Why is Evolution True - Book Report/Review Example

Why is Evolution True? Evolution refers to the changes that occur in the inherited features or characteristics in living things over time through successive generations. Through evolution, living things attain diversity that enables them to cope with the changing environmental conditions that surround their habitats. Evolution is based on the notion that all life on earth originated from a common universal ancestor, who through repeated speciation and divergence, led to the rise of different species. The common ancestry if inferred upon through the study of existing species and fossil records of species shared sets of DNA sequences; biochemical and morphological traits are elucidated. The evolution scientific theory was first postulated by Charles Darwin who argued that beings and new species came into being through a process called natural selection. The theory of natural selection is based on the notion of ‘survival for the fittest’ as forwarded by Darwin. According to Darwin, in order for species to survive, they produced more offspring increase their probability of survival with varying traits among individuals. These traits infer upon species varying rates of reproduction and survival. Traits that infer these characteristics on individuals are inheritable from one generation to another with minute improvements or declines. Evolution is a process that occurs over time with some aspects being rapid while others take years to manifest. There exists criticism and resistance towards the acceptance of evolutionary theory by some quarters of society, and it is this paper’s aim to dispel some this reservations and prove that evolution is real. Neil Shubin’s book is meant to address the various instances in history that evidence has been gathered up to support the theory of evolution, and the notion of common ancestry. The book seeks to dispel any doubts that may exist in the minds his readers that evolution exists and it is still taking place in the world around us. The primary goal of Shubin’s book is shed light into the evolutionary process and how the common man can visualize the intricacies involved in the process. The first chapter of the book dwells on this by drawing an example from a zoo to describe the nested hierarchy of living things (Shubin, 2009). The author uses the example of the common limb ancestry of all land animals characterized by five fingers, a wrist, one major bone and two lower bones. This strengthens the author’s argument that all living things are descendants of a common ancestor. Chapter one uses a hypothesis postulating that since land animals descended from a common ancestor with similar limb structure; then this evidence should be available. The transition from one stage of evolution to another and from a lower species to higher one is recognized through the study of intermediates. Chapter one illustrates the evidence of these intermediates through a fish intermediate called Tiktallik (Shubin, 2009). This was an intermediate between a fish an amphibian indicating the movement from sea living to land living animals (Shubin, 2009). The most compelling evidence from this fossil was the presence of a neck and the common bone and limb structure. The subsequent chapters in Shubin’s book are dedicated to accumulating evidence from various sectors of the animal kingdom, both living and dead, that provides evidence of the existence of evolutionary theory. Chapter two of the book carefully looks at the anatomy of land animals with special reference to human limbs especially the hands. Comparison with fossil records of both land and water vertebrates reveals a resounding similarity between different vertebrates. They all have the common limb bone structure and a vertebrae column that gives these animals advanced mobility and locomotion ability compared to invertebrates. Revelations in this chapter bring a lot of facts and previously confusing aspects like the similarities between hippopotamus and the whale. The ability of some animals like parrots to grasp at perches and owls’ ability to turn their heads at an almost 1800 degree angle makes it easier to connect the notion of common ancestry. Technological advancement has furthered the understanding of the relationship between land and water animals in terms of ancestry. Chapter three introduces the reader to advancements made in the study of evolutionary theory with the use of technology, which has made it possible to elucidate more factual evidence. Technology has made it possible for scientist to study the nature of life beyond morphology. DNA provides indisputable evolutionary evidence as to the relationship between species, and their advancement from one stage to another. DNA contains the building blocks of life in the sense that it acts a carrier of information regarding the being of an organism. DNA and genes are chemical substances that determine the nature of a living organism, from its body, size, number of limbs, teeth and all other morphological features that identify and characterize a living organism. Through the study of DNA from fossils and living species, scientists have been able to establish some common genes and DNA characteristics present in both samples of the living and the fossilized. This chapter of the book provides the reader with invaluable