Unit1-4 Flashcards
(23 cards)
What is systematics?
The study of evolutionary relationships among organisms using traits like morphology, DNA, and ecology.
What is a phylogeny?
A hypothesis about the evolutionary relationships among species, often depicted as a branching tree.
Why are fossil records not enough to determine evolutionary history?
They are incomplete and imperfect, so scientists use other data like DNA and morphology.
What is a cladogram?
A diagram showing the hypothesized evolutionary relationships among species.
What is a clade?
A group of organisms that includes a common ancestor and all its descendants.
What is a synapomorphy?
A shared, derived trait that is unique to a clade.
What is an ancestral character state?
A trait inherited from the most recent common ancestor.
What is a derived character state?
A new trait that evolved in a clade, not present in the ancestor.
What is homoplasy?
A shared trait not inherited from a common ancestor, often due to convergent evolution.
What principle is used to choose between competing cladograms?
Parsimony — the simplest explanation with the fewest evolutionary changes.
What is taxonomy?
The science of naming and classifying organisms.
What is the correct format for a scientific name?
Genus species (italicized, Genus capitalized, species lowercase).
What are the 8 levels of taxonomic hierarchy?
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.
What does ‘monophyletic’ mean?
A group containing a common ancestor and all its descendants.
What is a paraphyletic group?
A group containing a common ancestor but not all its descendants.
What is a polyphyletic group?
A group that does not include the most recent common ancestor.
What is the difference between homologous and analogous structures?
Homologous structures come from a common ancestor; analogous do not (result of convergent evolution).
What do phylogenies reveal about parental care in birds, crocodiles, and dinosaurs?
It is a homologous behavior inherited from a common ancestor.
What role did plant evolution play in beetle diversification?
Beetles specializing on angiosperms diversified more; specialization occurred independently 5 times.
What is the relationship between HIV and SIV?
HIV descended from SIV, with multiple independent transfers to humans from primates.
What did phylogenetic analysis reveal about HIV-1 subtypes?
They originated from different SIV strains in chimpanzees and gorillas.
How was phylogeny used in a legal case involving HIV?
It traced the viral strain in a victim to a patient, helping convict the source of infection.
What did phylogenetic analysis reveal about the spread of COVID-19?
It showed multiple introductions of the virus and patterns of community transmission.
