This is the visual for the project that we are doing in the place of a test this chapter.
Well, life forms change through natural and artificial selection, which are processes where life forms with favorable traits survive and reproduce, eventually eliminating unfavorable traits. That is how evolution works.
I know all dogs came from wolves, but how are so many different kinds of dogs? How did they change?
Becca, Jaides, & Hope
Most organisms change because something changes in their environment. Some examples include climate change, invasive species, deforestation, and pollution.
Oh, that makes sense. But why did they have to change?
Dogs are different, though. Wolves became dogs because people bred them for specific traits, creating many breeds of dogs. For example, some dogs were bred to hunt, others to herd, and others to have a specific coat color.
When scientists find fossils from the same species that lived in different points in time, the fossils are often different even though they were the same kind of organism, which proves that life forms have changed.
Last question: How do we know that life forms have changed so much over earth's history?
We need to take Rocky home, but I'm so glad that I learned more about how life forms change!