Just another dissertation

[NHE]

Just Another Dissertation - by Christina Petersen

God loosened his tie and hoped the committee would go easy on him. He faced five professors seated in the front row of the biology department conference room.

Zeus spoke first. "Very nice presentation, God," he said, looking over his wire-rimmed reading glasses at the nervous student. Zeus was chair of the department of biology. He sported bushy white eyebrows and a long mane of white hair. Zeus always seemed to look fierce, even when handing out a compliment. He wore a worn tweed sport coat, blue button-down shirt, and jeans.

"Thank you," God said, without a smile. He knew it was far too early to let down his guard.

The man to Zeus' right spoke next. "So who would like to go first?" he asked of the committee. Speaking was Zarusthustra, God's thesis advisor. Most called him "Dr. Z" for short.

"I have just a few things," the woman at the end of the row spoke up.

"Very well, Hera," Dr. Z said, leaning forward to look at the older woman. "Go ahead."

Hera was Zeus' wife. Some in the department whispered that her marriage to Zeus was the only reason she landed a faculty position. For twelve years her lab turned out publications of mediocre quality and graduated a handful of students. Hera continued to eke out funding to keep her lab afloat, but she was never flush. She did just enough to prevent discontentment in the department, but it was clear she was never going to be a star like her husband.

Hera paged through her copy of God's dissertation and looked up at the young man.

"I really like the results you've reported today. Especially the differences you've shown in Planet A and Planet B. You mentioned that Planet A life forms were given DNA that was able to mutate and Planet B was not. Could you go into a little more detail about how that was done?"

God furrowed his eyebrows. These were the kind of questions that really pissed him off. He glanced at Dr. Z who rolled up his eyes in commiseration with his student. God had carefully described the procedure he had used to create the replicating machinery for the two planets in the Methods section of his dissertation. Hera had just revealed that she had not read past page 36.

"Hera!" Zeus snapped. "All that is in the dissertation. Do you have any more pertinent questions?"

An embarrassed silence fell upon the room. Zeus, for the most part, was a good department chair, but sometimes he lacked tact and embarrassed people needlessly. This was one of those times.

Hera's cheeks flushed and her lips pursed. God hoped this wasn't the beginning of another one of their infamous public fights. "I don't mind going over it again," he blurted out, hoping to quell a disaster. He walked to the chalkboard at the front of the room.

"The DNA for both planets consisted of four bases, G, A, T and C, in an anti-parallel double helical conformation." He drew two parallel spirals, in white, on the board. "On both planets, the DNA was replicated by DNA polymerase in the usual fashion." He split the two parallel lines at the bottom of the spiral and drew an oval on one line to represent the DNA polymerase. "However, on Planet B, the enzyme was given a perfect proofreading capacity, whereas the enzyme on Planet A allowed an error rate of 0.01 percent." He wrote 0 and 0.01 on the board. "This was the only difference between the two systems."

"And where did you get the enzymes?" Hera asked.

"I purchased them from Sigma," God replied, now relieved that the potential battle appeared to have been averted.

The biology conference room had six rows of chairs facing a chalkboard-covered wall. A white screen was pulled down in the middle of the wall. There were no windows, as this was an interior room, so it tended to get hot and stuffy towards the end of a presentation. The back and side walls were lined with shelves, filled with periodicals. The floor was carpeted, but after ten years of use, the carpet was worn and stained from countless coffee spills.

"I am still astounded at what an impact the climactic changes had on the two planets," Ra interjected, leaning forward and looking at Dr. Z. A few of the committee members nodded their head in agreement.

Ra was a slight man of Egyptian ancestry. He wore his graying hair in a closely-cropped crew cut. Ra was a favorite with graduate students, partly because of his infectious enthusiasm for science and partly because he was known to throw back a few beers at student happy hour from time to time.

"Yes, it was amazing," God agreed, enthusiasm rising in his voice.

"Tough going for a while, huh?" Ra asked God with a twinkle in his eye.

God nodded, recalling the first four years in the lab. After setting up the two planets with their differing mutation rates, God thought the hard work was behind him. He couldn't have been more wrong! While there was a slight difference in life forms on Planet A and Planet B, the differences were neither interesting nor statistically significant. That time represented a low point in God's graduate career. He and Dr. Z had discussed switching projects, but God resisted, feeling he had invested so much time in this project that he needed to stick it out. It had actually been Zeus who had suggested stressing the environments to see if they could produce more disparity between the two planets. God had chosen climactic variability as his mode for providing the stress. He alternated periods of warmth with periods of freezing cold. He also introduced earthquakes and volcanic eruptions, and even generated a large cloud of debris by flinging a meteor at each planet. The results had been greater than either God or Dr. Z had hoped for. Life on Planet B, with the perfect proofreading enzyme, was nearly obliterated, while life on Planet A underwent a frenzy of changes resulting in an explosion of different lineages of life forms.

"It was very surprising," God said excitedly. "We expected some differences but not to this magnitude!"

"Imagine Planet B possessing only bacteria, and Planet A creatures from fungi to hairless apes," Ra remarked. "Didn't you mention that the hairless apes even began to develop their own complex societies?"

"Hmmm? What's this?" Zeus asked looking up from the dissertation.

"Yes, it's true," God added eagerly. "I didn't add that to my dissertation, but it appears that the hairless apes have formed quite complex social groups."

"What is your evidence for this?" Vishnu asked, obviously interested.

"I've seen structures that appear to have been built by them and I've detected radio and television waves that consist of a crude form of language."

"How interesting!" Vishnu said, folding his arms across his chest. Vishnu was the youngest member of God's committee. He had joined the faculty four years ago, but had made remarkable scientific progress in that short time. Vishnu was of Indian descent. He was slightly overweight, with a round face and dark hair, badly in need of a trim. He wore round wire-rimmed glasses that accentuated the plumpness of his face.

"I told God that if he let Planet A continue to incubate, the hairless apes would evolve into us!" Dr. Z said with a chuckle. The entire committee erupted into laughter. God breathed a sigh of relief. Things seemed to be loosening up.

There was a time when God thought this day would never arrive. He had two failed projects before this one. For the most part, the two previous projects had been too grandiose. Dr. Z finally convinced him to try something more manageable. The mutated DNA project appealed to God and luckily, with perseverance and a little help from his committee, he was able to publish his results in Nature.

God thought back to the long nights, low pay and failed experiments that characterized his graduate career. Perhaps the toughest aspect of graduate school was the constant feeling of insecurity. He never felt as if he worked hard enough, generated enough data or read enough of the published literature in his field. In the end, he realized that the best he could hope for was "good enough."

God wondered if he had sold out or wised up. Did the constant self-doubt make him a better person or a spineless coward?

Seven years ago, when he started graduate school he would have judged his present-day self as a failure. Seven years to graduate?! That was ridiculous! His classmate Siddhartha graduated in four years. Yet God knew in his heart that he was more talented than Sid. Sid stumbled upon the one intangible that could make or break a scientist, regardless of intelligence: luck. Sid had a can't-lose project and everything just fell into place. Ironically, God thought, in their first two years of school, Sid used to ask him for help with his course work.

But, he wasn't bitter, at least not today. Today he was just going to bask in the joy of completion and not worry about how long it took him to get here.

"What future experiments do you foresee with these two planets?" Zeus asked.

God was a little alarmed by the question. He hoped Zeus didn't assume that he was going to do any more experiments with these planets!

"Well, to be honest, not much, at least not for the question I set out to answer," God replied. "But these may be great models to use for the study of species development."

"Are you planning to do that?" Zeus asked, leaning forward to look at Zarusthustra.

Dr. Z shook his head. "I have a shortage of hands as it is," he sighed. "Hands," of course, referred to workers in the lab.

"So what will you do with the planets?" Vishnu asked of God.

"Sacrifice them," God said leaning up against the blackboard. His lower back was beginning to ache from standing for so long.

"I have another question," Ra stated, shifting in his seat and recrossing his legs. "You stated that the climactic changes produced the variability, but isn't it also a possibility that the climactic changes revealed the variability that was already there?"

God nodded his head vigorously. "Yes, of course you're right," he agreed.

"Wait a minute," Hera interrupted. "You already told us that there was no difference between the two planets before introducing the climactic changes."

"Well, actually there was no statistically significant difference," God corrected. "But there were small differences. Also, I was only quantitating outward, physical difference. Any difference at a cellular or lower level would not have been detected by the method I employed."

"I see," Hera mused. "So then Ra has a very good point."

"Were you one of the reviewers of our paper?" Dr. Z asked playfully, leaning forward to look at Ra. The group, including God this time, laughed merrily.

"We did leave that possibility open in the discussion of the paper," God explained. "I mean, certainly all of the variability after the introduction of the climactic changes was due to the stresses on the system."

