Understanding Cladograms and Phylogenetic Relationships

What is the primary purpose of a cladogram?

• To classify organisms based on physical characteristics
• To hypothesize evolutionary relationships among organisms
• To determine the age of different species
• To identify the geographical distribution of species

In a cladogram, what does a branching point represent?

• A common ancestor of the organisms that branch from it
• The extinction of a species
• A significant evolutionary event
• The introduction of a new species

Which of the following statements about outgroups in a cladogram is true?

• Outgroups share all characteristics with the ingroup
• Outgroups are the most closely related species
• Outgroups help to root the cladogram and provide a point of comparison
• Outgroups are always the first species listed in a cladogram

How does the theory of parsimony apply to constructing cladograms?

• It suggests that the most complex explanation is usually correct
• It favors the simplest explanation that requires the least number of evolutionary changes
• It requires that all characteristics be included in the cladogram
• It states that all organisms must be included in a single branch

If a new species is discovered, how should it be placed in an existing cladogram?

• It should be placed randomly
• It should be placed based on shared characteristics with existing species
• It should be placed at the end of the cladogram
• It should replace one of the existing species

What is the primary purpose of a cladogram?

• To show the exact evolutionary timeline of species
• To present a hypothesis of how organisms may be related
• To determine the age of fossils
• To classify organisms based on their habitat

In the video, what characteristic do all of the hypothetical organisms (Anderseni aquaticus subspecies) share?

• An eye
• Defensive spikes
• A cell membrane
• Teeth

According to the video, why is species F more closely related to species E than to species A?

• F and E have more similar physical characteristics
• F and E share a more recent common ancestor
• F and E live in similar environments
• F and E have the same number of traits

What principle is being applied when choosing the most likely placement for a new species on a cladogram?

• Natural selection
• Genetic drift
• Parsimony (Occam's Razor)
• Convergent evolution

In modern biology, what is the primary basis for creating accurate cladograms?

• Physical characteristics
• Habitat preferences
• DNA sequences
• Fossil records