What is a clade?
A group of organism that includes all of the evolutionary descendants of a common ancestor
What is a cladogram?
A tree diagram that shows the most probable sequence of divergences in a clade
According to this diagram are reptiles a clade?
No reptiles are not a clade because they do not include all descendant of a common ancestor.
How do you identify members of a clade?
Evidence for which species are part of a clade can be obtained form the base sequence of a gene or the corresponding amini acid sequence.
What is a molecular clock?
Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species.
Changes in the DNA base sequence for a specific gene expected to occur gradually, at a constant rate
What is an analogous trait?
An analogous trait is a characteristic that two organisms share due to convergent evolution, not common ancestry
What is a homologous trait?
A homologous trait is a characteristic that two organisms share due to common ancestry
How are cladograms and reclassification related?
Evidence from claditics has shown that classifications of some groups based on structure did not corespond with the evolutionairy origins of a group of species
What is falsification?
Falsification of theories with one theory being susperseded by another plant families have been reclassified as a result of evidence from cladistics.
What is an example of a plant taxon that has been reclassified in light of new evidence?
Figwort family is an example of a plant taxon that has been reclassified in light of new evidence from DNA analysis and cladistics