Science Notes For Revision - EVOLUTION PDF
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These notes provide a summary of different concepts related to evolution, including definitions for biodiversity, species diversity, and genetic diversity. It also introduces the theory of evolution and the causes of genetic variation, along with relevant examples. The text covers topics like mutations, gene pools, allele frequencies, along with specific examples such as the bottleneck and founder effects, and their importance to natural selection and speciation.
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Science Notes For Revision "EVOLUTION" - Biodiversity (biological diversity) is defined as the number and variety of genes, species, or ecosystems. - Species diversity is the number of different species within an ecosystem. - Genetic diversity is the range of variation in the genes...
Science Notes For Revision "EVOLUTION" - Biodiversity (biological diversity) is defined as the number and variety of genes, species, or ecosystems. - Species diversity is the number of different species within an ecosystem. - Genetic diversity is the range of variation in the genes within a species. - Evolution is the change in the characteristics (physical traits and appearances) of a species over long periods of time and over several generations. THEORY OF EVOLUTION: - The idea behind evolution is that every living thing on the planet originated from a common ancestor. Causes of Genetic Variation - Genetic variation: mutations within genes that are passed on through generations - Environmental variation: acquired characteristics which are selected for in response to the environment **[MUTATIONS-]** random alterations in genes produce new gene options and new phenotype outcomes - Mutation can occur in all organisms and is the source of new genetic variation. - A change in the genetic code in DNA can lead to a change in the production of the protein that is coded for and produced by that section of DNA. - This can drastically change an organism's characteristics. Gene pool of a population consists of all the copies of all the genes in that population. Allele frequency refers to how common an allele is in a population BOTTLENECK EFFECT FOUNDER EFFECT  Genetic variation is important as it can code for an individuals phenotype, some of which may better suit that organism to a particular environment than others, giving it an increased chance of survival. If it survives it has an increased chance of reproducing and passing that advantageous gene onto its offspring -- which increases overall species survival. NATURAL SELECTION AND SPECIATION - - According to Darwin, the driving force behind evolution is NATURAL SELECTION -
