Speaker 1: Welcome to Stuff from the Science Lab from how stuff
Speaker 1: works dot com. Hey guys, and welcome to the podcast.
Speaker 1: This is Alison Matamilth, the science editor at how stuff
Speaker 1: works dot com, and this is Robert Lamb, science writer
Speaker 1: at how stuff works dot com. Today we're talking about contraception,
Speaker 1: specifically immuno contraception. But don't turn off the podcast just yet,
Speaker 1: because we're kicking off by talking about out of control rabbits. Yeah,
Speaker 1: so let me lead you into I actually hadn't heard
Speaker 1: of immuno contraception until an article by our very own
Speaker 1: intern marian english Um on five invasive species you should
Speaker 1: know was just written. It's not up yet, so don't
Speaker 1: go look for it, but it is gonna be up
Speaker 1: and it is going to be good. Thank you, Marianne.
Speaker 1: Be good. So one of the ones that made Marianne's
Speaker 1: list was none other than the rabbit, famed for its
Speaker 1: ability to of course reproduce like matt so they're known
Speaker 1: for so all wonder that they're invasive, and especially in
Speaker 1: Australia thanks to one Thomas Austin who purposefully introduced the
Speaker 1: European rabbit to as a state in Geelong, Australia back
Speaker 1: in the eighteen fifties. What old Thomas didn't know was
Speaker 1: that handful of rabbits that he purposefully introduced we're going
Speaker 1: to escape their enclosures and multiply to ten billion by wow,
Speaker 1: that is a lot of rabbits just out of control,
Speaker 1: rampaging across the countryside. Yeah. So in the article that
Speaker 1: Marianne wrote, she said that the Free Invasion also inspired
Speaker 1: the commonly coined phrase breeding like rabbits. I did not
Speaker 1: know that. I knew that it inspired a nineteen sixty
Speaker 1: four novel by the name of the Year of the
Speaker 1: Angry Rabbit Um. It was written by a guy named
Speaker 1: Russell Brandon, and it's it basically had to do with
Speaker 1: like giant, giant rabbits rampaging across Australia, tearing up the country,
Speaker 1: and then somehow Australia ends up being the global superpower.
Speaker 1: Is kind of somehow. Yeah, I have not read it,
Speaker 1: but it's supposedly really tongue in cheek, and it actually
Speaker 1: inspired a movie that more people are probably familiar with,
Speaker 1: called A Night of a Lelipis. And you, of course
Speaker 1: have seen it, because you've seen every film under the sun. Well, no,
Speaker 1: I think it used to come on TBS a lot
Speaker 1: or something. But but yeah, it's just like I think
Speaker 1: it takes place in Arizona instead of Australia, and it's
Speaker 1: just bunny rabbits running all over like a toy town
Speaker 1: and people running in fear and all it's it's it's horrible.
Speaker 1: I highly recommend seeing it. I always think of Danny
Speaker 1: Darko and that crazy rabbit. Yeah, but that was just
Speaker 1: a kind of from the future in a rabbit suit.
Speaker 1: That's time travel. That's a different podcast altogether. That's a
Speaker 1: pretty creepy rabbit though, you have to admit it was.
Speaker 1: So Australia knows creepy rabbits, and Australia actually has been
Speaker 1: hit really bad when it comes to invasives. Yeah, they
Speaker 1: have that. They have like a mouse problem on a
Speaker 1: regular basis. The hordes of mice teeming across the fields,
Speaker 1: eating everything in their path, rampaging into barns. Yeah, they've
Speaker 1: lost a ton of mammal species um in large Part
Speaker 1: two to invase this. So, of course Australians have triedal
Speaker 1: sorts of things to control these rabbits. They've erected fences
Speaker 1: that are thousands of miles long. They've used poison. Um,
Speaker 1: what was that? You're telling me something about the fences?
Speaker 1: The climate right right right? So, Um, the fence on
Speaker 1: one side of the fence, According to this New York
Speaker 1: Times article, Um, the bunnies have eaten all the vegetation.
Speaker 1: It's parched. It's you know, it's a it's a desolate town.
Speaker 1: It's parked, it's it's no good. And there are no clouds.
Speaker 1: There's no cloud cover above this particular side of the fence,
Speaker 1: on the side of the fence where there are no bunnies,
Speaker 1: it's nice and lush and there is cloud cover. So
Speaker 1: the bunnies are affecting climate change. Just to show just
Speaker 1: how out of control it is, it's actually affecting the weather.
