What evidence is there that oxygen levels in the sea increased due to photosynthetic bacteria?(1 point) Responses rust deposits in the ancient ocean rust deposits in the ancient ocean decreases in anaerobic organisms decreases in anaerobic organisms rust deposits in today’s ocean rust deposits in today’s ocean global cooling
The evidence that oxygen levels in the sea increased due to photosynthetic bacteria includes:
- Rust deposits in the ancient ocean: Iron deposits, commonly known as banded iron formations, can be found in ancient ocean sediments. These formations suggest that there was an abundance of dissolved iron in the ancient ocean, which is consistent with higher oxygen levels resulting from photosynthetic bacteria producing oxygen as a byproduct of photosynthesis.
- Decreases in anaerobic organisms: Anaerobic organisms are organisms that can survive without oxygen. As oxygen levels increased in the sea, anaerobic organisms would have faced a less suitable environment, causing their population to decline. The decrease in anaerobic organisms is an indirect indication of increased oxygen levels due to the activity of photosynthetic bacteria.
- Rust deposits in today's ocean: Similar to ancient ocean sediments, modern ocean floors also contain rust deposits, indicating the presence of dissolved iron. The presence of these iron deposits suggests ongoing oxygen production by photosynthetic bacteria, leading to increased oxygen levels in the sea.
- Global cooling: The presence of photosynthetic bacteria and the subsequent increase in oxygen levels in the sea can be linked to global climate changes. As photosynthetic bacteria remove carbon dioxide from the atmosphere during photosynthesis and release oxygen, the overall greenhouse effect decreases, leading to a cooling effect. This cooling effect can be observed in climate records, suggesting a relationship between photosynthetic bacteria and changes in global temperatures.