How Life BeganEvolution's Three Geneses

How Life BeganEvolution's Three Geneses

Alexandre Meinesz

Print publication date: 2013

ISBN: 9780226519319

Publisher: University of Chicago Press

Abstract

The origin of life is a hotly debated topic. The Christian Bible states that God created the heavens and the Earth, all in about seven days roughly six thousand years ago. This episode in Genesis departs markedly from scientific theories developed over the last two centuries, which hold that life appeared on Earth about 3.5 billion years ago in the form of bacteria, followed by unicellular organisms half a millennia later. It is this version of genesis that is explored in this tale of life's origins and evolution. It elucidates three origins, or geneses, of life—bacteria, nucleated cells, and multicellular organisms—and shows how evolution has sculpted life to its current biodiversity through four main events—mutation, recombination, natural selection, and geologic cataclysm. As an ecologist who specializes in algae, the first organisms to colonize Earth, the author brings a novel voice to the history of biodiversity and emphasizes here the role of unions in organizing life. For example, the ingestion of some bacteria by other bacteria led to mitochondria that characterize animal and plant cells, and the chloroplasts of plant cells. As the author recounts, life's grandeur is a result of an evolutionary tendency toward sociality and solidarity. He suggests that it is our cohesion and collaboration that allows us to solve the environmental problems arising in the decades and centuries to come. The book is rooted in the science of evolution but enlivened with many illustrations from other disciplines and the arts.