MRCA

MRCA

[josephwb]

There is a wiki which describes things.

Each node in a tree represents the (hypothetical) ancestor of the descendant tips. An MRCA is the most recent ancestor of a set of tips. For example, in the following tree:

(((A,B)1,C)2,((D,E)3,F)4)5;

the root (denoted with 5) is an ancestor of A and B, but node 1 is the most recent ancestor. MRCA statements are used to identify specific nodes to place constraints on the ages of nodes (maximum or minimum ages). Only two descendant tips need to be specified. For example, node 2 is the ancestor of tips A, B, and C, but it can be specified with either the tip pairs A and C or B and C (but not A and B, as that identifies node 1).

The config file needs to be plain text.
HTH.

Thank you so much Joseph, I got the point now. I'm going to constraints ingroup ages so that mean I need to mention ingroup and then two taxa according to you explained. so if I want to fixed that like 42 million years so I just need to write 42 or need to convert this value into million?

[josephwb]

You can use 42 (don't use 42,000,000).

To fix the age of a node, you put both an upper and lower constraint:

mrca = INGROUP tip1 tip2
min = INGROUP 42
max = INGROUP 42

Thank you Joseph. Best,

I don't know I got this error, when I run:

tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
tiny branch length at internal node. setting to 0.00048076923
problem with taxa for mrca INGROUP = [MRCA doesn't exist

Please see and help me out.
Thank you,
Best,

[josephwb]

Can you post your tree and config file?

I have sent you via email. Thank you,
Best,

[josephwb]

I don't know if that was directed at me, but I never received an email.

I have sent to this address: [email protected]
is that you?

[josephwb]

Nope! Try phylo.jwb @ gmail.com

fine but whose that address?

sent.