Relics: Travels in Nature’s Time Machine
What would you rather save from extinction: 3 different species of parrots, or a hummingbird, an owl, and a parrot? With an increasing frequency, such heartbreaking choices are becoming the reality of nature conservation. Given their limited resources, and the even more limited attention span of politicians and governments, conservation biologists face the need to select targets of their conservation campaigns very carefully. Traditionally, conservation actions have focused on areas that sheltered the highest numbers of species. But now biologists are shifting their priorities away from simple species richness towards what is known as the phyletic diversity, or deep genetic divides among organisms. Rather than trying to protect every single species on Earth, they try to save representatives of as many distinct and diverse evolutionary lines as possible. And the easiest way to find phyletic diversity is to look at the survivors of the oldest lineages of life.
In my recent book “Relics: Travels in Nature’s Time Machine”, the result of several years of globetrotting and many nasty tropical diseases, I put a spotlight on some of the most remarkable, but often little known and underappreciated survivors from the long gone eras. These animals and plants are sometimes the last living relatives of groups that dominated our planet’s ecosystems millions of years ago, giving us a glimpse of what life might have been like in those strange days known as the Paleozoic and Mesozoic.
What drove horseshoe crabs, relics of a lineage that blossomed in the Carboniferous, to leave the ocean every spring and lay trillions of eggs on the sandy beaches of Delaware Bay? Why are cycads, plants that thrived in the Mesozoic, full of toxins so powerful that they will alter your DNA if ingested? What did the first proto-crickets sound like? We are incredibly lucky to be able to try to answer these questions by studying the last living members of these ancient lineages. Some of them are still around because of their unparalleled resilience and adaptability, having weathered countless changes to Earth’s climate and topography. Others have managed to outlive their then contemporaries by exploring niches created by newly evolved, more advanced groups of organisms. Still others owe their survival to sheer luck of complete isolation from the rest of the world, following a breakup of ancient continental landmasses.
But individual species and lineages are not the only relics that still grace the surface of our ancient planet. Entire habitats and ecosystems are sometimes survivors of long-gone conditions, and frequently they shelter unique assemblages of species that can be found nowhere else. They are sanctuaries of biodiversity and, increasingly, sanctuaries of life as it appeared before our kind left the African savannas and spilled over the globe, altering and wiping out countless biological communities and species. Like the organismal relics, these sanctuaries of life must be the first to be considered for preservation and protection from development.