This relatively low heritability estimates for CI could be explained by large environmental variance
The trends of additive and permanent environmental variances
across lactation obtained for the traits studied (MY, PY and FY) are comparable to those reported by Jamrozik and Schaeffer (4) and Silvestre et al (5), who estimated higher additive and permanent environmental variances
at the beginning and end of lactation for MY, PY and FY in dairy cows.
Comparing phenotypic, genotypic and environmental variances
in parental and [M.
However, in the case of carotene content, the environmental variance
and mean were highly correlated (r = 0.
For both CRP and SAA, the pattern of variances and covariance in the twins was best explained by a model that contained only additive genetic and unique environmental variance
components (AE model).
Nevertheless, it is notable that the increase in variation for BPb is entirely attributable to an increase in environmental variance
, regardless of whether this is a cohort or an aging effect.
Furthermore, to consider an increased variance an adaptation in the strict sense (Stearns 1992, Gotthard and Nylin 1995), one has to demonstrate the nonzero heritability of the amount of random environmental variance
m]), path coefficient 3, representing the square root of the proportion of the total phenotypic variance [Mathematical Expression Omitted] determined by the maternal additive genetic variance [Mathematical Expression Omitted]; (2) the maternal environmental variance
[Mathematical Expression Omitted] as a fraction of the total phenotypic variance [Mathematical Expression Omitted], path coefficient 4; (3) direct-maternal additive genetic covariance ([[Sigma].
Comparing the variance in population densities to the environmental variance
along the same eigenvectors gives the desired measure of stochastic resilience.
The similar trend was observed for permanent environmental effect but the highest permanent environmental variance
Some stability parameters are: environmental variance
Heritability was estimated as the ratio of the additive genetic variance to total phenotypic variance; and repeatability, as the ratio of the sum of the additive genetic variance plus permanent environmental variance
to phenotypic variance, as described by Falconer and Mackay (2001), according Equation 4 and 5: