PERCEPTIONS OF PUNCTUATED EQUILIBRIUM: SURVEY RESULTS AND GUIDANCE FOR TEACHING AND LEARNING

Punctuated equilibrium (PE) is an essential concept in paleontology and evolutionary biology but remains controversial 50 years after it was first proposed. While many paleontologists and evolutionary biologists view PE as foundational to modern paleobiology, forming the basis for quantitatively treating species as evolutionary entities, others downplay its importance or dismiss it outright. We conducted a survey study to better understand how practitioners define PE and to what extent they use it in their research and teaching. We also sought to determine which core concepts within PE are more or less accepted by paleontologists and evolutionary biologists and what misconceptions about PE are common. An anonymous online survey was developed with 20 items tied to these research goals. The survey invitation was distributed via social media and email networks; anyone working or studying in paleontology or the biosciences over the age of 18 could participate. Survey results (N=121) show that both paleontologists and evolutionary biologists feel it is important to include PE in textbooks. Most respondents include PE in at least one course they teach. However, when asked to agree or disagree with specific concepts related to PE, respondents often showed internal inconsistencies between items (e.g., thinking that anagenesis is common and also that speciation primarily occurs by lineage splitting) and there was a striking lack of consensus on many items. Both paleontologists and evolutionary biologists held misconceptions about PE, with the youngest cohort (highest degree 1-5 years ago) having more misconceptions than older respondents (16-20 years since degree). Both empirical (the belief that anagenesis is a common phenomenon) and conceptual (that PE states that morphological change occurs within just a few generations during the speciation process) misconceptions are common. These results demonstrate that there is still no shared understanding of PE within this sampling of paleontology and evolutionary biology communities, which complicates efforts to teach about PE. To build this shared understanding, teaching strategies and learning materials need to be developed that target the specific PE concepts identified as challenging by our survey results.