If these topics ring your bells as well, then we're off to a good start. If not, then none of the hard work required to become a professional biologist will be worth it. Fewer than half of new Ph.D.'s obtain academic positions of the sort for which universities have traditionally trained graduate students. All right, put down your pencils. Now I'll answer a few questions for you.
Graduate education is fundamentally about becoming an independent scientist.
You also must know how to make convincing arguments to funding agencies to provide the financial support for these activities. All of these things require self-motivation and organization. You should also develop a broad knowledge of the natural history of the taxon or geographical region that your work focuses on. Most importantly, I will expect you to hone your oral and written communications skills. You get professional credit for having mastered these skills by writing successful proposals and publishing papers in high-quality journals, so I would expect you to pursue these ends soon and often.