Chapter 26 Flashcards
Chapter 26
Mass extinction
Widespread and rapid decrease of biodiversity on earth
Taxonomy
Branch of biology that identifies, names and organizes biodiversity into related categories
The Linnaean system of classification
-Species - Most specific
-Genus
-Family
-Order
-Class
-Phylum
-Kingdom
-Domain - Least Specific
Bacteria
Single Celled, prokaryotic, microscopic, cell walls contain chemical called peptidoglycan
Archaea
Single celled, prokaryotic, microscopic. Call walls DONT have chemical called peptidoglycan. Live in extreme environments
Eukarya
Multicellular, Some unicellular, membrane bound nucleus/ organelles, sexual reproduction is common, contains kingdoms of fungi, protists, plants, animals
Cladogram
A diagram which shows the relationship between different species based on their characteristics
Clade
Common ancestor and all of its descendants
Ancestral Traits
Traits common because of a common ancestor
Derived traits
Traits not common to the ancestor, evolved along the way
Phylogenetic tree
A diagram which shows the phylogenetic history of organisms with respect to the geological time scale
What is the difference between a cladogram and phylogenetic tree?
-Cladogram branches are arbitrary, focuses on common traits
-Phylogenetic Tree’s Branch length indicates amount of time since speciation
Node
Speciation event
Root
Common Ancestor
Outgroup
Species that does not fit into a clade or ingroup
Convergent Evolution
Adaptations of two distinct species evolved separately, but appear similarly
Molecular comparisons
Mutations accumulate over time. More closely related two species are, the more similar the DNA sequence will be
Molecular Clocks
Genetic Timers that estimate the liming of evolutionary events based on the rate of genetic mutations
Protein Comparisons
Since DNA codes for proteins, differences in protein sequence helps determine phylogeny
