Chapter 20: Development of Evolutionary Thinking

1.

Question: What is the fundamental organizing principle of Biology? Answer: Evolutionary science.

2.

Question: How do genetic basis of inheritance, molecular biology, developmental biology, and evolutionary biology provide a better understanding of organisms? Answer: Together, they provide a better understanding of an organism's function and its relationship with its physical and biotic environment.

3.

Question: When did evolutionary thinking emerge as a significant school of thought? Answer: In the nineteenth century in Europe, specifically gaining significance at the end of the eighteenth century.

4.

Question: Who independently described natural selection as the major basis of biological evolution? Answer: Charles Darwin and Alfred Russel Wallace.

5.

Question: When was the field of evolutionary science firmly established? Answer: Not until Charles Darwin and Alfred Russel Wallace independently described natural selection in 1858, providing an explanation for how species change and new species evolve.

6.

Question: What is the definition of biological evolution? Answer: Biological evolution occurs when specific processes cause the genomes of organisms to differ from those of their ancestors.

7.

Question: What acts as raw materials for evolution? Answer: Genetic changes, phenotypic alterations, and the environment.

8.

Question: What is Scala Naturae? Answer: The entire natural world arranged as a single continuum in a hierarchical ladder of all matter and life, as decreed by God.

9.

Question: What is Natural Theology? Answer: The belief that each organism was specially created by God, species would never change or become extinct, and new species would never arise.

10.

Question: What was a goal of natural theologists? Answer: To name and catalog all creations, merging Aristotle's Scala naturae and the Great Chain of Being.

11.

Question: How did the Great Chain of Being illustrate nature's hierarchy? Answer: As a series of steps: stone, flame, plant, animal, man, heaven, angel, God.

12.

Question: What was the limitation of the Great Chain of Being for classifying life's diversity? Answer: It provided a fixed hierarchy, but was not very useful for classifying life's diversity at a finer scale.

13.

Question: When was the birth of Taxonomy and systematics? Answer: In the 1600s.

14.

Question: What is Taxonomy? Answer: The branch of Biology that classifies organisms.

15.

Question: Who organized all living things known at that time into a nested hierarchy of groups or taxa? Answer: Carl Linnaeus.

16.

Question: What is the Binomial system of nomenclature? Answer: The modern system of naming organisms using two parts: Genus species.

17.

Question: What did Linnaeus believe about the classification of plants and animals? Answer: He believed they had been created by God and could be placed into natural groups revealing God's divine plan.

18.

Question: What is the significance of the 15th-18th century in the history of science? Answer: Modern science came of age, with scientists proposing mechanistic theories to explain physical phenomena.

19.

Question: Who proposed the heliocentric model? Answer: Nicolaus Copernicus.

20.

Question: Who formulated the theory of universal gravity and invented calculus? Answer: Isaac Newton.

21.

Question: Who is regarded as the "Father of Modern Philosophy" and made important connections between geometry and algebra? Answer: René Descartes.

22.

Question: Who established the importance of observation, experimentation, and inductive reasoning? Answer: Francis Bacon.

23.

Question: Scientific Method process. Answer: Generally involves observation, asking a question, forming a hypothesis, making predictions, experimentation, analyzing results, and checking if data supports the hypothesis.

24.

Question: What new disciplines promoted a growing awareness of change in living forms, challenging Natural Theology? Answer: Biogeography, Comparative morphology, and Paleobiology.

25.

Question: What is Biogeography? Answer: The branch that studies the world distribution of plants and animals.

26.

Question: What puzzling questions did biogeography raise for natural theology? Answer: Why did some species have limited geographical distribution, why were species from far-flung locations similar, and where did all the new species fit in Scala naturae.

27.

Question: What is Comparative morphology? Answer: The comparison of the morphology or anatomical structures of organisms.

28.

Question: What similarities were observed in comparative morphology (e.g., forelimbs)? Answer: Similarities in body plans, construction using similar tissues, and homologous traits having developmental similarity.

