Fig. 1.5. OLP 4. Tubeworms, anemones, and mussels colonize near a low-temperature hydrothermal vent. Early life forms on earth may have evolved near hydrothermal vents like this one 3.5 billion years ago.
Image courtesy of National Oceanic and Atmospheric Administration (NOAA) Ocean Explorer
Life started in the ocean. The millions of different species of organisms on Earth today are related by descent from common ancestors that evolved in the ocean (Fig. 1.5). The accumulation of oxygen in Earth’s atmosphere through photosynthesis was necessary for life to develop and be sustained on land.
<p>Most of the oxygen in the atmosphere originally came from the activities of photosynthetic organisms in the ocean. This accumulation of oxygen in Earth’s atmosphere was necessary for life to develop and be sustained on land.</p>
OLP 4.A
Most of the oxygen in the atmosphere originally came from the activities of photosynthetic organisms in the ocean. This accumulation of oxygen in Earth’s atmosphere was necessary for life to develop and be sustained on land.
OLP 4.A
