Thursday, February 22, 2024

Charles Darwin's On The Origin of Species by Dr. Michael Leach and Dr. Meriel Lland

This oversize nonfiction picture book explores Charles Darwin's theory of evolution and his ideas about the natural world that were published in his book, On The Origin of Species.

In this book, evolution is defined as "the way that living things here on Earth have changed and continue to change." It "explains why there are so many different kinds of plants and animals." This explanation comes from Charles Darwin who described his ideas in his book, On the Origin of Species by Means of Natural Selection, published in 1859. 

This nonfiction picture book sets out to describe how naturalist Charles Darwin came to develop the idea of evolution and natural selection and explain his "big idea".

After identifying some of the great scientific thinkers in the late 1700's and early 1800's, the authors describe the early life of Charles Robert Darwin who was born in 1809. His love of studying the natural world led him to leave the study of medicine and enroll in courses to become an Anglican minister. He obtained the position of a naturalist on the HMS Beagle and journeyed to the Galapagos Islands, off the coast of South America.
 
In 1835, Darwin studied the wildlife on the various islands of the Galapagos, making records and collecting samples. When he returned home to England, Darwin married Emma Wedgwood in January, 1839. They had ten children. Over the next sixteen years, Darwin came to develop a theory as to how species change, by passing on small variations that made them better adapted to their environment. These traits eventually became common to all members of that species. This process was named "natural selection" by Darwin. Another British man, Alfred Russel Wallace also came to have a similar theory and sent his idea to Darwin.

In 1858, their idea of the theory of natural selection was presented at a scientific meeting in London. Wallace admitted that this idea was first Darwin's. This radical idea was very controversial leading to many public debates. Darwin published his theory in a book titled, On the Origin of Species in 1859. In 1871 he further developed his ideas and published a book on the evolution of humans called The Descent of Man, and Selection in Relation to Sex. Because Darwin considered humans as part of the animal kingdom, he believed humans shared a common ancestor with apes.

Darwin continued his thinking and research all his life, writing fourteen books and corresponding with many people regarding his ideas. He died in 1882 and is buried in Westminster Abbey, London.

From this point on, examples of natural selection in action are featured. Other concepts such as "common descent", "survival of the fittest", "the struggle for life", and sexual selection are presented. How island life forms unique organisms, Darwin's tree of life and the interdependence of species are also discussed. The authors also incorporate pages about convergent evolution, the fossil record, the rise of birds, plate tectonics and how this has affected life on Earth, and some of Darwin's ideas that ultimately proved to be wrong.

Discussion

Charles Darwin's On The Origin of Species offers young readers a short biography of Charles Darwin, the British naturalist who posed the theory of evolution and natural selection. Darwin's ideas on how natural selection works to help species adapt better to their environment and his theory of evolution - how life on Earth may have developed over hundreds of millions of years are also discussed.

This book begins by offering some key definitions about evolution, stating that "People and species of plants and animals also change bit by bit over many generations. These processes are gradual and are the basis of evolution - or how living things change over time."  This definition is somewhat vague and doesn't explain what Charles Darwin's theory of evolution has come to embody today. The Merriam-Webster definition is probably more accurate: "the scientific theory explaining the appearance of new species and varieties through the action of various biological mechanisms (as natural selection or genetic mutation)"

It's important for children's science books to strive to be accurate. Darwin brilliantly recognized that living organisms adapt to small changes in their environment so they can better survive. He was able to  describe this with his detailed observations of various animals on the Galapagos. Drs Leach and Lland do an excellent job of presenting this evidence by describing Darwin's finches from the Galapagos and the rainforest frogs in Thailand. 

But Darwin also had another part of his theory which the authors describe as  "Evolution also helps us to understand how groups of animals and plants become extinct, and how new groups emerged - including humans."  In other words, Darwin believed that evolution could explain how new species come about, a process he believed happened gradually, through small changes over a vast period of time. To prove this many, transitional forms must be found to show the development from one species to a completely new one. As Leach and Lland do mention, transitional fossils are not common, making such proof difficult. They present the evolution of whales from a land ancestor  called Indohyus as one example and also the belief today, that birds are the descendants of dinosaurs based on the discovery of dinosaur fossils with feathers, and what is considered an intermediary, Archaeopteryx. 

Leach and Lland also present some of the problems Darwin considered but was unable to solve during his lifetime. One was how plants and animals passed on their characteristics to their offspring. We now know since the discovery of DNA in 1953, that traits are passed on through segments of DNA called genes which are inherited from the parents of an organism. Genes describe protein chains, amino acid by amino acid.  During reproduction DNA is copied but often the duplication is not perfect. These flaws lead to mutations. Most major mutations are fatal, as the work of the German geneticists Christiane Nusslein-Volhard and Eric Wieschaus demonstrated. When Darwin posed evolution, he knew nothing about DNA, amino acids, proteins and inheritance. Had he known, would he have believed that random mutations that occurred early enough in development to affect the body plan of the organism - could drive macro-evolution? Today, many microbiologists and geneticists understand that minor mutations do not create significant evolutionary change as Darwin proposed. And major mutations are usually fatal to an organism. Leach and Lland describe DNA and confidently state that these mutations which they describe as "faults" are what "...create the variants that drive evolution." They do not explore the question that microbiology presents regarding evolution: since genes contain information that is coded in various combinations of the twenty amino acids, where did that biochemical information initially originate? Did the information come from random mutations? Or from some other source? 

The second problem Darwin couldn't solve was "how a species could appear in different places around the Earth." We now know that the Earth is a dynamic system in which the crust is made up of  tectonic plates that are constantly moving. The continents as we currently know them were arranged very differently in the past, into one supercontinent called Gondwana.

One interesting spread in the book is titled The Slow March of Evolution in which Earth's history is presented in the form of a twenty-four hour clock instead of using the geologic time scale such as Cambrian, Ordovician etc . The appearance of different forms of life are assigned a time ( for example, 04.20 First Single Cell Life appears). One issue with Darwin's theory of evolution is how to explain things like the incredible emergence of life at the beginning of the Cambrian Period - known as the "Cambrian explosion." Using the clock instead of the geologic time scale means this "explosion of new life forms" is not as readily apparent.

Charles Darwin's On The Origin of Species offers an overview on the topic of evolution that may encourage young readers to further explore the ideas featured here.  This book could have been made much more engaging with the use of photographs of some of the major characters such as Charles Darwin, Thomas Huxley, and Samuel Wilberforce, photographs of the Galapagos Islands and of the unique animals such as the long nosed horn frog mentioned in the book, as well as the use of maps and the geologic time scale. There is a small glossary at the back which could have been expanded. In addition, there is no information offered on the authors or their credentials. 

Book Details:

Charles Darwin's On The Origin of Species by Dr. Michael Leach and Dr. Meriel Lland
London: Arcturus Publishing Ltd.     2024
64 pp.

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