Evidence of Evolution

12 Key excerpts on "Evidence of Evolution"

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  eBook - ePub

  Evolution

  The Origins and Mechanisms of Diversity

  • Jonathan Bard(Author)
  • 2021(Publication Date)
  • CRC Press

    (Publisher)

  THE EVIDENCE FOR EVOLUTION

  DOI: 10.1201/9780429346217-6

  1. 5Analysing Evolutionary Change
  2. 6The Anatomical Evidence for Evolutionary Change
  3. 7The Genomic Evidence
  4. 8The Evo-Devo Evidence

  The evidence for evolution set out in this section comes from comparative anatomy of both living and extinct species, together with genetic-sequence analysis and comparative embryology of extant species. The fossil record, briefly discussed in Chapter 4 , is the most obvious source as it demonstrates the major lines of species radiations and extinctions, particularly over the past ∼600 My. Although this record provides a historical context for evolution, individual fossil descriptions are only a start: direct evidence for evolutionary descent comes only from a close comparison of the anatomy of similar fossils to identify those features that are common and those features that might indicate descent with modification. The formal approach for analysing such differences is known as cladistics and will be discussed in Chapter 5 .

  In terms of the direct evidence for evolution on the basis of the fossil record, the most important data comes from fossil sequences in which the details of transitions from one anatomical feature to another can be closely followed, revealing the ways in which descent with modification happened. Three examples are discussed in Chapter 6 : the formation of pentadactyl limbs from the pectoral and pelvic fins of fishes, the changes that led from the skull of stem mammals to one with the basic features of modern mammals, and the evolution of the modern horse (Equus) taxon, whose feet have a single hoofed toe, from its multitoed ancestors.

  A second means of elucidating evolutionary relationships among living species comes from computational analysis of homologous DNA and protein sequences on the basis of their mutational differences. Once homology (common ancestry) has been established on the basis of the similarity of sequence, computational and statistical methods can be used to generate a hierarchy known as a phylogram (Chapter 7)

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  Barron's Biology Practice Plus: 400+ Online Questions and Quick Study Review

  • Deborah T. Goldberg, Marisa Abrams, Barron's Educational Series(Authors)
  • 2022(Publication Date)
  • Barrons Educational Services

    (Publisher)

  CHAPTER 8

  Evolution

  Learning Objectives In this chapter, you will learn:

  ∘Evidence of Evolution

  ∘Lamarck vs. Darwin

  ∘Darwin’s theory of natural selection

  ∘Types of natural selection

  ∘Diversity within a population

  ∘Population stability—Hardy-Weinberg

  ∘Isolation and formation of new species

  ∘Patterns of evolution

  ∘Theories about evolution

  ∘How life began

  ∘The heterotroph hypothesis and the theory of endosymbiosis

  ∘Mass extinctions

  ∘Important concepts of evolution

  An understanding of evolutionary theory helps scientists understand every field of biology from molecular biology to ecology. Evolution is the change in the genes of a population on Earth over time. Microevolution refers to the changes in one gene pool of a population over generations. Macroevolution refers to speciation, the formation of an entirely new species.

  REMEMBER

  Individuals never evolve; only populations evolve.

  A critical thing to remember is that individuals never change or evolve. A population is the smallest group that can evolve. A population consists of all the members of one species in one place. For example, all the lions on the Masai plain in Kenya, or the blue jays in Madison, Wisconsin, are populations.

  Evidence of Evolution

  Six areas of scientific study that provide evidence for evolution are: 1.Fossil record 2.Comparative anatomy 3.Comparative biochemistry 4.Comparative embryology 5.Molecular biology 6.Biogeography

  Fossil Record

  The fossil record reveals the existence of species that have become extinct or have evolved into other species. The fossil record shows these important facts. •Ninety-nine percent of all organisms that ever lived on Earth are now extinct. •Through studies of radioactive dating and half-life, we know that Earth is about 4.6 billion years old. •Prokaryotic cells are the oldest fossils and were the first organisms to develop on Earth.

