HEADLINE: Life on Land Collaboration: Devonian Mycorrhizae and Silurian Deep-Sea Vents BOOK TITLE: Other Lands, A Journey Through Earth's Extinct Worlds GUEST AUTHOR NAME: Thomas Halliday 200-WORD SUM

HEADLINE: Life on Land Collaboration: Devonian Mycorrhizae and Silurian Deep-Sea Vents BOOK TITLE: Other Lands, A Journey Through Earth's Extinct Worlds GUEST AUTHOR NAME: Thomas Halliday 200-WORD SUMMARY: This source details the move of life onto land and the origins of ecosystems. In the Devonian(407 million years ago), life thrived through collaboration, notably the crucial partnership of Mycorrhizae (fungi and roots). This collaboration was essential for plants to develop roots and extract mineral resources from rocks, while the fungi gained energy from plant photosynthesis. Evidence from Rynie, Scotland—a Yellowstone-like ecosystem with hot springs—shows detailed preservation of these interactions. The largest organism on land at this time was Prototaxites, a lichen structure that grew up to 9 meters tall. Arthropods, such as the freshwater shrimp Rhyniella, were among the first animals to inhabit the land. The conversation shifts to the Silurian (435 million years ago) and the deep ocean. The site of Yaman-Kassie is the earliest known fossilized hydrothermal vent with organisms living on it. These deep-sea vents support life via a chemical-based food chain independent of light. Halliday references the major hypothesis that life itself originated at similar deep alkaline vents, based on replicable chemistry that naturally creates the necessary hydrogen ion gradients. The segment concludes with the Ordovician mass extinction (444 million years ago), the first of the "big five" mass extinctions, which was caused by global cooling followed by rapid warming, stressing marine life with a high rate of climate change.