Who killed the Neanderthals? It’s been a long-standing debate in the anthropological world.‚  A mystery that none can solve.

The disappearance of Neanderthals is odd. A whole species, Homo neanderthalensis, living in modern day Asia and Europe for nearly 200,000 years disappears thousands of years after modern humans, Homo sapiens, evolve.

Many theories have been formulated over the years, some outrageous, some founded in environmental and evolutionary fact. Some say extreme climate change knocked out the Neanderthals’ main food supply: bison and large deer. The Neanderthals, who hunted using very primitive spears, could not catch up with smaller game and thus died of hunger, or so the theory goes.

Another theory flatters modern humans, some believe the Neanderthals were not as smart as or as good at making tools as Homo sapiens and thus went extinct as they competed for land and food, according to Discover Magazine.

Many theories have been ventured, but one remains the most popular. It implies a brutal war and old-fashioned ethnic cleansing on the part of modern humans. Did we, Homo sapiens, slaughter the Neanderthals?

It seems like something we’d do. After all, humans have taken to killing indigenous populations that inhabit land they desire. Humans and Neanderthals were competing for land, food and, ultimately, survival and as the smarter species it is highly likely that we waged war against them and won.

A piece of evidence, discovered in modern day Iraq, suggests at least one case of prehistoric murder. A skeleton found with a deep slice below its ninth rib.

The skeleton, one of nine Neanderthal bodies discovered between 1953 and 1960 in a cave in Iraq, belonged to a 40- to 50-year-old Neanderthal named Shanidar 3.

Duke evolutionary anthropology associate professor Steven Churchill believes a Homo sapien launched a projectile weapon at the Neanderthal, causing the deep cut. “We think the best explanation for this injury is a projectile weapon, and given who had those and who didn’t, that implies at least one act of inter-species aggression” he said, according to Live Science.

A Neanderthal skull was found in France a while ago, suggesting another case of murder. Scalp injury caused by a sharp object hitting the head, an act quite possibly inflicted by a human.

“If the Shanidar 3 case is also a case of inter-specific violence and if Shandiar 3 overlaps in time with modern humans, we’re beginning to get a little bit of a pattern here,” said Churchill, according to Live Science.

Scientific analysis showed Shanidar 3 died as his wound was healing, suggesting the weapon pierced his lung or caused lethal internal bleeding. Without any medicine, Shanidar 3 is thought to have died within weeks of sustaining the injury.

Does this solve the debate? No. Is it a useful clue? Yes.

Would it make a badass movie? Hell yes. Hollywood, get to work.

CAMBRIDGE — Sure, we’ve evolved, but there’s still a lot we can learn from our primate relatives. When it comes to the evolution of our sex lives, researchers have been taking notes on what separates man from ape. The human approach to sex may be different, but there are still lessons we can take away from a primate’s way of handling business. (Insert your own Curious George reference here.)

Zarin Machanda, a Harvard biological anthropology graduate student and resident primate “sexpert” shared her thoughts on sexual evolution at the Harvard Museum of Natural History on June 18. Her lecture, “Everything You’ve Always Wanted to Know about Primate Sex but Never Wanted to Ask,” covered some lessons to be learned from the sex lives of our closest links.

1. Be a lover, not a fighter

Our DNA may be 98.6 percent identical to chimpanzees, but their relative bonobos take a more human approach when it comes to the value of sex. According to Machanda, if two bonobos become anxious about sharing a resource like food, they will engage in sexual activity to relieve anxiety and then share the goods. “Let’s reduce tension with some sexual behavior, and then we’ll share some fruit,” Machanda explained. Bonobos will use this tactic for conflict resolution and stress reduction. So the next time the stock market crashes or rent is due, take a note from the bonobos.

2. Size matters

The need to compete and exert their sexual dominance has made male primates much larger than their female counterparts. For a male primate to survive and pass on his genes, bigger is always better — in more ways than one. “What would be your reaction,” Machanda asked, “if I told you a chimpanzee brain is the same size as a chimpanzee testicle?” The ability for chimps to reproduce frequently is just as important as their ability to think. According to Machanda, human males compete less, which changed these proportions. (Although some females who attended the lecture strongly suggested this was up for debate.)

3. Sometimes quantity is just as important as quality.

Quality can never be overrated, but when it comes to chimps, the good, old-fashioned quickie is key. Not that it doesn’t take a certain amount of patience. According to Machanda, who videotaped chimpanzee interaction in Uganda, male chimpanzees are experts in persistence. “He’s been shaking that tree for half an hour waiting for her to come down,” she said, showing a video of a male chimp coaxing a female from a tree. Eventually, his patience paid off. But when all is said and done, chimpanzee sex lasts a whopping eight seconds– less time than it takes to read this paragraph. This time frame allows females to have sex up to 50-60 times per day.

4. Don’t rule out the cougars.

According to Machanda, both human and chimpanzee males discriminate by age. “Human males are really interesting,” said Machanda. “It is almost always the younger, the better.” Chimps on the other hand, prefer to put age before beauty. “If you are a male chimp,” she said, “the oldest, sagging breasts female– that is your Venus.” Why? According to Machanda, the oldest females have proven their fertility, which makes them more desirable mates.

5. Attraction makes us civilized.

The defining factor between primate and human sexual interactions rests in the hands of the females. “One of the biggest differences with humans is that human females are permanently attracted to the males,” said Machanda. Instead of only desiring companionship during ovulation, human females are attracted to their mates at any point in the month. According to Machanda, “That has a lot of implications for our social system.” And our sex lives. It is this difference that allows humans to bond in pairs for life, and what makes our sexual practices distinct from our primate kin. “The human condition is very interesting in terms of sexual behavior,” Machanda said. “That is really, strikingly different.”

Machanda’s lecture was the first of three on evolution, as part of the Harvard Museum of Natural History’s, “Summer Nights at the Museum.” The next event, “Life’s a Niche,” will be held July 16. For more information, click here.