Evolution-Formulas

– All formulas of the chapter at one glance. 1 Hardy-Weinberg Equilibrium Hardy-Weinberg principle states that the genetic constitution in a population remains constant if there is no external influence. This statement gives us a formula that is used to solve the numerical problems of this chapter. Check the formula and the example below. 2 Calculating …

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Evidences from morphology and anatomy

1. Comparative morphology and anatomy of individual organ and organ systems of diverse forms of organisms reveal their phylogenetic relationships and thus provides important evidences of evolution.2. Homology is a relationship defined between structures or DNA derived from a common ancestor and illustrates descent from a common ancestor.3. A common example of homologous structures in …

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Stages in Human Evolution

The following are the stages of human evolution: 1. Dryopithecusi) Ancestors of both man and apes. ii) Lived in China, Africa, Europe and India. iii) Predominantly herbivores2. Ramapithecusi) First remains were discovered from the Shivalik range in Punjab and later in Africa and Saudi Arabia. ii) Lived in open grasslands. iii) Thickened tooth enamel, robust jaws and shorter caninesiv) Usage of …

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Mutation theory of Hugo de Vries

The salient features of mutation theory are as follows:1. Mutations or discontinuous variations are the raw material of evolution.2. Mutations appear all of a sudden. They become operational immediately.3. Unlike Darwin’s continuous variations or fluctuations, mutations do not revolve around the mean or normal character of the species.4. The same type of mutations can appear …

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Types of natural selection

Natural selection is of three types directional, stabilizing, and disruptive selection.1. Directional selection occurs when natural selection favors one extreme of continuous variation. Over time, the favored extreme will become more common and the other extreme will be less common or lost.3. Stabilizing selection occurs when natural selection favors the intermediate states of continuous variation. Over time, the intermediate …

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