Essential Idea: The ancestry of groups of species can be deduced by comparing their base or amino acid sequences.
- Outline answer to each objective statement for topic 5.4 (coming soon)
- Quizlet study set for this topic
5.4.U1 A clade is a group of organisms that have evolved from a common ancestor.
- Define clade and cladistics.
5.4.U2 Evidence for which species are part of a clade can be obtained from the base sequences of a gene or the corresponding amino acid sequence of a protein.
- Outline the relationship between time, evolutionary relationships and biological sequences (nitrogenous base or amino acid).
5.4.U3 Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species and the time since they diverged from a common ancestor.
- Outline the use of a “molecular clock” to determine time since divergence between two species.
- State the source of differences between biological sequences (nitrogenous base or amino acid).
5.4.U4 Traits can be analogous or homologous.
- Contrast analogous and homologous traits.
- State an example of analogous and homologous traits.
5.4.U5 Cladograms are tree diagrams that show the most probable sequence of divergence in clades.
- Define cladogram and node.
- Outline how computer programs analyze biological sequence data to create cladograms.
- Identify members of clades given a cladogram.
5.4.U6 Evidence from cladistics has shown that classifications of some groups based on structure did not correspond with the evolutionary origins of a group or species.
- Outline the role of technological advancements in the development of cladistics.
- Explain why the development of cladistics lead to the reclassification of some species.
5.4.A1 Cladograms including human and other primates.
- Interpret a cladogram depicting primate species.
5.4.A2 Reclassification of the figwort family using evidence from cladistics.
- Outline the reason and evidence for the reclassification of the figwort family.
5.4.S1 Analysis of cladograms to deduce evolutionary relationships.
- Analyze a cladogram to explain the evolutionary relationship between species.
- Discuss the use of cladograms as hypotheses of evolutionary relationships.
5.4.NOS Falsification of theories with one theory being superseded by another- plant families have been reclassified as a result of evidence from cladistics.
- Outline the reason why biological theories may change with time.