Evolutionary History 3.3 (3/11) Exit Ticket

All species have their own specific body structures, so it is a coincidence that the octopus and surf clam each happen to have mantle structures that are different.

The octopus and surf clam are different species, so they do not share an ancestor population. These species had separate ancestor populations, and each evolved a mantle that helps it survive in its environment.

It is impossible to explain the body structures of different species. The way that structures change over time is very complex, and no one has ever observed these changes occurring.

The octopus and surf clam both inherited the mantle structure from a shared ancestor population, but this population separated into different environments. In each environment, different types of mantle evolved, which helped the populations survive.