BIO-8 Lecture Notes - Lecture 3: Statistical Unit, Marine Snow, Statistical Hypothesis Testing
Document Summary
In early 1800s: scientists thought deep ocean waters were devoid of life. Sunlight could not penetrate beyond 275 m and they thought if no sunlight, no photosynthesis and with no photosynthesis there would be no plants or algae. Cold temps and pressure also can cause absence of deep-sea life. But dragged a large, open sided, heavy box that was suspended from ropes behind the hms challenger ship found 5,000 previously unknown species. Marine snow: tiny particles produced by death and decomposition of organisms living in the surface waters of the ocean (dead whales) -> provided energy. Hydrothermal vents (extremely hot water with high conc. of sulfur compounds and other mineral nutrients) around these vents were a great diversity of deep- sea species. These animals are consumed by other larger animals such as fish. Hypotheses: ideas that potentially explain a repeated observation. Proximate hypotheses: address the cause of immediate changes in the individual phenotypes or interactions.
