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

by Connie Barlow

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 understand the entire flora and fauna of the Americas. This fascinating book will enrich and deepen the experience of anyone who enjoys a stroll through the woods or even down an urban sidewalk. But this knowledge has a dark side too: Barlow's "ghost stories" teach us that the ripples of biodiversity loss around us now are just the leading edge of what may well become perilous cascades of extinction.

Genres: Science, Nonfiction, Nature, Biology, Evolution, Natural History, History

304 pages, Paperback

First published April 1, 2001

Reviews

[Petra X · Rating 2 out of 5]

Update Giant sloths lumbering around 'distributing' avocado seeds. I've just realised this makes no sense at all. Sloths don't lumber around, they move very slowly upside down in the trees and only go down the trunk to have a shit and back up again. So how did they 'distribute' them?
____________________

I am told I missed the point which was about the disappeared animals that consumed the fruits. I didn't miss it. But the most interesting thing to me was the author saying that evolutionary-plants don't evolve as fast as animals. That was the point I took to write the review on since I didn't see why they needed to.
____________________

I don't always read the introductions, but I did with this book. It was really good and I thought it was going to live up to the title. What the book is about is gigantic fruit like melons or fruits with gigantic seeds like avocados that had evolved to be eaten by mammals far larger than any alive (except elephants and whales, and whales, having gone back to the sea don't eat fruit). So what animals became extinct at the end of the Pleistocene that these fruits were designed for?

Plants evolve far more slowly than animals, says the book, but this isn't necessarily true. It is possible to get wild crosses of plants in a single generation that reproduce, let alone the one's deliberately engineered. Also even though there are no giant sloths picking up ripe avocados and swallowing them whole only to shit out the seed a day or so later where it can grow into another tree, what are the evolutionary pressures on the avocado tree to (slowly) adapt, is what I was asking myself.

There aren't any. Avocados, melons, peaches and the rest are happily being dispersed by present day animals and people. It isn't as if only the smaller fruits able to be swallowed by the sloths we have now are going to prevail as in times past the bigger ones that appealed to the lumbering SUV sized creatures did. Once primates came on the scene, they were happy to eat anything ripe and throw away the seed. Primates have replaced the huge beasts of prehistory, so it's not that the plants adapt slowly, it's that they haven't needed to adapt at all.

This point is not made in the book, but seems obvious to me, arguable though.

The endless, dry, text-book details of the giant fruits, trees and other plants and their extinct, first partners in evolution was too much. I gave up somewhere over half-way through. I think if you are a young, prospective evolutionary biologist this book would be fascinating, but I can't think anyone else would go, 'oh wow, thanks for this, I didn'r really want the latest John Grisham anyway' (or in my case, another book on ants).

[Dan · Rating 4 out of 5]

The Ghosts of Evolution is an account of fruits and their missing seed dispersers.

Ever wonder what eats crazy-looking fruits like the Osage Orange? It could be that nothing living does, that the preferred organism for spreading the seed has been lost to the sands of time. Connie Barlow investigates fruits from around the world and points out the probable ecological anachronisms.

For instance, the avocado seems to be intended to be devoured whole by some megafauna, possible a ground sloth, but no such megafauna exists in its range. Fortunately for some of the tastier species, mankind has taken on the role of seed dispersement but some species aren't so lucky.

The Ghosts of Evolution was one of the more interesting non-fiction books I've ever read. It made me harken back to my pre-teen days of wanting to be a scientist, several years before deciding having friends was more important than being the smartest kid in the room. What was I thinking?

Anyway. The Ghosts of Evolution is a fascinating exploration of the ecosystem and what happens when it gets disrupted. Four out of five stars.

