Re: [R-sig-phylo] small sample size and detecting phylogenetic signal with Blombergs K statistic

2011-07-06 Thread Charlotte De Busschere
: Thursday, June 30, 2011 6:58 PM To: charlotte De Busschere; r-sig-phylo@r-project.org Subject: RE: [R-sig-phylo] small sample size and detecting phylogenetic signal with Blombergs K statistic Dear Charlotte, No, you do not want to do this. As shown in Blomberg et al. (2003), the tests

Re: [R-sig-phylo] small sample size and detecting phylogenetic signal with Blombergs K statistic

2011-06-30 Thread Theodore Garland Jr
Dear Charlotte, No, you do not want to do this. As shown in Blomberg et al. (2003), the tests for statistical significance do not work well when you have fewer than about 20 species. The estimate of the K statistic (indicating the amoung of phylogentic signal) is fine for small sample sizes,