Final answer:
Genetic changes contributing to evolution include genetic drift, gene flow, mutation, nonrandom mating, and the forces of natural selection. Both microevolution and macroevolution encompass these mechanisms, resulting in small or large-scale changes respectively. Such genetic alterations also play a role in the development of diseases, such as cancer.
Step-by-step explanation:
Genetic Changes in Evolution
The genetic changes that contribute to gene alteration and genome evolution include several mechanisms. Genetic drift refers to changes in allele frequencies due to random sampling effects, especially in small populations. Gene flow is the transfer of alleles between populations, which can introduce new genetic material and alter allele frequencies. Mutation is a direct change in the DNA sequence, which can create new alleles and serves as the raw material for evolution. Nonrandom mating might affect which individuals reproduce, thus influencing allele frequencies. Environmental variances can lead to differential survival and reproduction, called natural selection, which in turn changes allele frequencies in a population over time.
It’s important to note that evolution can occur on different scales: microevolution involves small alterations over a short period of time within a population, while macroevolution refers to larger-scale changes that can result in the emergence of new species. Both gradual changes, through mechanisms like natural selection, and more rapid shifts due to dramatic environmental changes, can contribute to the evolutionary process.
Finally, in the context of diseases such as cancer, genomic changes like mutations and aneuploidy (the presence of an abnormal number of chromosomes), which is not a mutation, may contribute to the generation of cancer cells. While the principle of evolution is commonly associated with species' adaptation and survival, it is also relevant in understanding the development of diseases at a genetic level.