The correct answer is A. A burst of speciation
Explanation:
Adaptative radiation is part of evolution and occurs when a single organism or species diversify into a wide range of species (speciation), this process is called "adaptative" because the speciation occurs due to changes in the environment that make challenging survival usually due to the reduction of resources available and therefore organisms change to adapt to new conditions. Additionally, in adaptive radiation, the new organisms share traits with their common ancestor but also have different and unique traits. Considering this, it can be concluded adaptative radiation a burst of speciation.
Inbreeding compresses the gene pool, making it more likle for a genetic abbheration to occur.
The correct answer is Oxygen.
The surface of the Earth was liquefied. As the Earth cooled, an atmosphere generated primarily from gases erupted from volcanoes. It constituted methane, hydrogen sulfide, and ten to 200 times as much as carbon dioxide in comparison to today's atmosphere.
It was considered that there was an extreme volcanic activity for the initial billion years of the existence of the Earth. The initial atmosphere was possibly majority carbon dioxide will no or little concentration of oxygen. There were slight quantities of ammonia, water vapor, and methane.