Final answer:
The Early Modern Synthesis, or evolutionary synthesis, is a foundational concept in biology that combines natural selection with genetic inheritance, explaining how evolutionary processes lead to changes within species and the formation of new ones. It based on the study of allele frequencies within populations, which change under evolutionary pressures, driving both microevolution and macroevolution.
Step-by-step explanation:
The Early Modern Synthesis, also known as the evolutionary synthesis, is a pivotal concept in biology that amalgamates Charles Darwin's and Alfred Russel Wallace's theories of natural selection with Gregor Mendel's principles of genetics. It emerged during the 20th century, primarily through the 1930s and 1940s, as scientists integrated findings from various biological fields to form a cohesive understanding of evolution. This synthesis clarifies how evolutionary pressures like natural selection affect genetic variation within populations and how this can lead to microevolution (changes within a species) and macroevolution (the emergence of new species).According to the Modern Synthesis, evolution is defined as a change in allele frequencies within a population over time. This notion was supported by the principles of population genetics, which predict that allele frequencies will remain constant—known as Hardy-Weinberg equilibrium—unless disturbed by factors like mutation, natural selection, genetic drift, or migration. Thus, observing changes in allele frequencies allows scientists to detect evolutionary processes at work.