Hello :)
Question: What is the original source of all genetic variation?
Answer: Mutation
Hope this helps and have a great day!
Id say D
as the tide range may affect at how close to the sea a species can live without being submerged by the tide
length of exposure can determine what species can live on the shore as they may be submerged underwater for different periods of time
wave action can also determine what species can live on rocks as depending on the action it will favour diffrent species
hope that helps
Answer:
They cross over. Hope this helped