  •Paleontologists have discovered many transitional fossils that link older extinct fossils to modern species. For example, Archaeopteryx is a fossil that shows both reptile and bird characteristics. There also exist transition fossils that demonstrate that Hyracotherium (Eohippus), the ancient horse, is an ancestor of the modern horse, Equus

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  Evolution

  • Mark Ridley(Author)
  • 2009(Publication Date)
  • Wiley-Blackwell

    (Publisher)

  .. 3 The Evidence for Evolution H ow can it be shown that species change through time, and that modern species share a common ancestor? We begin with direct observations of change on a small scale and move out to more inferential evidence of larger scale change. We then look at what is probably the most powerful general argument for evolution: the existence of certain kinds of similarity (called homologies) between species b similarities that would not be expected to exist if each species had originated independently. Homologies fall into hierarchically arranged clusters, as if they had evolved through a tree of life and not independently in each species. The order in which the main groups of animals appear in the fossil record makes sense if they arose by evolution, but would be highly improbable otherwise. Finally, the existence of adaptation in living things has no non-evolutionary explanation, though the exact way that adaptation can be used to suggest evolution depends on what alternative is being argued against. .. 44 PART 1 / Introduction 3.1 We distinguish three possible theories of the history of life In this chapter, we shall be asking whether, according to the scientific evidence, one species has evolved into another in the past, or whether each species had a separate origin and has remained fixed in form ever since that origin. For purposes of argument, it is useful to have some articulate alternatives to argue between. We can discuss three theories (Figure 3.1): (a) evolution; (b) “transformism,” in which species do change, but there have been as many origins of species as there have been species; and (c) separ- ate creation, in which species originated separately and remain fixed. The chapter will therefore look at evidence for two evolutionary claims. One is that species have changed in Darwin’s sense of “descent with modification.” The other is that all species share a common ancestor a that the change has been through a tree-like history.

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  Evolution's Clinical Guidebook

  Translating Ancient Genes into Precision Medicine

  • Jules J. Berman(Author)
  • 2019(Publication Date)
  • Academic Press

    (Publisher)

  9

  Medical Proof of Evolution

  Abstract

  Until now, when it comes to proving the theory of evolution, the supportive scientific arguments have come from the fields of paleontology, geology, zoology, anatomy, and genetics. Throughout this book, we have seen how the theory of evolution has greatly benefited the field of medicine, but we have not discussed how the field of medicine has confirmed the theory of evolution. The purpose of this chapter is to revisit the theory of evolution, from a clinical perspective, to test our assumptions and to validate our hypotheses. Specifically, we will show that organisms that develop through intelligent design are necessarily different from organisms that develop through the process of evolution; and that the millions of species of organisms living on earth today have the genomic traits that could only have been acquired through evolution. Furthermore, we shall see that most of what we recognize as modern medicine simply could not exist if the theory of evolution through natural selection were false.

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  The Changing Earth

  Exploring Geology and Evolution

  • James Monroe, Reed Wicander(Authors)
  • 2014(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  18.5 Evidence Supporting Evolutionary Theory When Charles Darwin proposed his theory of evolution, he cited supporting evidence such as classification, embryology, comparative anatomy, geographic distribution, and, to a lim-ited extent, the fossil record. He had little knowledge of the Connection Link You can find more information on dinosaurs and their extinction in Chapter 22. Time Change in form Shark Shark Lungfish Placoderm Salamander Dinosaur Bird Opossum Lungs Gills Feathers Four toes Placenta Hair, mammary glands Amniotic egg Four limbs with five fingers and toes Bony internal skeleton Vertebral column Horse Cat Lungfish Salamander Opossum Horse Cat Dinosaur Placoderm Bird Two openings behind eye b A cladogram showing inferred relationships. Some of the characteristics used to construct this cladogram are indicated. ❚ Figure 18.11 Phylogenetic Tree and Cladogram a A phylogenetic tree showing the relationships among various vertebrate animals. © Cengage Learning ® . All Rights Reserved. © Cengage Learning ® . All Rights Reserved. Copyright 2013 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s). Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it. mechanism of inheritance, and both biochemistry and molec-ular biology were unknown during his time. Studies in these areas, coupled with a more complete and much better under-stood fossil record, have convinced scientists that the theory is as well supported by evidence as any other major theory. Of course, scientists disagree on many details, but the central claims of the theory are well established and widely accepted.

