chapter 1 Flashcards
Phenomenon
something in nature that we wish to explain
Hypotheses
educated guesses of cause and effect
Theory
the conceptual framework within which our hypotheses are framed
Predictions
logical deductions of our hypotheses (predictions must be independent of the data or knowledge that went into formulating our hypotheses)
Tests
empirical falsification or verification of our predictions
Biological evolution
Any change in the inherited traits of a population that occurs from one generation to the next
What does evolution explain?
The diversity of life
Evolutionary case studies
Whales:mammals gone to sea. Viruses: deadly escape artists.
Lineage
A chain of ancestors and their descendants. A lineage may be the successive generations of organisms in a single population, the members of an entire species during an interval of a million years, or a group of related species descending from a common ancestor.
Natural Selection
A mechanism that can lead to evolution, whereby differential survival or reproduction of individuals causes some genetic types to replace (out complete) others.
Convergent evolution
the independent origin of similar traits in seperate lineages.
Homologous
characteristics are similar in two or more species because they are inherited from a common ancestor.
Synapomorphy
derived form of a trait that is shared by a group of related (i.e. one that evolved in the immediate common ancestor of the group and was inherited by all its descendants).
Phylogeny
A visual representation of the evolutionary history of populations, genes, or species.
Mutation
any change to the genomic sequence of an organism.
Reassortment
Viral reassortment occurs when genetic material from different strains gets mixed into new combinations within a single individual.
Molecular Clock
technique in molecular evolution that uses fossil constraints and rates of molecular change to deduce the time in geologic history when two species or other taxa diverged.
How did whales and fish lineages evolve?
independently, converged on body forms that are superficially similar.
Ambulocetus
fossil whale that had legs. The animal had traits that were intermediate between modern whales and their terrestrial ancestors.