Explain the origin and importance of the buildup of free oxygen in the atmosphere for the evolution of animal life.

Prior to the buildup of oxygen, organisms were mainly anaerobic and used mechanisms where no oxygen was present or needed. Once the buildup of oxygen starting occurring, organisms were forced to either evolve to survive or they would die off due to the presence of oxygen. The organisms needed to evolve so that they could use and benefit from the abundance of oxygen. The presence of oxygen is a huge evolutionary milestone that kick started the evolution of many new species. Organisms began to metabolize and perform all of its functions with oxygen present.

Prior to the buildup of oxygen, organisms were mainly anaerobic and used mechanisms where no oxygen was present or needed. Once the buildup of oxygen starting occurring, organisms were forced to either evolve to survive or they would die off due to the presence of oxygen. The organisms needed to evolve so that they could use and benefit from the abundance of oxygen. The presence of oxygen is a huge evolutionary milestone that kick started the evolution of many new species. Organisms began to metabolize and perform all of its functions with oxygen present.

Explanation:

you must remain stopped until the stop signal is retracted and the red lights are turned off. approaching traffic in the opposite roadway of a divided highway shall not be required to stop, even if the school bus has the stop-arm extended and the alternately flashing warning signal lamps on.

lizards have adapted to life in the desert. some desert lizards have toes with spiny scales to them run across the sand without sinking. some use the sand to hide from predators, or to search for small animals that they prey upon.