Speaker 1: So Australians have tried this fence business. Um, clearly that
Speaker 1: hasn't been entirely successful. They've they've employed poison, they've also
Speaker 1: hunted them, and they introduced a seriously infectious viral disease
Speaker 1: by the name of mixomatosis as a biological control agent
Speaker 1: back in the nineteen fifties to control all the huge
Speaker 1: rabbit population. And the thing about the disease was that
Speaker 1: it was host select so it was only going to
Speaker 1: infect one type of animal and that being the European rabbit.
Speaker 1: And their efforts were successful. Initially. They wiped out about
Speaker 1: the budding population in Australia only six months after release.
Speaker 1: So that's some pretty good results, right, But inevitably you're
Speaker 1: gonna have some um, some of the rabbits are going
Speaker 1: to be immune, and they're going to survive and they're
Speaker 1: going to breed, and then what you get what they
Speaker 1: ended up having happened, and that's just now you have
Speaker 1: a new population um um that's out of control and
Speaker 1: all the rabbits are immune to miximatosis. Right, Plus you
Speaker 1: have a couple of new strains of the virus developing too,
Speaker 1: and maybe a Radiohead song the same name off of
Speaker 1: the the album Held of the Thief, the second best
Speaker 1: Radiohead album in my opinion. So the Australians aren't given
Speaker 1: up on controlling their rabbit population. Their latest effort involves
Speaker 1: immuno contraception, which is basically birth control for rab its,
Speaker 1: birth control with a twist, and that you can kind
Speaker 1: of think about immunocontraception as an internal battle between an
Speaker 1: organism's reproductive system and its immune system. Okay, and this
Speaker 1: is what stirs up the battle between the two. See,
Speaker 1: the animal's immune system is going to manufacture antibodies that
Speaker 1: may then target sperm, eggs, or reproductive hormones, thereby preventing
Speaker 1: fertilization or the generation of sperm or over. So, an
Speaker 1: immunocontraceptive could be delivered to a wild animal via a
Speaker 1: deliberately introduced virus, or it could be given in the
Speaker 1: form of a vaccine, and the vaccine might be via
Speaker 1: dart Yeah, they're really um, they're really strong on the
Speaker 1: whole using it like a dart or a dart gun
Speaker 1: kind of a situation. Um, it could be injected manually
Speaker 1: as well, but ideally, especially wild animals, you know, the
Speaker 1: farther way you are, the better, Right, You're gonna want
Speaker 1: to minimize contact. Yeah, So I feel like we should
Speaker 1: give just a backup on how a regular birth control
Speaker 1: pill works. Regular birth control for humans not administered by
Speaker 1: art gun at all. Good point, Robert, good point. So
Speaker 1: human birth control pill relies on hormones generally to prevent
Speaker 1: ovulation or the reaths of eggs. Even if eggs are released,
Speaker 1: they may have a hard time rolling down the old
Speaker 1: Philippian tube and sticking to the wall of the uterus.
Speaker 1: Pill also makes it harder for sperm to slip past
Speaker 1: the gate, that being the cervix and into the uterus
Speaker 1: for fertilization. So it's a little bit of a different
Speaker 1: game for a contraceptive versus an immuno contraceptive. And it's
Speaker 1: it's really interesting that the number of animal welfare groups
Speaker 1: are really into this, um, namely the Humane Society of
Speaker 1: the United States. Yeah. Um, they've been pushing up, pushing
Speaker 1: to use it for dear population in the United States
Speaker 1: because we have quite a deer problem in many areas. Um,
Speaker 1: what's the area up in New York? Fire Island? Have
Speaker 1: you been there? I'm not sure you've traveled. I have
Speaker 1: not been to Fire Island. So Fire Island, for those
Speaker 1: of you guys who have seen Jersey Shore, is one
Speaker 1: of those places where people like to go the Hamptons
Speaker 1: or the Jersey Shore or Fire Island for the weekend.
Speaker 1: So you get a bunch of New Yorkers rolling out
Speaker 1: of Manhattan and taking over the island and partying and
Speaker 1: going to the beach and women in the face, right,
Speaker 1: is that what they do on Jersey Shore. That's the
Speaker 1: only thing I know about Jersey Shore. Punched in the face.
Speaker 1: I am kind of curious, but I've not seen it. Um.
