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Are There Really Virgin Births?

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Christmas is upon us. While our minds may be focused on finishing up our shopping, the reason for this season (as my good Catholic aunts will remind me) is the birth of Jesus.


The fact that Jesus' mother Mary conceived him while remaining a virgin has long been part of Christian faith. No natural father. No sex. No sperm. Chalk it up as a miracle. Some people don't have "miracle" in their vocabulary, though, so we have to ask: "Are virgin births possible?"


You bet they are! There's actually a lot more "“ or less, really "“ to the birds and the bees than our parents told us.

Hot, Steamy Asexual Reproduction

Reproduction usually follows the same basic blueprint: Boy meets girl; sperm meets egg; congratulations, you have a baby.

Sometimes, though, there's no boy and there's no sperm. There's just a girl, an egg and eventually a baby. This virgin birth is called parthenogenesis (from Greek, meaning "virgin creation"), and it happens when an embryo develops by itself without fertilization of an ovum (egg cell).

The resulting baby is called a parthenogen, and because it results from the inheritance of only a single sex chromosome from the mother, it will always be female in animals where two like chromosomes determine the female sex (the XY sex-determination system), and always male in animals where two like chromosomes make for a male (the ZW sex-determination system, where WZ is female, ZZ is male and WW is inviable).

Scientists have found a number of animals that can reproduce this way, and have also figured out how to induce other animals to perform the trick. Some researchers have even tried to make it happen in humans.

Some Examples:

honeybee.jpgIn insects, parthenogenesis is common among honeybees. In a hive of domesticated honeybees, the queen bee is the only fertile female, but the female worker bees, through parthenogenesis, produce male drones to mate with the queen. Additionally, some parasitic bacteria can induce parthenogenesis in insects.
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Marmorkrebs, a type of crayfish discovered only a decade ago, produce parthenogens that are genetically identical to their mother.
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Fifteen species of whiptail lizard found in the American Southwest reproduce exclusively by parthenogenesis (populations are all female), but still exhibit mating behavior (including one female mounting another that is about to lay eggs) because the sexual behavioral stimulates maximum reproductive success.
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The Komodo dragon, the sex of which is determined by the WZ system, has been observed to switch to sexual reproduction after parthenogenetic reproduction. Scientists think this helps the lizard colonize islands.
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Several cases of parthenogenesis have been documented in sharks. In each case, pups were born in aquarium tanks that contained only female sharks. The parthenogenetic reproductions concern shark experts and conservationists because, while the population increases, genetic diversity decreases. Additionally, sharks have an XY sex-determination system, so female populations can only produce more females.
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While there are no known cases of parthenogenesis occurring naturally in mammals in the wild, scientists have successfully induced it in rabbits, mice and monkeys. The resulting embryos ran into problems, however, because of biological phenomenon in mammals (and some flowering plants) known as genomic imprinting. During the formation of sperm and egg cells, certain genes necessary for embryo development are shut down by chemical marks, or imprints. Some of these imprints are in sperm, others are in the egg. All the key genes are there only when a sperm and an egg meet, so without paternally imprinted genes, a mammalian embryo created by parthenogenesis develops abnormally.

Virgin Birth in Humans?

Because of the problems stemming from genomic imprinting, research into human parthenogenesis isn't focused on reproductive therapy, but the production of embryonic stem cells for medical treatment. Last year, Dr. Elena Revazova and her research team at International Stem Cell Corporation produced the first intentional human stem cells from unfertilized human eggs through parthenogenesis. Intentional is the key word there, because before ISC's achievement, Hwang Woo-Suk, who famously fabricated the results of his attempt to extract stem cells from cloned human embryos, unknowingly produced the first human embryos from parthenogenesis.

Stem cells are one thing, but a bouncing baby is another. Could a human naturally be produced by virgin birth? In theory, yes, if a number of biochemical events occur by chance or genetic defect in close succession and the egg doesn't complete meiosis (when an egg does this, it loses half of its genetic material to make room for the paternal DNA in the sperm. But without the sperm, each half of the divided egg would come up short on genetic material). The chances of all that happening are almost zero. But even if nature found a way, we run into genomic imprinting again, so we wouldn't wind up with a viable embryo.

There is one documented case of a natural half-parthenogenetic birth. In 1995, Nature Genetics reported a child that had some cells (about 50%) that consisted of genetic material only from his mother and some that were normal and consisted of a DNA from both parents. Doctors who studied the child theorized that one of the mother's eggs that had been fertilized by the father fused with an unfertilized egg that was dividing parthogenetically.

Might Jesus been a biological one-in-a-billion like that kid? Not according to Christian belief, which holds that the virgin birth of Jesus was not parthenogenesis, but strictly miraculous and not explainable by science as a natural process.

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iStock // Ekaterina Minaeva
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technology
Man Buys Two Metric Tons of LEGO Bricks; Sorts Them Via Machine Learning
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iStock // Ekaterina Minaeva

Jacques Mattheij made a small, but awesome, mistake. He went on eBay one evening and bid on a bunch of bulk LEGO brick auctions, then went to sleep. Upon waking, he discovered that he was the high bidder on many, and was now the proud owner of two tons of LEGO bricks. (This is about 4400 pounds.) He wrote, "[L]esson 1: if you win almost all bids you are bidding too high."

