"T he apparent contradiction between the lack of evidence for extraterrestrial civilizations and various high estimates for their probability leads to a paradox called the Fermi paradox .." Our home earth is believed to be 4.543 billion years old. As of now, we have an existence of about 8.7 million species of plants and animals. According to demographics world, the population of human beings estimates to 7,800,000,000 as of March 2020. It took over 2 million years of human prehistory and history for the world's population to reach 1 billion, and only 200 years more to reach 7 billion. Human history has always remained a mystery even today. Wikipedia says: "Genetic measurements indicate that the ape lineage which would lead to Homo sapiens diverged from the lineage that would lead to chimpanzees and bonobos, the closest living relatives of modern humans, around 4.6 to 6.2 million years ago. Anatomically modern humans arose in Africa about 30...