Speaker 1: So the other thing about Fire Island, apart from all
Speaker 1: these New Yorkers, is that they have a crazy deer population,
Speaker 1: so much so that when you step off the boat
Speaker 1: to get to Fire Island, you just walk across the
Speaker 1: backs of deer. Right, it's just right in certain New Yorkers,
Speaker 1: you know, ride deer to get to the parties. Now,
Speaker 1: I'm just just kidding. The interesting fact you can't ride
Speaker 1: a reindeer, you know, their backs are two weeks that's
Speaker 1: when you took him up to slay. So the Humane
Speaker 1: Society is experimented with immune contraceptives on the Fire Island
Speaker 1: deer population. Yeah, and they've they've also tried it out
Speaker 1: in South Africa with some African elephant preserves there, which
Speaker 1: kind of surprised me at first because I'm like, you know,
Speaker 1: African elephants. We were trying to protect those guys. But
Speaker 1: that's the thing. You start protecting a species, uh, you know,
Speaker 1: giving it free reigin within a you know, preserved area,
Speaker 1: and the next thing you know, they're breeding like wildfire
Speaker 1: and you're having for elephants, yeah, or bringing breeding like
Speaker 1: elephants and you have to step in and keep them
Speaker 1: from eating up all the resources. Yeah. They've also tried
Speaker 1: it on the wild horses of assatigue. Oh see that one.
Speaker 1: That's another one that when I first read that, I'm like, oh,
Speaker 1: the wild horses. Don't take the wild horses away. But
Speaker 1: obviously if you want to keep wild horses, you need
Speaker 1: them to not go to get out of control and
Speaker 1: starve themselves. The Humane Society is also working on immuno
Speaker 1: contraceptive and sterilization agents for dogs and cats as well.
Speaker 1: That's awesome because I do hate to see uh. I think,
Speaker 1: like most people hate to see straight dogs and cats, right,
Speaker 1: I think that this would be pretty useful in that sense.
Speaker 1: And also you know for the feral cats. Yeah, I
Speaker 1: mean that's that's one of those um I mean, whether
Speaker 1: you like animals or or hate them, you know, it's like,
Speaker 1: this is an idea you can get behind, probably less
Speaker 1: um expensive as well than you know, bringing in a
Speaker 1: cat to be spade or neutered. Yeah, just hit it
Speaker 1: with a dart gun from down the street. You get
Speaker 1: to go Peter, seems to be behind immuno contraceptives too.
Speaker 1: I read at least one letter in which a Peter
Speaker 1: wildlife biologists recommended an immuno contraceptive program as a means
Speaker 1: for controlling a deer population. And this particular population I
Speaker 1: think was in a Texan town. So yeah, that shows
Speaker 1: you how humane it is, because Peter, generally they don't
Speaker 1: get behind anything unless it's pretty pretty humane, ridiculously humane.
Speaker 1: Even so, let's talk about how these immuno contraceptives work.
Speaker 1: I could find two that are out there. So the
Speaker 1: first one that I look at, it was called the
Speaker 1: spay back vaccine, and this is still experimental, and this
Speaker 1: is the one made from picks, right, well, a lot
Speaker 1: of them are a lot of them rely on poor
Speaker 1: signs Zona pellucida antigens, and these are just proteins drived
Speaker 1: and extracted from pig ovaries. The spayvack vaccine has poor
Speaker 1: sign Zona pellucida antigens or p Z p antigens, and
Speaker 1: these are the common ones in immunocontraceptives. And the pc
Speaker 1: p antigens are just proteins that are extracted and purified
Speaker 1: from pig overies. An antigen you remember, is just a
Speaker 1: foreign body that will get your immune system all riled up,
Speaker 1: and then it combine with whatever your immune system throws
Speaker 1: at it, usually like an antibody or a T cell.
Speaker 1: So spay back causes female mammals to produce antibodies that
Speaker 1: adhere to the surface of her own egg, and it
Speaker 1: blocks sperm from binding to the egg, so preventing fertilization.
Speaker 1: Spay Back has been tried on seals and rabbits, she pourses,
Speaker 1: grizzly bears and wolves. Just to give you an idea
Speaker 1: of its longevity, it worked for ten years on a
Speaker 1: population of gray seals with a single with a single dose,
Speaker 1: so you can just completely shut down reproduction for an
Speaker 1: entire decade species. It's pretty incredible. So this is still experimental.