Mattheij had noticed that bulk, unsorted bricks sell for something like €10/kilogram, whereas sets are roughly €40/kg and rare parts go for up to €100/kg. Much of the value of the bricks is in their sorting. If he could reduce the entropy of these bins of unsorted bricks, he could make a tidy profit. While many people do this work by hand, the problem is enormous—just the kind of challenge for a computer. Mattheij writes:

There are 38000+ shapes and there are 100+ possible shades of color (you can roughly tell how old someone is by asking them what lego colors they remember from their youth).

In the following months, Mattheij built a proof-of-concept sorting system using, of course, LEGO. He broke the problem down into a series of sub-problems (including "feeding LEGO reliably from a hopper is surprisingly hard," one of those facts of nature that will stymie even the best system design). After tinkering with the prototype at length, he expanded the system to a surprisingly complex system of conveyer belts (powered by a home treadmill), various pieces of cabinetry, and "copious quantities of crazy glue."

Here's a video showing the current system running at low speed:

The key part of the system was running the bricks past a camera paired with a computer running a neural net-based image classifier. That allows the computer (when sufficiently trained on brick images) to recognize bricks and thus categorize them by color, shape, or other parameters. Remember that as bricks pass by, they can be in any orientation, can be dirty, can even be stuck to other pieces. So having a flexible software system is key to recognizing—in a fraction of a second—what a given brick is, in order to sort it out. When a match is found, a jet of compressed air pops the piece off the conveyer belt and into a waiting bin.

After much experimentation, Mattheij rewrote the software (several times in fact) to accomplish a variety of basic tasks. At its core, the system takes images from a webcam and feeds them to a neural network to do the classification. Of course, the neural net needs to be "trained" by showing it lots of images, and telling it what those images represent. Mattheij's breakthrough was allowing the machine to effectively train itself, with guidance: Running pieces through allows the system to take its own photos, make a guess, and build on that guess. As long as Mattheij corrects the incorrect guesses, he ends up with a decent (and self-reinforcing) corpus of training data. As the machine continues running, it can rack up more training, allowing it to recognize a broad variety of pieces on the fly.

Here's another video, focusing on how the pieces move on conveyer belts (running at slow speed so puny humans can follow). You can also see the air jets in action:

In an email interview, Mattheij told Mental Floss that the system currently sorts LEGO bricks into more than 50 categories. It can also be run in a color-sorting mode to bin the parts across 12 color groups. (Thus at present you'd likely do a two-pass sort on the bricks: once for shape, then a separate pass for color.) He continues to refine the system, with a focus on making its recognition abilities faster. At some point down the line, he plans to make the software portion open source. You're on your own as far as building conveyer belts, bins, and so forth.

Check out Mattheij's writeup in two parts for more information. It starts with an overview of the story, followed up with a deep dive on the software. He's also tweeting about the project (among other things). And if you look around a bit, you'll find bulk LEGO brick auctions online—it's definitely a thing!

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iStock
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Health
One Bite From This Tick Can Make You Allergic to Meat
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iStock

We like to believe that there’s no such thing as a bad organism, that every creature must have its place in the world. But ticks are really making that difficult. As if Lyme disease wasn't bad enough, scientists say some ticks carry a pathogen that causes a sudden and dangerous allergy to meat. Yes, meat.

The Lone Star tick (Amblyomma americanum) mostly looks like your average tick, with a tiny head and a big fat behind, except the adult female has a Texas-shaped spot on its back—thus the name.

Unlike other American ticks, the Lone Star feeds on humans at every stage of its life cycle. Even the larvae want our blood. You can’t get Lyme disease from the Lone Star tick, but you can get something even more mysterious: the inability to safely consume a bacon cheeseburger.

"The weird thing about [this reaction] is it can occur within three to 10 or 12 hours, so patients have no idea what prompted their allergic reactions," allergist Ronald Saff, of the Florida State University College of Medicine, told Business Insider.

What prompted them was STARI, or southern tick-associated rash illness. People with STARI may develop a circular rash like the one commonly seen in Lyme disease. They may feel achy, fatigued, and fevered. And their next meal could make them very, very sick.

Saff now sees at least one patient per week with STARI and a sensitivity to galactose-alpha-1, 3-galactose—more commonly known as alpha-gal—a sugar molecule found in mammal tissue like pork, beef, and lamb. Several hours after eating, patients’ immune systems overreact to alpha-gal, with symptoms ranging from an itchy rash to throat swelling.

Even worse, the more times a person is bitten, the more likely it becomes that they will develop this dangerous allergy.

The tick’s range currently covers the southern, eastern, and south-central U.S., but even that is changing. "We expect with warming temperatures, the tick is going to slowly make its way northward and westward and cause more problems than they're already causing," Saff said. We've already seen that occur with the deer ticks that cause Lyme disease, and 2017 is projected to be an especially bad year.

There’s so much we don’t understand about alpha-gal sensitivity. Scientists don’t know why it happens, how to treat it, or if it's permanent. All they can do is advise us to be vigilant and follow basic tick-avoidance practices.

[h/t Business Insider]

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