The idea that a person can be invaded by other human cells, which then go on to live and probably reproduce in the host body, following their own hidden agenda, is a reasonably disconcerting one. However, we’ve known for a long time this happens, and not just freak accidents like a twin getting absorbed in the womb; fetus cells often cross the placenta and take up residence in their mother’s bodies, and remain there for the life of the mother.
The easiest way to detect this is to look for y-chromosomes in women – if there is one, it’s due to microchimerism, where there are some male cells living in the female body. But now there’s this: Male microchimerism in women without sons: quantitative assessment and correlation with pregnancy history. This study found that one in five women were male microchimeric, which is a huge figure even if it’s skewed by women who had induced abortions (where one in two are male microchimeric).
We can infer some things from this. First, total microchimerism is probably double that reported, since there’s no real reason to assume that male cells are better at colonising a mother’s body than female cells, they’re just easier to detect. If we assume there is no greater tendency to abort male fetuses than female fetuses, we can also infer than effectively everyone who had an induced abortion is microchimeric and carries with them the cells of the fetus. This is the sort of creepy detail that can lead to b-grade horror sci-fi stories, but it can also be considered beautiful and romantic: No fetus really dies, it lives on within the mother. There’s also a high chance that any dead child continues to live in the body of its mother. I guess it depends on your point of view.
However, perhaps the most interesting result from the study was that of the women who had only had daughters 8% were male microchimeric, and the nulligravid (never-pregnant women) had a rate of 10% of male microchimerism. There are two ways to look at this. The first:
Sperm is alive. It is living cells. When it is injected into you it swims and attaches and burrows into your flesh. If its in your mouth it swims and climbs into your nasal passages, inner ear, and behind your eyes. Then digs in. It enters your blood stream and collects in your brain and spine. Like something out of a sci-fi movie.
This rather frenzied interpretation is the result of the conclusion stating: “Besides known pregnancies, other possible sources of male microchimerism include unrecognized spontaneous abortion, vanished male twin, an older brother transferred by the maternal circulation, or sexual intercourse.” Again, some people may consider it romantic that women carry around the living cells of the men they sleep with, and it gives a whole new meaning to the phrase “he got under my skin”. However, I think it unlikely that sperm manage to invade and survive in a woman’s body considering that: a) It’s a very hostile environment for sperm, and b) If the sperm don’t join with an egg cell they die in a few days. They can’t reproduce on their own because they only have one set of chromosomes.
So the second point of view is that all of those “freak accidents” that cause microchimerism that we think are so rare, like a vanished twin or maternal circulation, are actually far more common than we thought. Not just in women, either – a lot of these can apply to men too.
If you’re sitting around a campfire late at night this might raise other questions as well, such as: What does it mean for how we view an organism? Does it change our sense of self? Does it count as “consuming human flesh”?
(Here’s a story about Evil Sperm)
I just spent Saturday night researching late 19th century theatre in Sydney, in order that a few throw-away lines about a supporting character fit my chosen time period. Time well spent. Even more well spent, because I stumbled upon this fantastic photo:
If you were to imagine someone who would organise a cabal, you would imagine this, wouldn’t you?
A week ago I went to a course on iguana farming, basically to see whether I could set one up in my backyard. This course is a result of a central strategy of the Mexican government in its Program of Conservation of Wildlife and Production Diversification in the Rural Sector; they created the category of UMA (Units of Conservation, Management, and Sustainable Use of Wildlife) to let people farm native animals and plants.
The idea is to use the native ecologies to produce income rather than replace it with monocultures and grazing herds of introduced species. This includes animals that are on the endangered list. If the UMA is built correctly there are quite a few subsidies for the farmers, to help with construction of infrastructure. There are two main types of UMA: Intensive UMA which breeds animals in enclosures, and Extensive UMA which utilises the animals in their native environment. People create an UMA to breed and/or manage animals for breeding stock, or for consumption, or for medicinal purposes, for ecotourism, for hunting, for releasing into the wild… pretty much any use for animals is allowed, as long as the UMA follows the specifications.
I was interested in farming iguanas because they’re native animals and I thought they’d allow vertical farming; that is, that I could build a tall and thin cage with lots of branches for the iguanas. Iguanas are endangered because of loss of habitat due to humanities expansions, and also due to hunting in the wild. There are a lot of reptiles that are endangered solely because they are hunted, and often they’re hunted for the pet industry.
As it turns out iguana farming isn’t for me, for three main reasons:
– The green iguana, Iguana iguana, spends a lot of time in trees. The iguana native to my region is the black iguana, Ctenosaura pectinata, and they prefer to be on the ground. There are dozens of species of iguana in Mexico, and if I had more land in another part of the country I might try breeding those native to that place.
– I’d need four cages. I had assumed I could have a large cage for the iguanas to breed and take it from there, but I would actually need four large cages. One for the new-borns, one for the juvenile iguanas, one for the young adult iguanas, and one for the adult iguanas. This is because iguanas are very teritorial, and the larger iguanas will prevent the smaller iguanas from eating if they’re together. I’d also need a place for eggs, and the eggs need to be removed after being laid or another female iguana might come to the nest, kick out the eggs that are there and lay her own.
– Iguanas eat a lot. They need a serious amount of food in the right proportions (80% leafy greens, 15% vegetables and 5% fruit), and from what I saw the best chance of making an iguana farm profitable is to grow the food yourself. So if I do set up an iguana UMA, it would be an extensive one where I would nudge the environment to be more friendly to iguanas, and then hunt the excess lizards.
The photo above shows the adult enclosure of the UMA we visited. That’s the main breeding male being held by the owner. Those stacks of building bricks provide both a perch for the iguanas so they can regulate their temperature, and caves for them to hide in; if they can’t hide, they get stressed. This just has a concrete wall surrounding it so the iguanas can’t escape, a pile of dirt (off screen) for them to lay eggs, and those piles of building bricks. In the course we were told we needed trees to provide a bit of shade and habitat, but the lady running the UMA said it made handling the iguanas difficult. Still, you can’t see other iguanas because they’re all in the artificial caves hiding from the intense heat.
This is an iguana enclosure that is sealed with wire, which keeps predators from getting in and eating the iguanas. We were told how a cat got into one of the juvenile enclosures and killed 120 iguanas just for fun…because people don’t think it’s their responsibility to control their cats. This particular enclosure holds juvenile iguanas, as well as some Australian Bearded Dragons, but is a good example of what is need for new-born, juvenile and young adult enclosures. As stated, predators are kept out. That black plastic around the doors is to keep the iguanas away so people can enter without hurting them, and without them escaping. The bricks are there for caves, and there’s also some plants of a type that iguanas don’t eat, so the leaves are left there (these are castor plants). You can see bowls with pellets, but the juveniles also need living protein, which is provided in the form of tenebrios (mealworms).