English to Arabic Science Genealogy Theory of Evolution

How would link "with an instant split" to the previous clause/sentence: "And it isn’t to say that the dividing line between species is sharp and distinct with an instant split from a common ancestor into a distinct species."

Context:

Common ancestry isn’t just based on fossil evidence; it’s also based on genetic evidence. And it isn’t to say that the dividing line between species is sharp and distinct with an instant split from a common ancestor into a distinct species. This occurs over thousands and thousands of years.