Rough ER - protein synthesis, transport of proteins throughout the cell
Smooth ER - lipid synthesis and cell detoxification
This evidence suggest that all three living creatures that are mentioned have a common ancestor, even though they have been split into different types of groups of living organism millions of years ago.
Science suggests that all of the living organisms on the planet have a common ancestor. Since we are talking about a common ancestor that lived few hundred million years ago, the living organisms split into different groups, and they do not resemble each other nowadays. The fruit fly is an insect, and the humans and mice are mammals, so they are into totally different groups, and it is easy to see by the genetic evidence that they are very distantly related, but the humans and mice are much more closely related because they belong to the same super family, and their connection is much more recent.
The fossil record
This supports Darwin's theory of evolution, which states that simple life forms gradually evolved into more complex ones. Evidence for early forms of life comes from fossils. By studying fossils, scientists can learn how much (or how little) organisms have changed as life developed on Earth.There are gaps in the fossil record because many early forms of life were soft-bodied, which means that they have left few traces behind. What traces there were may have been destroyed by geological activity. This is why scientists cannot be certain about how life began.
Fossils provide a snap shot of the past and allow us to study how much or how little organisms have changed as life developed on Earth.
300 Identified and confirmed with the exception of 200 that still need to be evaluated.