Yes, there is evidence of living organisms evolving since the documentation of science began centuries ago. Evolutionary theory is supported by a vast body of evidence from various scientific disciplines, including paleontology, genetics, comparative anatomy, and molecular biology. While observing the process of evolution occurring within the span of a few centuries is challenging, there is evidence of evolutionary changes within populations over shorter timescales, as well as evidence of speciation (the formation of new species) over longer timescales.
Here are a few examples of observed evolutionary changes:
Antibiotic Resistance: Bacteria are known to evolve resistance to antibiotics through the process of natural selection. As antibiotics are used to treat bacterial infections, some bacteria with genetic variations that confer resistance to the antibiotics are more likely to survive and reproduce. Over time, the population of bacteria can evolve to become more resistant to the antibiotic.
Peppered Moths: The case of peppered moths in England during the Industrial Revolution is a classic example of natural selection. Initially, the majority of peppered moths had light-colored wings, which provided camouflage against light-colored tree trunks. However, as industrial pollution darkened the tree trunks, a genetic variant for dark-colored wings became advantageous as it provided better camouflage. Over time, the frequency of dark-colored moths increased in the population.
Galapagos Finches: Charles Darwin's study of finches on the Galapagos Islands provided important evidence for evolution. The finches showed variations in beak size and shape, which correlated with their diets and the availability of different food sources on different islands. This adaptive variation within the finch population demonstrated natural selection and diversification.
While these examples represent relatively short timescales, the accumulation of small-scale changes over longer periods can result in significant evolutionary transformations and the emergence of new species. Fossil records provide further evidence of past evolutionary changes, showcasing the existence of extinct species and transitional forms that demonstrate the gradual transformation of organisms over time.
It's important to note that evolution is a slow process that occurs over many generations, and the documentation of scientific inquiry over a few centuries may not capture all the observable evolutionary changes. However, the evidence from various scientific disciplines strongly supports the theory of evolution as a valid scientific explanation for the diversity and complexity of life on Earth.