Introduction
Evolution is a very interesting concept in anthropology. It refers to the biological populations’ alteration of the inherited characteristics over successive generations. The processes in evolution bring diversity at each biological organization level including, individual organisms, molecules like proteins and DNA, and species. According to what we know, life on this universe actually originated and afterwards evolved from universal common ancestor. Perhaps this is what makes the subject of evolution appear more interesting since through it we get well informed about where we originated from and about our evolution.
The concept of evolution is basically categorized under both micro and macroevolution processes. Microevolution refers to changes in the allele frequencies which occur overtime within a given population. For that reason, microevolution refers to the smaller evolutionary changes. For that reason, microevolution is gene pool changes of a population over a certain period of time that result in fairly small changes to organisms found in the population. A good example of such changes includes species’ size or coloring change. This change is essentially as a result of the four processes which in this case are mutation, gene flow, genetic drift, and selection both artificial and natural.
Mutation is actually a nucleotide sequence change of an organism genome, extra chromosomal genetic element, or virus. These processes come as a result of unrepaired damage to the RNA genomes or to DNA, the deletion or insertion of DNA segments by the mobile genetic elements, or from the errors that result from replication process. Mutations therefore play an imperative role in both abnormal and normal biological processes.
Natural selection is a process whereby the traits that characterizes a certain population can essentially change overtime when the individuals in it vary in heritable traits, which are accountable for differences in reproduction and survival. Gene flow is changes in the allele frequency which result from individual migration between populations. In the absence of this process, the populations can be genetically distinct by genetic drift from one another. Genetic drift is a genetic variation among the allele frequencies as a result of random chance in a population. The alleles that are in the population offspring are actually a random sample of those that the parents have. In this gene drift, chance determines whether an individual reproduces or survives. The allele frequency in a population refers to the percentage or fraction of the population gene copies as compared to the whole number of gene alleles which share a certain form.
On the other hand, macroevolution is the evolution on a scale of gene pools that are separated. The focus of macroevolution is on the change which occurs above or at the species level. In this type of evolution the newer organisms are considered as entirely new species, which are unable to mate with the ancestors. The speciation process may in essence fall within the purview of both, depending on forces that are thought to drive it. The evolutionary biology, paleontology, genomic phylostratigraphy, and comparative genomics contribute the most evidence for the processes and patterns, which can be classified as Macroevolution. A good example of this phenomenon is feathers appearance during birth evolution from theropod dinosaurs.
Genetic variation is a phenomenon that is related to microevolution. It is in reality variation in genes alleles that occur both among and within populations. It is important since it provides the natural selection genetic material. Isolating mechanisms is another concept that is vital in evolution. These are features of morphology, genetics, or behavior that serve to stop breeding between the species. Reproductive isolation of the populations is therefore established. Particularly it is crucial to the concept of biological species since species are essentially defined by the reproduction isolation.
