Based on the passage below, match each perspective or group mentioned in the text with the statement that best captures its explicit main point regarding evolutionary biology.
Throughout the latter half of the twentieth century, the consensus within evolutionary biology, known as the Modern Synthesis, maintained that macroevolutionary changes are driven entirely by random genetic mutations acted upon by natural selection. According to this orthodox framework, the environment selects for advantageous traits, but it possesses no mechanism to directly induce heritable variations.
Recently, however, the discovery of epigenetic inheritance—mechanisms by which environmental factors alter gene expression without changing the underlying DNA sequence—has prompted some biologists to propose a neo-Lamarckian paradigm. These theorists contend that environmentally acquired characteristics can be passed directly across generations, thereby undermining the foundational primacy of random mutation in evolutionary development.
A more moderate faction champions the Extended Evolutionary Synthesis (EES). Proponents of the EES argue that epigenetic inheritance does not invalidate the Modern Synthesis but rather operates parallel to it. In their view, epigenetic markers serve as an additional tier of heritable variation that must be integrated into standard evolutionary models to fully account for the speed of certain evolutionary adaptations.
Despite the enthusiasm surrounding these discoveries, a careful analysis of transgenerational epigenetic stability leads to a more constrained conclusion. Because epigenetic markers are typically reset after a few generations and lack the permanence of genetic mutations, epigenetic inheritance functions merely as a temporary adaptive buffer against rapid environmental fluctuations, rather than serving as an independent driver of long-term macroevolution.
- Traditional Modern Synthesis proponentsLong-term evolutionary change is exclusively the result of natural selection acting upon random alterations in the DNA sequence.
- Neo-Lamarckian theoristsEnvironmental factors can directly trigger heritable adaptations, fundamentally challenging the notion that evolutionary variation is strictly random.
- Extended Evolutionary Synthesis (EES) advocatesEpigenetic mechanisms constitute an additional layer of heritable variation that should be incorporated into existing evolutionary frameworks without discarding them.
- The author of the passageBecause environmentally induced genetic expressions are transient, they act as short-term survival mechanisms rather than primary engines of species-level change.