How do surface colonies differ from deep or buried colonies?

• Respiratory Differences.

Essentially, the most basic difference is between oxygen tolerant and aerobic bacteria growing on top of the surface whilst the anaerobic bacteria colonizes the deeper areas.

Extremophile bacteria growing deep beneath the Earth or around the black smokers of the deep ocean ridge do not necessarily use oxygen or even consume what would be considered normal nutrients, breaking down sulphur compounds instead.

The black smoker bacteria have an extraordinary resistance to heat and pressure, as their origin suggests. Deep dwelling bacteria (and recently discovered nematode worms) live far underground: They are found in certain rock strata in the deepest diamond mines of South Africa, for example. They exist by breaking down compounds in the rocks.

There is considerable argument and theory about how the oxygen utilizing bacteria (the aerobics bacteria) actually evolved. The initial production of oxygen on Earth deep in its prehistory would have resulted in a gas that was highly toxic to most of the anaerobic bacteria that formed the majority of the biome and the time.

• Resources strategies: Differences between colonies.

Stromalites are a good example of a surface colony, and they are also believed to be the direct cause of large amounts of oxygen being released into the atmosphere. These use photosynthesis to break down carbon dioxide, making sugars as food.

Their access to the sunlight depends on them remaining as surface dwelling colonies; without the sunlight, they would die. Stromalites are found in the coastal waters of Australia.

Clearly, the use of resources will determine where a colony grows. Stromalites need sunlight and access to carbon dioxide, deep dwelling bacteria need sulphur compounds or minerals in the rocks they live in; in evolutionary terms they have adapted to use these, and in the process exploited environments that other creatures cannot even access.