If you were using cladistics to build a phylogenetic tree of cats, which of the following would be the best outgroup?
a. Wolf
b. Domestic cat
c. Lion
d. Leopard

Verified step by step guidance

1. Understand the concept of cladistics: Cladistics is a method of classifying species based on their evolutionary relationships. It involves identifying shared characteristics that are derived from a common ancestor.
2. Define an outgroup: In cladistics, an outgroup is a species or group that is closely related to but not part of the group being studied (the ingroup). The outgroup helps to root the phylogenetic tree and provides a point of comparison for determining evolutionary relationships.
3. Identify the ingroup: In this problem, the ingroup consists of various species of cats, including domestic cats, lions, and leopards.
4. Determine the best outgroup: The best outgroup should be a species that is closely related to the ingroup but not part of it. Among the options given, a wolf (option a) is not a cat but is a member of the Carnivora order, which includes both cats and wolves. This makes it a suitable outgroup for the phylogenetic tree of cats.
5. Use the outgroup to root the tree: Once the outgroup is identified, it can be used to root the phylogenetic tree, helping to clarify the evolutionary relationships among the species within the ingroup.

Key Concepts

Cladistics

Cladistics is a method of classifying organisms based on common ancestry and evolutionary relationships. It involves constructing phylogenetic trees that represent the branching patterns of evolution, focusing on shared derived characteristics (synapomorphies) to determine the relatedness of different species.

Phylogenetic Tree

A phylogenetic tree is a diagram that represents the evolutionary relationships among various biological species based on similarities and differences in their physical or genetic characteristics. It illustrates how species are related through common ancestors, with branches indicating divergence from a common lineage.

Outgroup

An outgroup in cladistics is a species or group that is closely related to but not part of the group being studied (the ingroup). It serves as a reference point for determining the evolutionary relationships within the ingroup, helping to root the phylogenetic tree and clarify the direction of evolutionary changes.