Bluetongue1
Well-Known Member
I am going to do a Pauline Hanson here. Please explain what you mean by “Your maths are back of an envelope level stuff and do not take into account the potential of modern GM cats”.
CSIRO investigates gene war strategy to rub out feral cats
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I am going to do a Pauline Hanson here. Please explain what you mean by “Your maths are back of an envelope level stuff and do not take into account the potential of modern GM cats”.
There are lots of ways of doing this, it can target multiple genes. The simplistic idea of 50/50 is not required unless that is the best they can do.
I will post this guy to distract you
Bluetongue1
Well-Known Member
@cris, you have avoided answering my question. By the way, I understand about GM plants (‘Roundup Ready’ soy, canola, cotton etc). How is that relevant to the current discussion involving animals?
The 50/50 refers to the ratio of GA males to normal males in the imaginary scenario I generated. This scenario was generated to illustrate/explain the point that I had made that this would “not be a quick fix”. I figured as I made that statement I should be able to back it up. The arithmetic is correct and there is nothing wrong with the maths behind it. It was never touted as a model of the population dynamics of feral cats, as you seem to have interpreted it being. That’s your mistake, not mine. So I don’t appreciate your deprecating comments.
The 50/50 refers to the ratio of GA males to normal males in the imaginary scenario I generated. This scenario was generated to illustrate/explain the point that I had made that this would “not be a quick fix”. I figured as I made that statement I should be able to back it up. The arithmetic is correct and there is nothing wrong with the maths behind it. It was never touted as a model of the population dynamics of feral cats, as you seem to have interpreted it being. That’s your mistake, not mine. So I don’t appreciate your deprecating comments.
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Assuming the mutation is on the Y chromosome and destroys all X chromosomes during meiosis, or otherwise makes X sperm non viable, all offspring from the modified males would be modified males.
I'm not sure how the mechanism could work to produce 50% modified males, 25% normal males and 25% normal females; sperm is haploid and males only have one version of their Y chromosome, so all offspring of mutant males should be mutant males. Females only produce X eggs - correct me if I'm wrong about this assumption.
If we assume the males will have equal virility and breeding success (which is highly likely and would be a requirement of bothering to do it), a single male added to a population of 100 would have no males capable of producing daughters within about 10 generations. If we wanted to start by adding multiple males it would happen more quickly. Even if some crazy freak wanted to catch one and take it out of Australia for some really weird reason, there is a fairly brief time between when the mutant males become common and when the population collapses. If they try to catch one early on it's probably just going to be a really nasty, feral cat which no sane person would want much to do with. The mutant males are in the minority of males until generation 7, and the populations ceases to exist at around generation 11, but they are becoming extremely difficult to find because they're so rare well before they go extinct with all remaining individuals being mutant males. And feral cats are pretty elusive at the best of times.
I made a spreadsheet to calculate, you can plug in any numbers of starting population size (number of normal males, introduced daughterless males and females) you want and it will give you the figures of mutant males, normal males and females for the next x generations. If anyone wants a copy by email you can shoot me a message.
Naturally we aren't going to be able to introduce mutant males to every single population/region in the country, but once the mutation is spreading and doing its job it will seed itself around very effectively with the assistance of strategic releases, and when a new population is discovered it can have a few mutant males added which should knock it over quickly. It may be difficult to completely erradicate cats from every remote region of Australia, but in terms of conservation 99% is about as good as 100% and once the vast majority are gone, managing the remaining ones should be easy. New populations will spring up from irresponsible owners releasing them, and they can be dealt with too. The vast majority of the cats would be cleaned up with minimal effort and managing the situation from there should be easy. New populations will primarily spring up around human occupied areas rather than remote areas, making them easy to detect and deal with.
Someone asked if it would affect domestic cats - sort of, and only in a good way. It's not a virus or anything so your actual pet cat won't be at any risk. If your pet cat is a male this changes nothing. If your pet cat is female and she has an accidental litter to an unknown father (which means you are a very irresponsible cat owner) and you're lucky enough for it to be a special male, it means the resulting kittens will all be males incapable of making females, which means if you give them to other people as pets and they're irresponsible they won't be having unexpected litters. No self respecting cat breeder in Australia should be using wild/random males produce more pet cats, and if they do, anything slowing them down is a good thing. Responsible breeders making kittens with deliberate pairings will be completely unaffected.