[Aerin · Rating 3 out of 5]

During the later Pleistocene, as humans were inexorably invading nearly every landmass on the planet, a gradual extermination was simultaneously taking place. This mass extinction, the latest in a long line throughout the history of the biosphere, primarily targeted megafauna - from the mastodons and giant sloths of North America, to the woolly mammoths and woolly rhinoceroses of Europe, to the giant lizards and flightless birds of Australia. In most cases, their annihilation shortly followed the arrival of humans, and it is hypothesized that some combination of overkill by human hunters and climate change (that had, in many cases, allowed humans to colonize the area in the first place) led to their demise. (Interestingly, the reason that wild megafauna have survived in Africa, parts of Asia, and virtually nowhere else, is thought to be that humans have been in those areas the longest and actually co-evolved with large animals there.)

In North America, humans began to arrive some 40,000 years ago, and it wasn't long before the native relatives of horses, camels, elephants, and rhinos began to die off. Most native American megafauna have been long gone now for some 10-15,000 years, but their legacy remains in odd places. The botany of the Americas, particularly, bears witness to what Connie Barlow calls "the ghosts of evolution".

It's well known that many plant and animal species have evolved mutually beneficial partnerships. Often plants will attract animals with nutrient-rich fruit, which animals will devour, defecating the seeds intact elsewhere. The animal gets a tasty meal and the plant gets a new start in life for its offspring, far from the malignant shade of the parent. But there are many plant species whose fruits now go uneaten, rotting away on the forest floor, their seeds undispersed. Barlow argues that no plant would expend the energy to evolve a fruit that is destined to rot en masse. No, there are animals who eat these fruits - they just don't exist anymore.

Take the avocado, for instance. This is a medium-sized fruit with a relatively large seed, and it was clearly designed to be swallowed whole. After all, animals with smaller maws (like us) will just eat around the seed, which doesn't help the plant at all. But what animal in the Americas has a mouth and a throat big enough to effortlessly swallow an avocado seed? Well, many do - glyptodonts, toxodons, gomphotheres, ground sloths... but they are all extinct.

Plants take longer to evolve than do animals, and in any case 10,000 years is an eyeblink in evolutionary time. In essence, these plants that evolved in tandem with megafauna have not had time to "notice" that their partners have gone extinct. In some cases, these species have started to adapt to the loss of their primary dispersers; in others, they make do with less effective means of seed dispersal (flood waters, domesticated horses and cows); and in others, they are slowly diminishing and dying away. It's important to recognize these evolutionary "ghosts" if we want to understand, and to save, many of these species.

In this book, Barlow sets out to identify potential evolutionary anachronisms, from extreme examples like the osage orange (no living species is known to eat its toxic fruit) to milder cases that just seem somehow overbuilt for the purposes of any extant partnerships.

Overall, I found the book's premise really interesting, but its execution was fairly dry. Still, it's a topic I hadn't read much about and there were all kinds of little tidbits that made slogging through the boring parts worthwhile. For instance, did you know that ginkgo fruit - which smells like rotting flesh - may have evolved to attract carrion-eating dinosaurs? How cool is that?

[Zan · Rating 4 out of 5]

This is a fascinating book with some occasionally irritating foibles.

The broad concepts here are intriguing and open a new window into the history of our natural world. The basic premise is that a number of plants in North America evolved to form partnerships with the megafauna that once dominated the landscape, but which is now largely extinct. This has resulted in a number of ecological "anachronisms"—plants whose seeds are nestled in large fruits no current animals can swallow whole, or whose fruit pulp is noxious to all current animal residents. The author examines and describes a wide range of examples in great detail.

I enjoyed this aspect immensely, and began to recognize some anachronisms in my own neighborhood. I was even more struck by Barlow's proposal that the recent reintroduction of megafauna to some North American ecosystems, in the form of horses and cattle, might be actively beneficial, partially replacing the animals that humans rendered extinct. (Barlow notes that horses and camels actually evolved first in North America, before spreading to other continents, and were endemic here until humans arrived. She makes a decent case that the American west would be better off now if it still had camels.)

Intermixed with the natural history lesson, however, is an extensive discussion of the history of this idea, and its reception in the scientific community. This, too, is interesting and worthwhile, up to a point. But she goes on about it rather past that point, until it seems like she's either hung up on vindicating her academic mentors, or desperate for material to pad this out to book length. Certainly it could have been shorter without sacrificing worthwhile content.

