Chapter 22 Reading Quiz

2. Chapter 22 Reading Quiz • Who wrote “On the Origin of Species”? • What branch of biology is concerned with naming and classifying life? • What is the proposed mechanism for evolution? • What is the geographic distribution of a species known as? • In what types of rocks are fossils typically found?

3. 1. State the two major points Darwin made in The Origin of Species concerning the Earth’s biota. • Species evolved from ancestral species that were not specially created • Natural selection is a mechanism that could result in this evolutionary change 

4. 2. Compare and contrast Plato’s philosophy of idealism and Aristotle’s scala naturae. • Plato – idealism/essentialism: believed that there were two coexisting worlds  an ideal, eternal, real world and an illusionary imperfect world that humans perceive with their senses • Aristotle – beliefs also excluded evolution - recognized that organisms vary from simple to complex and believed that they could be placed on a scale of increasing complexity (scala naturae) - species fixed and didn’t evolve 

5. 3. Describe Carolus Linnaeus’ contribution to Darwin’s theory of evolution. • 1707 – 1778; Swedish; sought order in the diversity of life • Father of taxonomy (naming and classifying organisms) - developed binomial nomenclature - hierarchy of taxonomic categories - did NOT imply evolutionary relationships - believed that species were permanent creations 

6. 4. Describe Georges Cuvier’s contribution to paleontology. • Cuvier founded the study of fossils or “paleontology” • Realized life’s history was recorded in fossil-containing strata and documented succession • Understood that extinction had been a common occurrence in the history of life science as new species appeared and others disappeared 

7. 5. Explain how Cuvier and his followers used the concept of catastrophism to oppose evolution. • Catastrophism  theory that major changes in the earth’s crust are the result of catastrophic events rather than from gradual processes of change • Proposed that there were periodic localized catastrophes resulted in mass extinctions • After local flora and fauna had become extinct, the region would be repopulated by foreign species 

8. 6. Explain how the principle of gradualism and Charles Lyell’s theory of uniformitarianism influenced Darwin’s ideas about evolution. • Gradualism  principle that profound change is the cumulative product of slow, continuous processes • Uniformitarianism  theory that geological processes are uniform and have operated from the origin of the earth to the present • Darwin rejected uniformitarianism, but was influenced by that the earth must be ancient and slow and subtle processes persist and cause substantial change 

9. 7. Describe Jean Baptiste Lamarck’s model for how adaptations evolve. …mechanism by which specific adaptations evolve: • Use & disuse  those body organs used extensively to cope with environment become larger and stronger while those not used deteriorate • Inheritance of acquired characteristics: the modifications an organism acquired during its lifetime could be passed along to its offspring - was incorrect, yet evolution is the best explanation and the earth is ancient - adaptation to the environment is a primary product of evolution 

10. 8. Describe how Charles Darwin used his observations from the voyage of the HMS Beagle to formulate and support his theory of evolution. • All species have such great potential fertility that their population size would increase exponentially is all individuals that are born reproduced successfully • Populations tend to remain stable in size, except for seasonal fluctuations • Environmental resources are limited • Individuals of a population vary extensively in their characteristics; no two are alike • Much of this variation is heritable; survival is not random – unequal ability 

11. 9. Describe how Alfred Russel Wallace influenced Charles Darwin. • Wallace was a specimen collector in the East Indies and sent a letter that detailed a theory of natural selection almost identical to Darwin’s • Darwin evaluated the theory and sent it to publication • Darwin is considered the main author of the idea because he developed and supported natural selection much more extensively than Wallace 

14. 10. Explain what Darwin meant by the principle of common descent and “descent with modification”. • Principle of common descent  closely related animals share a recent common ancestor, etc. • Descent with modification  perception that there is a unity in life with all organisms related through descent as diverse adaptations accumulate through years 