Speaker 1: Um I did find another one called GonaCon, not to
Speaker 1: be confused with dragon con or comic con, but there's
Speaker 1: a there's a great joke about nerds rereading there somewhere,
Speaker 1: but that the listeners to come up with. So GonaCon
Speaker 1: was just granted regulatory approval by the e p A
Speaker 1: in February. And this is also a single shot, multi
Speaker 1: year vaccine, and it stimulates the manufacture of antibodies that
Speaker 1: bind to Canada trope and releasing hormone and animals, and
Speaker 1: it basically puts a deer in a nonreproductive state. This
Speaker 1: is also the one UM that they make a point
Speaker 1: of of mentioning that if you eat one of these deer,
Speaker 1: it's not going to have an effect on your own
Speaker 1: reproduction system. Yeah, so the ideas that the proteins are
Speaker 1: digested as opposed to a hormone based contraceptive that you
Speaker 1: might ingest good enough. So I feel like I should
Speaker 1: give you some idea of how effective this particular gona
Speaker 1: con contraceptive is. One study that I found numbers for
Speaker 1: UM had twenty eight deer and it was found to
Speaker 1: be eighty eight percent effective among in the first year
Speaker 1: and forty seven percent effective in the second year. I
Speaker 1: found another study that was kind of roughly correlated with that,
Speaker 1: and it was July two five, again maybe a handful
Speaker 1: of deer, like under fifty or something like that, relatively small,
Speaker 1: sixty seven percent effective UM the first year and forty
Speaker 1: eight percent effective the second year. So while they're saying
Speaker 1: that it can last for years, I'm not so sure
Speaker 1: that it's effective for that The whole time period, right,
Speaker 1: It's just sum depends on the individual animal. I'm guessing.
Speaker 1: The other interesting thing is, I mean you're basically putting
Speaker 1: an animal in a non reproductive state for an extended
Speaker 1: period of time, I mean decades, right, and you have
Speaker 1: to wonder does this have significant implications for on the
Speaker 1: animal's behavior. But maybe this isn't so different from a
Speaker 1: woman being on birth control for an extended period of time. Yeah,
Speaker 1: didn't you say that there's a study like you have
Speaker 1: women on birth control like they're they're less enamored with
Speaker 1: like husky men. That. Yeah, there was actually a big
Speaker 1: study that came out in two thousand nine in the
Speaker 1: journal Trends in Ecology and Evolution, and the authors were
Speaker 1: tending that birth control pills were altering mate selections. So
Speaker 1: women who are on the pill, um, the authors said,
Speaker 1: mate with Yeah, the less preferred partners. Cool, that's all
Speaker 1: I managed to get married, so you know you a pill? Uh? So.
Speaker 1: I mean the flip side of that is that women
Speaker 1: who are ovulating tend to be attracted to so called
Speaker 1: the manly men. Those were the those with the more
Speaker 1: masculine facial features, the traits of dominance and competitiveness, and
Speaker 1: women also tend to prefer the man who's not like
Speaker 1: them genetically speaking. So there are a number of arguments
Speaker 1: against this that are out there, according to reproductive expert
Speaker 1: Desk Cooper from the University of New South Wales. What
Speaker 1: does that? What does Cooper have to say? Yeah, so
Speaker 1: it goes back to our earlier discussion about the rabbits. Um,
Speaker 1: not all the rabbits were um, we're susceptible to the virus,
Speaker 1: and then the ones that survived ended up reading and
Speaker 1: then you had a new population of rabbits it was immune.
Speaker 1: So not every organism is going to is going to
Speaker 1: be susceptible to these different immuno contraceptions. All right, So
Speaker 1: well that also means the individuals who wind up surviving
Speaker 1: and reproducing maybe what Professor Cooper calls genetically unusual individuals. Right, So,
Speaker 1: if they're in the genetic minority and they've become a majority,
Speaker 1: I mean, should they should they assume that position? What
Speaker 1: what kind of impact does that have on the genetic point?
Speaker 1: Should be a superorganism or it could be UM like
Speaker 1: a very you know, disease prone organism, organism, and either
Speaker 1: extreme is going to be an unbalancing effect on the ecosystem.
