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.
Gradualism is referred to the theory about how fast evolution occurs in this type of species.
<h3>What is
Gradualism?</h3>
This type of evolutionary changes occurs gradually and not in large steps or volume.
This however explains why the species had very little changes for a very long time as a result of the environment being best suited for them.
Read more about Gradualism here brainly.com/question/20463574
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Energy loss is demonstrated more clearly on an energy pyramid than on a food web.
The biome that has over 100 inches of rain each year is the Rainforest. Therefore, the Rainforest has abundant rainfall.
