What are the physical properties of the intertidal zone that make it an extreme environment for the animals that inhabit it?

What causes darkening of the skin as melanin production increases

Which of the following statements most accurately describes convergent evolution? the process in which two similar species evolve separately from each other and share similar characteristics the process in which a single species evolves into two or more new species the process in which two entirely different species evolve in response to each other the process in which two different species evolve separately from each other but still share similar characteristics

What enzyme is most important for dna replication and why?