Question

Choose the true statements about the evolution of complex characters, such as powered flight.

Answer 1

Answer:

b. Often the initial stage in the evolution of a complex character was an adaptation to some unrelated selection pressure.

d. Phylogenetic analysis using cladistics can help reveal the sequence leading to the evolution of a complex character.

Explanation:

The evolutionary developmental program of complex characters can be analyzed by examining synapomorphies, i.e., by examining shared, derived characters common between an ancestor of a given taxonomic group and its descendants. Synapomorphies are able to create evidence for historical relationships between closely related organisms. Moreover, cladistics is a method used to categorize species/taxa into groups called 'clades' based on arranging organisms with similar traits, which can provide useful information on the evolutionary history of complex traits in different species/taxa. In phylogenetics, the analysis of complex characters involves two different stages: 1-character analysis and 2-cladistic analysis. Homology refers to structures that look similar because they were inherited from a common ancestor (i.e., they have a common origin); whereas characters are considered as parts of transformation series. In cladistics, characters used for inferring phylogenetic relationships are considered as hypotheses of homology that are subject to tests of similarity. In consequence, such characters can provide useful information on the evolutionary history of complex traits.