I believe it's aerobic exercise.
Some individuals are more likely to survive and reproduce than others because they are fit and easily adapting. This idea is called 'survival of the fittest'.
The precambrian era makes up about 90% of the earths history, but there was little to no living organisms at the time other than microscopic ones. The first eukaryotes were found in the cambrian period after the precambrian period, not only that but at the end of the precambrian era in the Proterozoic era there was a mass extinction of about 70-80% of all living organisms
B. subcutaneous skin layer
Mid ocean ridges occur where two tectonic plates diverge or move away from each other. This separation occurs under the ocean.The Mid-Atlantic Ridge is such an example and is where the North and South American plates pull away from the Eurasian and African plates. Mid ocean ridges are usually a combination of divergent and transform plate boundaries. At transform boundaries plates slide past each other in opposite directions.