Bio Lab Quiz 3 (Labs 11, 2, and 3) Flashcards
What is a genealogy
An ancestor and its descendants
What is a change in a characteristic or attribute in the descendant relative to the ancestor?
Modification
Because characters do not all change at the same rate or to the same degree, descendants are a combination of Unmodified (_________) and modified (__________) character states
Ancestral, Derived
What is a character?
An observable trait of an organism
If the character trait being observed is forelimbs, what are examples of modified character states?
no forelimbs, two forelimbs, or four forelimbs
If an ancestor does not have forelimbs but the descendant has two forelimbs, the descendant has the derived _____ _______.
Character state
What are homologous characters?
found in two or more species and are derived from the same structure in a common ancestor (it looks the same and is found in the same place)
What is apomorphy?
A new or descendant character state
What is a synapomorphy?
a shared derived character, an apomorphy found in two or more taxa
What is used to infer phylogenetic relationships?
Synapomorphies
What is plesiomorphy?
ancestral character state
What is a symplesiomorphy?
a shared ancestral character state
What does monophyletic mean?
All members of the group and all descendants share the same, most recent ancestor
What are the two assumptions on which outgroup comparison works?
- The ingroup (the group being studied) is monophyletic
2. The outgroup is not a part of the ingroup
Any homologous character state found in the outgroup and in the ingroup is considered _______
Plesiomorphic
Character states found in the ingroup and not in the outgroup are considered __________
Synapomorphic
What is a paraphyletic group?
An ancestral group, but not all of its descendants are included
What is a polyphyletic group
organisms that do not share the most recent common ancestor are included as one group
What is a clade?
A group of taxa consisting of an ancestor taxon and all of its descendant taxa
What does a node represent?
A speciation event
What are multistate characters?
They exist in more than two different states; not binary (present/absent)
What technique is used to deal with multistate characters?
Hennigian argumentation
What is the evolutionary relationships among organisms?
Phylogeny
What is a cladogram?
A branching tree showing the most simple relationships between organisms