based on the given description of each chapters, identify what component theory (Evolution as such, Common descent, Gradualism, Populational change, or Natural selection) does each chapter fall into?
The theory of evolution by Darwin is a composite theory, i.e. it has five component theories:
1. Evolution as such is the simple proposition that the characteristics of lineages of organisms change over time
2. Common descent is a radically different view of evolution than the scheme Lamarck proposed. Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time.
3. Gradualism – Darwin’s proposition that the differences between even radically different organisms have evolved incrementally, by small steps through intermediate forms. The alternative to this theory, as discussed in later sections, is saltation with great reference to large differences that are believed to have evolved by leaps without intermediates.
4. Populational change – Darwin’s thesis that evolution occurs by changes in the proportions of individuals within a population that have different inherited characteristics.
5. Natural selection – Darwin’s brilliant hypothesis, independently conceived by Wallace. Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways.
Given the titles of the three chapters of the theory of Evolution with their descriptions:
CHAPTER I.
Variation under Domestication.
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Causes of Variability—Effects of Habit and the use or disuse of Parts—Correlated Variation—Inheritance—Character of Domestic Varieties—Difficulty of distinguishing between Varieties and Species—Origin of Domestic Varieties from one or more Species—Domestic Pigeons, their Differences and Origin—Principles of Selection, anciently followed, their Effects—Methodical and Unconscious Selection—Unknown Origin of our Domestic Productions—Circumstances favourable to Man's power of Selection
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CHAPTER II.
Variation under Nature.
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Variability—Individual differences—Doubtful species—Wide-ranging, much diffused, and common species, vary most—Species of the larger genera in each country vary more frequently than the species of the smaller genera—Many of the species of the larger genera resemble varieties in being very closely, but unequally, related to each other, and in having restricted ranges
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CHAPTER III.
Struggle for Existence.
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Its bearing on natural selection—The term used in a wide sense—Geometrical ratio of increase—Rapid increase of naturalised animals and plants—Nature of the checks to increase—Competition universal—Effects of climate—Protection from the number of individuals—Complex relations of all animals and plants throughout nature—Struggle for life most severe between individuals and varieties of the same species: often severe between species of the same genus—The relation of organism to organism the most important of all relations
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The question is, based on the given description of each chapters, identify what component theory (Evolution as such, Common descent, Gradualism, Populational change, or Natural selection) does each chapter fall into?
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The theory of evolution by Darwin is a composite theory, i.e. it has five component theories:
1. Evolution as such is the simple proposition that the characteristics of lineages of organisms change over time
2. Common descent is a radically different view of evolution than the scheme Lamarck proposed. Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time.
3. Gradualism – Darwin’s proposition that the differences between even radically different organisms have evolved incrementally, by small steps through intermediate forms. The alternative to this theory, as discussed in later sections, is saltation with great reference to large differences that are believed to have evolved by leaps without intermediates.
4. Populational change – Darwin’s thesis that evolution occurs by changes in the proportions of individuals within a population that have different inherited characteristics.
5. Natural selection – Darwin’s brilliant hypothesis, independently conceived by Wallace. Natural selection is the process through which populations of living organisms adapt and change. Individuals in a population are naturally variable, meaning that they are all different in some ways.
Given the titles of the three chapters of the theory of Evolution with their descriptions:
CHAPTER IV.
Natural Selection; or the Survival of the Fittest.
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Natural Selection—its power compared with man's selection—its power on characters of trifling importance—its power at all ages and on both sexes—Sexual Selection—On the generality of intercrosses between individuals of the same species—Circumstances favourable and unfavourable to the results of Natural Selection, namely, intercrossing, isolation, number of individuals—Slow action—Extinction caused by Natural Selection—Divergence of character, related to the diversity of inhabitants of any small area, and to naturalisation—Action of Natural Selection, through Divergence of Character and Extinction, on the descendants from a common parent—Explains the grouping of all organic beings—Advance in organisation—Low forms preserved—Convergence of character—Indefinite multiplication of species
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CHAPTER V.
Laws of Variation.
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Effects of changed conditions—Use and disuse, combined with natural selection; organs of flight and of vision—Acclimatisation—Correlated variation—Compensation and economy of growth—False correlations—Multiple, rudimentary, and lowly organised structures variable—Parts developed in an unusual manner are highly variable: specific characters more variable than generic: secondary sexual characters variable—Species of the same genus vary in an analogous manner—Reversions to long-lost characters
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CHAPTER VI.
Difficulties of the Theory.
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Difficulties of the theory of descent with modification—Absence or rarity of transitional varieties—Transitions in habits of life—Diversified habits in the same species—Species with habits widely different from those of their allies—Organs of extreme perfection—Modes of transition—Cases of difficulty—Natura non facit saltum—Organs of small importance—Organs not in all cases absolutely perfect—The law of Unity of Type and of the Conditions of Existence embraced by the theory of Natural Selection
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The question is, based on the given description of each chapters, identify what component theory (Evolution as such, Common descent, Gradualism, Populational change, or Natural selection) does each chapter fall into?
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