Thursday, September 4, 2008

More phylogenetics

Here are the extra phylogenetics resources in an easier to access format:
Tree thinking quizzes (select 'download supplement')

2 comments:

Anonymous said...

I understand how to construct a tree, but I do not understand how we know if the tree we construct is wrong, like the example in the "icp" website. How do we know when the tree is wrong by looking at the numbers in the table?

Becky said...

Great question. The answer is that you don't know, and you have no way on knowing, unless you watched the evolution occur (as with experimental evolution or computer simulation) or you made the tree up (as in the icp website example). The point is that sometimes some methods of phylogeny reconstruction don't give you the right tree. That's why researchers often use several different methods to build a phylogeny, and are continuously working to find methods that give the "wrong" tree less often.