Microevolution happens through processes such as mutation, selection, gene flow, and genetic drift. However, macroevolution is the final result of such microevolutionary changes. Microevolution refers to the small scale changes that is happening in gene frequency in a group of organisms that share a common gene pool.
This type of changes occurs due to recombining of genetic material within a group of organisms. Thus, this type of changes occurs due to four processes: mutation, selection, gene flow, and genetic drift. Mutation refers to the changes in the DNA sequence of a genome of the cell.
DNA sequence or nucleotide can be altered due to radiation, viruses, transposons, and mutagenic chemicals; they can be also due to errors that occur in DNA replication process. Mutation can cause alteration of the function of a gene or can create new genes through duplication. There are two types of selection: natural selection and artificial selection. Natural selection occurs when favorable mutations pass through generations; here, the unfavorable phenotypes of the population diminish with time.
Reproductive success of mutated traits keeps them in the population. Natural selection is the primary process of evolution. Artificial selection is the process of selecting phenotypes using animal or plant breeding systems. Artificial selection produces hybrids of good characters. Gene flow is the exchange genes between populations, between same species. Migration into and out of the population change the allele frequencies and induce variations.
Genetic drift is the change in frequency of an allele due to random sampling. How can a mutation lead to evolution? How does variation lead to evolution? What are sources of variation for evolution? What are sources of variation within a species? What is independent assortment, and how does it contribute to variation within a species? How is genetic variation increased by fertilization? How would you explain how independent assortment, crossing over, and random fertilization Why is genetic variation important to living organisms?
How would you explain why crossing-over is an important source of genetic variation? See all questions in Sources of Variation. But, their scales of the evolutionary changes are different. Overview and Key Difference 2. What is Microevolution 3. What is Macroevolution 4. Similarities Between Microevolution and Macroevolution 5. Microevolution is a process of series of evolutionary changes that occur in a single species population within the lifetime. It simply refers to the change in gene frequency within a population over a short period of time.
Besides, it looks at the way of changing individual traits within the population. Natural selection, migration, mating, mutation, gene flow and genetic drift are some of the causes for microevolution of a population. Though microevolution study is narrow in the evolution of populations within the same species, it helps to understand broadly how differences arose between human population, how humans became susceptible to certain diseases over the time, how fertility factors have been decreased in humans over the time, etc.
Microevolution can provide insight into any differences in a particular population. Especially, scientists use microevolution of the human population in order to gain insight into the causes of diseases. Furthermore, the study of microevolution helps to understand the mechanism of antibiotic resistance developed in pathogens as well.
Not only in humans but also other animal populations, microevolution provides deep analysis and reasons for their differences. As an example, you can see how selective breeding of dogs leads into a series of changes that are induced in the resulting breed of dogs.
Macroevolution is the process that takes place over several thousands of years and describes how humans have evolved from primates and how reptiles turned into birds, etc. Besides, macroevolution is changed that is gross, so much so that the new species that evolves cannot mate with members of the ancestor species.
However, macroevolution is outrightly rejected by creationists as they say that dogs can become smaller or bigger or can have new features, but they can never become a new species.
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