bio 102 test 2 Flashcards
(84 cards)
A scientific discipline focused on classifying organisms and determining their evolutionary relationships.
What is systematics?
The movement of genes from one genome to another, complicating efforts to build a tree of life.
What is horizontal gene transfer?
Definition of a species as a group of populations whose members have the potential to interbreed in nature and produce viable, fertile offspring.
What is the biological species concept?
A process in which individuals with certain inherited characteristics are more likely to obtain mates.
What is sexual selection?
A process in which traits that enhance survival or reproduction tend to increase in frequency over time.
What is adaptive evolution?
The state of a population in which frequencies of alleles and genotypes remain constant from generation to generation, provided that only Mendelian segregations and recombination of alleles are at work.
What is the Hardy-Weinberg Theorem?
A change in the nucleotide sequence of an organism’s DNA or in the DNA or RNA of a virus.
What are mutations?
Differences among individuals in the composition of their genes or other DNA sequences.
What is genetic variation?
The aggregate of all copies of every type of allele at all loci in every individual in a population.
What is a gene pool?
The group of organisms/taxa whose evolutionary relationships are the focus of a particular phylogenetic analysis.
What is an ingroup?
A species/group of species closely related to the ingroup that diverged before the ingroup.
What is an outgroup?
The simplest explanation for a phenomenon that is most likely to be correct.
What does parsimony refer to in evolutionary biology?
Characteristics present in an ancestral species shared exclusively by its descendants.
What are synapomorphies?
An evolutionary novelty unique to a particular clade.
What is a shared derived character?
A character that originated in an ancestor of the taxon.
What is a shared ancestral character?
Consists of an ancestral species and some, but not all, of the descendants.
What is a paraphyletic group?
A branch from which more than two groups emerge.
What is a polytomy?
Diverges early in the history of a group and originates near the common ancestor.
What is a basal taxon?
Groups that share an immediate common ancestor.
What is a sister taxon?
A hypothesis about evolutionary relationships, showing patterns of descent.
What does a phylogenetic tree represent?
Includes distantly related species but does not include their most recent common ancestor.
What is a polyphyletic group?
A valid clade that consists of an ancestor species and all its descendants.
What is a monophyletic group?
A group of species that includes an ancestral species and all its descendants.
What is a clade?
Groups organisms by common descent.
What is cladistics?