How Does DNA Support the Theory of Evolution Quizlet?


Diego Sanchez

DNA, or deoxyribonucleic acid, is the genetic material that encodes the information necessary for the development and functioning of all living things. The DNA molecule contains a unique sequence of nucleotides that serves as the blueprint for an organism’s traits.

The theory of evolution holds that all living things share a common ancestor and have evolved over time through natural selection and other mechanisms. But how does DNA support this theory? Let’s explore.

What is the Evidence for Evolution in DNA?

One key piece of evidence for evolution in DNA is the fact that all living things share many similarities in their genetic code. For example, humans share about 99% of their DNA with chimpanzees, our closest living relatives. This suggests that we share a common ancestor with chimps and have diverged from one another over time.

Another piece of evidence is the existence of “vestigial” genes – genes that have lost their original function over time but still remain in an organism’s genome. For example, humans have a gene for producing Vitamin C, but it is non-functional due to mutations. This suggests that our ancestors once had a functional version of this gene but no longer needed it because they obtained Vitamin C from their diet.

How Does DNA Show Common Ancestry?

One way in which DNA supports the theory of evolution is through its ability to show common ancestry between different species. By comparing the DNA sequences of different organisms, scientists can determine how closely related they are and how recently they shared a common ancestor.

For example, studies have shown that humans and apes share many identical or nearly-identical stretches of DNA, indicating that we shared a relatively recent common ancestor. In contrast, humans and bacteria share very little DNA in common, indicating that we diverged from bacteria much earlier in evolutionary history.

  • What is Genetic Drift?

Genetic drift is another mechanism that can be observed in DNA and supports the theory of evolution. Genetic drift refers to random changes in the frequency of different alleles (versions of a gene) in a population over time. These changes can occur due to chance events like genetic mutations or environmental factors.

Over time, genetic drift can lead to the accumulation of differences between populations, which can eventually lead to speciation (the formation of new species). By studying the patterns of genetic variation within and between populations, scientists can gain insights into how evolution has occurred over time.

The Bottom Line

In conclusion, DNA provides strong evidence for the theory of evolution. By comparing DNA sequences across different species, scientists can determine how closely related they are and how recently they shared a common ancestor.

Additionally, genetic drift and other mechanisms observed in DNA support the idea that evolution occurs through natural selection and other processes. As our understanding of genetics continues to advance, we will undoubtedly gain even more insights into the fascinating story of our evolutionary history.