The signs began the night before. Dr. Jakobek, the biologist, would have missed it if he hadn't been on a blind date that took him to the trendy part of town. They had failed to hit it off (a common occurrence in his life) and she had left in a taxi. He walked the streets a little, and noticed something odd: the lesbian club was empty on a Friday night. At first he didn't think much of it (perhaps the Indigo Girls were doing a concert), but as he climbed the stairs to his loft, the thought struck him: Maybe it happens in human populations too...

He climbed back down and into his Volvo. He drove around town several hours, and took careful notes of his observations. At the Country & Western joint, some classy trophy-wife types were flirting with cowboy construction workers. At the biker bar, it looked like an orgy with bikers on their backs underneath soccer-moms, with more soccer-moms waiting, watching, stripping, and licking their lips.

This was no spring fever.

He found the lesbians at the old-folks home, looking for any elderly man who still had some spunk in him. They were prowling the corridors like the packs of wild dogs he had studied in India. When a bottle of Viagra was discovered, it was like the shark frenzy he had studied off Madagascar, as women grabbed pills, then went looking for old men to feed the pills to.

He went over his observations on a clip board. The patterns matched. Tomorrow would be even weirder.

Now where would the least attractive men in town be tomorrow? He smiled at himself: where he planned to be, the Comic Book Convention.

When Catherine entered the Convention, she was shocked. For every guy, there were at least two girls. All of them young, all of them very attractive, all of them dressed in skimpy clothes. Her biology Prof once told her that she should always note when animals (or even people) are not acting normally, and observe her behavior. She was going to get laid today, but let's see what's going on first.

A ravishing redhead was listening to a thin teen with glasses and acne. He was expounding on The Incredibles vs. The Fantastic Four, and she was staring at him as if he was truly Mr. Fantastic. He made a joke about some obscure writer, and she laughed, and put her hand on her arm. He became nervous; he had never been so close to a woman other than his mother.

"You know so much about the Fantastic Four," she said breathlessly, "Do you suppose we could get away to talk some more?" Arm in arm they left the convention center to the hotel next door.

Back at the convention, she saw an overweight East-Indian fending off the advances of two beautiful girls, one a blonde, the other a brunette. They were giggling, twirling their hair, touching him, stroking his back, and almost daring each other to go further.

He was smiling. He had to be dreaming, right? "You two are so gorgeous, I don't know which one to choose!"

The girls looked disappointed. The one said, "Why choose? You can have us both!" The other brightened up.

"No way!" He looked around. "If you mean it, come this way..." He led them out the back to the loading bay. Catherine followed them discretely as they discovered an employees lounge and snuck in. It had a window to the loading bay, but the blinds quickly snapped shut.

Catherine was able to peak through a gap in blinds: the women had pushed the fellow to the couch, and were now pulling down his pants. There was a boner in his Fruit-Of-The-Looms, so that was quickly pulled off too. His dick popped up, and the girls smiled at each other. Then the blonde took it in her mouth while the brunette pealed off her clothes. She gently pushed the blonde aside and straddled the young man. As she bounced up and down, the blonde removed her clothes, but before the final piece of underwear had hit the ground, he grunted and jerked...and was done. The brunette stepped up with a satisfied look on her face. The blonde said, "I hope you can do that again, lover, it's my turn." The brunette kneeled down and pulled the slick penis into her mouth. It wasn't long before he was hard again, and soon the blonde was on her knees as he thrust from behind, his belly jiggling.

He lasted much longer this time. Catherine envied the women.

Catherine returned to the convention. She overheard a couple of guys talking: "Twenty years of nothing, then twice in one day! How about you?" "Just the one, but you should check her out, she was gorgeous! Even paid for the hotel room next door!"

A nerd walked in like the cock of the walk. He saw Catherine and began walking towards her. She was powerless to move, even though he was everything she found unattractive: arrogant (even though his first time was probably today), skinny, greasy-haired, short...and she knew that whatever he asked of her, she would do, as long as he came in her throbbing pussy. She started walking towards him, when another girl walked in front of him. He touched the other girl's arm, and she turned and smiled. He said, "If I told you that you had a great body, would you hold it against me?" She giggled and said, "Why don't you try?" He looked at her breasts, and said, "Let's get out of here!" "I thought you'd never ask!" And they walked away from Catherine towards the exit, with their hands on each others asses.

Catherine was getting desperate. At a booth a chubby fellow was flipping through some old X-Men, when a cheerleader type approached him and started asking questions. It was obvious that she hadn't even seen the movies ("Are those knives coming out of that guys hands?"), and was just trying to get his attention. He had no experience with flirting, and knew it, but she was gentle and patient with him, drawing him away.

Catherine, jealous and horny, turned to go...and walked right into one of her professors.

"Dr Jakobek!" He was on his cell-phone. "...Yes, here in America too." He saw her and smiled, held up his hand in a ‘Wait Here’ gesture. She couldn't move if she wanted.

In class, she thought him the most brilliant man (if not very good looking), and he had amazing tales of the unusual animal behavior he had observed around the world. The university was lucky to get him, his availablility was due to the controversy raised by his book, touching on Intelligent Design, ESP in animals or something, which lead to his blacklisting by more prestigious universities. A brilliant man, indeed, but he had never seemed so...sexy. "What else could it be? Of course I'm right, just talk to Nardi in India... Must run...bye" Dr. Jakobek hung up and looked up at Catherine.