29.

Question: What are homologous traits? Answer: Characteristics that are similar in two species because of genes they inherited from a common ancestor.

30.

Question: What was the natural theologists' counter argument to morphological similarities despite different functions? Answer: Body plans were perfect and there was no need to invent a new plan for every species; the creator used the same materials.

31.

Question: What did George-Louis Buffon observe that puzzled natural theology? Answer: The existence of body parts with no apparent function, like the two toes on pigs' feet that don't touch the ground.

32.

Question: What are vestigial structures/organs? Answer: Useless parts or tissues that had some function in ancestral organisms, or traits/organs that have lost all or most of their original functions through evolution.

33.

Question: Examples of vestigial structures in humans. Answer: Coccyx (tailbone), vermiform appendix, wisdom tooth.

34.

Question: What is Paleobiology? Answer: The study of fossils.

35.

Question: What is stratification in geology? Answer: The horizontal layering of sedimentary rocks.

36.

Question: What pattern was observed in the fossil record regarding rock layers? Answer: Relatively small and simple fossils appeared in deeper layers, while more complex fossils appeared in the layers above them.

37.

Question: Who was a founder of paleobiology and realized fossil layers represented organisms from successive times? Answer: Georges Cuvier.

38.

Question: What is Catastrophism? Answer: The theory that each layer of fossils represents creatures that had died in a local catastrophe (e.g., floods), causing abrupt changes between geological strata.

39.

Question: Who proposed Gradualism? Answer: James Hutton.

40.

Question: What is Gradualism? Answer: The idea that slow, continuous physical processes, acting over long periods of time, produced Earth’s geological features; variations come about gradually.

41.

Question: Who proposed Uniformitarianism? Answer: Charles Lyell.

42.

Question: What is Uniformitarianism? Answer: The geological processes that sculpted Earth’s surface over long periods are exactly the same as the processes observed today.

43.

Question: Who proposed the most significant pre-Darwinian evolutionary hypothesis? Answer: Jean Baptiste de Lamarck.

44.

Question: Lamarck's theory overview. Answer: Life was driven from simplicity to complexity; species change over time in response to environments, and acquired characteristics are passed on.

45.

Question: What metaphysical principle did Lamarck believe caused organisms to become better suited to their environments? Answer: A perfecting principle.

46.

Question: Lamarck's mechanisms of evolutionary change. Answer: 1. Principle of use and disuse. 2. Inheritance of acquired characteristics.

47.

Question: What is the Principle of use and disuse? Answer: Body parts grow in proportion to how much they are used, and structures not used get weaker and shrink.

48.

Question: What is the Inheritance of acquired characteristics? Answer: Changes an organism acquires during its lifetime are inherited by its offspring.

49.

Question: What was a major downfall of Lamarck's theory regarding acquired characteristics? Answer: Structural changes acquired during an organism's lifetime are not inherited by the next generation.

50.

Question: When did Charles Darwin embark on the voyage of HMS Beagle? Answer: In 1831.

51.

Question: What was Captain Robert Fitzroy looking for when he invited Darwin on the Beagle voyage? Answer: An unofficial naturalist and a gentleman for companionship to avoid depression on the long journey.

52.

Question: What type of specimens did Darwin collect during his voyage? Answer: Fossils of extinct mammals, birds, barnacles, plants.

53.

Question: What geological observations did Darwin make in South America? Answer: Recognized layers of rock that formed gradually and were reworked into mountains/valleys, observed shoreline uplift after an earthquake.

54.

Question: Darwin's observation about fossils resembling organisms in the same region. Answer: Fossils like glyptodonts resembled living organisms like armadillos in the same region.

55.

Question: Darwin's reasoning for fossils resembling living organisms in the same region. Answer: Living armadillos may be living descendants of the extinct glyptodonts.

56.

