####function to calculate the sum of absolute phylogentically independent contrasts values and compare them to null values. Requires the package "ape". Arguments: dat is a vector of values sorted according to species in phylogeny, tree is the phylogeny and n.rand is the number of randomizations. Example sorting: dat<-trait.data$trait1[match(tree$tip.label,trait.data$species)]

pic.func<-function(dat,tree,n.rand=1000){
	
		pic.null<-NULL

	for (i in 1:n.rand){
		tmp<-sample(dat,size=length(dat))
		pic.null[i]<-sum(abs(pic(tmp,tree)))
		}

	results<-data.frame(pic.obs=sum(abs(pic(dat,tree))),
		pic.null.mean=mean(pic.null),
		pic.null.05=quantile(pic.null,probs=c(0.05,0.95))[1],
		pic.null.95=quantile(pic.null,probs=c(0.05,0.95))[2],
		row.names=NULL
		)
	
	return(results)
	}