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  New Thinking About Evolution

  • Britannica Educational Publishing, John P Rafferty(Authors)
  • 2010(Publication Date)
  • Britannica Educational Publishing

    (Publisher)

  The second and third issues—seeking to ascertain evolutionary relationships between particular organisms and the events of evolutionary history, as well as to explain how and why evolution takes place—are matters of active scientific investigation. Some conclusions are well established. One, for example, is that the chimpanzee and the gorilla are more closely related to humans than is any of those three species to the baboon or other monkeys. Another conclusion is that natural selection, the process postulated by Darwin, explains the configuration of such adaptive features as the human eye and the wings of birds. Many matters are less certain, others are conjectural, and still others—such as the characteristics of the first living things and when they came about—remain completely unknown. Since Darwin, the theory of evolution has gradually extended its influence to other biological disciplines, from physiology to ecology and from biochemistry to systematics. All biological knowledge now includes the phenomenon of evolution. In the words of Theodosius Dobzhansky, “Nothing in biology makes sense except in the light of evolution.” The term evolution and the general concept of change through time also have penetrated into scientific language well beyond biology and even into common language. Astrophysicists speak of the evolution of the solar system or of the universe; geologists, of the evolution of Earth’s interior; psychologists, of the evolution of the mind; anthropologists, of the evolution of cultures; art historians, of the evolution of architectural styles; and couturiers, of the evolution of fashion

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  Visualizing Earth History

  • Loren E. Babcock(Author)
  • 2012(Publication Date)
  • Wiley

    (Publisher)

  124 Biologic Evolution 5 S o far, you have learned that Earth’s changes have been carefully recorded in stratigraphic layers and that we can use correlation techniques to decipher the “chapters” and “pages” of Earth’s long saga. That narrative, however, is written not just in rock layers but also partly in biologic organisms. Life forms are the source of two important types of information about Earth history. First, they are the most obvious outcome of biologic evolution over geologic time spans. Second, life forms carry a superb repository of evolutionary information—their genetics. The evolutionary history of every living organism is succinctly recorded in its genetic code. This code is contained in DNA molecules such as the one shown here. Researchers can use that information to determine species relationships and even to estimate when organisms diverged from each other. In this chapter, you will learn how biologic evolution has left its mark in the great diversity of fossil organisms through geologic time. You will also learn about two factors that govern how evolution proceeds and that influence the morphologic outcome: natural selection and inheritance. Understanding these central concepts of evolutionary biology provides the metaphorical “character development” that is essential to understanding the story written in Earth’s stratigraphic “pages.” CHAPTER OUTLINE ■ Evidence of Biologic Evolution and Natural Selection p. 126 ■ Variation and Inheritance of Traits p. 133 ■ Speciation p. 140 ■ Phylogenetics: Reconstructing Evolutionary History p. 143 ■ Evolutionary Patterns and Extinction p. 148 volution in organisms simply refers to change through time. That change can be thought of as occurring along a spectrum of scales. At the smallest scale, individual or- ganisms go through changes during their lifetimes. Such changes are usually regarded as ontoge- netic changes.

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  Evolution, Chance, and God

  Understanding the Relationship between Evolution and Religion

  • Brendan Sweetman(Author)
  • 2015(Publication Date)
  • Bloomsbury Academic

    (Publisher)

  We should also point out again that, while our aim in this book is not to undermine evolution, but instead to probe its implications for other important matters on the assumption that it is true, and to examine how evolution and religion might be compatible, it is also obviously essential that we have an understanding of the main lines of evidence offered for the theory. We need some appreciation for whether the evidence is strong or weak, or somewhere in between. We also need some understanding of the deeper questions that might be raised by the way the evidence is often presented (e.g., what role does chance play in the explanation of the theory; is evolution progressive?). In this chapter, we will provide an overview of the main lines of support offered for the theory, consider some objections, and raise other issues that are germane to the discussion of the evidence, such as whether it is accurate or fair to describe evolution as “only a theory,” and whether it would ever be possible to falsify evolution. I will adopt a question-and-answer format when discussing the evidence. I find this a helpful, fruitful strategy for elucidating the evidence and arguments used to support evolution. The questions raised are the ones the general educated reader asks about the theory, and responding to these questions will enable us to explain in a lucid way what the evidence is, how it fits together, what the weaknesses might be, and how the evidence might raise other lines of inquiry that relate to the implications of the theory. (The implications will be then brought out in the next chapter.)