Speaker 1: The other, very real downside of immuno contraception is that
Speaker 1: it could be slow. You're gonna have to wait for
Speaker 1: natural causes to run their course among a particular animal population,
Speaker 1: which is why wildlife agencies a lot of the time
Speaker 1: are probably going to employ another strategy in addition to
Speaker 1: immuno contraception, So like shooting with the dart, wait a
Speaker 1: little bit, once it gets up, then you shoot with
Speaker 1: the rifle. Possibly I'm just saying the herd in more
Speaker 1: than one way. It could be expensive too. There's a
Speaker 1: lot of fieldwork involved. You have to hit enough of
Speaker 1: the population to make a difference. Um, and I think
Speaker 1: this might be about And lastly, your animal could suffer
Speaker 1: side effects, although I didn't find a clear explanation of
Speaker 1: what these might be in my research other than you know,
Speaker 1: just the usual puffiness at the injection site. I guess
Speaker 1: they might die, but I mean, you're trying to cut
Speaker 1: down their number anyway, right, that's true. That's true. So
Speaker 1: the big question for me was what about immuno contraception
Speaker 1: for say, human males. Yeah, I think there's a I mean,
Speaker 1: it sounds like there's a huge possibility there. Obviously, you know,
Speaker 1: you'd have to go through trials and experiments and legislation.
Speaker 1: I mean, you have to go through so many hoops
Speaker 1: to get it to you know, to finally be on
Speaker 1: the market. But I think it would be a good option. Yeah.
Speaker 1: There's a two thousand four study by rand at All
Speaker 1: that was published in Science and its studied reversible immuno
Speaker 1: country reception in monkeys. It was a pretty small study.
Speaker 1: It was just seven out of nine monkeys who became
Speaker 1: infertile after receiving a dose of epin and this is
Speaker 1: a protein specific to the testes and epididymis. After the
Speaker 1: monkeys stopped receiving the open, five out of the seven
Speaker 1: became fertile again, right, so to you know, stayed infertile.
Speaker 1: So that should promise um. And but if we were
Speaker 1: to adopt that for for humans, of course, it would
Speaker 1: have to go three years and years of clinical trials
Speaker 1: and take up a whole lot of cash to get there.
Speaker 1: I still hope it's the administered by dark gun because
Speaker 1: I think that's the way that you could really make
Speaker 1: it be like the manly option, you know, because this
Speaker 1: is they're not taking pills and little you know, around containers.
Speaker 1: It's like they're having to shoot themselves in the foot
Speaker 1: with a dark guns. Well better, yeah, let your partner
Speaker 1: take out a little aggression and yeah, shoot your everybody
Speaker 1: everybody daily basis. So I think that about wraps it
Speaker 1: up from Uni Contraception this week. If you want to
Speaker 1: find out a little bit more about regular contraception, head
Speaker 1: on over to how staff works dot com. Hey, got
Speaker 1: a few minutes, you want to do some listener mail? Sure, sure, yeah,
Speaker 1: I'd love to. We had a couple of people right
Speaker 1: in on our Weapons that Changed the World podcast, and
Speaker 1: you guys feel strongly about your weapons. Yeah, we got
Speaker 1: a lot of responses, some of some of them were
Speaker 1: pretty awesome. And by a lot we mean like five
Speaker 1: well that's that's a lot, but a lot. They listed
Speaker 1: a lot of weapons. Um, you know, everything like the
Speaker 1: club got mentioned, um right right. A gentleman by the
Speaker 1: name of Joey thinks that we definitely definitely should have
Speaker 1: mentioned boats and clubs and swords and bows and arrows.
Speaker 1: Although he thinks us and he says, keep up the
Speaker 1: good work. Awesome. We're always always open for you know, suggestions.
Speaker 1: Blaine from California also writes that he thought that the
Speaker 1: episode was titled a little bit misleadingly. Yeah, yeah, the
Speaker 1: title was a little misleading because we really dealt more
Speaker 1: with weaponized technologies as opposed to specific weapons. Um and
Speaker 1: and certainly things like the long bow have had a
Speaker 1: huge impact on the evolue of warfare. Yeah, Blaine would
Speaker 1: have liked to see machine gun on on our list,
Speaker 1: but we'll have to come back to these. We could
Speaker 1: easily do an entire podcast on on on how the
Speaker 1: machine gund changed warfare or the law of the long book.
Speaker 1: Fan of the longbow, Yeah, Tim from Dallas was a
Speaker 1: big fan of the long bow as well. He wrote
Speaker 1: that the long bow allowed for British military domination during
Speaker 1: medieval times, and the crossbow, invented yet again in China,
Speaker 1: did much the same there. So thanks to him for that. Yeah.
Speaker 1: So thanks everyone for writing in with your comments and
Speaker 1: feedback on the Military Technologies podcast. We do appreciate it.
Speaker 1: If you want to send us more suggestions or just
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