Timeline of Photosynthesis on Earth
Q. How is evolution both a theory and a fact?
Evolution, in this context, is both a fact and a theory. It is an incontrovertible fact that organisms have changed, or evolved, during the history of life on Earth. And biologists have identified and investigated mechanisms that can explain the major patterns of change.”
Q. What are two types of bacteria that can make you sick?
They reproduce quickly in your body. Many give off chemicals called toxins, which can damage tissue and make you sick. Examples of bacteria that cause infections include Streptococcus, Staphylococcus, and E. coli.
| 4.6 billion years ago | Earth forms |
|---|---|
| 3.4 billion years ago | First photosynthetic bacteria appear |
| 2.7 billion years ago | Cyanobacteria become the first oxygen producers |
| 2.4 – 2.3 billion years ago | Earliest evidence (from rocks) that oxygen was in the atmosphere |
Q. Which comes first oxygen or life?
For the first 2 billion years, most scientists believe very little oxygen was present in the atmosphere or ocean. But about 2.5-2.3 billion years ago, atmospheric oxygen levels first increased. Critical to helping to resolve this debate is pinpointing when atmospheric oxygen levels rose to near modern levels.
Q. When did multicellular life first show up on Earth?
600 million years ago
Q. What came first bacteria or algae?
“They all come so close to each other—phosphate came first, algae came second, animals came third,” Brocks tells Yong. “The algae provided the food and energy source that allowed organisms to become big. I just don’t think an ecosystem with sharks in it would be possible with just bacteria.”
Q. Do humans come from algae?
Surprisingly, the answer comes down to algae. The project’s lead researcher, Associate Professor Jochen Brocks from the Australian National University (ANU), said they discovered an algae explosion 650 million years ago that allowed human and animal life to evolve.
Q. When did the first grass appear on Earth?
55 million years ago
Q. Did grass exist with the dinosaurs?
Some piles of fossilized dinosaur dung in India have revealed a surprising fact: some dinosaurs ate grass. Although grasses are dominant in habitats across the world today, they weren’t thought to exist until some ten million years after the age of dinosaurs had ended.
Q. Which era did dinosaurs exist?
Mesozoic Era
Q. Did grass and dinosaurs coexist?
One of the most common “mistakes” in the prehistoric book is not wrong after all – dinosaurs did eat grass. Textbooks have long taught that grasses did not become common until long after the dinosaurs died at the end of the Cretaceous period, 65 million years ago.