"Miss, uhm, Johnson, I can't say that I'm surprised to see you here." But he did look slightly disappointed. "Here to meet some fellow?"

The way he stared at her, she felt like one of the animals he studied. "I...guess so."

"I understand. I would have been more surprised if you were unaffected."

"Affected by what?" She knew that there was something odd going on, and that her behavior was out of the norm, but to have it noticed by someone else, especially someone she respected, was an embarrassment.

"Look at that," He pointed to a booth with a curtained area in the back. "The guy who runs that booth keeps dirty comics back there. That's him, the fat guy." A lovely oriental girl with a lithe figure and tiny shorts approached the fat guy. After a moment of conversation, the girl practically flew behind the curtain, followed by the fat guy. As he closed the curtain, Catherine caught a glimpse of the girl pulling off her top.

Catherine felt aroused and jealous, and had to keep herself from storming the booth to get some of the fat guy for herself. She asked, "How do you know he keeps x-rated comics back there?"

"That's not important. What is important is that all the guys here are scoring with women way out of their league."

"Yeah, that's true..." Catherine described her observations, but stumbled when it came to her own feelings. "And I know that I need...I'm going to...I have to..."

"Join in the fun?"

"Yeah. What's going on here?"

"We will go to my apartment, I will explain everything on the way, and then we will fuck like neovison visons."

Something other than her heart leapt, and she felt something other than a tear run down her inner thigh. "Let's go!" Her emotions were a mess, but she knew she needed to have sex with this small, unkempt, magnificent man.

In his Subaru, he asked her, "Did you read my book?"

She was smushed against him, stroking his chest, and said, "Not yet...I've been meaning to..." And thinking, Don't blow it, let him talk, he'll soon be inside you...

"No one did, but a few flipped through enough pages to get me knocked down to this third rate community college. Anyways, I have been studying abnormal mating practices in animals."

"Abnormal? How?" Catherine was thinking of some positions she had seen when she had once flipped through the Kama Sutra, and was hoping he would suggest one.

"Well, you know how peahens mate with peacocks with the most feathers? I observed a sudden change in peahen behavior, where they started mating with peacocks with straggly feathers. A few months later, a disaster hit that area, and the chicks survived because there feathers were not as unwieldy. And then there were the walruses of Antarctica: usually the males fight it out and then the female goes with the winner, but in one region the females came into heat way out of season, and selected the type of male that usually loses the fight, the puny ones. Then a few months later that region experienced the greatest cold snap in history and the ice closed them in. The walruses were trapped and died, except for the offspring that were able to escape the ice through tunnels too small for the usual size offspring."

He parked his car and led her upstairs to his apartment. It was a mess, his campsites in the jungle were probably neater, and his observation sheds in swamps probably smelled better. But Catherine was not going to quibble, she kissed his bald spot, then got on her knees, pulled off his shirt and started kissing his chest. Her hands moved down and into his pants, and were rewarded by the discovery of a cock that had probably been hard for some time.

He pulled up her t-shirt and said, "I always wanted to see these..." And indeed he had, she was near-impossible to miss in his class, and he would often stroke himself to sleep with a fantasy starring her... Fantasy? Not anymore. But why?

"Listen: this would happen time after time: animals would suddenly changed their mating patterns, and soon afterwards a disaster would strike the region, one that would have destroyed the offspring, had they not been sired by what is usually an unmatable set of males."

She pushed him back and straddled him, her skirt bunched up around her waist. Just fuck me, she thought, just fuck me...

And so he took her virginity. She lowered her vagina over his penis and was soon bouncing on top of him, and experiencing the greatest pleasure of her life. She wanted him to come...please come...so we can do this again (or so I can find someone else). He writhed under her and suddenly his hips shot up as he shot his load into her waiting pussy.

Catherine rolled off him, satisfied for now. She would give him a couple of minutes, and then see if he could do a repeat performance. As she lay beside him, her brain started functioning again at near normal levels.

"Wait a minute...we are acting this way...I feel this way because some disaster is coming?"

He smiled sadly at her. "Yes. Did you see any couple using protection? You saw some start with oral sex, but they finished with a dick in the pussy. All women in this town, are compelled to have sex with guys they don't usually go for. Lesbians with the elderly. Society dames with construction workers. Housewives with bikers. Oriental girls with black gangsta types. Cheerleaders with nerds. Like me."

"So I need a different type of child than I would probably have if I could choose my...husband."

"Yes."

"Can we leave town?"

"No. This is happening all around the world in different forms. Indian princesses are chasing Untouchables. French girls are seducing fat American tourists. You should see how bizarre Japan is right now! I’m afraid that whatever’s coming is going to affect the whole planet."

"I don't get these match-ups."

"Our genes understand, better than our brains. What matters is the compulsion we are programmed to feel."

She shuddered. "Hold me." He did. "What should we do?"

"What nature has programmed us to do. We will make fuck again and again. In a little while you will find yourself pregnant, you and most of your girlfriends too. Maybe we'll still be together, I would like that, but probably you'll leave me since your attraction to me will die once I've served natures purpose. You will find it impossible to abort your baby, and in a couple of years...the child might survive whatever is coming. We probably won't."

He was stroking her back, trying to give her comfort.

Her face had a tear streaming down it. "Couldn't it be some kind of mad scientist zapping us with a ray?"

"The maddest scientist of all, the programming we have carried and modified over millions of generations. But nature will provide us with a springtime after the coming winter. Something of us will survive."

His dick began to harden again and her sadness evaporated back into a haze of desire, just as nature intended.