By Faye Flam
The Philadelphia Inquirer

"Carnal Knowledge," Faye Flam's column on the science of sex, ran for nearly three years, with occasional quizzes. Her book about the male sex was published this month.

It's time for another quiz.

Do you really understand how males evolved? (Does anyone?) To find out, take this quiz. Answers are at the end - and in "The Score: How the Quest for Sex Has Shaped the Modern Man."

1. Which came first: males or females?

a. Females, since males can't reproduce by themselves.

b. Both sexes emerged at the same time - descending from creatures with just one intermediate sex.

c. Males came first, and then two males, named Adam and Steve, got together and begat the first female.

2. How many sexes do mushrooms have?

a. Two, just like everything else.

b. None _ fungi don't have sex.

c. Some species boast of around 30,000 sexes. That means they can mate with any of the 29,999 other sexes.

3. What happened when scientists injected a single gene (called SRY) from the Y chromosome into fertilized mouse embryos that were otherwise destined to be female?

a. They were born male, but their favorite color was pink.

b. They were born female, but became male as adults.

c. They grew up male, but shot blanks.

4. What else did scientists find on the Y chromosome?

a. Three genes for math ability and one for spatial reasoning.

b. Mostly inactive genes except for one that influences height, one involved in tooth enamel, and several needed to make sperm.

c. Genes that influence pornography use and steak grilling.

5. How did physicist and author Frank Tipler explain the way Jesus acquired a Y chromosome in The Physics of Christianity?

a. Jesus didn't have DNA.

b. Mary had a Y chromosome that had been "inactivated" but was "reactivated" in her son.

c. The chromosome created itself from stray DNA.

6. What do scientists suspect is the reason that chimpanzees' testicles are twice the size of humans'?

a. Chimps make giant sperm.

b. Early humans needed smaller testicles to escape predators and avoid getting caught on nettles.

c. Female chimps mate so promiscuously that only males with high sperm counts beget progeny.

7. What happened to mole voles when the Y chromosome disappeared from the males of the species?

a. The mammals went extinct in two generations.

b. The females figured out how to clone themselves and never looked back.

c. The species went on as normal, appropriating another chromosome to determine maleness.

8. What error did Leonardo da Vinci make in drawing the penis?

a. He drew two urethras, one for urine and one for disseminating semen.

b. Not understanding the mechanism of erections, he drew it with a retractable bone.

c. Claiming to use himself as a model, he drew it twice as long as is considered realistic.

9. What female organ is analogous to the penis - formed from the same bit of tissue in an embryo?

a. The brain.

b. The clitoris.

c. The appendix.

d. The funny bone.

10. What did Dutch scientists discover when they put couples into an MRI scanning tube and asked them to have intercourse?

a. The human penis is slightly magnetic.

b. It's physically impossible to have sex inside an MRI machine.

c. They could make millions of dollars by selling the images on the Web.

d. When aroused, the human penis is twice as long as it appears, since it extends as far inside the body as it does outside. During intercourse, it's also bent like a boomerang.

11. Who has sex for the longest duration?

a. The stick insect. The male can stay attached to the female for several months to prevent other males from getting to her.

b. The giant squid. These deep-sea dwellers come across so few potential mates that they latch on for weeks.

c. Human beings who have mastered "tantric sex."

12. Which of the following has the longest penis relative to total body size?

a. A species of sea worm called phallus gigantis.

b. The Argentine lake duck.

c. The duck-billed platypus.

d. Johnny Holmes.

13. Who discovered the first sperm?

a. Christopher Columbus, whose scientific curiosity kept him busy during those long weeks at sea.

b. Galileo, when the great astronomer looked through the wrong end of his telescope at an opportune time.

c. Antonie van Leeuwenhoek, often considered the father of the microscope.

d. Xaviera Hollander.

14. What unusual abilities have been discovered in sperm?

a. They can see in the dark.

b. They can smell certain chemicals.

c. After entering an egg, they can eject themselves in a fit of commitment phobia.

15. In a survey by psychologists, how many women did college-age men say they aspired to have sex with over their lifetimes?

a. 18.

b. 4, but they obviously lied.

c. 100.

d. 1,000.

16. The orange-colored alpha male of California's side-blotched lizard species is about twice the size of the female, and beats up any other lizard that tries to horn in on his game. Yet smaller males seem to thrive and pass on their genes. How do they do it?

a. By helping take care of the little lizards.

b. By singing an irresistible courtship song.

c. Some fool the alpha males by looking like females. Others work in pairs, with a "wing man" distracting the alpha male.

d. By bringing the female lizards "gifts" of dragonflies and other favorite foods.

17. To what male trait do many scientists attribute the ability of early humans to expand our populations far beyond those of other primates?

a. Aggression.

b. Ingenuity.

c. Caring for and helping raise babies.

18. Some biologists argue that many male traits cannot be explained by natural selection alone. Which of the following do they suspect helped design men?

a. Lucifer.

b. Aliens from the planet Quaoar.

c. Women _ by breeding certain traits into males through a process called sexual selection.

ANSWERS

1: b; 2: c; 3: c; 4: b; 5: b; 6: c; 7: c; 8: a; 9: b; 10: d; 11: a; 12: b; 13: c; 14: b; 15: a; 16: c; 17: c; 18: c.

YOUR SCORE

12 to 18 correct: Congratulations! You are probably either a sexpert or a biologist, or you should consider a career change.

7-12 correct: Congratulations! You have a healthy but not pathological interest in sex.

0-6 correct: Congratulations! You're too busy scoring in the real world to know all this nerdy stuff.

For "Carnal Knowledge" column archives, more about the book and the author _ or to buy "The Score: How the Quest for Sex Has Shaped the Modern Man" _ go to www.fayeflam.com.