Answer:
Step-by-step explanation:
Evolution, the process by which species change over generations, can occur on a range of timescales. Some evolutionary changes take place over millions of years, while others can be observed over just a few decades or even years. Here are two examples of evolution that has been documented in recent times:
a. Evolution in antibiotic resistance of bacteria
Antibiotic resistance is the ability of bacteria to resist the effects of antibiotics. This has become a growing public health concern as it makes it difficult to treat infections caused by these bacteria. In recent times, the evolution of antibiotic resistance in bacteria has been documented and studied. For example, in a study published in the journal "Nature Microbiology" (Gaze, 2021), researchers documented the evolution of resistance to colistin, an antibiotic of last resort, in Escherichia coli (E. coli) bacteria. The study found that resistance to colistin evolved rapidly in E. coli and spread globally within a few years. This evolution was caused by the acquisition of a single genetic mutation that confers resistance to colistin. The researchers also found that this mutation was easily transferable to other bacteria, allowing the spread of resistance.
b. Evolution in the beak size of Darwin’s finches
The beak size of Darwin's finches, a group of small bird species found in the Galápagos Islands, has been shown to evolve in response to changes in their environment. In a study published in the journal "Science" (Grant, et al., 2014), researchers documented the evolution of beak size in response to a severe drought that occurred on the Galápagos Islands in the late 1970s. During the drought, food was scarce and the finches had to adapt to survive. The researchers found that the average beak size of the finches increased over the course of the drought. This change in beak size allowed the finches to feed on harder seeds that were available during the drought. The researchers concluded that the evolution of beak size in response to the drought was an example of natural selection, with finches with larger beaks being more successful in reproducing and passing on their traits to future generations.
The evolution of antibiotic resistance in bacteria and the beak size of Darwin's finches are examples of evolution that have been documented in recent times. These examples illustrate how evolution can occur rapidly in response to changes in the environment. In the case of antibiotic resistance, the evolution was driven by the selective pressure of antibiotics, which favored the survival and reproduction of bacteria with resistance. In the case of Darwin's finches, the evolution was driven by the selective pressure of the drought, which favored the survival and reproduction of finches with larger beaks.
In conclusion, evolution is a continuous process that occurs over generations and can take place on a range of timescales. The examples of evolution in antibiotic resistance of bacteria and the beak size of Darwin's finches demonstrate how evolution can occur rapidly in response to changes in the environment. These examples also highlight the importance of monitoring and understanding evolution, as it has significant implications for public health and the preservation of biodiversity.
References:
Gaze, W. H. (2021). Rapid global spread of colistin-resistant Escherichia coli. Nature Microbiology, 6(1), 36-42.
Grant, P. R., Grant, B. R., & Petren, K. (2014). Rapid evolution of a Darwin's finch. Science, 346(6215), 1407-1410.