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Mammals generally have evolved the same basic, boring way for males to fertilize an egg: just send a bunch of tiny individual sperm into the female reproductive organs. But in insects like the diving beetle, it gets way more insane. More »
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Zebedee is a captive zebra shark in the Burj aAl Arab hotel's aquarium in Dubai. It has never met a male shark in its entire life, and yet for the last four years it has successfully, miraculously produced healthy offspring. More »
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Spider sex carries a very definite danger for male arachnids: genital loss. Spiders can actually lose their reproductive organs during intercourse, turning them into spider eunuchs. But, unlike humans, this "castration" actually turns the spiders into even more aggressive fighters. More »
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If you're tying to figure out how cute a baby is, you had better ask a premenopausal woman: they're scientifically proven to have the highest cuteness sensitivity. Yes, this experiment involved coming up with an objective scale of baby cuteness. More »
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Admittedly, there's not much competition, but I'm declaring fig wasps to be the most gallant of all wasps. Males are the only known insects to put pregnant females ahead of themselves...even if they haven't had a chance to mate yet. More »
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Guppies have been a separate species for 500,000 years, and during that time their color has changed drastically. But one thing has stayed the same: an orange patch on males. This is quite possibly the most romantic adaptation ever. More »
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When animals practice monogamy, we can generally tell right away. After all, couples like to hang out together, whether they're humans or squirrels or hawks. But one fish keeps its monogamy so top-secret that researchers actually called their pairings "invisible." More »
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This might seem like a bit of just deserts for all the times people have been woken up early by chirping birds, but human noise pollution is actually making it impossible for birds to mate. Humanity has crossed the line! More »
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Over 40% of male marsh harriers look like females, spending their lives sporting the brown plumage and white heads characteristic of females. They're one of only two bird species that does this. What's the evolutionary advantage of gender bending? More »
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The phrase "battle of the sexes" applies pretty literally to the Assam macaques of southeastern Asia. During mating season, males become extremely aggressive, and females rely on various tactics to defend themselves... including all having sex at the same time. More »
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Many animals sacrifice for the sake of their children, but red crossbills are on another level entirely. Crossbills with kids have dangerously low stress hormone levels compared to their childless couples...all to make sure they don't suddenly abandon their nest. More »
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If you're walking in the woods, you're probably going to get more annoyed by a loud, screeching bird call than a soft, complex birdsong. But dark-eyed juncos are just the opposite. These birds will find and fight their soft-singing peers. More »
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Reproductive arrangements don't get much stranger than those of the Batura toad of Pakistan. The entire species is the result of two unknown species interbreeding, and each toad carries three sets of genes...which makes passing on its genome extremely tricky. More »
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Dark-eyed junco birds are one of many species that practices monogamy...to a point. While a male and female are pair-bonded - the junco equivalent of marriage - both partners will take on additional partners in the name of better genetics. More »
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It's fairly well-established that the children of older mothers are more likely to have genetic defects than those of their younger counterparts. Now we have some of the first solid evidence that older dads could carry a risk as well. More »
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The western United States is full of many different species of scincid lizards, commonly known as skinks. These skinks come in all shapes and sizes, and yet they still try to mate with each other. Too bad it's physically impossible. More »
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Researchers can now determine if newly-fertilized mouse eggs will produce healthy offspring simply by observing them. Their findings may have implications for improving the rate of conception in couples undergoing in vitro fertilization, many of whom can only afford to perform the expensive procedure once or twice. More »
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At first glance, there's no good reason why humans would evolve the ability to give birth to twins. Indeed, human reproductive systems make having even one child difficult. But twins are doing a big favor for their siblings' survival chances. More »
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Sexual reproduction that involves two partners is far less efficient than self-fertilization — at least, from the perspective of evolution. So why did creatures like humans ever start having sex with each other? According to a new study, we did it to fight parasites. We spoke with the researchers to discover what this says about sex. More »
