Final answer:
The central idea is that two long-lived mammals were discovered through paleontological research, shedding light on mammalian evolution and the deep history of life on Earth.
Step-by-step explanation:
The central idea in the title "Seeking Long-Lived Mammals, Paleontologist Finds Two That Lasted at Least 23 Million Years" is that two long-lived mammals have been discovered through paleontological research, as this references the timespan which the mammals survived. Paleontologists, who are scientists that study prehistoric life, utilize fossils to understand the evolutionary process and often investigate how different species interacted with their environment. The discovery of long-lived mammal species that have withstood the test of time significantly contributes to our understanding of mammalian evolution as well as the broader history of life on Earth. This requires knowledge in a variety of scientific disciplines, such as mathematics, biology, ecology, chemistry, and geology. Furthermore, this discovery contributes to the ongoing conversation about species' longevity and the diversification of life after major extinction events, such as after the dinosaurs' extinction at the end of the Cretaceous.