Comparing Gmatrices: A Manova Approach

Roff, Derek A.

doi:10.1111/j.0014-3820.2002.tb01439.x

Cited by 12 publications

(16 citation statements)

References 40 publications

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“…The Flury and MANOVA methods bear strong statistical kinship and in the one case in which they have been compared reach the same statistical conclusion (Roff, 2002). An advantage of the MANOVA method for the present analysis is that it permits the incorporation of those offspring-parent combinations for which not all measurements were taken (see below) and does not suffer the problem arising from nonpositive-definite matrices.…”

Section: Methodsmentioning

confidence: 65%

“…An alternate approach is the 'jackknife followed by MANOVA' method of Roff (2002), hereafter referred to simply as the MANOVA method. The Flury and MANOVA methods bear strong statistical kinship and in the one case in which they have been compared reach the same statistical conclusion (Roff, 2002).…”

Section: Methodsmentioning

confidence: 99%

“…The 'jackknife followed by MANOVA' method is described in detail in Roff (2002). Briefly, the method is as follows.…”

Section: Methodsmentioning

confidence: 99%

“…In the cases of Thamnophis ordinoides (Brodie, 1993) and Holcus lanatus (Shaw and Billington, 1991), Allonemobius fasciatus and A. socius no differences were observed. Significant differences were found in populations of Gammarus minus (Fong, 1989;Jernigan et al, 1994;Roff, 2002), Thamnophis elegans and Drosophila melanogaster (van 'T Land et al, 1999). With one exception, in all of the preceding cases and those involving higher taxa the offspring generation and typically the parental generation were raised in the laboratory.…”

Section: Introductionmentioning

confidence: 99%

“…Estimates of the matrix elements were made using offspring on female parent regression and the matrices then compared using two statistical approaches, the Flury approach ) and the jackknife followed by MANOVA method (Roff, 2002). The first method examines the structure of the matrices (equality, proportionality, common principal components, etc), whereas the second tests for equality and correlations between the matrices and other variables such as sex, latitude of origin, etc.…”

Section: Introductionmentioning

confidence: 99%

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Geographic variation in the G matrices of wild populations of the barn swallow

et al. 2004

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In this paper, we present an analysis of genetic variation in three wild populations of the barn swallow, Hirundo rustica. We estimated the P, E, and G matrices for six linear morphological measurements and tested for variation among populations using the Flury hierarchical method and the jackknife followed by MANOVA method. Because of nonpositive-definite matrices, we had to employ 'bending' to analyse the G and E matrices with the Flury method. Both statistical methods agree in finding that the P and G matrices are significantly different but comparison between the analysis of the P matrices and pairwise analyses of the P, E, and G matrices suggests caution in interpreting the Flury results concerning differences in matrix structure. The significant variation among the populations in the G matrices appears to be due in large measure to the most geographically distant population.

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Section: Methodsmentioning

confidence: 65%

Section: Methodsmentioning

confidence: 99%

“…The 'jackknife followed by MANOVA' method is described in detail in Roff (2002). Briefly, the method is as follows.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Geographic variation in the G matrices of wild populations of the barn swallow

et al. 2004

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The effects of reproductive specialization on energy costs and fitness genetic variances in cyclical and obligate parthenogenetic aphids

Carter

Simon

Nespolo

2012

Ecology and Evolution

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Organisms with coexisting sexual and asexual populations are ideal models for studying the consequences of either reproductive mode on the quantitative genetic architecture of life-history traits. In the aphid Rhopalosiphum padi, lineages differing in their sex investment coexist but all share a common parthenogenetic phase. Here, we studied multiple genotypes of R. padi specialized either for sexual and asexual reproduction and compared their genetic variation in fitness during the parthenogenetic phase. Specifically, we estimated maintenance costs as standard metabolic rate (SMR), together with fitness (measured as the intrinsic rate of increase and the net reproductive rate). We found that genetic variation (in terms of broad-sense heritability) in fitness was higher in asexual genotypes compared with sexual genotypes. Also, we found that asexual genotypes exhibited several positive genetic correlations indicating that body mass, whole-animal SMR, and apterous individuals production are contributing to fitness. Hence, it appears that in asexual genotypes, energy is fully allocated to maximize the production of parthenogenetic individuals, the simplest possible form of aphid repertoire of life-histories strategies.

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Comparing ecological and evolutionary variability within datasets

Royauté

Dochtermann

2021

Behav Ecol Sociobiol

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Many critical questions in ecology and evolution use variance ratios, such as repeatability, heritability, or individual resource specialization, to make inferences about ecological and evolutionary processes. In many cases these inferences rely on the comparison of variance ratios among datasets (populations, sexes, or environments). In this article, we show that current approaches of drawing inferences about group differences from comparisons of ratios are inappropriate because ratios can differ due to differences in the numerator, denominator, or both. We investigated how questions regarding differences in variance ratios and constituent variance components can be evaluated using Linear Mixed Model approaches (LMMs) and provide guidance for appropriate sampling schemes under different scenarios and discuss common pitfalls associated with estimation of differences in variance component among datasets.

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Comparing Gmatrices: A Manova Approach

Cited by 12 publications

References 40 publications

Geographic variation in the G matrices of wild populations of the barn swallow

Geographic variation in the G matrices of wild populations of the barn swallow

The effects of reproductive specialization on energy costs and fitness genetic variances in cyclical and obligate parthenogenetic aphids

Comparing ecological and evolutionary variability within datasets

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