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Mayflies spend a year awaiting their birth, and then most die after living just one day. Their sole purpose is to pass on their genes, and most never even bother eating...and that's been the status quo for 100 million years. More »
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A Laysan albatross named Wisdom was first tagged for monitoring and identification back in 1956, and 55 years later she's the oldest known wild bird in the United States. Even more amazingly, she's still laying eggs and raising young. More »
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Mindlessly copying everything your parents did may seem like a silly thing to do. But from an evolutionary standpoint, not thinking might be the best possible strategy for survival. More »
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Deep sea fish assimilating males for extra sperm, flies frozen mid-coitus for 20 million years, and a walrus's penis bone... it's all part of "Sexual Nature", a new exhibition at London's Natural History Museum that spotlights the many awesomely strange forms that animal intercourse can take. Let's go on a Valentine's Day stroll through the animal kingdom, shall we? More »
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The reward for big brains may not be art, culture, comfort, or even basic survival. Instead, it may just be the development of larger penises. More »
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Female spiders are famous for their ruthless reproductive strategies — but in fact, they're at the mercy of a parasitic bug that forces them to have only female offspring. More »
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How did a bunch of lifeless molecules transform themselves into living cells, turning the ancient, dead Earth into a planet teeming with life? It's an incredibly difficult question to answer, but a new model might explain part of the story. More »
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Butterflies have an odd quirk in their mating practices: during warm months, the males pursue the females, but when it's cold, the females go after the males. This unusual reversal is a matter of life and death for the females. More »
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It really is better to be a human than an insect. We don't have to deal with anything as horrible-sounding as "traumatic insemination." I realize there's no such thing as "bad evolution"...but this is some bad evolution right here. More »
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Even for evolutionary psychology, this latest finding is really bizarre. Cell phone bills suggest women avoid talking to their fathers during periods of high fertility, which might be a relic of an evolutionary imperative to avoid mating with close relatives. More »
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Any future astronauts here who are hoping to make the first space baby might want to think again - embryonic stem cells don't act the same way in zero gravity, making successful procreation in space almost impossible. More »
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Cryopreservation was once the domain of sci-fi novels and B-rate movies. (Think Encino Man.) But it's increasingly real, as the recent birth of a healthy boy from a frozen embryo created 20 years earlier shows. More »
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The filter-feeding whale shark is the biggest fish in the ocean. A recent study indicates that female whale sharks may be able to save sperm from a single mating session and fertilize their eggs at a later time. More »
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It's one of the most basic problems facing the study of sexual reproduction: sperm are just too tiny, too numerous, and too similar-looking to be studied individually. But that's changing — thanks to glow in the dark sperm. More »
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In tonight's National Geographic special Sizing Up Sperm, the act of conception is re-imagined as an insane, dystopian game show replete with booby traps, gangs of killer leukocytes, and 250 million pushy contestants. More »
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It's a classic tale of how mediocrity is maintained. Evolutionary biologists in California have discovered that when males shower attractive females with attention, it actually undermines those females' fitness as mothers. That means fit females don't pass their genes on. More »
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This geranium is having sex right now, before your very eyes. Those little grains of pollen clinging to the flower's stigma are competing to plunge their genetic material deep into this flower and reproduce. More »
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Many space age dreams involve humans spreading out into the far reaches of the galaxy, but our extraterrestrial breeding program might need a little help. Scientists in Japan have found microgravity may function as a form of birth control. More »
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Well, this explains a lot. We've been wondering where all the ladybug aliens in District 9 were hiding. Turns out: right in front of the camera. Learn all about the self-pollinating aliens from District 9, in this little PSA. More »
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Flowering plants go through a complicated double-fertilization process that involves a lot of sperm. But until today, researchers hadn't fully understood the genetic mechanism behind plant sperm production (pictured) and how flowers have sex. More »
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Sexology, or the study of human sexuality, is a science at the nexus of biology, neurology, psychology and sociology. And like any science, sexology has its eureka moments. Here are some of the biggest. More »
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