The Ghosts of Evolution Nonsensical Fruit, Missing Partners, and Other Ecological Anachronisms

by Connie Barlow

Book Overview

A new vision is sweeping through ecological science: The dense web of dependencies that makes up an ecosystem has gained an added dimension-the dimension of time. Every field, forest, and park is full of living organisms adapted for relationships with creatures that are now extinct. In a vivid narrative, Connie Barlow shows how the idea of "missing partners" in nature evolved from isolated, curious examples into an idea that is transforming how ecologists...

• Format: Paperback
• Language: English
• ISBN: 0465005527
• ISBN13: 9780465005529
• Release Date: March 2002
• Publisher: Basic Books
• Length: 304 Pages
• Weight: 1.15 lbs.
• Dimensions: 0.8" x 5.9" x 9.0"

Customer Reviews

Who mourns for the mastodons?

"The tusks that clashed in mighty brawlsOf mastodons, are billiard balls..." --from a poem by Arthur GuitermanThe exciting idea in this book is that there are trees that "lament" the passing of the mastodons and the other extinct megafauna that once distributed their seeds. What animal now regularly eats the avocado whole, swallows the seed and excretes it far from the tree in a steamy, nourishing pile of dung? No such animal exists in the Western Hemisphere to which the avocado is native. (Barlow reports that elephants in Africa, where the avocado has been introduced, eat the avocado and do indeed excrete its pit whole.)How about the mango with its pulp that adheres so tightly to the rather large pit? As Barlow surmises, such fruits were "designed" for mutualists that would take the fruit whole and let the pit pass through their digestive systems to emerge intact for germination away from the mother tree. Note that the avocado pit is not only too large to pass comfortably through the digestive system of any current native animal of the Americas, but is also highly toxic so that such an animal would have quickly learned not to chew it. Note too that the mango pit is extremely hard, thus encouraging a large animal to swallow it along with the closely adhering pulp rather than try to chew it or spit it out. Consider also the papaya. The fruit are large and soft so that a large animal could easily take one into its mouth and just mash it lightly and swallow. Note too that the fruits of the papaya tree grow not high in the tree, nor is the tree a low lying bush. Instead the tree is taller than a bush but its fruits are clustered at a height supermarket convenient for a large animal to pluck.Barlow considers a number of other trees, the honey locust and the osage orange, for example, as examples of ecological anachronisms, trees that have out-lived their mutualists and consequently must form new partnerships with other seed distributors or face extinction. For those trees that have pleased humans, the avocado, the mango, the papaya, etc., there is no immediate danger, but some other trees are at the edge of extinction. Their fruits fall to the ground and stay there until they rot. New trees grow only down hill when an occasional flood of water moves their fruit to a new location. Barlow also sees ghosts from the Mesozoic era. She writes, "Ghosts of dinosaurs are easy to conjure in October and November wherever city landscapers planted ginkgo trees...even when I forget to look for the ghosts of dinosaurs my nose alerts me to their presence. Only a carrion eater could find the odor of fallen ginkgo fruit appealing. Before beginning this book, I wrongly blamed the alcoholic homeless for the vomitlike stench in Washington Square Park." (p. 12)In short this book is about those trees--anachronisms--have been without their mutualists since the mass extinction of the megafauna of the Western Hemisphere that took place about 13,0

The most important ecology book of 2001, but...