"Hmmm," Vishnu said with a frown.

"What?" Dr. Z questioned, turning to face his colleague.

Vishnu stroked his chin, reminding God of a cartoon character of a scientist deep in thought.

"I'm not so sure you can conclude that from this data."

"Vishnu, surely it's obvious that the stress on the system caused the variability," Dr. Z said raising his voice ever so slightly. "There were essentially no differences between the planets for two years before God introduced them!"

"True," Vishnu agreed. "But that doesn't mean the climactic changes caused them."

"Well, what did?!" Dr. Z shot back.

"I dunno," Vishnu said shrugging his shoulders. "Maybe they were random."

"Random?!" Dr. Z snorted.

"Random," God said softly. All of the committee members turned to look at the student.

"Random," he repeated, now beginning to nod his head. Their conclusion of external stress causing the variability had always bothered him. He couldn't envision a way that changes in weather could change the pattern of DNA, even though it seemed apparent that was exactly what was happening. But Vishnu was right. There was absolutely nothing in his data to suggest the changes weren't random.

"What if the changes were completely random?" God put forth to the committee. "And the external stress simply revealed the random variability that helped the creature survive?"

"Wait a minute," Dr. Z interrupted. "That can't be. If the variability were completely random, then most of it would not favor the creature, it would be detrimental or at least neutral."

"Yes," God agreed, turning to his mentor. "But I wouldn't have seen those effects. If it killed the organism, I never would have counted it. I only counted the organisms that survived."

"Yes, he's right," Zeus said. "The way he did his measurements, he couldn't rule out a random process of mutagenesis."

"But back to what Dr. Z said," Hera interrupted. "I can see how you would miss detrimental mutations if they were detrimental enough to kill the organism. But what about neutral mutations? I would think if it were a random process, the vast majority of mutations would be neutral."

Dr. Z nodded vigorously at Hera's observation.

God paused to ponder that objection.

"What if a neutral mutation was only neutral in the absence of stress?" Vishnu suggested.

Zeus raised his bushy eyebrows as he looked at his younger colleague.

"The system was under stress. Maybe there was no such thing as a neutral mutation. The beneficial mutations would win out because the organisms that held them were superior to the 'neutral' organisms."

"How?" Dr. Z asked.

A silence fell upon the room as each scientist thought about this.

Suddenly, a thought flashed into God's brain. "Limited resources," he blurted out.

Dr. Z looked at his student curiously.

"What if there wasn't enough stuff to go around?" God postulated.

"Then the organism with the advantages would win!" Ra stated excitedly.

"And the neutrals and deficients would die!" Vishnu added.

"And I wouldn't have detected them," God added triumphantly. The whole thing suddenly had a beautiful symmetry to it. Of course it could be possible. In fact, he was starting to think it was likely.

Dr. Z looked at his student in amazement. God could see the pride on his mentor's face and he finally knew in his heart that he was worthy of this degree.

"OK, how could we test that?" Dr. Z asked no one in particular.

"Repeat the experiment with two different planets," God suggested.

"And . . . ?" Dr. Z asked.

"And, if the climactic changes were causing the variability, we should get very similar organisms the second time around. But if the mutations were completely random, there is no reason to expect we would see the same final complement of creatures that we saw at the end of this experiment."

"So instead of hairless apes, we may get sociable asps!" Dr. Z exclaimed. The room, once again, burst into laughter.

It was this excited discourse and exchange of ideas that drew God to science in the first place. Maybe he and Dr. Z would have stumbled onto this new interpretation of his data on their own, but they certainly wouldn't have gotten there so quickly. It was the effort and experience of the combined minds that got them there this afternoon.

"Aren't you glad you left that possibility open in your paper?" Ra asked.

Dr. Z and God laughed. God realized now why it was so important to not become too attached to a theory.

"Z, you have to do that experiment!" Ra implored.

Dr. Z smiled. "Well, it does sound tantalizing. Send me another student like God and I'll get right on it."

God smiled at the compliment. He also smiled because he knew it was over. He had passed and they were going to give him his Ph.D. He felt euphoric and calm all at the same time. He wished he could savor this moment forever.

"Nicely done, God," Zeus said with finality. "If there aren't any more questions, let's sign off on God's thesis and let him get out of here."

God watched as the papers were being passed around for signatures. It was really over. The lab was throwing him a party as soon as the meeting was over, but what he found himself most looking forward to was going home to his wife and spending time with their son. Tonight he would be going home as Dr. God. It sounded very good.