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Chapter 2: Major Themes in Evolution
Pages 11-26

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From page 11...
... stated that the earth had received the power to produce organisms and criticized the idea that species had originated in accordance with the timetables in Genesis.i During the early 1800s, many naturalists speculated about changes in organisms, especially as geological investigations revealed the rich story laid out in the fossilized remains of extinct creatures. But although ideas about evolution were proposed, they never gained wide acceptance because no one was able to propose a plausible mechanism for how the form of an organism might change from one generation to another.
From page 12...
... 12 Teaching About Evolution and the Nature of Science The Rubble Space Telescope has revealed many astronomical phenomena that ground-based telescopes cannot see. The images at right show disks of matter around young stars that could give rise to planets.
From page 13...
... Variation: Genetically determined differences in the characteristics of members of the same species. Natural selection: Greater reproductive success among particular members of a species arising from genetically determined characteristics that confer an advantage in a particular environment.
From page 14...
... Evolution was thus seen to depend both on genetic mutations and on natural selection. Mutations provided abundant genetic variation, and natural selection sorted out the useful changes from the deleterious ones.
From page 15...
... The modification of DNA through occasional changes or rearrangements in the base sequences underlies the emergence of new traits, and thus of new species, in evolution. At the same time, all organisms use the same molecular codes to translate DNA base sequences into protein amino acid sequences.
From page 16...
... In brief: · Fossils found in rocks of increasing age attest to the interrelated lineage of living things, from the single-celled organisms that lived billions of years ago to [Iomo sapiens. The most recent fossils closely resemble the organisms alive today, whereas increasingly older fossils are progressively different, providing compelling evidence of change through time.
From page 17...
... The continued use and overuse of antibiotics has had the effect of selecting for resistant populations because the antibiotics give these strains an advantage over nonresistant strains.4 ~~ ~ . ~ >A ~ The North American lacewing species Chrysoperla cameo and Chrysoperla downesi separated from a common ancestor species recently in evolutionary time and are very similar.
From page 18...
... For example, many closely relate(1 species have been identified that split from a common ancestor very recently in evolutionary terms. An example is provided by the North American lacewings Chrysoperta cornea and Chrysoperla downesi.
From page 19...
... Homo sapiens, one of 185 known living species in the primate order, is a member of the hominoids, a category that includes orangutans, gorillas, and chimpanzees. The succession of species that would give rise to humans seems to have separated from the succession that would lead to the apes about 5 to 8 million years ago.
From page 20...
... For example, in the 1960s Robert MacArthur carefully stu(lie(1 three North American warblers of the same genus that were regularly seen feeding on insects in coniferous trees in the same areasindeed, often in the same trees. MacArthur's painstaking observations revealed that the three were actually specialists: one fell on insects on the major branches near the trunk; another occupied the mid-regions of branches and ate from different parts of the foliage; and the third fed on insects occupying the finest needles near the periphery of the tree.
From page 21...
... plants manufacture and store chemicals that deter herbivorous insects; but usually one or more insect species will have evolved biochemical mechanisms for inactivating the deterrent, providing them with a plant they can eat relatively free of competitors. Another classic example of coevolution involves the introduction of rabbits and the myxomatosis virus into Australia.
From page 22...
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From page 23...
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