Early Scientists Used Morphological Characteristics to Create a Phylogeny of Animals

question 125

Multiple Choice

Early scientists used morphological characteristics to create a phylogeny of animals, but recently, DNA sequence data have helped in the revision of phylogenies of taxa within the larger groups (i.e., bilaterians, sponges, cnidarians) . Why are morphological characteristics like "fate of the blastopore" or "body symmetry" relatively good at predicting larger-scale branching patterns on phylogenies?

• A)The development of these characteristics is controlled genetically, therefore similarities in DNA sequence would be expected in more closely related taxa.
• B)Characteristics like those described are necessary for living, therefore all organisms must have those traits.
• C)All animals are descended from a common ancestor that had the traits described above.
• D)These features reflect adaptations to life on land.

---

Definitions:

American History

The historical events, figures, and periods that have shaped the United States from its founding to the present day.

Physical Conditions

The state of the physical environment or an individual's physical health and well-being.

Basically Good

The belief in the inherent goodness of people, suggesting that individuals are fundamentally inclined towards positive behavior.

Reactive Response

An action or behavior that is a direct reaction to a stimulus or situation, often without premeditated planning.