Prof. Charles Wellman
Department of Animal and Plant Sciences, University of Sheffield
The Earth is an astonishing 4,600 million years old. Life evolved very early in Earth history, possibly as early as 3,500 million years ago, and began to thrive in the oceans. Rather surprisingly, however, for much of Earth history the land surface were essentially barren of life. Even following the Cambrian Explosion of animal life 540-or-so million years ago, when the oceans began to teem with a bewildering diversity of multicellular animals, the land only harboured a simple biota dominated by algae. Eventually a group of green algae acquired the necessary physiological and morphological attributes enabling them to thrive out on the land surface. This momentous step (the evolution of land plants) was one of the most important events in the history of life on Earth, from an evolutionary, ecological and environmental perspective. Once plants had conquered the land they rapidly diversified with increasingly larger areas of the land becoming vegetated by larger and more complex plants associated in increasingly complex terrestrial ecosystems. The new food source and habitats encouraged various animal groups out onto the land (worms, arthropods and eventually tetrapods). But more importantly, plants began to modify the environment of planet Earth. They began their long history of influencing atmospheric composition (and hence weather patterns), rates of weathering/erosion and patterns of sedimentation (in addition to the nature of soil formation). This talk will examine the remarkable story of how plants invaded the land and how they changed it.
MEETING FORMAT: Our speaker talks, uninterrupted for 20 minutes, to introduce his topic. During a break to get drinks, the Hat goes round. Then there is an hour’s chaired question and answer session. Cafe Sci is funded by the Hat (no sponsors). We suggest a contribution £5 (waged) or £2 - £3 (unwaged). Full details here