  Two kinds of natural selection: Is the evidence convincing?

  We noted in the previous chapter that natural selection is the process or mechanism by which changes take place in what are called varieties within species, and in species themselves (microevolution). It is a process that eventually produces dramatic changes that lead to widely different species (macroevolution). So while it is true that the thesis of natural selection and the thesis of common descent are two different, separate theses, they are nevertheless connected in an intimate way. This is because natural selection is the process by which not just microevolution but also macroevolution occurs. And macroevolution means that all of the various species, both now and in history (including insects, all the lower life-forms, and plants), are genetically related. Natural selection explains the process by which a species of finch with predominantly short beaks evolves into a species of finch with predominantly long beaks over time. But it is also supposed to explain the process by which the descendants of fish gradually over a very long period of time evolved into birds. It also describes the process by which the species of great ape gradually evolved into the species of Homo sapiens

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  Logic, Methodology and Philosophy of Science VIII

  • J.E. Fenstad, I.T. Frolov, R. Hilpinen(Authors)
  • 1989(Publication Date)
  • North Holland

    (Publisher)

  9 Foundations of Biological Sciences This Page Intentionally Left Blank J.E. Fenstad et al., eds., Logic, Methodology and Philosophy of Science VIII @ Elsevier Science Publishers B.V. (1989) 481-493 EVOLUTION -MATTER OF FACT OR METAPHYSICAL IDEA? ROLF LOTHER Akademie der Wissenschaften der DDR, Zentralinstitut fur Philosophie, 1086 Berlin, GDR How do we know that organismic evolution indeed has occurred in the past and goes on? We cannot observe evolution immediately at the present time. Although evolution is taking place today, it is much too slow to allow us to recognize evolutionary processes as such if we do not know by other means that they are evolutionary processes. The occur- rence of evolution is demonstrated not by direct observation but in other ways. How? In many textbooks of evolutionary biology we find chapters containing so-called evidence for evolution from different parts of biology: from systematics, comparative anatomy, comparative embryology, serology, comparative biochemistry, biogeography, paleontology, and so on. Es- sential to this kind of demonstration are the homologous similarities of organismic structures. The anti-evolutionistic objection that evolutionary biology is founded on a circulus vitiosus is related to this kind of demonstration: on the one hand there is the conclusion from the patterns of homologous similarity to evolution, on the other hand there is the explanation of the origin of the same patterns by evolution (cf. KUHN 1947, RIEPPEL 1983). That, indeed, is a circulus vitiosus. But this objec- tion is not evidence against evolutionary biology. It is only an objection against an incorrect argumentation. That evolution has taken place and takes place is demonstrated by the theory of descent which is fundamental to evolutionary biology (cp. L~~THER 1972, 1983, TSCHULOK 1922).

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  Historical Geology

  • Reed Wicander, James Monroe(Authors)
  • 2015(Publication Date)
  • Cengage Learning EMEA

    (Publisher)

