Chapter 24, Problem 1TYK

The evolutionary history of a group of organisms is called its:

a. classification.

b. taxonomy.

c. phylogeny.

d. domain.

e. outgroup.

Summary Introduction

Introduction:

Classification of organisms based on the shared common characteristics is called biological classification. It helps in identification, naming, and comparison of an organism using many modern techniques, such as taxonomic classification and binomial nomenclature.

Answer to Problem 1TYK

Correct answer:

Phylogeny.

Explanation of Solution

Justification/explanation for the correct answer:

Option (c) is, ‘phylogeny.’ It is the branch of biology that studies the relationship and history of all the groups of the organism in the form of phylogenetic trees. The phylogenetic trees are illustrated in vertical directions from most ancient at the bottom to the most recent organisms at the top of the tree. The root represents the common ancestor of all species. Hence, option (c) is correct.

Explanation for the incorrect answers:

Option (a) is, ‘classification.’ It is the process of classifying the organisms based on their morphological similarities and differences. It does not include the evolutionary history of the organism. So, it is an incorrect option.

Option (b) is, ‘taxonomy.’ Taxonomy includes identification, classification, and naming of the organisms based on their shared characteristics. Taxonomy ignores evolutionary history while classifying. So, it is an incorrect option.

Option (d) is, ‘domain.’ Domain constitutes the highest taxonomic rank in taxonomy and it contains three domains named Eukarya, Bacteria, and Achaea. These are above the kingdom and thus called the super kingdom. So, it is an incorrect option.

Option (e) is, ‘outgroup.’ Outgroup represents the distantly-related group of organisms in the study of a phylogenetic tree and helps as a related source for studying phylogeny. So, it is an incorrect option.

Hence, options (a), (b), (d), and (e) are incorrect.

Conclusion

It can be concluded that phylogeny is the study of an evolutionary relationship in organisms and it is often represented in the form of a phylogenetic tree. It shows recent organisms at the top and ancient organisms at the bottom of the tree. The common ancestor of all species is represented by the root.