Last Minute Lecture

The History of Life on Earth — Fossil Record, Macroevolution, and Evolutionary Milestones Explained | Chapter 25 of Campbell Biology Welcome to Last Minute Lecture! In this post, we journey through the vast evolutionary history of our planet, as detailed in Chapter 25 of Campbell Biology . Discover how life has changed over billions of years, from the earliest protocells to today’s incredible biodiversity. Watch the full video summary below and subscribe for more chapter-by-chapter guides to evolutionary biology! Introduction: Macroevolution and the Story of Life Earth’s history is marked by dramatic evolutionary transitions and major events that have shaped all life. Macroevolution encompasses large-scale patterns above the species level, including the origin of new groups, mass extinctions, and adaptive radiations. By studying the fossil record , scientists trace these milestones and the evolutionary relationships among organisms. Origins of Life: Early Earth and Proto...

The Origin of Species — Speciation, Reproductive Isolation, and Hybrid Zones Explained | Chapter 24 of Campbell Biology Welcome to Last Minute Lecture! This post unpacks speciation and the formation of new species, as covered in Chapter 24 of Campbell Biology . Learn how reproductive isolation leads to genetic divergence, what defines a biological species, and how allopatric and sympatric speciation create Earth’s biodiversity. Watch the full video summary below and subscribe for clear, chapter-by-chapter biology study guides! Introduction: What Is a Species? Speciation is the evolutionary process by which new species arise, bridging microevolution and macroevolution. The biological species concept defines a species as a group of populations whose members can interbreed and produce viable, fertile offspring—but not with other such groups. The emergence of new species (speciation) is key to understanding the unity and diversity of life. Reproductive Isolation: Barriers to...