OR Gene Family Phylogeny
1.之前关于ORs基因构建系统生发树的研究中的不足：bootstrap support values在有些family中高，bootstrap support values在有些family中低。而我们现在的这个研究bootstrap support values在大部分物种（48 birds +2 爬行+Niimura 2009b中的物种）中超过80%。树如图：
bootstrap support values：对n个样本进行多次重复实验（这里是1000次）得到相同结果的占比（这里是80%）
As an example, consider a sample of 100 sheep of which you have tested their buoyancy. You can give the mean and standard deviation of these 100 sheep, but we wish to infer more about the general buoyancy of sheep. However, after our experiments, we are banned from the farm and cannot test more sheep. When taking a sample of a population, we assume they are representative of the entire population; thus if we repetitive sample by replacement from our 100 sheep and calculate the same test statistics, we get an idea of the whole population. This is the basic idea of bootstrapping.
In terms of your phylogenetic tree, the bootstrapping values indicates how many times out of 100 (in your case) the same branch was observed when repeating the phylogenetic reconstruction on a re-sampled set of your data. If you get 100 out of 100 (and your data is sufficiently large to support this), we are pretty damned sure that the observed branch is not due to a single extreme datapoint. If you get 50 out of 100, we cannot be as certain.