Tag Archives: Biology

Just How Scientifically Possible Are Gremlins?: Part 3

Happy Monday, everyone!

It’s been a while since I’ve written anything here, as I’ve been pretty damn busy of late. I’ve written a couple of articles for different websites and have given a presentation, which I’ll be writing up into a blog post for later on in the week. Plus I’ve had to do a little something called a PhD! But here we are and it’s time for the long-overdue final instalment on Gremlins and Mogwai.

Given how long it’s been since I started this (I’ve had something of a mental block), I’d advise heading to Part 1 and Part 2 for a quick recap on what these posts are about….

…*twiddles thumbs; makes cup of tea….thinks about PhD work and adds whisky…*

All done?

Right then. Let’s get cracking with a reminder of the final rule for keeping a Gremlin or Mogwai. Enjoy!

Rule 3: Never get them wet

If a Mogwai or Gremlin gets wet then it will spontaneously spawn offspring, which pop out of its back.


The best Gremlin in the films – the Brain Gremlin (Photo Credit: Warner Bros/Amblin Entertainment & ‘’)

Given that there is no sexual intercourse involved here (unless something happened off-camera that we really don’t want to know about), it’s safe to say that Mogwai/Gremlins are asexual. So far so obvious I hear you say; but now we need to look at what type of asexual reproduction they undergo. It turns out there are quite a few types, but only two of them are seen in the animal kingdom. They are known as ‘Fragmentation’ and ‘Parthenogenesis’.

In the former, new organisms grow from a piece, or fragment, that has broken off from the parent organism. You know when you take a cutting of a plant and give it to someone else to grow in their garden? That’s artificial fragmentation and your friend’s plant will have the same genetic material as yours. However, outside of plants and fungi, this is obviously only a feasible method of reproduction in relatively simple animals like worms and starfish. It certainly wouldn’t be possible in something as complex as the mammalian Mogwai and reptilian Gremlins.

That leaves us with Parthenogenesis. In this case, females’ eggs can develop into embryos without needing to be fertilised. This is certainly seen in many different animals, including some sharks, insects and reptilian species, such as the Komodo Dragon. However, I came to the conclusion in Part 1 that Mogwai/Gremlins are mammals, so can a mammal reproduce through parthenogenesis? The answer is….sort of.


Kaguya the Parthenogenetic Mouse (Photo Credit: Wikipedia)

No mammal reproduces in this way naturally. However, in 2004, a Japanese research group did manage to produce a mouse from two mothers, with no sperm involved. The offspring, named Kaguya, even went on to have her own children…in a more conventional manner! The research group concluded that, at least in mice, fathers’ genetic material prevented parthenogenesis occurring naturally so as to ensure the need for males. Now, I’m feeling in a forgiving mood as I write this. Despite the fact that parthenogenesis doesn’t occur naturally in mammals, I’d say it’s a reasonably realistic explanation for how Gremlins reproduce. After all, they’re not your typical mammal! So, score one for realism!

Now let’s deal with this business about ‘spontaneously’ spawning offspring. If you haven’t seen the films, this video shows what happens when you get a Mogwai wet. Basically Mogwai and Gremlins that get wet immediately start shaking, at which point fur balls or sacks, respectively, pop out of their backs. These then grow quickly into full-sized Mogwai or Gremlins, depending on which made them. The whole thing takes about 1 minute.

If we ignore the ridiculous idea that dropping water on an animal that is 90% water would cause it to reproduce, just how realistic is this reproduction time? To answer this, let’s have a look at a few records in the field of reproduction.


Clostridium perfringens (Photo Credit: Marler Blog)

The organism with the fastest known reproduction time is the bacterium Clostridium perfringens (if we don’t count viruses as living organisms…ooh future post idea!). This single-celled organism is found pretty much everywhere and is a leading cause of food poisoning. It reproduces asexually, with a new cell budding off from the parent in just 10 minutes.

Now, given that C. perfringens is a unicellular organism, you’d expect it to be able to reproduce much faster than a complex organism like a Mogwai or Gremlin. Its method of reproduction – binary fission – isn’t burdened by the need for embryonic development either, so doesn’t take up as much time. As such, the idea that a mammalian creature could produce fully grown offspring in less than a minute is, I’m afraid to say, a figment of the imagination. To put it into perspective, the title of the shortest known gestation period for a mammal belongs to the Short Nosed Bandicoot. It pops out its sprogs (note, not a technical term) after just 12 days!

And that, as they say, is that. Over these 3 posts we’ve had a look at a fair range of biological processes and phenomena that Mogwai and Gremlins seem to demonstrate in the films. Hopefully you’ve enjoyed reading about them and learned a bit more about the world too – I certainly have! So, what’s the overall verdict? Are Gremlins realistic or not? I’ll answer by leaving you with the final scores – there are 2 points for each post: 1 for realism of the rule and 1 for realism of the sub-topic discussed. Till the next time!