And finally, there's a lot of poetic description and personal anecdote woven in. Some of this is colorful and gives some life to the text. Some of it is goofy, and occasionally even cringe-worthy. Combined with occasional academic fuzziness (things don't "devolve," Barlow, they just evolve in a different direction), it lends a slightly sloppy air to the book.

But with that said, the book is largely an engaging introduction to a fascinating concept in natural history, and I definitely recommend it.

[Himanshu Bhatnagar · Rating 3 out of 5]

The book, at first, reminded me of Shaw’s rather mean-spirited review of a budding author’s manuscript, “There’s too much space between the covers.” Reading the book, I found myself skipping words, then sentences till by the end I felt like Spiderman, able to leap over entire chapters in a single bound.
But brickbats apart, I do not mean to say that the actual subject matter of the book i.e. there are flora today with anachronistic traits which seem adapted to now extinct mega-fauna is uninteresting, not in the least. It’s just that you get the feeling that this book is made out of a scientific article that should have remained a scientific article.
The Hypothesis is very intriguing, but once you’ve explained the concept in the first twenty pages or so, what else do you do to fill up the rest of the pages? So we find Ms. Barlow getting interminably repetitive, flogging the same dead horses (no pun intended) every few pages, and providing needless details that are not only not pertinent to the topic but are rather uninteresting at that.
The journalist in Ms. Barlow shines through in her repeated attempts to keep her readers hooked; “X will be further explained in a further chapter”, “Y is further discussed in chapter so-and-so”. It’s like she’s still writing for a newspaper and wants you to continue reading her article from the front page into the jumble of the middle pages.
Midway through the book, I started getting the feeling that Ms. Barlow was truly fascinated by this subject and wanted to present it to everyone in a readable and easily understandable format.
The problems are that
A) There is scant literature evidence or actual research into this hypothesis, and
B) The author is, sadly, not quite up to the task of piquing everyone’s interest.
The handful of examples that she has available are inadequate to fill up almost 250 pages and her attempts to romanticize the topic by repeatedly referring to “Ghosts of extinct Pleistocene mega-fauna” also do not have the required effect.
Still given the author’s passion and the intriguing idea she presented, I still finished the book and did not consider it time wasted.
A most glaring omission, and one that’s been mentioned by a number or readers is the complete absence of even a line drawing of all the Pleistocene mega-fauna that are invoked in every chapter. Where are the Giant Sloths, the Mastodons, and the Gomphotheres? Surely they shouldn’t be as elusive as ghosts in a book that’s dedicated to the partners they’ve left behind? How much could it have cost to get publishing rights to a few pictures?
In the end I would still recommend this book to anyone interested in evolution and its little, fascinating mysteries. The only advice I would give the author would be to pare the book down to almost half and add a few illustrations of mega-fauna
Not a must-read, but definitely not unreadable either.

[Adam · Rating 4 out of 5]

While some exceptions have made their way into popular purview - chiefly the understanding that industrial humans are destructive - ecology is still largely seen the way it was presented by William Paley: a web of interactions in which inefficiencies and waste are pared away by the exigencies of natural selection and where every piece has its function, even if it's not yet clear to us. This is evident in Optimal Foraging Theory and Optimal Defense Theory, which are essentially tautological: whatever organisms do must be the optimal choice to make, because of Evolution.

The Ghosts of Evolution is Barlow's attempt to explode that vision out into a historically complex picture of the world. The premise, of course, is that there are plant traits (mostly fruit, but a few thorns and growth habits are thrown in for good measure) that evolved in response to a specific sort of mutualism that no longer exists.