Unfortunately this virtual nobrainer will be seen as a 'debate' because people don't understand the situation and despite eating GMO foods every day they're scared of the term GMO (FTW I'm a geneticist and see some concerns with GMO foods but these cats are a totally different thing), and they'll irrationally think it means cats are going to suffer or it will harm their pet moggy or wipe out the few remaining wild tigers or something, and I'm guessing this will mean the research gets done, the product gets perfected, but the release never happens because of uninformed public opinion, and actual real Australian native animal extinctions will continue.
I'm not sure how the mechanism could work to produce 50% modified males, 25% normal males and 25% normal females; sperm is haploid and males only have one version of their Y chromosome, so all offspring of mutant males should be mutant males. Females only produce X eggs - correct me if I'm wrong about this assumption.
If we assume the males will have equal virility and breeding success (which is highly likely and would be a requirement of bothering to do it), a single male added to a population of 100 would have no males capable of producing daughters within about 10 generations. If we wanted to start by adding multiple males it would happen more quickly. Even if some crazy freak wanted to catch one and take it out of Australia for some really weird reason, there is a fairly brief time between when the mutant males become common and when the population collapses. If they try to catch one early on it's probably just going to be a really nasty, feral cat which no sane person would want much to do with. The mutant males are in the minority of males until generation 7, and the populations ceases to exist at around generation 11, but they are becoming extremely difficult to find because they're so rare well before they go extinct with all remaining individuals being mutant males. And feral cats are pretty elusive at the best of times.
I made a spreadsheet to calculate, you can plug in any numbers of starting population size (number of normal males, introduced daughterless males and females) you want and it will give you the figures of mutant males, normal males and females for the next x generations. If anyone wants a copy by email you can shoot me a message.
Naturally we aren't going to be able to introduce mutant males to every single population/region in the country, but once the mutation is spreading and doing its job it will seed itself around very effectively with the assistance of strategic releases, and when a new population is discovered it can have a few mutant males added which should knock it over quickly. It may be difficult to completely erradicate cats from every remote region of Australia, but in terms of conservation 99% is about as good as 100% and once the vast majority are gone, managing the remaining ones should be easy. New populations will spring up from irresponsible owners releasing them, and they can be dealt with too. The vast majority of the cats would be cleaned up with minimal effort and managing the situation from there should be easy. New populations will primarily spring up around human occupied areas rather than remote areas, making them easy to detect and deal with.
Someone asked if it would affect domestic cats - sort of, and only in a good way. It's not a virus or anything so your actual pet cat won't be at any risk. If your pet cat is a male this changes nothing. If your pet cat is female and she has an accidental litter to an unknown father (which means you are a very irresponsible cat owner) and you're lucky enough for it to be a special male, it means the resulting kittens will all be males incapable of making females, which means if you give them to other people as pets and they're irresponsible they won't be having unexpected litters. No self respecting cat breeder in Australia should be using wild/random males produce more pet cats, and if they do, anything slowing them down is a good thing. Responsible breeders making kittens with deliberate pairings will be completely unaffected.
Unfortunately this virtual nobrainer will be seen as a 'debate' because people don't understand the situation and despite eating GMO foods every day they're scared of the term GMO (FTW I'm a geneticist and see some concerns with GMO foods but these cats are a totally different thing), and they'll irrationally think it means cats are going to suffer or it will harm their pet moggy or wipe out the few remaining wild tigers or something, and I'm guessing this will mean the research gets done, the product gets perfected, but the release never happens because of uninformed public opinion, and actual real Australian native animal extinctions will continue.
Hey Wally ,if we can get rid of the feral cats that will be a big step forward and then we can look to the next project.
Bluetongue1
Well-Known Member
@Sdaji ,
Your calculations of a total population collapse are based on are based on a 1% seeding rate of GM cats. (I checked the figures your way by hand just to be sure.) Given that the feral cat population in Australia is estimated to be 1.8 million, this would require release of some 18,000 GM moggies. That is an awful lot of cats. That of course ignores variations in population density and assumes a prorate release rate accordingly. Realistically the seeding rate will be likely be at least an order of magnitude less I would imagine. So one could probably add another couple of generations at least. Given the determined life expectancy of feral cats is 2 years, that’s probably around the 25 year mark.
I see a huge potential in it so long as there is no chance of the modified genes getting into any other of the natural populations of small feline species. It also has to be kept out of the domestic cat populations of overseas countries or we might find ourselves in real strife. It is all very well to say it ain’t gunna happen, but it needs some serious looking at first.
