DNA research has changed how we understand evolution and how new species form. It gives us a way to study the differences in genes and how different species are related to each other.

Before we knew about DNA, scientists mainly looked at an organism's appearance and traits to understand evolution. But once DNA was discovered as the material that carries genetic information, scientists could explore how traits are passed down from one generation to the next.

One important idea from DNA research is called molecular phylogenetics. This is a fancy term for studying the genetic codes of different organisms. By doing this, scientists can create diagrams, called phylogenetic trees, that show how different species are related over time. For instance, by comparing mitochondrial DNA (which is passed down through mothers) among various species, we can see how certain groups of organisms became different from one another. This process of becoming new species is known as speciation.

Also, when we talk about population genetics, we look at how genes change in different groups of organisms. This helps us understand how things like genetic drift, natural selection, and gene flow play a role in evolution. Ideas like genetic bottlenecks (when a population's size is suddenly reduced) and the founder effect (when a new population starts with a small group of individuals) show that even tiny changes in genes can have big impacts on how a species evolves, especially if the environment changes.

In short, our knowledge of DNA has not only supported old ideas about evolution but has also helped us learn more about how genetics influences the way species change and develop over time.