EVERYDAY SCIENCE

Detailed explanation-1: -The earliest life forms we know of were microscopic organisms (microbes) that left signals of their presence in rocks about 3.7 billion years old.

Detailed explanation-2: -Mineral-laden water emerging from a hydrothermal vent on the Niua underwater volcano in the Lau Basin, southwest Pacific Ocean. The microorganisms that live near such plumes have led some scientists to suggest them as the birthplaces of Earth’s first life forms.

Detailed explanation-3: -Among the oldest known fossils are those found in the Fig Tree Chert from the Transvaal, dated over three billion years ago. These organisms have been identified as bacteria, including oxygenic photosynthetic bacteria (cyanobacteria)-i.e., prokaryotes rather than eukaryotes.

Detailed explanation-4: -Carbon analysis detects three kinds of microbes in ancient Australian rocks. In 1992, researchers discovered evidence of what was then potentially the earliest life on Earth: 3.5-billion-year-old microscopic squiggles encased in Australian rocks.

Detailed explanation-5: -Many scientists believe that RNA, or something similar to RNA, was the first molecule on Earth to self-replicate and begin the process of evolution that led to more advanced forms of life, including human beings.