This splendid addition to the popular scientific literature is almost as insightful and as well written as David Quammen's "Song of the Dodo". A fine overview of Dr. Paul Martin's and Dr. Daniel Janzen's pioneering work on "ecological anachronisms" in New World plants, it should be read by ecologists and evolutionary biologists, as well as the scientfically interested public. Connie Barlow has made an important contribution to Martin's and Janzen's ideas by distinguishing relative degrees of ecological anachronisms. Yet her book does contain some serious omissions and factual errors which I shall note later. Let me first sing its praises. Connie Barlow's overview of "ecological anachronisms" is absolutely superb. She has a tremendous eye for detail, but never gets completely bogged down by it. Instead, much of what she writes is replete with insightful humor. She opens with an excellent history of Martin's and Janzen's work. Her vivid writing is a wonderful synthesis of science, natural history and biography all thrown in for good measure. I suspect historians of science interested in ecology and evolutionary biology will turn to this book as a primary reference on "ecological anachronisms". Readers will find compelling Connie Barlow's descriptions of Paul Martin and Daniel Janzen. She treats them as a dynamic pair passionate about their unique insights into ecology and other aspects of evolutionary biology. They will also find compelling her attempts at scientific research. I suspect they will chuckle as much I did while reading about her experiments on "ecological anachronisms" in the wilds of New Mexico and the urban jungle that is New York City. Having sung some praises, let me point out some flaws. Robert MacArthur, the greatest ecologist of the late 20th Century, is tossing in his grave, hearing from Connie Barlow that evolutionary ecology is a new science. At the time of his death in 1972, he recognized the importance of history - or rather, "deep time" - in understanding ecological patterns. Indeed, he covers evolutionary ecology in the final chapter of his text "Geographical Ecology", an elegant synthesis and literary epitaph to his career. One of MacArthur's former graduate students, Dr. Michael Rosenzweig, a colleague of Paul Martin's at the University of Arizona, has looked upon paleontology as the source of interesting questions relevant to ecology which many ecologists don't have training, interest, or time to pursue. His interest has spanned decades, culminating in his "incumbent replacement" hypothesis on the role of adaptation in promoting "evolutionary success" in clades (groups of related species that share a common ancestor) that was published in 1991 in the scientific journal Paleobiology. "Devolution" is a scientifically inaccurate term which Connie Barlow mentions several times, most notably on pages 220-221. What she describes as devolution sounds a lot like neoteny to me. In neoteny, juvenile features are retained by

The Mystery of the Overbuilt Species

As is often the case in my morning carpool to Kansas City, passions ran high when I raised the topic of megafaunal dispersal. George was at the wheel, I was riding shotgun, and Bob and Stan were scrunched up in the back of George's old Honda Accord. I was, to the best of my ability, explaining the arguments in Connie Barlow's new book about extinct seed dispersal partners: The Ghosts of Evolution. Connie asserts (along with veteran paleobiolists Paul Martin and Dan Janzen), that certain largish animals had big enough gullets to swallow fruits like Osage oranges whole and then poop out the seeds several miles away, thus expanding the plant's territory in the next generation. Unfortunately, nobody provides this service for Osage oranges anymore, which is why they all lie around rotting within a few yards of the mother tree every autumn. In an attempt to confirm that a creature like a mastodon would willingly eat Osage oranges, Martin and Barlow persuaded the director of the Brookfield Zoo in Chicago to offer the fruit (scientific name maclura pomifera) to three of the zoo's elephants. "Affie, the matriarch of the Brookfield elephants, did eat maclura--but just the first fruit she was offered. After that, she showed no interest in any more. The reactions of the other elephants were strongly negative. One wasn't even willing to smell the fruit when the offer was first made. Finally, she took it from her keeper and hurled it down the hall. The second elephant did the same thing but aimed for the public area." I can't say that I blame them. As a child, I was under the impression that Osage oranges (or hedge apples) were poisonous.Zoo elephants' finickiness notwithstanding, the book argues that some species are obviously "overbuilt" for the ecological niche they inhabit today. Why would natural selection lead to such an outcome? For example, pronghorns can run not just a little faster but way the hell faster than any of their nearest predators (wolves and coyotes). This speed is apparently a relic of days when something faster than wolves or coyotes were chasing pronghorns, possibly a New World cheetah that became extinct thirteen thousand years ago. Well, you may ask, why haven't the pronghorns slowed down and devoted their evolutionary energy to something more productive, like jumping barbwire fences? More generally, what is a believable schedule on which a species reacts to changes in its environment?As Connie Barlow analyzes the results of experiments with the exotic fruits and seeds in her New York apartment kitchen, she writes with delight and authority. She teaches us technical and colorful terms such as seed predator and pulp thief. The former destroys seeds by eating them rather than by defecating them intact. The latter eats the flesh around the seed and discards the seed without transporting it to a promising new sprouting site. We humans are guilty of both depredations, although with our compost heaps we have introduced a modest new dispe

