In producing waste, there must be a stable environment in which you can place the waste. For example, if the waste contains radio active isotopes, then you cannot simply throw it into a landfill, as it can contaminate the lands surrounding with water run-off and agents travelling through (such as animals, humans, etc). The waste also needs to be eliminated with relative ease as to not strain the actual production. For example, there has been suggestion to eliminate radioactive material by shipping it to space. However, it is extremely limited and expensive, and was not taken up. This shows that while there are ways to eliminate dangerous substances created through technological advances, it does not mean it is cost-effective or simple enough to use full-scale.
Explanation: they provide them shelter because the rock acts as a media(surface) in which glue to hold or stick to organism. The glue been secreted by seeweed is an adaptation(survival) mechanism they have to Rocky intertidal
Birds and butterflies don't have a common ancestor because one is a member of a insect and the other is well a bird. They both have different body structure. One has bones and the other has an exoskeleton. hope this helps
