One of the two taxa on either side of a split in a cladogram. In practice: the taxon to which another taxon is more closely related than any other taxon. Usually refers to sister species, i.e., taxa at the species level.
I can no longer send private messages (and maybe not receive?), even though my inbox and outbox are not yet full. I write, click "send" and they disappear and never show up in the outbox.
Tried to attach an image to a forum post. jpg, 32kB, 72dpi, no blanks, ... File name is correctly displayed, but when I click "Preview Thread" it just vanishes. Help!