Документ взят из кэша поисковой машины. Адрес
оригинального документа
: http://mouse.belozersky.msu.ru/tools/svetka/articles/fours.html
Дата изменения: Fri Jun 9 07:23:11 2006 Дата индексирования: Tue Feb 5 10:46:11 2013 Кодировка: |
|
|||
Back to the help page | Back to the description of this program | ||
Rule of fours | |||
The sequences in alignment can be casual. Though it can't be so, even in this awful case distences between them should satisfy several rule. One of the simple and both important rules is the following.
Imagine that four sequences (they are called "taxons" in
phylogeny) are united into a tree. Knots E and
F are, generally speaking, not known. But,
accordingly to phylogeny, they must exist (even in conceptual
formed). It is considered, that, during molecular evolution,
taxons A and B evaluated from the
taxon E; analogously, taxons C and
D evaluated from the taxon F. As
distance between sequences is a kind of measure of
evolutionary changes, and, besides, it is an
additional quantity, we can say,
that: |
|||
Upstairs |
|||
When mistakes or interesting facts are found, please tell! |