Many of us involved in teaching botany feel a sense of urgency in our profession. Botany departments, botany majors, and botany curricula have gradually shrunk or disappeared from most colleges and universities in the US, and I suspect in many other parts of the world as well. Too many students are graduating with little or no understanding of the unique ways in which plants meet the challenges of survival and reproduction in the Earth’s diverse ecosystems. Biology faculty who don’t have training or experience with plants are often ill-prepared to relate to or take advantage of the unique contributions plants might make to their own teaching and research.
In the evolutionary story of sexual reproduction in plants, we find that the algae similar to those that gave rise to land plants, and simpler land plants themselves, are haploid and do produce sperm and egg directly. In both cases, however, the joining of sperm and egg does not result in a new plant, but rather in a short-lived diploid zygote that produces spores through meiosis. Spores are adapted for long-distance dispersal, and germinate to form new haploid plants that will eventually produce gametes. So spores, not gametes, are produced through meiosis in plants.
Yes, it’s complicated, but if the story unfolds from the perspective of how and why it evolved, it does make sense. And it is an important story. Understanding how plants and algae reproduce impacts both agriculture and ecology.
“Plant Life – A Brief History,” provides the adaptive perspective of plant features for students, instructors, and others interested in the biology of plants.