Skeletons: The Frame of Life pdf

Jan Zalasiewicz, professor of paleobiology at the University of Leicester, delves into the Anthropocene. Jan Zalasiewicz is Professor of Palaeobiology at the University of Leicester, UK. In early career he was a field geologist and palaeontologist at the British Geological Survey, working to decipher the strata of eastern England and then the mountains of central Wales. Now, he teaches geology and Earth history to undergraduate and postgraduate students, and studies fossil ecosystems and environments across over half a billion years of geological time. Over the last few years he has been involved in helping develop ideas on the Anthropocene, the concept that humans now drive much geology on the surface of Earth, and chairs the Anthropocene Working Group of the Intrnational Commission on Stratigraphy.

Skeletons: The Frame of Life pdf by Jan Zalasiewicz

Over half a billion years ago life on earth took an incredible step in evolution, when animals learned to build skeletons. Using many different materials, from calcium carbonate and phosphate, and even silica, to make shell and bone, they started creating the support structures that are now critical to most living forms, providing rigidity and strength. Manifesting in a vast variety of forms, they provided the framework for sophisticated networks of life that fashioned the evolution of Earth's oceans, land, and atmosphere. Within a few tens of millions of years, all of the major types of skeleton had appeared. Skeletons enabled an unprecedented array of bodies to evolve, from the tiniest seed shrimp to the gigantic dinosaurs and blue whales. The earliest bacterial colonies constructed large rigid structures - stromatolites - built up by trapping layers of sediment, while the mega-skeleton that is the Great Barrier Reef is big enough to be visible from space. The skeletons of millions of coccolithophores that lived in the shallow seas of the Mesozoic built the white cliffs of Dover. These, and insects, put their scaffolding on the outside, as an exoskeleton, while vertebrates have endoskeletons. Plants use tubes of dead tissue for rigidity and transport of liquids - which in the case of tall trees need to be strong enough to extend 100 m or more from the ground. Others simply stitch together a coating from mineral grains on the seabed. In Skeletons, Jan Zalasiewicz and Mark Williams explore the incredible variety of the skeleton innovations that have enabled life to expand into a wide range of niches and lifestyles on the planet. Discussing the impact of climate change, which puts the formation of some kinds of skeleton at risk, they also consider future skeletons, including the possibility that we might increasingly incorporate metal and plastic elements into our own, as well as the possible materials for skeleton building on other planets. Table of contents :