It is also worth bearing in mind there are factors that may reduce its effectiveness somewhat. They cleaned out most of the foxes in large tracts of land in SW WA, released a bunch of critters such as numbats, and the cats moved in and cleaned them out. Hopefully the reverse won’t happen, or at least not to the same degree. The presence of rabbits are known to support higher populations of cats and foxes. I wonder if there will be an increase in them and what flow-on effect that might have? It surely could not be anyway near as bad as the cats.
Your calculations of a total population collapse are based on are based on a 1% seeding rate of GM cats. (I checked the figures your way by hand just to be sure.) Given that the feral cat population in Australia is estimated to be 1.8 million, this would require release of some 18,000 GM moggies. That is an awful lot of cats. That of course ignores variations in population density and assumes a prorate release rate accordingly. Realistically the seeding rate will be likely be at least an order of magnitude less I would imagine. So one could probably add another couple of generations at least. Given the determined life expectancy of feral cats is 2 years, that’s probably around the 25 year mark.
I see a huge potential in it so long as there is no chance of the modified genes getting into any other of the natural populations of small feline species. It also has to be kept out of the domestic cat populations of overseas countries or we might find ourselves in real strife. It is all very well to say it ain’t gunna happen, but it needs some serious looking at first.
It is also worth bearing in mind there are factors that may reduce its effectiveness somewhat. They cleaned out most of the foxes in large tracts of land in SW WA, released a bunch of critters such as numbats, and the cats moved in and cleaned them out. Hopefully the reverse won’t happen, or at least not to the same degree. The presence of rabbits are known to support higher populations of cats and foxes. I wonder if there will be an increase in them and what flow-on effect that might have? It surely could not be anyway near as bad as the cats.
While this is mice I assume a similar mechanism could be possible with cats. Go to the link to see the figure or read the paper if interested, this alone does not give the full picture.
from
Caroline M. Leitschuh, Dona Kanavy, Gregory A. Backus, Rene X. Valdez,
Megan Serr, Elizabeth A. Pitts, David Threadgill & John Godwin (2017): Developing gene drive
technologies to eradicate invasive rodents from islands, Journal of Responsible Innovation, DOI:
10.1080/23299460.2017.1365232
https://research.ncsu.edu/ges/files...s-eradicate-invasive-rodents-islands-2017.pdf
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I played around with the numbers (it's very quick to do on a spreadsheet) for various population sizes and starting numbers of mutants. Obviously I was talking about an individual hypothetical population rather than the entire continent. As I said, total erradication from the entire continent may not ever be possible, but specifically targetted populations could be dealt with in that sort of ballpark timeframe, and the mutants would spread of their own accord. You can crunch the numbers on how quickly they would get up to 18,000 individuals when left to their own devices. Absolutely, it's not like we're talking about every last population of them being wiped out in the next 10-20 years. I think the iimportant thing is that it would work, and that it never stays common for a long time. As soon as it becomes common in a population, the population vanishes. ('as soon as' being within a small number of years/generations).
I agree, this is a concern. The one and only concern.
I think that was really obviously short sighted, but even so, exterminating the foxes wasn't a problem, it was only a partial solution. People being stupid enough to feed numbats to cats doesn't mean wiping out the foxes was a bad thing. I would advocate doing a similar thing with foxes, which should have even less risk than with cats.
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Thanks for this information, much appreciated. If it's the same system in cats it would certainly be a much longer process. If they can use an X-destroying mechanism instead it would be much better.
Flaviemys purvisi
Very Well-Known Member
RN Breakfast
By Stephanie Smail
Posted about 9 hours ago
PHOTO: There are millions of feral cats across Australia, and that has been taking a heavy toll on native wildlife. (Supplied: Hugh McGregor, Arid Recovery.)
Gene drive technology considered in the fight to save native animals from feral cats
Feral cats kill thousands of native animals every minute — now a controversial plan to use gene drive technology as a weapon against them is being considered by the Federal Government.
Conservation groups want cats that only produce male offspring to be released into the wild as a way to save native mammals, such as bilbies and bettongs, that are under attack.
The CSIRO is investigating the technology, which the Federal Government said could be a "powerful tool" subject to careful study.
But scientists acknowledge there are risks, particularly if genetically modified cats made it to other countries and wiped out native cats there.
PHOTO: A feral animal caught on camera after catching and killing a native rodent. (Supplied: Dr Aaron Greenville)
Killing machines
Unlike other feral predators, cats live in every habitat in Australia, from the rainforest to the desert, the east coast to the west.
They are hard to see, hard to trap and hard to bait because they prefer their prey live.
Atticus Fleming, chief executive of the Australian Wildlife Conservancy, said there were millions of feral cats across the country, and that has been taking a heavy toll on native wildlife.
