seen in southern Australian koalas, supporting the need for further research into the genetic basis of these conditions, and highlighting that genetic selection in managed populations may need to be considered in the future.

Interpreting and Re-interpreting Heritability Estimates in Educational Behavior Genetics

2021 ◽  
Author(s):  
Sally A. Larsen
Keyword(s):  
Cultural Evolution ◽  
Genetic Basis ◽  
Behavior Genetics ◽  
Genetic Research ◽  
Policy And Practice ◽  
Practice Recommendations ◽  
Research Findings ◽  
High Heritability ◽  
Heritability Estimates

Interpreting heritability estimates through the lens of cultural evolution presents two broad and interlinking problems for educational behavior genetics. First, the problem of interpreting high heritability of educational phenotypes as indicators of the genetic basis of traits, when these findings also reflect cultural homogeneity. Second, the problem of extrapolating from genetic research findings in education to policy and practice recommendations.

scholarly journals Ovarian Morphology Is a Marker of Heritable Biochemical Traits in Sisters with Polycystic Ovaries

2008 ◽  
Vol 93 (9) ◽  
pp. 3396-3402 ◽  
Author(s):  
Stephen Franks ◽  
Lisa J. Webber ◽  
Micaela Goh ◽  
Anne Valentine ◽  
Davinia M. White ◽  
...  
Keyword(s):  
Genetic Basis ◽  
Polycystic Ovary ◽  
Serum Testosterone ◽  
Polycystic Ovaries ◽  
Ovary Syndrome ◽  
Biochemical Traits ◽  
Ovarian Morphology ◽  
High Heritability ◽  
Uncertain Etiology ◽  
Biochemical Features

Context: Polycystic ovary syndrome (PCOS) is a common endocrinopathy of uncertain etiology but with strong evidence for a genetic contribution. Objective: The objective of the study was to test the hypothesis that the typical polycystic ovarian morphology is a marker of inherited biochemical features in families of women with PCOS. Design: A study of probands with PCOS and their sisters. Patients: Patients included 125 probands and 214 sisters. All probands had PCOS, defined by symptoms of anovulation and/or hyperandrogenism with polycystic ovaries on ultrasound. Affected sisters were defined by polycystic ovaries, regardless of symptoms, and unaffected sisters defined by normal ovarian morphology. Setting: This was a clinic-based study. Main Outcome Measures: Clinical, endocrine, and metabolic features in the various groups were compared, and estimates of broad-sense heritability were obtained using the quantitative transmission disequilibrium test. Results: Although affected sisters had fewer symptoms than probands (30% had no symptoms of PCOS), serum testosterone, androstenedione, LH, and fasting insulin and insulin sensitivity were similar in the two groups with polycystic ovaries but significantly different from those in unaffected sisters or controls. We observed moderate to high heritabilities for all traits studied in affected sister pairs, whereas heritabilities calculated from discordant siblings were substantially lower. Conclusions: These data provide further evidence for a genetic basis of PCOS. The high heritability of biochemical features in probands and affected sisters, despite wide variation in symptoms, shows that not only are these biochemical traits strongly influenced by genetic factors but also, importantly, that polycystic ovarian morphology is an index of inherited traits in families with PCOS.

scholarly journals Estimation of genetic variability and frequency distribution in F2 generation of rice under normal and deficit water supply

2021 ◽  
Author(s):  
Nessreen N. Bassuony ◽  
József Zsembeli ◽  
Csaba Juhász ◽  
Mostafa M. Elshenawy
Keyword(s):  
Water Supply ◽  
Water Deficit ◽  
Yield Components ◽  
Block Design ◽  
Training Centre ◽  
Randomized Complete Block Design ◽  
High Heritability ◽  
F2 Generation ◽  
Two Populations ◽  
And Training

AbstractThe investigation was conducted at the experimental farm of the Rice Research and Training Centre, Kafr el Sheikh, Egypt, during the summer seasons from 2017 to 2019 using the experimental material consisting two populations with their two parents (P1, P2, F1 and F2) to study the variability in the F2 population of four crosses: IR 78,936-B-B-B-B (water deficit tolerant) x Giza 177 (water deficit sensitive), FL-496 (moderately water deficit tolerant) x Giza 177, IR 78,936-B-B-B-B (water deficit tolerant) x Giza 178 (moderately water deficit tolerant), FL-496 × Giza 178 under normal (NWS) and deficit water supply (DWS). The experiment was conducted in a randomized complete block design with three replications. The results indicated that the phenotypic values of the measured characters were significantly different between the two parents of all the studied crosses under the two water supply conditions. The means of all the studied characters under DWS were lower than the means under NWS, but the yields and the yield components under DWS varied greatly among the parents due to stress. The averages of the measured traits of the F1 plants and the F2 populations in all crosses were near the averages of those of the parents. The results showed no consistent reduction in heritability under DWS compared to NWS. High heritability in a broad sense coupled with high genetic advance (GA) was observed for grain yield in Cross 1 under the two studied conditions offering good scope for selection.

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