The Monkey’s Bridge

The Monkey’s Bridge: Mysteries of Evolution in Central America, David Raines Wallace, Sierra Club Books, 1997 (paperback 1999), 277pp, ISBN 1-57805-018-9

The Monkey’s Bridge is a New York Times notable book; in my experience this is a good recommendation.

This book is about Central America, its geography, its flora and fauna, its paleontological and evolutionary past, its history, and the peoples who live there. It is also very much about David Wallace being in Central America.

It is an odd sort of book. An ordinary work of exposition, a text or a treatise, is usually hierarchically structured and is written in the impersonal didactic voice. Naturalists, perhaps, write more personal books. Wallace writes a combination of a travel book – I went here and I did that – and exposition. It reads well but there are no maps. One feels the need for maps with which to match the abundance of place names.

Central America is a fascinating part of the world because it is a land bridge with an incredibly varied geology. The ecologies of the region reflect both the continuing migrations into and through the area from North and South America and the continually changing geography. Indeed, Central America has a surplus of geography concentrated in a small part of the world.

Central America came into being some three million years ago as a land bridge between South America and North America. Its birth was geologically violent and its history has continued to be geologically violent. South American species migrated North and North American species migrated South. Some species passed all the way through and others stopped in Central America.

During the past three million years the climate and the ecological regimes in both South and North America have varied widely. Central American life ecologies are a mosaic of species from the two continents. Some species are remnants from a North American rain forest that ceased to exist long ago. Migration paths varied. There are lands now drowned which were once major migration paths and rich fossil beds under a hundred feet of Caribbean water. Rain forests came and went, serving as barriers to migration whilst they were present.

Wallace mixes in a good deal of history into his exposition in a haphazard sort of way. He shines a spotlight on interesting events that happened in places that he happened to visit. He really records two visits. The first was in the early seventies when he was doing the hippy Wanderjahr thing. The second was much later when he had a solid career as a naturalist and conservationist under his belt.

Central America presents unique challenges to the conservationist. The usual activity of the conservationist is to protect a region from change. The normal state of Central America is geological and biological change; species are always on the move through the region. There is no fixed past to preserve.

It is a good book. The reader is left with a strong sense of the variety of landscape and life. I do wish, however, that he had included maps.