An amazing and juicy ghost story full of fruit and animals

E. O. Wilson writes, "Our species and its way of thinking are a product of evolution, not the purpose of evolution." Connie Barlow's "The Ghosts of Evolution" is an eloquent gift to all of us who yearn to discover more about the great adventure that is the evolutionary saga. The mystery at the center her book connects the reader in a profound way to the unfurling of evolution, to extinction, and to those who "remember" in their limbs and organs ancient relationships with beings long departed. Be ready for a whirlwind ride that will transform the most familiar and mundane details of our present world and plunge you into a Pleistocene universe where rhinos and camels roam ancient American deserts, giant 20-foot ground sloths lumber with gaping mouths toward tropical fruits, and mammoths and mastodonts rumble among themselves while browsing in the avocado trees and crunching honey locust pods against their enormous teeth. With some help from the author, we are quickly seeing evidence of this continent as it was before history, before humans, when the trees evolved to disperse their young through the bowels of their partners, the giant mammals, reptiles, dinosaurs, and birds. This was a world of creatures with gapes large enough to take in an entire fruit, swallow the pit intact, and plant it amid a steamy pile of fertilizer. While we no longer live among those giants, we are sojourners among their partners, the "anachronistic" plants, trees, and fruits that recall a world that, from our human perspective, ceased to exist between ten and twenty thousand years ago. As Barlow tells the story, "An avocado sitting in a bin at the grocery store is thus biology in a time warp. It is suited for a world that no longer exists. The fruit of the avocado is an ecological anachronism. Its missing partners are the ghosts of evolution." The "ghosts" from our past haunt the pages of Barlow's book and eventually drift into our modern world. Her book has crept into my head and now follows me down the grocery aisles, resurrecting enormous megafaunal ghosts who stalk the avocadoes and papaya bins. Who was Honey Locust seducing when she wrapped her seeds in foot and a half long pods dangling from the tops of her lacy limbs? No one who is here today, that's for sure! And so Honey Locust waits for a ghost, probably the elephant doomed by our ancestors at the end of the last Ice Age. "The Ghosts of Evolution" is a science book that explores the new field of evolutionary study surrounding surviving anachronisms and extinct creatures. For a nonscientist such as myself, there is an enormous amount of information about the ways in which plants and animals interact to produce new generations. The book is also full of stories about the scientists themselves and the studies that have produced this knowledge. The stories are told with undaunted enthusiasm, a persistently inquisitive spirit, and a wonderfully eccentric sense of humor. As e-mails and counter-arguments sho

Don't read this book while cooking

I burned three pieces of French toast while browsing around in Ghosts of Evolution. If the statement "Connie Barlow eats hedge apples" appeared on the wall of the men's room at the Field Museum of Natural History, I would normally have dismissed it as a tasteless slur on a slow graffiti day. But because I have actually read the book, I knew the shocking truth. Connie actually has chewed on the pulp of the Osage orange and lived to tell about it. In fact, she gamely asserts that something way too big to fit into the men's room routinely chowed down on these fruits (and many others) back in the Pleistocene period: American mastodons. And just to bring the point home, on page 183 she shows us a picture of an Osage orange fruit resting on the molar of Mammut americanum. It looks like a mere gum ball on that humongous jaw.So what, you say. Who cares? People who want to know the truth. People who stop talking on their cell phones long enough to look at a honey locust pod and not see something boring or annoying that needs to be cleaned up, but instead a naturally-posed puzzle that is more exasperrating than "White to move and mate in three moves" in a chess column. "I'm here," the pod is saying, "but why? My seeds are so tough that ants and birds don't give them a second look. The seeds won't even germinate unless they have been vigorously scratched up. And yet I manufacture a honey in the pod that would be a great meal for a hungry animal." What's missing in this picture? Connie Barlow, reporting on the research of Dan Janzen and Paul Martin, makes a strong case for ghosts, the megafauna that once roamed our landmass but which were wiped out by Guess Who back when there was still a land bridge between Asia and the Americas. I'm still devouring this book and already have friends trying to grab it away from me. I like the fact that it is in first person, and that Connie doesn't write stuffy prose. For example, "We might hope to find a seed in a coprolite, but whose turd is that anyway?" This is science journalism at its best, and it provides my first believable explanation of why hedge apples are so useless.