"Basically, every minute, across Australia, feral cats are killing … 2,000 native animals a minute," he said.
He has been fuelling the push to develop so-called gene drive technology as a weapon against feral cats.
"We are watching species go extinct before our eyes," Mr Fleming said.
"We need to act now and we need to put feral cats at the top of the list of priorities."
Mr Fleming said while the large feral cat free zones were working to protect many native animals vulnerable to attack, there was no broader strategy.
He said gene drive technology offered the only glimmer of hope.
"[There are] 30 mammals extinct [in Australia] since European settlement. In the US since their European settlement it's one, so we're off the charts," he said.
How does it work?
The CSIRO agreed to work with the Australian Wildlife Conservancy on the idea, and their scientists have already begun work in the field.
The team genetically modified so-called "daughterless carp" so the fish only produced male offspring, but they were never released into the wild.
Andy Sheppard, research director at CSIRO Health and Biosecurity, said the method would not require the introduction of a vast number of genetically modified cats.
"[This] technology allows all offspring of any coupling between a gene construct and a wild-type animal to all have the gene construct," he said.
And this, he said, was what everybody is getting exciting about — whether or not the gene technology could be used to control a whole range of feral pests.
"The primary focus globally at the moment is whether or not it would be an acceptable technology to manage mosquitos to try and rid the world of diseases like malaria," Dr Sheppard said.
He said the technology would remove the need for baiting or trapping because the population would die out naturally — but he acknowledged there were risks.
So, what's the catch?
Dr Sheppard said the main risk was if the genetically modified animals somehow escaped into areas where cats were not a pest, it could endanger those cats which may be valued and might in fact be native.
"There's a lot of movement of animals around the world, either legally or illegally, which raises the potential risk of those GM animals being moved around," he said.
PHOTO: Galahs are among the many native species being killed by feral cats. (Supplied: Mark Marathon)
He said authorities would need to be sure before gene drive technology is rolled out.
"Once you've released your genetic construct into the field, under that scenario, it's very, very hard to stop it," he said.
"So, you would be making a decision that may be hard to withdraw."
Dr Sheppard said if it went ahead, it would be a world first.
He said work has not started, and would not without Federal Government approval.
Professor John Woinarski speaks about feral cats in Australia
http://www.abc.net.au/news/2017-10-04/cats-in-australia-kill-the-equivalent-of-more-than/9014922
VIDEO: Cats in Australia kill the equivalent of more than one million birds a day (ABC News)
If the decision was made to push forward, Dr Sheppard said the technology had huge potential for managing even the most elusive pests.
"Managing invasive species, once they've established and become widespread and are causing harm, has been a huge challenge for society," he said.
"Pretty much the only technology we've had available to us up to now has been classical biological control, as exemplified by the rabbit biological control program in Australia over the last 60 years."
He said for the first time they have a technology that could "potentially" eradicate some very harmful pests from the environment, such as rodents on islands where there is high biodiversity, without having to use poisons.
The cat always wins
Australia's feral cat population swings between about 1.5 million and 5.5 million, with more cats after heavy rain.
Native mammals do not stand a chance against that, said Sarah Legge from the Threatened Species Recovery Hub of the Federal Government's National Environmental Science Program.
"Our mammals in particular are just not very good at being aware of cats and avoiding them," she said.
PHOTO: Dr Legge said gene drive technology could finally bring feral cats under control. (Landline: Prue Adams)
"On top of that, cats breed generally much more quickly than our native species, so they can out-breed their prey."
She said gene drive technology could finally bring feral cats under control.
"There are a heap of techniques available and that we use, but none of them are going to get rid of cats at the continental scale," she said.
"If it wasn't to get rid of cats altogether, it might be to reduce them to a point where they're not having such big impacts on native wildlife."
But Dr Legge said there was still a long way to go before the idea became a reality.
"I think we've got quite a long period in the lab before we get to the point of even thinking about letting it go outside of the lab," she said.
"In that time there needs to be a public conversation that hasn't even started yet as far as I'm aware, about the place of technology like that in our world and how comfortable we are with using it."
In a statement, Minister for Environment and Energy Josh Frydenberg said gene editing technologies were not a panacea, but could be a powerful tool in fighting extinction, subject to further careful study.
He said his department and others had been in discussions with the CSIRO about the technology.
Wally
Very Well-Known Member
Outlaw domestic cat keeping in this country first and we might have a chance.
Then again, it's one less feral I get to shoot.
If they got this going you don't need to ban cats as pets. Humans are an important predator, always plenty of native animals to eat and skin.
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