Through detailed analysis of patterns in the fossil record, scientist David Jablonski reconstructs the rules that helped dictate who lived and died in past mass extinctions. This research profile describes his surprising discoveries and their disturbing implications for the biodiversity crisis today.
UC Museum of Paleontology
This article challenges stereotypes of paleontologists and the misconception that hypotheses about past events cannot be tested. For an advanced biology course, the side trip on levels of selection will provide a new way to look at natural selection. This research profile includes discussion and essay questions that can be assigned to students. Get tips for using research profiles in your classroom.
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- During the course of evolution, only a small percentage of species have survived until today.
- Background extinctions are a normal occurrence.
- Rates of extinction vary.
- Mass extinctions occur.
- The fossil record documents the biodiversity of the past.
- The fossil record documents patterns of extinction and the appearance of new forms.
- Random factors can affect the survival of individuals and of populations.
- A hallmark of science is exposing ideas to testing. (P3, P4, P6, P7)
- Scientists test their ideas using multiple lines of evidence. (P6, NOS2)
- Scientists can test ideas about events and processes long past, very distant, and not directly observable.
- Scientific knowledge is open to question and revision as we come up with new ideas and discover new evidence. (P4, P6, NOS3)
- The real process of science is complex, iterative, and can take many different paths.
- Scientists use multiple research methods (experiments, observational research, comparative research, and modeling) to collect data. (P2, P3, P4, NOS1)
- Science is a human endeavor. (NOS7)
- Our knowledge of the evolution of living things is always being refined as we gather more evidence.
- Scientists use fossils (including sequences of fossils showing gradual change over time) to learn about past life.
- As with other scientific disciplines, evolutionary biology has applications that factor into everyday life.
- Extinction can result from environmental change.