Life on Earth: Diversity and Abundance

Join Paul Broady for this 2 part exploration of life on earth from a remarkably different angle:

Part 1: The diversity of life on Earth. We should celebrate our vastly increased knowledge of life’s amazing diversity whilst remaining humble about our ignorance. All peoples of the Earth have for thousands of years named the different organisms within their immediate experience. The scientific recognition that all organisms are related has developed only within the last couple of centuries.

As new technologies have been applied to the description and classification, and to the knowledge of the evolutionary origins, of this diversity a vast previously hidden world has come into view. This is mostly a microbial world in which numerous major lines of evolution overwhelm the few with which most people are familiar in their daily lives.

But we remain hugely ignorant about the life-styles of much of this microbial diversity. Also, it seems certain that there is far more diversity yet to be discovered including major new groups of organisms.

Part 2: The abundance of life on Earth – do we really know how much? Most people now live in crowded cities and might easily think that humans are the most abundant organism on Earth. How wrong they would be. So what are the most abundant organisms? Where do they live? Are they on the land surface or in the oceans? Or may be somewhere else? How do we even measure “abundance”? After all, there are as many bacteria in a few spoons full of soil as there are humans. It might be easy to estimate the weight of humans on Earth but is it so easy to estimate the weight of bacteria? So how accurate are our measurements of this very fundamental biological characteristic of our planet?