Question: Darwin's observation about animals in different South American habitats. Answer: Animals encountered in different South American habitats clearly resembled each other, but differed from species in similar habitats on other continents (e.g., nutria vs beaver).

57.

Question: Darwin's reasoning for why animals in different South American habitats resembled each other. Answer: They had inherited their similarities from a common ancestor.

58.

Question: Darwin's observation about the distribution patterns on the Galapagos Islands. Answer: Many species resembled those on the distant South American mainland, but varied slightly from island to island.

59.

Question: Darwin's hypothesis about Galapagos species origins. Answer: The plants and animals of the Galapagos islands were descended from a South American ancestor, and each species had changed after being isolated on a particular island.

60.

Question: Darwin's observation about Galapagos finches. Answer: Great variability in bill shapes among finches from different islands.

61.

Question: Darwin's questions about Galapagos finches. Answer: Why did finches on nearby islands differ slightly, and how did these different species arise?.

62.

Question: What common knowledge and hypotheses did Darwin use to develop his theory? Answer: Selective breeding/Heredity, artificial selection, the struggle for existence, and natural selection.

63.

Question: Darwin's observation about offspring production. Answer: Most organisms produce more than one or two offspring.

64.

Question: Darwin's observation about population size. Answer: Populations do not increase in size indefinitely.

65.

Question: Darwin's observation about resources. Answer: Food and other resources are limited for most populations.

66.

Question: Darwin's observation about individual characteristics. Answer: Individuals within populations exhibit variability in many characteristics.

67.

Question: Darwin's observation about inheritance of variations. Answer: Many variations appear to be inherited by subsequent generations.

68.

Question: Darwin's inference about competition. Answer: Individuals in a population compete for limited available resources.

69.

Question: Darwin's inference about hereditary traits enabling survival/reproduction. Answer: If certain hereditary traits enabled some individuals to survive and reproduce more than others, those traits would become more common in the next generation.

70.

Question: What is Natural Selection, according to Darwin's first fundamental insight? Answer: The environment selects on variation in the traits of individual organisms because some variants are more successful at surviving and reproducing.

71.

Question: What is the concept of Common Ancestry, according to Darwin's second fundamental insight? Answer: All species have descended from one or a few common ancestors; species sharing recent ancestry tend to resemble one another.

72.

Question: How does natural selection allow species to change and diverge? Answer: By favoring individuals well adapted to their environments, leading to evolutionary divergence over time.

73.

Question: What is Descent with modification? Answer: The evolutionary alteration and diversification of ancestral species; species diverge from a common ancestor, accumulating differences over time.

74.

Question: What was a problem with Darwin's views that was later resolved? Answer: He used complex characteristics but lacked the genetic basis of heredity to fully explain variation and inheritance.

75.

Question: Who studied simple characteristics in pea plants and proposed factors (genes) control the expression of traits? Answer: Gregor Mendel.

76.

Question: What is "Mutationism"? Answer: An early 20th-century idea that evolution occurs in spurts induced by chance appearance of "hopeful monsters," not gradual change.

77.

Question: Who identified that genes are present in chromosomes? Answer: T. H. Morgan.

78.

Question: What field links the ideas of Mendel and Darwin and recognizes the importance of genetic variation? Answer: Population genetics.

79.

Question: What is the Modern Synthesis? Answer: A unified theory of evolution (1930s-1940s) integrating data from various fields (biogeography, morphology, embryology, paleontology, taxonomy).

80.

Question: Principles embraced by proponents of the Modern synthesis. Answer: Focus on gradual evolutionary change within populations, consider natural selection the primary mechanism, and support Darwin's gradualism.

81.

Question: What are the two basic levels of evolutionary change identified by Modern Synthesis? Answer: Microevolution and Macroevolution.

82.

Question: What is Microevolution? Answer: Describes small-scale genetic changes in populations in response to specific environmental shifts (e.g., shift in finch bill size).

83.

Question: What is Macroevolution? Answer: Describes larger-scale evolutionary changes in species and more inclusive groups (above the species level).