Possible: 3          Not possible: 3

It’s a draw! So…erm…I guess they’re sort of scientifically possible but not quite… I was hoping for a clean outcome there…bugger!


Posted by on August 19, 2013 in Biology, Silly Science


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The Stem Cell – The Dorian Gray of the Bloodstream

Hi everyone! Apologies to those of you who follow me for the lack of postings over the past 2 weeks – things have been pretty hectic! However, as of now, I’m back on track and I’ll be bringing you 2 main posts this week to make up for the wait. This first one has been inspired by my reading Oscar Wilde’s ‘The Picture of Dorian Gray‘ – the story of a young man so consumed with his youth and beauty that he offers up his soul in order to retain his glory. I stumbled upon a research article into the damaging effects of ageing on the blood, which, given my reading material, struck a chord, so I thought I’d share what I read.

We all know that, as we get older, our bodies suffer – our bones become more brittle, we become weaker and, as I’ll discuss here, we become more susceptible to illnesses, including blood disorders. But why does all this happen? Well, for the most part, the cells from which we are made do not live very long. They are constantly dying and being replaced because of the countless toxins and physical pressures they have to cope with as they keep our bodies functioning properly. Imagine a weightlifter trying to hold his personal best above his head whilst someone continually punches him in the stomach and you’re probably on the right track! Replacements develop from special cells called stem cells. When first created, they have no specific function other than to make copies of themselves to maintain their numbers. However, stem cells have the potential to irreversibly take on the role of any other cell type when required. So, given this, why do stem cells don’t make us immortal? It is thought that their ability to function lessens over time, meaning that, eventually, fewer and fewer dead cells are replaced. The question is, in what way do they stop working?

Researchers at the University of California, San Francisco, have investigated this by looking specifically at stem cells made in the bone marrow – Haematopoietic Stem Cells (HSCs). These cells are responsible for replacing blood cells. When they don’t perform this role properly, as in aged individuals, numbers of healthy blood cells are reduced and unhealthy or dangerous cells and toxins become more prominent, resulting in blood disorders. This work aimed to understand why HSCs become less adept at producing healthy cells by studying their ability to carry out two essential cellular tasks: Autophagy and Apoptosis.

Autophagy involves sealing off, and breaking down, damaged or unnecessary cellular machinery. Normally, the resulting pieces can be used to build new machinery (like breaking down a Lego model to build a new one). During periods of starvation, however, they can be used as a source of nutrients and energy.
Apoptosis, meanwhile, essentially means ‘cell suicide’. Cells, including stem cells, that are severely damaged or unable to perform their given tasks can kill themselves.

The research group genetically engineered HSCs from mice so that they did not possess certain genes involved in these 2 processes – this is called a ‘gene knockout‘ technique. If a cell does not possess a certain gene then that gene cannot do its job. Scientists use this method to see exactly what roles individual genes play in a cell. The modified HSCs were exposed to both normal bloodstream-like conditions and those seen during periods of starvation. The group made the following observations (with the exception of the first one) by knocking out various genes and monitoring the effects they had on cell survival:

1. HSCs are far more capable of employing autophagy to react to starvation than other cells in the bone marrow. This is a well-known trait of stem cells.

2. Autophagy, as a process, exists to protect cells – if they can repair themselves then they don’t need to destroy themselves via apoptosis. As HSCs are excellent at launching autophagic responses, they can live and function longer than other blood cells before resorting to apoptosis.

3. HSCs possess a set of genes, which ensure that HSCs are always primed and ready to become autophagic quickly, to avoid starvation, damage and death.

4. Older HSCs are just as capable of launching an autophagic response as younger HSCs. In fact, it seems that the cells rely on the process to survive as they slowly lose the ability to uptake nutrients and produce energy.

This research proves to be something of a first step, rather than a full conclusion, in my opinion. We now know that autophagy is essential to stem cell survival and occurs properly, even in old age. However, that leaves us asking what happens – what breaks – in stem cells to cause them to slowly malfunction and die? Regardless, I hope you agree that this is a very interesting step closer to discovering why our blood system ages and deteriorates. I particularly like the idea that, as malfunctioning cells and harmful toxins build up and blood disorders become more likely, the failing HSCs remain obsessed with trying to keep themselves young, much like a certain Mr Gray…


This post was based on Warr, M. R. et al. (2013). FOXO3A directs a protective autophagy program in haematopoietic stem cells. Nature 494 (7437) 323-7.

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Posted by on February 27, 2013 in Biology


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