Test 3 Flashcards
(98 cards)
What are the main aspects of binomial nomenclature?
A Species name is Genus + species, Genus is capitalized and the entire name is italicized, higher taxonomic names are capitalized but not italicized
Define Taxon
The taxon is a group of any rank (which could include domain, kingdom, phylum, class, etc.)
Define Taxa
Taxa is plural for taxon. It is ideal to have the taxa be monophyletic (A common ancestor and all of its descendants)
What are the 9 taxonomic categories?
Life, Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
(King Philip Calls Out For Good Soup)
Define Phylogeny
Evolutionary history and relationship of organism or group of organisms.
What are Cladograms?
a tree/diagram where the data you have (DNA, embryological development, physiology, etc.) is used to display evolutionary relationships among the organisms in the tree
Organisms are grouped based on ________?
shared characteristics (synapomorphies)
What are synapomorphies?
something that has evolved recently (something new). This includes shape, size, structure, features, traits, characteristics that are newly derived.
What kind of data can be used to group organisms
Fossil records
Morphology
Physiology
Behavior
Embryological development
DNA/RNA sequences
Etc.
What is a clade?
a group of evolutionary ancestors and are descendants of a common ancestor. It is a group of organisms, or taxa, that are related.
What is a sister clade?
share an immediate common ancestor, and are next to each other, but something is different. They are each other’s closest relatives.
What are nodes in a cladogram and what do they indicate?
The splits in branches & they indicate a division of one lineage into two.
How can you tell which species is in the outgroup?
It has the least amount of nodes leading to it.
What are phylogenetic trees?
Cladograms with a few added bells and whistles. Branches on a PT can be proportional to amount of change or evolutionary time.
Phylogenetic trees are based on _______?
homology (traits inherited by two different organisms from a common ancestor)
What is homology?
traits inherited by two different organisms from a common ancestor (think homo means same)
What is an ancestral trait?
([sym]plesiomorphy)- In ancestor of group; may be retained or changed in descendants.
What is a derived trait?
([syn]apomorphy)- Differs from ancestral form; evolutionary novelty.
Phylogenetic trees are NOT based on ________?
homoplasies, features shared between species that were not inherited from a common ancestor; usually due to similar selection pressures / environment
How do you determine if a trait is ancestral or derived?
Look at the taxon! At some point the trait will be derived but ancestral after that point.
What is the principle of parsimony?
The preferred explanation of observed data is the simplest explanation. (Tree that requires the fewest number of evolutionary changes is favored)
What is a monophyletic group?
the group includes the common ancestor and all of its descendants (Considered the “best tree”)
d e g h
V V
c f
V
b
What is a polyphyletic tree?
a grouping that includes the descendants but not the common ancestor (Ex. Bats and birds: both have wings, but they have evolved separately)
d E G h
V V
c f
V
b
(E and G in this tree)
What is a paraphyletic tree?
a grouping that includes the common ancestor but not all of the descendants
d e G H
V V
c F
V
B
(B,F,G,H on this tree)