  • Several evolutionary trends, such as size increase or changing configuration of shells, teeth, or limbs, are well known for or-ganisms for which sufficient fossils are available. • The theory of evolution is truly scientific because we can think of experiments and observations that would support it or render it incorrect. • Fossils are important as evidence for evolution, but additional evidence comes from classification, biochemistry, molecular biology, genetics, and biogeography. Introduction A rugged group of islands belonging to Ecuador lies in the Pacific Ocean about 1,000 km west of South America. Called the Archipelago de Colon after Christopher Colum-bus, the group is better known as the Galápagos Islands ( ▼ Figure 7.1a). During Charles Robert Darwin’s (Figure 7.1b) five-year voyage (1831–1836) as an unpaid natural-ist aboard the research vessel HMS Beagle , he visited the Galápagos Islands, where he made important observations that changed his ideas about the then widely held concept called fixity of species . According to this idea, all present-day species were created in their present form and had changed little or not at all. Darwin began his voyage not long after graduating from Christ’s College of Cambridge University with a degree in theology, and although he was rather indifferent to reli-gion, he fully accepted the biblical account of creation. During the voyage, though, his ideas began to change. For example, some of the fossil mammals he collected in South America were similar to present-day llamas, sloths, and armadillos yet also differed from them. When he real-ized that these animals had descended with modification from ancestral species, he began to question the idea of fixity of species.

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  Defending Your Faith

  Reliable Answers for a New Generation of Seekers and Skeptics: Revised and Expanded Edition

  • Dan Story(Author)
  • 2019(Publication Date)
  • Kregel Publications

    (Publisher)

  evolutionists feel best support their theory. However, as you will see, these same evidences are much more believable and scientifically acceptable when viewed within the creationist’s model. This chapter will demonstrate that the scientific evidence overwhelmingly supports creation.

  The Fossil Evidence

  Historically, the most common evidence for evolution has been the fossil record. Darwinists claim the fossil record displays a gradual evolution of animal and plant life from primitive forms to complex forms with transitional phases between major classes (e.g., between fish and amphibians, amphibians and reptiles, reptiles and birds, and so on).

  But this scenario has virtually no support. There is no evidence that complex life evolved from primitive life forms because no genuine transitional species between any of these groups of animals have ever been found in the tons of fossil-bearing rock recovered over the past one hundred fifty–plus years. If evolution is true, paleontologists should have discovered many thousands of transitional fossil specimens between distinct kinds of animals. One example will drive this point home.

  A widely held evolutionary scenario is that whales evolved from an ancestral land mammal some fifty million years ago. For this to have happened, it would require, among other things, forearms evolving into fins, nostrils moving to the top of the head, and the emergence of tail flukes—not to mention all the other changes that would have had to take place simultaneously within the internal organs. Senior fellow of the Discovery Institute’s Center for Science and Culture, David Belinsky, calculated (his “most modest estimate”) that it would take 50,000 intermediate transitional stages for a land-dwelling mammal to evolve into a sea-dwelling marine mammal. This translates into countless millions of individual specimens. Where are they? The fossil record has yet to reveal them.1

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  Evolution and Belief

  Confessions of a Religious Paleontologist

  • Robert J. Asher(Author)
  • 2012(Publication Date)
  • Cambridge University Press

    (Publisher)

  A literal belief in this particular bit of scripture is irrational based on the principles of nature and common sense. HYPOTHESES DERIVED FROM NATURAL SELECTION Natural selection as a process behind evolution has fared much better than “flood geology” or intelligent design as a source of scientific hypotheses that have withstood many attempts at falsification. Here are several import- ant kinds of observations about the natural world, divided arbitrarily into four interrelated categories that will comprise the remaining chapters of this book. If the Darwin–Wallace theory about natural selection as a pro- cess behind evolution is true, then each class of observation listed below is a logical consequence. EVOLUTION AS A SCIENCE 39 1 Characters and common descent: Evolution by natural selection implies that most or all of life shares a common ancestor. 29 As a result, it predicts that characteristics of living organisms (e.g., avian feathers, mammalian milk) appeared on the Tree of Life independently of the groups of species for which we now regard those features as diagnostic. Following from this, natural selection predicts that certain organisms should mix adaptations and morphologies seen in others, comprising what are popularly known as “missing links,” or species that stretch the definition of exactly what consti- tutes a “bird,” “mammal,” or other such category of living things recognized today. 2 The fossil record: Many species formerly alive are now extinct. On the very large scale of the past 3.5 billion years of life history, evolution by nat- ural selection predicts that species deemed to be ancestral to the most living species should be found in relatively older strata of the Earth’s geological record. Conversely, those extinct species most closely related to specific, modern groups should be found in relatively younger strata.

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