But these mutations are organized, in a way. For example, let's say that 10,000 years after the most recent common ancestor, one of the mtDNA branches experienced a mutation. From that point on, that line of mtDNA would include that alteration. Another branch might experience a mutation in a different location. This alteration would also be passed on.
The pelagic zone can be contrasted with the benthic and demersal zones at the bottom of the sea. The benthic zone is the ecological region at the very bottom of the sea. It includes the sediment surface and some subsurface layers.Marine organisms living in this zone, such as clams and crabs, are called benthos.epending on the depth, the water column, rather like the Earth's atmosphere, can be divided into different layers. The pelagic zone occupies 1,330 million km 3 (320 million mi 3) with a mean depth of 3.68 km (2.29 mi) and maximum depth of 11 km (6.8 mi).
The Pelagic Zone. The word pelagic is derived from the Greek work pelagos, pÃ©lagos meaning open. Ocean it is the name for oceanic water not in direct contact with a shore or the. Bottom it is by far the largest aquatic biome terms of, volume but in comparison to many of the other, biomes it is a. deserthe pelagic zone is further divided up into vertical sub-zones as seen in the image below. This biome vertically joins with the Deep Sea biome once the illuminated surface layers are passed. For more information on the deeper pelagic waters, please also visit our deep sea biome page.