The book is initially kind of weak. Barlow's premised the whole thing on a "groundbreaking" paper Dan Janzen and Paul Martin wrote in 1982. She's enamored of the idea, she finds it romantic and exciting. Much of the book is structured around quotes from email exchanges she had with the two authors. For a book about such an old topic, it seems remarkably rich in speculation and low in primary research. She constantly presents these anecdotal "experiments" she's done, with the caveat that they're "not real science" so we shouldn't invest any Truth in them, but with the clear feeling that she really wants the suggestions they made to be true, just because she would find it Cool.

While the premise wears rather thin in the first few chapters - it's really sufficient to assert that honey locust, persimmon, pawpaw, avocado, and the Kentucky coffee tree are anachronisms and why without being so repetitive about it - the book picks up when Barlow broadens her scope.

There's a wonderfully intensive discussion of comparative digestive anatomy. She concludes, reasonably, that most of the anachronism fruit eaters were hindgut digesters - foregut digesters aren't made for fruit. She points out that the Pleistocene megafaunal extinction left a continent devoid of hindgut herbivores larger than a beaver - though she uncharacteristically fails to speculate on why this is. Most of the large animals that moved in from Eurasia were foregut digesters. I like discussions of digestive anatomy because they are inextricably linked with forage chemistry, which turns faunal assemblages into keys to and engineers of a chemical landscape.

The beautiful thing about the book is the way it expands our perceptions of the relationships among organisms. Anachronistic fruits are the living evidence of megafauna, and the present distribution of the plants that produce them is evidence of their absence. Barlow's knowledge of the specific histories of animals, plants, and their interactions as continents moved throughout North America's history seems rich and full, which is unusual. I find the whole thing complex and hard to wrap my head around - camels and horses arose in North America, while Bison arose in Eurasia, but they migrated across the Bering Straits at various different times up to the Pleistocene. I really want to learn this deep history with more familiarity, because I tthink the historical, evolutionary, dynamic perspective is the only way to understand the logic of a land community.

Overall, Barlow made an interesting picture and changed my view of ecology and evolutionary history (particularly just noting that evolution can leave anachronistic features as big as avocados for 13,000 years is remarkable). It's not the most eloquent or subtle book, but it works.

[Jente Ottenburghs · Rating 2 out of 5]

Great idea, but poor execution. The book relies heavily on a 1982 paper by Janzen and Martin. The author keeps referring to it. In general, the book is quite repetitive (like a stutterer with amnesia). However, for some reason I wanted to finish this book. And I did learn a lot from it.

[Ron Rayborne · Rating 5 out of 5]

Just finished The Ghosts of Evolution. Wonderful book. I first discovered this title when I worked at my local library years ago. I remember it coming out, leafed through it, and knew that one day I'd have to read it.

Though I already understood the premise of the book, the symbiotic connection between plants and their consumers, Connie Barlow, and by extension, Paul Martin and Dan Janzen, solidified in my mind how deep those connections are (or were). To Barlow (and me too) it's sad to think that a lot of extant flora are still putting out fruit for fauna that no longer exist, and haven't for thousands of years thanks to us. And slowly, one by one, with no one to spread their seed, they are declining. Take a hike in the woods and it is often a lonely, silent trek. Most all of those grunts and bellows, roars and mewlings, chirps and chatterings, the sounds of a healthy, vibrant forest that should be there, are now gone. With them many of the plants that depended on them are succumbing. Barlow warns us that if we allow them to go extinct, we will be forced to do the work of pollinating and planting that they did if we hope to survive. And indeed, humans are already being forced to hand-pollinate crops in some countries. Will we "awaken to a new ethos" in time as Barlow suggests?

The answer then is to reverse course while we can. Take responsibility for our past mistakes and reintroduce the cousins of those species we hunted into extinction. They were once here in America and Europe, so let's bring back the elephant and the camel, the rhino and the antelope, the wild dog and the hippo. Thereby we will also be reintroducing ourselves to them; an apology and symbolic handshake that says, "let's start over". And, as a byproduct, we'll be restoring some missing adventure to our lives. Despite what some people may believe, we don't own this planet. It's here for all of us together. I mean, do we really want to live in a one species world?

