Randomness and chance are also involved in genetic variation, and both harmful and beneficial mutation. Genetic variation contributes to the diversity of genes in a population.11 For example, eye colour, skin colour, ear shape, hair colour all vary differently in humans.11 The Hardy-Weinberg Principle is a method for geneticists to study genetic variation and evolution. It is a model that predicts the outcome and offspring of a non-evolving population. This model is then compared to an existing population and the differences between the non-evolving population and the existing population display evolution.12 An example is polyploidy. In animals, polyploidy is extremely rare, however, in plants, polyploidy is common and it is the source of
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For instance, a mutation on the hemoglobin gene can be harmful to organisms living at high altitudes but may not cause a big effect on organisms that live at sea level.15 Positive mutations allow organisms to survive, a result of natural selection. On the other hand, harmful mutations often lead to diseases such as sickle cell anemia. For example, the sickle cell gene mutation is prominent in Africa where malaria is rampant. Although sickle cell anemia causes major artery clogs and lower levels of hemoglobin, individuals with sickle cell anemia are immune to malaria. This mutation in the genome was kept in the population in Africa because those who had the gene survived malaria and were able to produce offspring15, thereby passing down their genes and contributing to natural selection and evolution. The example of sickle-cell anemia and malaria is also an example of microevolution. Microevolution is essentially evolution on a small-scale within a certain population. This type of evolution involves the heredity and change of alleles.16 In the case of sickle-cell anemia and malaria, many people from Africa are heterozygous for the gene because they are immune to …show more content…
It shows the relationships between organisms inferred from physical and genetic traits.18For instance, it is inferred that humans are related to hominids due to similar traits19, and that dogs are related to wolves.20 Phylogenetic trees are diagrams that represent the possible evolutionary relationships between different species. While phylogenetic trees are diagrams usually showing actual evolutionary relationships, cladograms are diagrams that show arbitrary and hypothesized evolutionary relationships.21 Comparative anatomy is used to study evolutionary changes and provide insight into evolutionary relationships. Comparisons of body structures are made to create links between different species.22 Darwin used comparative anatomy to show how structural differences and similarities were a result of natural selection and the origin of certain species.22 There are a few types of comparative anatomy. Homologous comparative anatomy is when there are the same structural traits shared between species but these structures do not perform the same function.22 For example, tetrapods originated from ancient aquatic finned animals with carpels and metacarpals.22 On the other hand, analogous comparative anatomy is when certain species perform the same function but the structures that enable that function are not the same.22 For instance, bees and birds both fly, but
For instance, a mutation on the hemoglobin gene can be harmful to organisms living at high altitudes but may not cause a big effect on organisms that live at sea level.15 Positive mutations allow organisms to survive, a result of natural selection. On the other hand, harmful mutations often lead to diseases such as sickle cell anemia. For example, the sickle cell gene mutation is prominent in Africa where malaria is rampant. Although sickle cell anemia causes major artery clogs and lower levels of hemoglobin, individuals with sickle cell anemia are immune to malaria. This mutation in the genome was kept in the population in Africa because those who had the gene survived malaria and were able to produce offspring15, thereby passing down their genes and contributing to natural selection and evolution. The example of sickle-cell anemia and malaria is also an example of microevolution. Microevolution is essentially evolution on a small-scale within a certain population. This type of evolution involves the heredity and change of alleles.16 In the case of sickle-cell anemia and malaria, many people from Africa are heterozygous for the gene because they are immune to …show more content…
It shows the relationships between organisms inferred from physical and genetic traits.18For instance, it is inferred that humans are related to hominids due to similar traits19, and that dogs are related to wolves.20 Phylogenetic trees are diagrams that represent the possible evolutionary relationships between different species. While phylogenetic trees are diagrams usually showing actual evolutionary relationships, cladograms are diagrams that show arbitrary and hypothesized evolutionary relationships.21 Comparative anatomy is used to study evolutionary changes and provide insight into evolutionary relationships. Comparisons of body structures are made to create links between different species.22 Darwin used comparative anatomy to show how structural differences and similarities were a result of natural selection and the origin of certain species.22 There are a few types of comparative anatomy. Homologous comparative anatomy is when there are the same structural traits shared between species but these structures do not perform the same function.22 For example, tetrapods originated from ancient aquatic finned animals with carpels and metacarpals.22 On the other hand, analogous comparative anatomy is when certain species perform the same function but the structures that enable that function are not the same.22 For instance, bees and birds both fly, but