84.

Question: How does Macroevolution result from Microevolution? Answer: Macroevolution results from the gradual accumulation of microevolutionary changes.

85.

Question: What is a key point about variation and natural selection? Answer: Natural selection does not create variation or new genetic traits; it selects for genes already present.

86.

Question: How are new genetic strains added to a population? Answer: Through mutation and horizontal gene transfer.

87.

Question: Evidence for evolutionary change comes from many disciplines, including: Answer: Adaptation by Natural Selection, The Fossil Record, Historical Biogeography, Comparative Morphology, and Molecular Techniques.

88.

Question: Example of natural selection operating on a short time scale. Answer: The development of pesticide resistance in insects or antibiotic resistance in bacteria.

89.

Question: How does the fossil record document evolutionary change? Answer: It documents continuity in morphological characteristics, providing evidence of ongoing change in biological lineages.

90.

Question: What fossil is considered a basic common ancestor of modern birds? Answer: Archaeopteryx lithographica.

91.

Question: How does Historical Biogeography support Darwin's theory? Answer: Geographical distributions of plants and animals are consistent with descent with modification, showing species on a continent are related and often distinct from others.

92.

Question: How does Comparative Morphology support evolution? Answer: Analyses of living and extinct organisms reveal homologous traits, reflecting inheritance from common ancestors and divergence over time.

93.

Question: How do molecular techniques contribute to understanding evolution? Answer: Provide powerful tools for exploring all aspects of life, including genome-level alterations and genetic changes.

94.

Question: Hox gene process in limb development. Answer: In reptiles, mammals, birds, Hoxc6 expressed alone causes limb buds to develop; when Hoxc6 and Hoxc8 are expressed together, only ribs develop.

95.

Question: Role of Hox gene expression in snake limb loss. Answer: In snakes, a mutation caused Hoxc8 expression to extend forward in the body, preventing limb bud formation where forelimbs would develop.

96.

Question: ZRS/shh gene process in limb development. Answer: ZRS (Zones of polarizing activity Regulatory Sequence) is an enhancer for the sonic hedgehog gene (shh), which produces a protein that triggers limb growth.

97.

Question: Role of ZRS/shh in snake hindlimb loss. Answer: Most recently evolved snakes have a less functional ZRS, leading to a lack of shh expression and therefore no hindlimb development. Primitive snakes (boas/pythons) retain some ZRS function, resulting in vestigial hindlimbs.

98.

Question: Woolly mammoth cold adaptation genes/parts. Answer: Differences in about 1600 genes coding for proteins involved in metabolism of fats/sugars, development of skin/hair, size of sebaceous glands, and immune system responses to cold viruses.

99.

Question: Which specific gene variant contributed to the woolly mammoth's cold tolerance? Answer: A variant TRPV3 gene, which is less active than in elephants and is involved in temperature sensation, hair growth, and fat storage.

100.

Question: What is Orthogenesis? Answer: An early 20th-century idea that evolution produces new species with the goal of improvement, derived from Scala Naturae.

101.

Question: How is the modern understanding of evolution different from Orthogenesis? Answer: Evolution proceeds as an ongoing process of dynamic adjustment, not a goal-oriented drive towards perfection or improvement.

102.

Question: Biological evolution process. Answer: Specific processes cause the genomes of organisms to differ from those of their ancestors, leading to genetic and phenotypic changes over time in populations.

103.

Question: Natural selection process. Answer: Variation exists in traits; individuals with advantageous adaptive traits are more successful at surviving and reproducing in a specific environment, and these traits become more common in subsequent generations.

104.

Question: Descent with Modification process. Answer: Species diverge from common ancestors over long spans of time, accumulating differences and leading to the diversity observed today.

105.

Question: Linnaean System of Classification parts. Answer: A nested hierarchy of groups or taxa, such as species, genus, family, order, class, phylum, kingdom.