Can it be done? Yes, with the will. Will we once again be forced to compromise with selfish ranchers and trigger-happy gun-nuts eager to begin the slaughter anew? To make these, our sister species on this planet, again learn to live in fear for their lives? God, I hope not! Wouldn't it be great if, this time around, with the resurrection of the megafauna, it was the destroyers, or at least their destroying mindset, that went extinct?

[L · Rating 3 out of 5]

I liked this book, but wanted to like it much more. It’s fascinating and offers insight into why common North American (or less common, or less American) species may be in their present form. It includes interesting dives into Osage orange, pawpaw, and of course the honey locust.

Where the book falters is in how the author is too casual on occasion, and it disrupts the narrative and the larger sense (hope?) the book isn’t just wishful thinking grounded in good science. One chapter posits a tree depended on the dodo, but it does a better job describing how the tree likely did not. Afterwards, it’s commonly referred to as depending on the dodo...it’s just odd, tonally. There’s another section where the author uses ‘shit’ again and again, and it’s funny in real life, between ecologists, but it feels off the mark in this book.

Finally, the last chapter is odd in how it turns into a rallying cry for the resurrection of the mammoth, which is fine, but it feels out of place when so much of the book focused on plants and their adaptations, anachronistic or not. I understand the intent, but it didn’t work.

All those caveats said...it’s entertaining and worth a read. As an urban forester and an arborist it’s given me fun facts to use and a different mindset with which to approach some common trees. Read the book and enjoy it for what it is.

[katdob · Rating 3 out of 5]

I recommend this book. Apparently designed for the non-scientist, the reviews of the characteristics of anachronistic flora is engaging and interesting. At times, I'm unsure if the book is directed at the science lay-person or to the non-botanist scientist, but it was still a good read. The idea of this book is an A+, while the actual text is more of a C-.

My only qualm is the personal message sometimes injected by the author. I recommend skipping chapter 8 (Who Are the Ghosts?), as it's filled with self-described metaphysical assumptive leaps.

[Ann · Rating 4 out of 5]

I'm afraid that everyone in my immediate circle has heard me talking about something from this book in the last few weeks. This book made me look at the world with new eyes, and feel like a kid learning something new every day. I learned fantastic new vocabulary words that were so fun to say I'd just repeat them to myself when I was puttering around the kitchen: divaricated, indehiscent, artiodactyl, megafauna. I learned about all sorts of extinct mammals that used to live in North and South America: gomphotheres, which were like elephants; toxodonts, which looked sort of like rhinos without horns; giant ground sloths; giant tortoises. I had never considered animals beyond the woolly mammoths.

The author's writing style is so full of enthusiasm and wonder that I couldn't help but be infected. She is upfront about the limits of the research; there's no direct fossil evidence for the ideas that are proposed, and some of her speculations are just speculations. Nonetheless, it made me feel excited and interested, reaching for more resources. I don't mind that her ideas are just ideas; they made me ask more questions and want to look for more answers, and I love feeling like that.

Yesterday I learned that one of the reasons President Jefferson wanted to send Lewis and Clark out west was because he was holding on to hope that they would find a living mammoth or mastadon; fossils had been found, but there was speculation that they could be living in pockets of unexplored territory. Thomas Jefferson did not believe that any animals were extinct, and he wasn't alone in that belief. It was a new notion at that time. I'd never even thought about a time when people didn't know animals could be extinct! This is the kind of thing that I felt like I was regularly reading...something I'd taken for granted for my entire life, suddenly presented in a way that made me look at it completely differently.

I did feel like the author's ideas veered off into left field in the last chapter, but again, I wasn't terribly bothered. I'm now too busy looking around my neighborhood for osage orange trees and honey locust and imagining who used to eat their fruits.

