Biology (Miller/Levine) Chapter 18: Classification; Section 18-2: Modern Evolutionary Classification
Terms in this set (17)
What traits did Linnaeus consider when classifying organisms?
generally visible traits
What problems are faced by taxonomists who rely on body-structure comparisons?
Organisms could look the same but not be the same thing
True or False: Darwin's theory of evolution changed the way biologists thought about classification.
True. Biologists now group organisms into categories that represent lines of evolutionary descent.
How do biologists now group organisms into categories?
Into categories that represent lines of evolutionary descent
True or False: Genera placed within a family should be less closely related to one another than to members of any other family.
The strategy of grouping organisms together based on their evolutionary history
Cladistic Analysis (True or False):
--It considers only traits that are evolutionary innovations
--It considers all traits that can be measured.
--It considers only similarities in body structure.
--It is a method of evolutionary classification.
Characteristics that appear in recent parts of a lineage, but not in older members
A diagram that shows evolutionary relationships among a group of organisms
True or False: Derived characters are used to construct a cladagram.
True or False: Some organisms do not have DNA or RNA.
False. All organisms have DNA.
How do similarities in genes show humans and yeast share a common ancestry?
Common DNA strip
A model that uses DNA comparisons to estimate the length of time that two species have been evolving dependently.
A molecular clock relies on the repeating process of ______.
Why are only neutral mutations useful for molecular clocks?
Neutral mutations have no effect on phenotype. They accumulate in the DNA of different species at about the same rate. A comparison of such DNA sequences in two species can reveal how dissimilar the genes are.
True or False: The degree of dissimilarity in DNA sequences is an indication of how long ago two species shared a common ancestor.
Why are there many molecular clocks in a genome instead of just one?
There are many molecular clocks in a genome because some genes accumulate mutations faster than others. These different clocks allow researchers to time different kinds of events.