Flashcards in CH 26: Taxonomy and Systematics Deck (14)
Science of describing, naming, and classifying living and extinct organisms and
Study of biological diversity and the evolutionary relationships among
organisms, both extinct and modern
What is at the top of the hierarchy of taxonomy and what groups comprise that level?
Domain is at the top and is comprised of Bacteria, Archaea, and Eukarya
What are the taxanomic groups from highest to lowest?
Domain, Supergroup, Kingdom, Phylum, Class, Order, Family, Genus, Species
What is a monophyletic group?
group of species, taxon, consisting of
the most recent common ancestor and all of its ancestors
What is a paraphyletic group?
contains a common ancestor and some, but not
all, of its descendants
What is a polyphyletic group?
contains a group of species with different common ancestors
What are systematics usually based on?
morphological or genetic homology
What is molecular systematics?
Using genetic homology to propose phylogenetic trees
-DNA and Amino Acid sequences are analyzed and closely related species have more similar sequences
What is cladistics?
Study and classification of species based on evolutionary relationships
• Cladistic approach requires choosing the least complex tree
• Make phylogenetic trees or cladograms
What are the character states in cladistics?
-Shared primitive character
-Shared derived character
What kinds of mutations are most common and why?
Favorable mutations are rare.
Detrimental mutations are weeded out due to natural selection.
Neutral mutations are the most common.
What are molecular clocks and how are they set?
Using accumulation of neutral mutations to measure evolutionary time
-Neutral mutations occur at a constant rate
-Divide the percentage of molecular difference by the number of years since they diverged from a common ancestor