Question

Features of organisms that are related to one another through common descent are a. convergent. b. homologous. c. divergent. d. analogous.

Short answer

b. homologous

Step-by-step solution

- Understand the question

The question asks which term describes features of organisms related to one another through common descent. This means that the organisms share a common ancestor, and their features have evolved from this common lineage.

- Define key terms

To solve this question, it's important to know the definitions of the given terms: a. Convergent: Features that evolve independently in different organisms but serve similar functions. b. Homologous: Features that are similar because they were inherited from a common ancestor. c. Divergent: Features that evolve in different directions from a common point. d. Analogous: Features that are similar in function but not from a common ancestor.

- Identify the correct term

From the definitions, the term that best describes features of organisms related through common descent is 'homologous'. Homologous features are similar because they were inherited from a common ancestor.

- Confirm the answer

Double-check the definitions to ensure that 'homologous' is the correct term. Features inherited from a common ancestor are indeed homologous, while the other terms do not fit this description.

Key concepts

homologous features

Homologous features are traits shared by different species due to shared ancestry. These features originated from a common ancestor and can vary in their form and function among descendants. Consider the forelimbs of humans, whales, and bats. While they serve different purposes (grasping, swimming, and flying), their underlying bone structures are remarkably similar.
These structural similarities stem from the same basic skeletal framework found in a common ancestor.
Examples of homologous features include:

• The arm bones in vertebrates: mammals, reptiles, and birds.
• Flower structures in flowering plants.
• Leaf structures in different plant species.

Homologous features provide strong evidence for evolutionary relationships.
Scientists utilize these traits to trace the lineage of species and understand how they have evolved over time.
By studying homologous features, researchers can question the purpose of adaptations and diversification in species across different environments.

evolutionary biology

Evolutionary biology is the study of how living organisms evolve and diversify over time.
The central concept is that all life shares a common origin.
Over millions of years, evolutionary processes have given rise to the immense diversity of life forms present today. Several key mechanisms drive evolution:

• Natural Selection: The process where organisms better adapted to their environment tend to survive and reproduce.
  Their advantageous traits become more common in the population over generations.
• Genetic Drift: Random changes in allele frequencies within a population.
  This can lead to significant changes over time, especially in small populations.
• Mutation: Changes in DNA sequences that can introduce new genetic variations.
  These variations can be beneficial, harmful, or neutral.
• Gene Flow: The transfer of genetic material between different populations.
  This can introduce new traits and increase genetic diversity.

Understanding these mechanisms helps researchers uncover how species adapt to their environments and the origins of new species.
It also provides insights into the shared ancestry of different organisms, highlighting how various life forms are interconnected through the tree of life.

ancestral traits

Ancestral traits, or primitive traits, are characteristics that were present in distant ancestors and inherited by descendent species.
Unlike derived traits, which are new features that appear in the lineage over time, ancestral traits tend to be more widespread among a group of species. For example, the presence of a backbone is an ancestral trait shared by all vertebrates.
This feature evolved in a common ancestor and is seen in fish, amphibians, reptiles, birds, and mammals.
By studying ancestral traits, scientists can construct phylogenetic trees that map out the evolutionary relationships between species. Identifying which traits are ancestral versus derived helps in understanding the evolutionary path from simple to more complex forms.
Traits that are ancestral in one context might be derived in another.
For example, having lungs is a derived trait within fish because it evolved later; however, it's an ancestral trait in land-dwelling vertebrates.