Systematics Flashcards
what are systematics
the scientific study of diversity and evolutionary history – basically classify and name who is related to whom
what is taxonomy
identifying, classifying, and naming of organisms
Linneaus’ binomial nomenclature
Species name = Genus + specific epithet
a group at any level is called a
taxon
Each species has a type specimen that usually was
collected by the person who named that species – used
to
compare potential same species or new species
what is a herbarium
a collection of preserved plant specimens and associated data used for scientific study
Phylogenetic trees represent
a hypothesis of how taxa are related
Homologous structures have a common ___ but not necessarily a common ___
origin, function
Analogous structures may have a similar ___ and ___, but have an entirely different evolutionary ___ - the result of ____ evolution
function, appearance, background, convergent
The most common method of classifying organisms today is known as cladistics, which explicitly seeks to ____
understand phylogenetic relationships
Synapomorphies are ___ – define a ___ group
character states that arose in the common ancestor of a group and are present in all of its members, monophyletic
Outgroups are ___
taxa that are closely related to but not a member of the study group (the ingroup) under investigation. Character states possessed by the closest outgroups are considered to be ancestral, while those present in the ingroup, but absent in the nearest outgroups, are considered to be derived
The result of cladistic analysis is a cladogram, which provides a
graphical representation of a working model, or hypothesis, of the phylogenetic relationships among a group of organisms, aka phylogenetic tree
Character tables summarize the
data of the taxa being compared
what do + and - mean in a character table
+ they have it, - they do not have it
Molecular systematics uses ___ as the ancestral or derived character states
DNA sequences
Most plant systematics uses the ___ genome for comparisons
chloroplast
why do we use the chloroplast genome instead of the mitochondrial genome?
Slowly evolving, Found in all plants and algae, No introns
Mitochondrial genes – evolve too slowly
dna barcoding was invented in animals using the mitochondrial gene. how do we use it in plants
In plants, uses a chloroplast gene rbcL,
Any plant at any stage of development can be ID’d!
how did plants change the planet about 1 billion years ago?
cambrian explosion resulted in a huge increase of atmospheric o2
how did eukaryotic cells evolve?
Serial endosymbiosis
Evidence of endosymbiosis in a modern protist
mitochondria and plastids
Primary, secondary, and tertiary endosymbiosis and example
primary - initial engulfment of cyanobacterium turned into chloroplast
secondary - secondary engulfment
tertiary - chloroplast has 3-4 membranes
ex: diatoms and other protists
Eukaryotic supergroups – everything that isn’t a plant, animal or fungi =
protist
