Discuss the advantages and disadvantages of using molecular sequences for phylogenetic analysis
Describe the methods a molecular systematist would use to resolve the hypotheses generated by
multiple possible phylogenies from molecular data. Then, explain how systematists might resolve a
strongly supported molecular phylogeny with a different traditionally established morphological
phylogeny.
What will be an ideal response?
Advantages include that molecular data provide independence of analysis for numerous characters, and
are appropriate for distantly or closely related group analyses. Disadvantages include a lack of
variation in characters that may occur due to developmental or environmental factors; that DNA or
RNA data provide a limited set of characters (just four) for evaluation; and that base pair changes can
arise multiple times. To resolve the multiple phylogenetic trees that could arise from molecular data,
systematists would use principles of parsimony and statistical tools such as maximum likelihood to
determine the most strongly supported trees. To resolve discrepancies in hypothetical trees from
molecular versus morphological data, a larger set of molecular sequences or of morphological
characters would have to be compared. Also, a more comprehensive grouping of taxa would help
provide resolution. The ongoing publishing and presenting of trees in primary literature and at
meetings provides venues for systematists to compare and resolve trees through discussion, argument,
and inclusion of novel information and interpretations.
You might also like to view...
Homing pigeons' ability to always return to their home, no matter where they are released, is an excellent example of _____
A) piloting B) compass orientation C) an innate behavior D) true navigation
Which of the following is unique to prokaryotes?
a. chemoautotroph b. chemoheterotroph c. photoautotroph d. photoheterotroph e. chemoautotroph and photoheterotroph
What normal process is blocked by cleavage and inhibition of SNARE proteins?
A.) budding of vesicles from the ER B.) fusion of vesicles with target membranes C.) entry of proteins with ER signal sequence into the ER luman D.) docking of vesicles to target membranes
Which of the following statements about post-translational modifications is false?
A) Additional inorganic factors could be added. B) Post-translational modifications can include the addition of extra amino acids. C) Post-translational modifications are often required for a protein to function. D) Post-translational modifications provide a way for cells to regulate gene product functionality. E) Additional organic factors could be added.