Evolution 5.4 Cladistics Flashcards Preview

Biology 5. Evolution > Evolution 5.4 Cladistics > Flashcards

Flashcards in Evolution 5.4 Cladistics Deck (10)
Loading flashcards...
1

What is a clade?

A group of organism that includes all of the evolutionary descendants of a common ancestor

2

What is a cladogram?

A tree diagram that shows the most probable sequence of divergences in a clade

3

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.

4

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. 

5

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 

6

What is an analogous trait?

An analogous trait is a characteristic that two organisms share due to convergent evolution, not common ancestry

7

What is a homologous trait?

A homologous trait is a characteristic that two organisms share due to common ancestry

8

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

9

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.

10

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