Question

Can someone please explain (with example if possible) what an OUTGROUP is??

Answer 1

An outgroup is a group of organisms that serve as a reference group for determination of the evolutionary relationship among three or more monophyletic groups of organisms.
Example:
Humans, chimpanzees — gorillas
Placental mammals, Marsupials — Monotremes
Tetrapoda, Actinopterygii — Elasmobranchii
Chordates, Echinoderms — Mollusks

The chosen outgroup is hypothesized to be rather closely related to the other groups, but less closely than any single one of the other groups is to each other. The evolutionary conclusion from this is that the outgroup branched from the parent group before the other two groups branched from each other.

Answer 2

Thank you! That makes so much more sense!