Search results
Results From The WOW.Com Content Network
In probability theory and statistics, the beta distribution is a family of continuous probability distributions defined on the interval [0, 1] or (0, 1) in terms of two positive parameters, denoted by alpha (α) and beta (β), that appear as exponents of the variable and its complement to 1, respectively, and control the shape of the distribution.
Gamma diversity and alpha diversity can be calculated directly from species inventory data. [2] [13] The simplest of Whittaker's original definitions of beta diversity is β = γ/α Here gamma diversity is the total species diversity of a landscape and alpha diversity is the mean species diversity per site.
In ecology, alpha diversity (α-diversity) is the mean species diversity in a site at a local scale. The term was introduced by R. H. Whittaker [ 1 ] [ 2 ] together with the terms beta diversity (β-diversity) and gamma diversity (γ-diversity).
Alpha male savanna baboons have high levels of testosterone and stress; over a long period of time, this can lead to decreased fitness. The lowest-ranking males also had high stress levels, suggesting that it is the beta males that gain the most fitness, avoiding stress but receiving some of the benefits of moderate rank. [ 20 ]
Alpha male Chiroxiphia manakins have full male colors, whereas beta males retain female-like plumage. Male Chiroxiphia manakins can typically be designated alpha and beta, since there is a clear dominance relationship between them. There is only ever one alpha male, but, depending on species, there may be one or two beta males.
In Bayesian statistics, the gamma distribution is widely used as a conjugate prior. It is the conjugate prior for the precision (i.e. inverse of the variance) of a normal distribution. It is also the conjugate prior for the exponential distribution.
Alpha is a way to measure excess return, while beta is used to measure the volatility, or risk, of an asset. Beta might also be referred to as the return you can earn by passively owning the market.
The term was introduced by R. H. Whittaker [1] together with the terms alpha diversity (α-diversity) and beta diversity (β-diversity). Whittaker's idea was that the total species diversity in a landscape (γ) is determined by two different things, the mean species diversity in sites at a more local scale (α) and the differentiation among ...