Semen science

"What?!" you exclaimed. "You mean semen is considered an important food source...for the entire galaxy?"

"Yes," confirmed the Grey doctor. "Nearly everyone should know that." He paused, "unless they're from a D-grade planet." He looked back at the console. "You mentioned earlier that your species didn't consider semen to be a food source, but I didn't make the connection. What volume of sperm do the males of your species produce per day?"

"I think the males on Earth usually produced a few milliliters (a tenth of an ounce) per day," you answered. What did he mean by D-grade planet? And why would it matter how much sperm the men on Earth produced each day?

"That's all?" the doctor replied. "I've never seen records of a species with such a severe semen deficiency. It's remarkable that your race survived long enough to achieve space flight." After scanning through several records, he added, "This may alter the parameters considerably. Although your power converter requires a certain volume of fluid to function, the exact mixture may not need to be as precise for your species since you are already accustomed to consuming alternate food sources.

"Semen deficiency? Does that mean the males of most other species produce significantly more?" you asked.

"Yes," he answered promptly. "A typical male biped of your size would normally produce between 0.25 liters (8.5 ounces) to 1 liter (34 ounces) per day. Some species produce even more. Furthermore, male semen production is one of the key factors in determining whether a planet's dominant species will ultimately survive or perish."

Then he moved to a console and brought up a tutorial related to planetary surveys. "We categorize planets into 3 broad grades: S, M and D. S-grade worlds are ones where the males produce a significant surplus of semen. As a result, the female dietary needs are completely satisfied by the amount of male semen production, while the male dietary needs are easily met by simple hunting and gathering or very limited farming. On such planets, the chances for the dominant species to survive long enough to achieve the technical prowess to master subspace communication or space travel is approximately 100 percent." The example worlds he showed looked like paradises with the main species living in absolute harmony with the native flora and fauna.

The next set of worlds he showed appeared less pristine. There was evidence of widespread farming, but large sections of the landscape were often left untouched and wild. He continued, "M-grade worlds are ones where the males produce a moderate amount of semen. On these worlds, approximately half of the female's dietary needs are satisfied by the male semen production. As a result, some areas of the planet need to become dedicated to food production to make up the difference. Depending on various resource constraints, this may ultimately be unsustainable. The chance for the dominant species of M-grade words to survive long enough to master subspace communication or space travel is about 50 percent."

"Finally, there are D-grade planets," he stated and began showing bleak images of other post-apocalyptic worlds. Some looked like giant deserts. Others may have once been lush, but were now stripped completely bare. Many looked like they'd suffered through massive wars. "These worlds were semen deficient, and as a result, the dietary needs of the species ultimately exceeded the resource capacity of the planet. On these worlds, groups of the dominant species usually resort to warfare, battling over key land or natural resources in an unsustainable quest for survival. Most scientific research is channeled directly into food production, storage and transportation as well as military advancement, leaving very little opportunity to master subspace communication or space travel before the dominant species ultimately exceeds the planet's resource capacity. In fact, we have yet to find a D-grade planet that has survived long enough to do so."