VISUAL SKILLS The relative lengths of the frog and mouse branches in the phylogenetic tree in Figure 26.13 indicate that a. frogs evolved before mice. b. mice evolved before frogs. c. the homolog has evolved more rapidly in mice. d. the homolog has evolved more slowly in mice.

Verified step by step guidance

1. Identify the phylogenetic tree in Figure 26.13 and observe the lengths of the branches for frogs and mice.
2. Understand that in a phylogenetic tree, the length of the branch can represent the amount of evolutionary change or the rate of evolution.
3. Compare the lengths of the branches for frogs and mice. A longer branch suggests a faster rate of evolution for that particular lineage.
4. Determine which branch is longer between the frog and the mouse. If the mouse's branch is longer, it indicates that the homolog has evolved more rapidly in mice.
5. Select the correct answer based on the observation: if the mouse's branch is longer, the correct answer is 'c. the homolog has evolved more rapidly in mice.'

Key Concepts

Phylogenetic Trees

Phylogenetic trees are diagrams that represent the evolutionary relationships among various biological species based on their genetic or physical characteristics. The branches of the tree indicate how closely related different species are, with the length of the branches often reflecting the amount of evolutionary change or time since divergence.

Homologous Structures

Homologous structures are anatomical features in different species that share a common ancestry, even if their functions may differ. The study of homologs helps scientists understand evolutionary relationships and the processes of adaptation and divergence among species.

Evolutionary Rates

Evolutionary rates refer to the speed at which genetic changes occur in a lineage over time. These rates can vary significantly between species, influenced by factors such as environmental pressures and reproductive strategies, and can be inferred from the lengths of branches in a phylogenetic tree, indicating how quickly certain traits have evolved.