They find shells that other crabs have left behind and use them
The study pushes back the clock on the origin of Earth's water by hundreds of millions of years, to around 4.6 billion years ago, when all the worlds of the inner solar system were still forming. Scientists had suspected that our planet formed dry, with high-energy impacts creating a molten surface on the infant Earth.
Answer: 4.6 billion years.
Answer:
Originally, the distinction was based on morphological differences. However, it soon became that some types of organisms had different forms at various stages in their lives, here is why
Explanation:
changed genes is passed on to the next generation. Most mutations are bad, but some of them make the organism more successful in its life. Organisms that inherit that favorable new gene are likely to become more abundant than others of the species. (geologic times)