[Mark Hartzer · Rating 4 out of 5]

“The Ghosts of Evolution” by Connie Barlow is a clear headed study on the nature of ‘anachronisms’. Specifically, why do some trees, shrubs and forbs produce fruit that nothing seems to want to eat? Barlow posits that extinct mega fauna were the primary consumer of these anachronistic plants. For example, virtually nothing eats ‘Osage Oranges’ any longer and Barlow puts together a good argument that perhaps something like a Giant Ground Sloth may have eaten the oranges whole and pooped out the seeds elsewhere. Currently, there is no animal (other than us) that voluntarily moves their fruit. The book fleshes this concept out in great detail and does not unduly patronize the reader. Barlow freely admits that she did not originate the idea regarding ‘ghosts’, or plants that no longer have a living primary animal benefactor. The ground sloth, or mastodon, or dodo is not around any longer and the ‘ghost’ can’t fulfil the plant’s needs. But she does a great job in making you think. Why exactly do the Kentucky Coffee Tree’s pods lay unconsumed when you walk past them on the sidewalk?

This book is very similar to Michael Pollan’s “The Botany of Desire” and Douglas Tallamy’s “Bringing Nature Home”. But unlike those books, Barlow jumps around quite a bit, so the narrative is jumbled more than necessary. Further, we don’t have any photos or drawings of giant ground sloths; Toxodons; Glyphodonts; etc... I found it difficult to visualize extinct species and even one drawing would have been helpful.

The next time you carefully eat the flesh of an avocado and toss the seed, ponder what animal ghost ate the entire fruit at once for millions of years before it disappeared forever. Food for thought indeed.

[Ryan · Rating 2 out of 5]

The author was very meticulous in her personal investigation into so-called 'anachronistic' fruits - those with traits evolved for mutualistic dependence on now extinct animals. However it was too much detail for me to stay interested, due to the unfamiliarity of the temperate American biomes that she focused on. I had hoped there would be more on the neotropics, since Janzen was the other author of the paper she talked about, but alas it was not to be.

Ended up skimming to get through the book, but glad I made it to the last few chapters, which became interesting again in their discussion of ungulate digestive systems. OK perhaps still a tad esoteric for most. I can only recommend this to researchers with an obsession for seed dispersal, with a focus on the Americas.

[Dennis Littrell · Rating 5 out of 5]

Who mourns for the mastodons?

"The tusks that clashed in mighty brawls
Of mastodons, are billiard balls..."
--from a poem by Arthur Guiterman

The 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 13,000 years ago. It is a popular expansion on some original work done by ethnologist Daniel H. Janzen and paleontologist Paul S. Martin, their seminal paper appearing in the journal Science in 1982. Connie Barlow's prose is not only very readable, but is full of the excitement of scientific discovery, vivid and concrete, and packed with an amazing amount of information so that not only the trees described, but the giant sloths, mastodons and mammoths--the ghosts of harvests past--come alive on the pages.

What Barlow does more than anything is open our eyes to the ecological nature of fruit and the relationships that exist between trees and the animals that eat the fruit. We learn how color, taste, aroma, texture, nutritional value, toughness of rind, size, shape, number of seeds and how they are encased, etc.--how all these qualities of fruit have evolved to entice the animals that will faithfully distribute the seeds, but also how some qualities discourage other animals, "pulp thieves" or "seed predators," that benefit from the food provided by the tree, but do not help in its propagation.

The story of the desert gourd was of particular interest to me because during many walks in the chaparral and deserts of California I have come across this vine with its hard, dry and unattractive gourds that were never picked or eaten. Barlow theorizes that the plant is also an anachronism, and that there did exist in the past animals that found the gourds, if not delicious, at least palatable.

Another curious anachronism reported on is the devil's claw of the Chihuahuan desert of Mexico. This plant produces a most amazing apparatus that wraps itself around an animal's foot and claw-like clings to the animal, dribbling its seeds to the ground as the animal moves. There is a photo of the claw on page 151 wrapped around a human ankle. Incidentally, the text is enhanced by a number of interesting black and white photos of the trees and their fruits.

This is one of the most interesting and original books on evolution that I have read in recent years, and one of the most informative.

