1. Organisms evolve slowly over time.

* Evolution is a gradual process: Evolutionary changes happen over many generations, often driven by mutations (changes in DNA) and natural selection (where organisms with traits that help them survive and reproduce are more likely to pass those traits on).

* The pace of evolution varies: Some species evolve much faster than others, depending on factors like generation time, environmental pressures, and the rate of mutation.

* Observable evolution: We can see evidence of evolution in action, such as the development of antibiotic resistance in bacteria, the changing beak shapes of finches in response to food availability, and the emergence of new viral strains.

2. Two different organisms can have a common ancestor.

* Universal common ancestor: All living things on Earth share a common ancestor, a single-celled organism that lived billions of years ago.

* Tree of life: We can trace the evolutionary relationships between organisms using tools like DNA sequencing and fossil records. This data helps us build a "tree of life" that shows how different species are related.

* Shared traits: Species that share a recent common ancestor often have similar physical traits, genetic makeup, or developmental patterns. For example, humans, chimpanzees, and gorillas all share a common ancestor and have similar skeletal structures.

In summary: Evolution is a slow, ongoing process that shapes life on Earth. All living things share a common ancestor, and the relationships between species can be traced through the study of evolution.