UC Berkeley
Image Caption
Character data for some major vertebrate lineages. Characters were limited to characters that are likely homologous (note that many vertebrate lineages and many characters were excluded from this example for the sake of simplicity).
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This image is part of a series:
Parsimony (2 of 5) Vertebrate ancestor characters
From studying fossils and lineages closely related to the vertebrate clade, we hypothesize that the ancestor of vertebrates had none of these features.
Parsimony (3 of 5) Amniotic egg clade and phylogeny
We focus in on the group of lineages that share the derived form of the egg character, an amniotic egg (A), and hypothesize that they form a clade (B.)
Parsimony (4 of 5) All clades and phylogeny
If we go through the whole table like this, grouping clades according to shared derived characters (C) we get the following hypothesis (D).