--Dennis Littrell, author of “The World Is Not as We Think It Is”

[Art Lasko · Rating 5 out of 5]

Fun and interesting. A very good read.

[Aditi · Rating 4 out of 5]

It's an excellent book. At one point it's very slightly repetitive and the last chapter (the one about the memorial service) is a bit self-indulgent, therefore 4 stars.

However, I must confess the book brought me a new perspective on all the trees I see on a daily basis, and the fruits I often eat. I recommend it to anyone interested in finding out more about our world as it is and as it was, and human impact on it.

[Lavinia · Rating 4 out of 5]

A little long-winded and studded throughout with somewhat corny anecdotes (the very short last chapter was extremely corny) and original research, this book presents a particular hypothesis of evolutionary biology and its repercussions if true. As science communication goes, it doesn't try to hit below the emotional belt (see most evolutionary biology books about human behavior... :shudder:) and it tells the story of the observations and the development of the hypothesis in an interesting and engaging way. It makes a lot of fascinating offhand claims -- in support of the idea that geophagy is an evolved behavior necessary to support the consumption of slightly-toxic plants (for micronutrient purposes), Barlow mentions that various human cultures have dishes that contain clay. This stood out to me enough that I was inspired to borrow the work she cites, With Bitter Herbs They Shall Eat It: Chemical Ecology and the Origins of Human Diet and Medicine.

The hypothesis, known as "megafaunal dispersal syndrome", is that many plants are adapted to long-extinct animals and, without them, are naturally fated to dwindle. This may seem somewhat obvious as a possibility, but nature enthusiasts and conservationists, as much as they may intellectually accept that possibility, do not behave as such. There's increased, reasonable interest in human cultural memory regarding the late Pleistocene, but the book points out that many plants have been around far, far longer than humans ever have. Thus the focus on returning the land to a state before industrialization or European colonization (where applicable) stops short of a fundamental question: to what end are we restoring the land? The upshot of this hypothesis is that if the goal is to expand the ranges of the endangered plants we know and love, the late Pleistocene may not be far enough back. Some plants may have been doomed by the time humans arrived to know them. The solution, should that be the goal, may be to introduce animals of the correct type to be mutualists with these plants, even if those animals (camels, horses, elephants, etc.) were not known to the humans who first encountered those plants.

Though I recognize that the point of the book is to challenge the orthodoxy that the ideal state for our populated landmasses is the ecosystem as it was just before humans arrived, I don't think Barlow ever acknowledges the next logical step of the conclusion. Yes, ecological systems are constantly in flux -- so why pine after specific plants simply because they exist now? There are untold numbers of extinct species that humans even now do not know about -- should we also desire their revival? Why introduce elephants (or cloned mammoths -- this still seemed plausible when the book was written) to restore the range of the honey locust and other mutualists of the proboscideans, simply because we've identified them? If the goal of environmentalism is to create ecosystems that support humans or that are "diverse" by some metric, why these plants and not others?

I think the implicit answer contained in this book is that ecosystems are so difficult to engineer that human ingenuity may well have no chance calculating a self-sustaining diversity of organisms and we might as well refer to historical relationships and save the ones we're familiar with. As described in the book, sometimes organisms exist whose place in the biome was fragile, and it so happens that humans like them enough to expend great effort to make them abundant again. It isn't sustainable and so we could, if desired, re-implement the entire mutualistic system they required. I don't much agree with the teleology that conservation (both generally and the radical kind espoused here) is humanity's debt to other species -- that we should bring proboscideans to North America to fulfill that lineage's evolutionary destiny. Rather, I think the book's strength is depicting this stark choice: that we can painstakingly maintain species "by hand", or painstakingly recreate the conditions necessary for their survival.