16. 11. Explain what evidence convinced Darwin that species change over time. • Perceived from studying the 14 types of finches from the Galapagos that the origin of a new species and adaptation were closely related processes, as new species could arise from an ancestral population by gradually accumulating adaptations to a different environment • Example: isolated populations of a species - food sources 

17. 12. State, in your own words, three inferences Darwin made from his observations, which led him to propose natural selection as mechanism for evolutionary change. • Production of more individuals than the environment can support leads to a struggle for existence among individuals of a population, with only a fraction of offspring surviving each generation • Survival in the struggle for existence is not random but depends in part on the hereditary constitution of the surviving individuals • The unequal ability of individuals to survive and reproduce will lead to a gradual change in a population with favorable characteristics accumulating over generations 

18. 13. Explain why variation was so important to Darwin’s theory. • Variation and overproduction in populations make natural selection possible - the end product of natural selection is adaptation of organisms to their environments - variations in a population arise by chance, but natural selection is not a chance phenomenon 

19. 14. Explain how Reverend Thomas Malthus’ essay influenced Charles Darwin. • Already aware of the struggle for existence caused by overproduction • The capacity for overproduction is common to all species, and only a fraction of new individuals complete development and leave offspring of their own; the rest die or are unable to reproduce 

20. 15. Distinguish between artificial selection and natural selection. • Natural selection  variation and overproduction in populations – the most fit individuals pass on their genes; results from environmental editing • Artificial selection  breeding of domesticated plants and animals have modified species • Conclusion  if so much change is achieved by artificial selection in a short period of time (humans), natural selection should be capable over hundreds of thousands of years 

21. 16. Explain why the population is the smallest unit that can evolve. • Population = a group of interbreeding individuals belonging to a particular species and sharing a common geographic area  Evolution can only be measured as change in relative proportions of variations in a population over several generations 

22. 17. Using some examples, explain how natural selection results in evolutionary change. • Finch beaks on the Galapagos - average beak depth oscillates with rainfall - natural selection is situational • Butterfly reproduction - they choose different plants depending on where they were laid • Antibiotic resistance in bacteria • Body size of guppies exposed to different predators 

24. 18. Explain why the emergence of population genetics was an important turning point for evolutionary theory. • Natural selection is a consequence of interactions between individual organisms and their environment but INDIVIDUALS do NOT evolve - acquired characteristics are not inherited • Evolutionists must distinguish between adaptations an organism acquires during it’s lifetime and those inherited adaptations that evolve in a population over many generations as a result of natural selection 

25. 19. Describe the lines of evidence Charles Darwin used to support the principle of common descent. 1. Biogeography – the geographical distribution of species 2. Fossil record – appearance of branches in the phylogenetic tree 3. Comparative anatomy – anatomical similarities among species grouped in the same taxonomic category are a reflection of their common descent 4. Comparative embryology – closely related organisms go through similar stages in their embryonic development • Theory  “ontogeny recapitulates phylogeny” the embryonic development of an individual organism is a replay of the evolutionary history of the species 5. Molecular biology – an organism’s hereditary background is reflected in its genes and their protein products - the closer two species are taxonomically, the higher the % DNA in common 

28. 20. Describe how molecular biology can be used to study the evolutionary relationships among organisms. • Closely related species have proteins of similar amino acid sequences (resulting from inherited genes) • Substantiated Darwin’s idea that all forms of life are related to some extent through branching descent from the earliest organisms 

30. 21. Explain the problem with the statement that Darwinism is “just a theory”. • Flawed because of: 1. Modern species evolved from ancestral forms 2. The mechanism for evolution is natural selection ( Darwin’s two claims) • That species EVOLVE (change over time) is FACT, the mechanism (how this occurs) is THEORY 

31. 22. Distinguish between the scientific and colloquial use of the word “theory”. • In science, “theory” is very different from the colloquial use of the word, which comes closer to what scientists mean by a hypothesis or educated guess • Unifying concepts do not become scientific theories unless their predictions stand up to thorough and continuous testing by experiment and observation 