information, knowledge and insight into the relevance of genetics and the evolutionary theory. It is apparent from the third chapter of the book that the author of this book focused his research and studies on the evolution of limbs to make his case for the evolution theory. According to Shubin (2009), scientific research has established the significant role played by DNA and genes in particular, the development of limbs. Manipulation of these chemical substances called DNA and genes enabled scientists to determine their function and purpose in evolution. The inclusion of DNA and genes into the debate on evolution by the author helps explain aspects that could otherwise not be understood by the mere analysis of evidence from fossils. The presence of different colored, sized and habituated bird types can only be explained through the evolution theory. All birds have the morphological features that exhibit variations in terms of size and shape depending on their habitat and feeding habits. The creation theory is put to test by this fact due to the existence of evidence establishing change in species through time. The creation theory does not account for the changes in morphology exhibited by various species through time. People have different complexions, hair and eye color and body sizes as exemplified by Africans, Caucasians and Asians, yet they all possess the same morphology. These variations can only be explained through speciation as contained in the evolution theory. Animals both on land and in water adapt to different environmental conditions in their living habitats. The environment has been noted to be the most significant instigator of evolution due to its constant dynamism through change. In order to survive, living organisms have had to change and adapt their bodies to their changing environments for purposes of movement, reproduction and nutrition. Extinction of species as illustrated by evidence from fossils was as a result of failing to adapt to changes in their surrounding environment and living conditions. This can explain the observable variations in bird species, with some being flesh or meat eaters while others feed on plants and their products. A notable example to explain this phenomenon is looking at the various shapes and sizes of birds’ beaks. Flesh eating birds have curved sharp beaks with complementing sharp curved talons or claws. Fish eating birds have long, sharp and pointed beaks that act as spears or harpoons for piercing and capturing fish with examples including Sea Gulls and king Fishers. Humming birds feed on flower nectar and their beaks are well adapted to this feeding habit by having thin, long and curved beaks for reaching the recesses where flower nectar is found. Ducks and Swans have webbed feet that makes them efficient swimmers, which gives them the ability to live and thrive in wet habitats. These are some of the variations that have been adequately explained by the evolution theory in comparison with other theories. Changes in environmental conditions cause minute variations in the genetic makeup of an organism that determines whether it will conform to the variation. Failure to conform to changing environmental variations reduces the survival chances of a species. The fourth chapter gives the reader a chance to explore notions that they rarely associate with evolution, or aspects that are not popular with evolutionary theorists. Shubin looks into the nature and morphology of teeth in different animal species and their relationship with regard to evolution. According to Shubin (2009), “much of the story of mammals is the story of new ways of processing foo”. This is understood to mean that a significant instigator of evolution in mammals and most of the other species is the need to adapt their feeding habits to changing environments and habitats. Mammals that hunt for food have had to develop strong jaws, streamlined bodies for maximum speed like the Cheetah and specialized teeth for tearing into flesh. This chapter explores the specialization of teeth in different species meant for feeding on various food types. There are classes of teeth namely the incisors, canines and molar which are for cutting, holding and grinding respectively. The dominance of one or more of these teeth types places an animal into either the carnivore, herbivore or omnivore families. Herbivores like goats and cows have dominant molars for grinding coarse vegetative fiber, while carnivores have well developed incisors and canines for tearing into flesh. Chapter four of Shubin’s book follows the established discourse of using the analysis of bones and their origin as a point of recognizing common ancestry in land animals. The author postulates that teeth are the origin of all hard parts or bones in all animals. This is in line with the author’s earlier postulate that evolution in most animals was as a result of the need to adapt to changing nutritional or feeding environments. Thus, it is evident that the development of teeth followed the premise of adapting to dynamic nutritional environments. Teeth in animals developed even before living organisms ventured onto land as a habitat. This was to enable these extinct animals cope with competition for food resources and defend against predators. Teeth were the predecessors of hard body parts like bones and cartilage. Genes that facilitated