[Matt · Rating 3 out of 5]

This book explores a very important ideas in plant evolution. In total, it was a nice introduction to an idea originally put forth by Janzen and Martin back in 1982. However, Barlow treats these ideas as facts rather than great hypotheses in dire need of investigation and testing. In retrospect, this entire book would have made a nice long-form article in a magazine or journal. By the time you get to the half way point, you can tell that Barlow was lacking enough information and data to write a compelling book. Barlow is clearly seduced by the ideas she writes about to the point that she has convinced herself that there are no other possibilities. This, in my opinion, makes for poor science writing. Tell us what is really going on, not what you have convinced yourself to be true. The megafaunal dispersal syndrome is amazing just on its own without having to pretend that it is the only explanation for the traits we see in some plant species. Overall I would say spare yourself the time and space on your shelf and simply read the original paper as well as the many articles on the subject that circulate around the web. That way you get a more accurate picture of what science has to say on the subject. Nice attempt but poorly executed.

[Ellis · Rating 5 out of 5]

Engaging and entertaining

Barlow has an interesting way of presenting the work of ecologists that came before her. She posits that some plant species in North America are missing their animal counterparts. These plants, like honey locust, persimmon, osage orange, and bitter melon, were being spread some 15,000 years ago by now extinct animals such as Mammoths, giant sloths, camels and native horses. She and others have laid out some pretty convincing evidence. I'm not sure I'm entirely convinced of all the examples, but I was thoroughly entertained and find a great deal of merit in her hypothesis.

[Evan · Rating 4 out of 5]

A bit repetitive in the beginning but full of interesting information. One note, though. It mentions on pp 135 that pawpaws were fruiting in the Harvard arboretum with only a single clone present, providing a counterexample to the rule that pawpaws aren't self fertile. However, I called the arboretum and they let me know there were actually multiple plantings at the time of the events relayed. Indeed, you can check Harvard's online arboretum references and see the dates of planting of presumably different pawpaw stocks which are also geographically too distant from each other to be sucker-clones unless aided by humans.

[Volcano Bee · Rating 3 out of 5]

The first half of the book is entertaining. Barlow delivers a good dose of speculation about the origins of certain plant species backed by what is known from the paleontological record and from modern-day observations.

I didn't care for the second half of the book as much though. It felt like she was trying to stretch out the book at that point to make it longer, like as if she was trying to stretch out the speculation part too far while running out of the facts to support it.

Overall, it was a fun read, but it would be even better if she cut out the "fluff" in the second half of the book.

[Colleen · Rating 3 out of 5]

The topic is interesting, but I was maybe not as deeply interested as I needed to be to truly enjoy. I liked the general information about adaptations such as pulp or thorns, the exhaustive listing of the various examples was more than I was looking for.
Good Information, and sobering, in its examination of future “widows”

[Karen · Rating 4 out of 5]

A great read for nature lovers. It challenged my perspective on conservation and how to think about native landscapes. The book mostly covers anachronisms in plants, based specifically around a research program initiated by two particular scientists. As such, the beginning of the book is rather technical and specific to the back and forth of that research program.

[Janelle · Rating 4 out of 5]

Who would have thought I could enjoy a whole book on this topic so much? Made even more charming by the enthusiastic author trying to feed anachronistic fruits to creatures large and small, digging through poop, and going on tangents. New interest unlocked!

[Mark Linsey · Rating 4 out of 5]

Fascinating account of how lots of fruits we know co-evolved with creatures no longer with us.

Main source for my odd salon March 2020 talk on avocados!

[Emily · Rating 3 out of 5]

Interesting and mostly good, but was in need of editing. Could have been much shorter and included ideas like "devolution" which is not a thing, organisms do not do this.

[Rodrigo Meza · Rating 4 out of 5]

Enjoyed the book, opens up the understanding of our curious world and the inexplicable shapes, tastes and defenses plants have, something's missing!

[Kai · Rating 4 out of 5]

If you are interested in this sort of thing, incredibly researched book.

Excellent discussion on hindgut vs foregut formenting, geophagy, dispersal agents.

[Phil · Rating 4 out of 5]

Wonderful book. Enjoyed every chapter!

[Callan Denham · Rating 3 out of 5]

Quite dry