Answer:
Evolution is the <u>biological process</u> that happens over time in a population, giving rise to new <u>species.</u> The theory of evolution states that all organisms alive on Earth today <u>have a common ancestor</u> which lived <u>years ago</u>.
Explanation:
Evolution is one of the fundamental reason of diverse life on Earth today. Principally, this process takes place by changes in genetic elements via mutations and crossing-over. The positive changes (mutations) allow the organism to develop better condition in order to survive in changing environmment. However, if the changes takes place at major scale, it also leads to the creation/development of new species. To explain this further, I have added a photograph where we can see how different organisms were evolved in the history of Earth.
In the case of liquid droplets, including water, surface tension is the factor, which is accountable for their shapes and configuration. Though can easily be malformed, the droplets of water seem to be pulled into a spherical shape due to the cohesive forces of the surface layer.
In the non-existence of other forces, involving gravity, the drops of almost all the liquids would be almost spherical.
The answer is fusion of gametes via fertilization.