Summary
This section explores fundamental evolutionary processes from microevolution to macroevolution. It emphasizes how human activities, like widespread antibiotic use, influence rapid evolutionary changes in microbial populations. The text details core concepts such as allele frequency, genetic equilibrium, and the Hardy–Weinberg principle, and illustrates various patterns of natural selection (directional, stabilizing, disruptive). It also examines speciation through reproductive isolation, providing models such as allopatric, sympatric, and parapatric speciation, ultimately linking these microevolutionary changes to large-scale, macroevolutionary trends such as adaptive radiation and coevolution.