Join thousands of students who trust us to help them ace their exams!Watch the first video
Multiple Choice
Which of the following statements is true of an outgroup in phylogenetic analysis?
A
An outgroup is a species or group that is closely related to, but not part of, the group of species being studied.
B
An outgroup is always the most evolutionarily advanced member of the group being studied.
C
An outgroup is used to root the phylogenetic tree and determine the direction of evolutionary change.
D
An outgroup is a member of the ingroup that shares all derived characteristics.
Verified step by step guidance
1
Understand the concept of an outgroup in phylogenetic analysis: An outgroup is a species or group that is closely related to the ingroup (the group of species being studied) but is not part of it. It serves as a reference point for comparison.
Recognize the purpose of an outgroup: It is used to root the phylogenetic tree, which helps determine the direction of evolutionary change by identifying ancestral and derived traits.
Clarify the distinction between an outgroup and an ingroup: The outgroup does not share all derived characteristics with the ingroup. Instead, it helps identify which traits are ancestral and which are derived within the ingroup.
Evaluate the incorrect statements: An outgroup is not necessarily the most evolutionarily advanced member of the group being studied. Evolutionary advancement is not a valid concept in phylogenetics, as evolution is not goal-oriented.
Conclude the correct statement: The correct statement is that an outgroup is a species or group that is closely related to, but not part of, the group of species being studied, and it is used to root the phylogenetic tree and determine the direction of evolutionary change.