Answer:
Due to presence at early days of the planet.
Explanation:
We only find the remains of single celled organisms in the oldest fossils because the single celled organisms are the organisms that were present in the early days of this planet. These single celled microbes were present about 3.7 billion years ago while on the other hand, the oldest rocks are only a little older i. e. 3.8 billion years so these single celled organisms are considered as oldest fossils on this planet.
The Sun is the main cause for our weather, and different season (in different areas where you live it depends on how hot or cold it is also caused by the sun)
Most seasons, like in summer it's hot Also caused by the sun, in winter it snows because the sun is in a different location.
What was the investigation? But from my best guess I'm assuming it's the second option. This may be incorrect.
The remains are called fossils. Fossils are remnants of animals, plants, or microorganisms that have been solidified in the process of fossilization, where the organism is surrounded by sediment, minerals, and other solid objects which are compressed and heated around the organism over time. This forms a solid mass with the preserved organism inside, other known as a fossil.
