How the Zebra Got Its Stripes: Darwinian Stories Told Through Evolutionary Biology by Leo Grasset

From the title, How the Zebra Got Its Stripes, I was expecting a children’s picture book, but the subheading – Darwinian Stories Told Through Evolutionary Biology – should have been a clue that the author Leo Grasset was not approaching this topic in a lighthearted manner, although this book is not without its humor when discussing unusual animals and their unexpected habits.

Grasset is a behavioral scientist/naturalist who drooled at the opportunity to spend time in Africa studying zebras in the wild of Zimbabwe under the tutelage of Simon Chamaille to complete his graduate degree at a French University. Despite months spent observing these animals in their natural habitat, he did not discover much variation in their behaviors and although he was able to distinguish one from another, the zebras, in essence, were lacking in personality.

To answer the question posed by the title: zebras have white stripes in a black background (not the other way around) and the pattern of stripes vary from animal to animal. It is difficult for scientists to pinpoint the exact reason for these stripes. Is it for camouflage? Perhaps they deter annoying tsetse flies and other insects? Or are the stripes an optical illusion which tricks predators? The white stripes might also dissipate heat, a nice characteristic during the hot summer months. Then, too, we cannot discount the possibility that their presence is for some other reason which is no longer viable.

My take away from this book is that ultimately scientists are still arguing about this and other concepts in evolutionary biology. The truth is – they don’t know. The theories are just that, theories. So all that Darwinian stuff we learned in school are guidelines, not absolutes. We might even call them educated guesses.

The author views Evolutionary Biology as an attempt to identify the origin and function of adaptations. The concepts of chance (think of how plants are pollinated) or random forms of behavior which somehow assisted survival must be taken into consideration. Sometimes survival is a matter of luck, being in the right place at the right time or vica versa, a sort of biological roulette.

Grasset takes a look at various animal behaviors in chapters titled: Evolution, Animal Behaviors, Unusual Animals, and The Human Factor. Through his observations, the lay person can glean some interesting information which might have some practical applications in our lives. Termite mounds have a natural air conditioning system which might be useful to study in order to more effectively ventilate mines. Animal such as antelopes live together in herds due to risk dilution resulting from more eyes being vigilant. The instinct to copy their neighbor also keeps them out of trouble with a feedback loop that reinforces the behavior. Studying the pattern of movement of a school of fish can help determine pathways out of a crowded stadium. The collective phenomena is seen by rhythmic clapping at concerts. Warm up acts are used since a critical mass is needed to “get people going”. Utilizing the criteria – a set of rules, critical mass, and copied behavior, reminds me of participating in The Wave at a Bill’s game.

None of this is new. Grasset quotes Aristotle who said, “The multitude is the better judge” and applies this to the many animal species who use consensus to determine actions versus those animals who practice despotism where one leader dictates the actions of the rest. However, consensus only works if each animal works independently and is not swayed by their peers, which might explain the results of our political elections.

Grasset also shares some of the unusual behaviors found in the animal kingdom:

Animals can be sneaky. Certain males in a species use deceptive signals/practices, like faking an alarm, to get their way, whether it’s acquiring food or keeping a female from leaving the herd. The zebra exhibits such behaviors.

The Dung Beetle navigates via the Milky away

In elephants it’s the oldest female who leads the herd since she has the experience to know what to do in an emergency. .

Elephants can hear sounds humans can’t using seismic communications by stamping on the ground causing underground vibrations that are picked up via the fatty pads of their feet which move up their legs through their shoulders and into the middle ear.

According to the Guinness Book of World Records, the Honey Badger is the most fearless creature on earth. When attacking they aim for the scrotum, literally castrating their prey (including animals the size of a male Buffalo) then waiting for them to bleed to death. They are also impervious to snake venom.

In addition to animal characteristics, Grasset explores the major impact human activity has on biodiversity which has lead to a biological crisis as species become endangered or extinct:

Often unwittingly, our actions directly impact animal behaviors. For example, the animals living a sheltered life in the National Parks in Africa no longer need to migrate because fresh water is readily available. House sparrows weave cigarette butts into their nests as a natural pesticide to keep parasites away from their chicks. When trophy hunters kill a male lion in its prime, the new male leader of the pride kills all the cubs to prevent future threats to their authority.

Deforestation has resulted in catastrophic changes such as the Dust Bowl in 1930’s. Once a certain threshold is breached, the change from a patchy tree environment to desert is rapidly achieved.

The environment has been affected over time as man evolved from walking on two legs to the invention of stone tools to the domestication of fire to the ability to stand upright. Cooking led to an easier technique for eating food with more nutrients added to the diet which resulted in more free time and the energy to invent more tools and become more social, eventually leading to migration and a larger brain size.

Current efforts are underway to reconcile human food needs with biodiversity and perhaps discovering ways to make deserts green again and protect our grasslands.

As an aside, there is a chapter highlighting the story The Lion King where the actions of the fictionalized animals are compared to the behaviors of similar animals in the wild.

This book included numerous drawings, charts, and a series of stunning photographs of African wildlife as well as an index and a list of references (of sorts) called Further Investigations.

Grasset shares numerous tidbits of information about the animal kingdom and doesn’t neglect to discuss man’s impact on the environment. The 256 pages gave me a lot to think about as I gained a new perspective on the teachings of Darwin and how it relates to my life choices. It should be noted that I don’t normally read books on scientific topics, even ones involving animals (unless I’m reading bedtime stories with my grandsons), so the fact that I enjoyed this book has extra relevance. Four stars.

A thank you to Netgalley and Pegasus Books for providing this ARC in exchange for an honest review. This review also appears on Goodreads.


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