the evolution of teeth underwent further changes leading to the development of skulls to protect increased brained matter. This enabled these animals to employ sophisticated and complex behavior, hunting and evasive tactics compared to other organisms in their habitats. Through these observations, the author is justifiably confident to conclude that teeth are the common ancestors of everything that comes from the skin. Embryological studies dominate chapter five of the book, and they are used to illustrate the common ancestry that exists between animals that goes beyond their limbs or adaptive feeding habits. The author uses a comparative approach to bring out his point to the reader, where he compares vertebrate embryos. The homologous similarity exhibited amongst embryos belonging to man, pigs, birds and reptiles is a clear indication of the common ancestry that exists between these animals (Shubin, 2009). The development of orifices in these animals follows a similar pattern, origin and arrangement at the embryonic stage. The fact that almost all animals exhibit the same arrangement of morphological perforations indicates a stronger link in their origin than mere chance. Most animals have embryonic orifices at specific points that later develop into significant and distinct body parts that serve almost similar functions. The morphology of most animals is determined by four arches that are present during the embryonic stage of development. These arches develop to the basic function parts of animals’ heads including the jaws, ears, larynx and muscles that control their functions. According to chapter six of Shubin’s book Your Inner Fish (2009), all land animals and some the water testify to the same body plan. This plan is characterized by having one head, four limbs that are arranged in two pairs across the body and tail. These features may not be visibly apparent but there exists some remnants of this body arrangement in their morphology. The basic body plan of all vertebrates is attributed to their genetic makeup that influences this development from the onset of life. The significance of genes in determining the basic body plans of vertebrates cannot be over emphasized because without their involvement life would not exist as it is today for all animals. Genes are chemical components in the DNA of all living organisms that determine the nature, appearance and features on an organism. These chemical components receive signals from an organism’s environment through its various sensory receptors. Genes in turn determine changes necessary for an organism’s functionality, performance and survival, and make alterations accordingly to achieve this purpose. Through gene modification, evolution has been taking place throughout the animal and plant kingdom. Evolution is true as evidenced by the numerous instances and situations where the notion becomes the only logical and viable explanation for observations made in life and nature. In what the author refers to as Volvox, a term that describes the ability of cells to specialize their functionality to carryout various functions within the body. This is cited as the beginning of all multicellular life, which can explain the different cell functionalities found in animals. Chapter seven strives to elucidate this fact to the reader. Cell specialization led to the development of tissues which are specialized body cells that serve to carry out a specific function in the body, examples being the nerve and skin tissues. The ability of cells to specialize into different functionalities from a similar and common origin points to the apparent evolutionary path followed by whole organisms. The need to function and perform at higher and better levels on land required that vertebrates develop traits and features that enabled them to survive. Specialization of cells is reflected in what is referred to as divergent evolution, where entirely different species emerge from a common ancestor. Through genetic adaptation and alteration, animals have been to develop morphologically different features from their ancestors in order to conform and survive. Paleontological evidence provides fossil evidence that helps scientists and scholars create the necessary links and relationships in order to support evolutionary theory. The book provides valuable insights as to the meaning of evolution and its purpose in life. Evolution is a true process in life that takes at every moment of life in both animals and plants. Through evolution, animals have been able to develop coping mechanisms and features in their anatomy and morphology that make them better than their predecessors. Evolution is only theory that can explain variations that are witnessed in living organisms. Darwin’s evolution theory has expanded the scope of man’s understanding of the environment and how to manage it for a better life. Variation and specialization of species is seen as the future of living organisms, which ensures that they are able to adapt to changing environmental conditions. Evolution of traits and morphological features will ensure the survivability of the world’s species and the emergence of new ones in the future because it is how nature works. Reference. Shubin, N. (2009). Your Inner Fish: The amazing discovery of our 375-million-year-old ancestor. London: Penguin Books Limited. Read More