Massachusetts Comprehensive Assessment System (MCAS) Biology Practice Test

What is the significance of studying DNA when considering evolutionary biology?

1. It helps in understanding protein synthesis

2. It allows researchers to compare genetic similarities across species

3. It provides insight into energy production

4. It is unrelated to evolution

The correct answer is: It allows researchers to compare genetic similarities across species

Studying DNA is crucial in evolutionary biology because it allows researchers to compare genetic similarities across species. This comparison provides essential insights into how different organisms are related to one another and how they have diverged over time through the process of evolution. By analyzing the DNA sequences of various species, scientists can identify shared genetic markers that indicate a common ancestry. The degree of similarity in DNA sequences can help illustrate the evolutionary distance between species; closely related species will have more genetic similarities compared to those that are distantly related. This genetic information enriches our understanding of evolutionary relationships, migration patterns, and the historical mechanisms that drive the diversity of life on Earth. In contrast, understanding protein synthesis and energy production, while important biological processes, do not directly address the evolutionary relationships among species. The claim that DNA is unrelated to evolution undermines the foundational role that genetic variation and heredity play in the evolutionary process. Thus, the study of DNA is a fundamental aspect of tracing evolutionary lineages and understanding how life forms have changed and adapted over millions of years.