New episode! - An introduction to: Insect Orders
We’ve all seen insects, right? Scuttling along the forest floor, buzzing between flowers, or simply basking in the sun. But what are the different types and how are they classified? Phil gets to grips with taxonomy and illustrates some common critters you might see on your travels.
Birds Wallpaper in Animalium
tuggywuggy asked: Is congenital myotonia found in non-domesticated animals?
This question comes from my video about GOATS! so you should watch that first to get an intro on fainting goats (congenital myotonia) and also just because goat science is awesome.
I just spent half an hour digging through scientific literature trying to find reports of congenital myotonia (“fainting syndrome”) in a wild animal and came up with exactly zilch, zero, and nada. We see it in goats, horses, dogs, cats, people… all of which are domesticated species (except for maybe people), but no reported cases in wild animals. Does that mean it’s impossible?
First let me summarize what should happen in a normal skeletal muscle contraction, then I’ll answer that question.
Muscle cells, like nerve cells, actively maintain different concentrations of ions on either side of their membrane. This resting membrane potential is super-interesting, but also pretty complicated, so instead of me turning this answer into a textbook chapter, all you need to remember right now is that the inside of a muscle cell is slightly negative compared to the outside. The ions we need to keep in mind right now are sodium (Na+, higher conc. outside), potassium (K+, higher concentration inside), and chloride (Cl-, higher concentration outside).
When a nerve impulse reaches a muscle fiber, the neurotransmitter acetylcholine opens a sodium-specific door on the muscle and lets some Na+ ions inside.
Sodium is a positive ion, so it makes the inside of the muscle more positive. Then that initial burst of Na+ leads to an even larger Na+ wave. Positivity breeds positivity, people!
This burst of positive charge into the muscle cell is essentially what makes it contract (although I’m leaving out a bunch of stuff, like how calcium comes into play, to dig into more detail on all this, check out these great illustrations from MDA.org)
Of course, muscles don’t usually stay contracted, unless you’re dead, diseased, or get a cramp. Why not? After a short amount of time, potassium ions flow out of the cell through their own special potassium doors (making the inside more negative again) and chloride ions move in through their special chloride doors (making the inside even more negative).
It’s the return to that original inside-negative state that makes the muscle relax (now maybe you can start to see why loss of salt/electrolytes can lead to cramps?)
Finally we come to the fainting goats. Congenital myotonia leads to a mutation in that chloride channel I mentioned up there (if you’re into gene and protein names, it’s called CLCN1), meaning that those muscle cells take longer to return to their normal negative-on-the-inside charge and stay locked in the “on” state.
That’s what we see in “fainting” goats, or any other creature with congenital myotonia. The muscles just lock up, and the “fainting” is really just “falling over thanks to suddenly obtaining the flexibility of a statue.”
So does this mutation exist in wild animals? Probably. There’s no reason a wild animal could gain a spontaneous mutation in its chloride channel gene and have particularly rigid offspring. Only these statue-creatures would be easy pickings for predators, as in “easiest meal evar,” and that mutation wouldn’t be able spread throughout the population. Since we can’t keep track of every single wild animal and their offspring, we probably never see it (although there might be isolated reports out there). Like, what’s happening with this panda? I don’t even know.
On the other hand, we inbreed the hell out of domesticated animals, and thanks to fences, sharp sticks, and sheepdogs, we tend to keep them fairly safe from predators (not to mention that humans don’t have any predators except each other). So whether or not they have the genetic misfortune of crumpling into a heap of myotonic hilarity every time we sneak up behind them, we’ve artificially (and accidentally) amplified this mutation in domesticated breeds (although breeders are often encouraged to not breed “fainting” animals).
So the answer to your question is almost certainly yes, although the Bad Wolves keep the Weeping Angels from taking over.
In love with my tattoo, first session is a success
The bird is so well done (what species is it? Looks a bit like the song thrushes I see in my back garden)
bioqueer asked: I saw on your response to an anon question on the first of march that you are "uncomfortable with a large part of behavioural science". I was wondering if you could elaborate? I'm currently studying behavioral science, and I'm curious what some of the weaknesses others see are. I see some methodological issues with the field, but think it's still quite valuable. I'd like to know where the problems are, so I can make an informed decision about where to put my further study energy.
A few big problems for me with behavioural science are how frequently experiments are poorly designed, the level of control is impossible to assess, and behaviours are subjectively interpreted. I also think that a lot of modelling that takes place in behavioural science tells us very little about the animals they are looking at except that they don’t necessarily behave like a computer simulation. Quantifying behaviour in a meaningful, informative, and interesting way is extremely difficult. There is also a problem of perceived significance (and the stupidity of arbitrary significance) and pathetic sample sizes in a LOT of behavioural research. I have read several behavioural studies where the effective sample size was about 3 individuals, because of the number that had to be discarded.
I am not saying it’s not a valuable field. I would be the last person to say that a field is valueless, considering how niche my own field is. What I am saying is that in my experience, from the behavioural research I have done, the literature I have read, and the lectures I have sat through, a lot of the conclusions that are being drawn in behavioural fields are stronger than the data warrants. This is something that should be avoided whenever possible in science.
Behavioural science is actually a really exciting field in terms of technological and methodological advancement. Hopefully we will be able to transfer experiments that have previously been done under lab conditions to the field, where control is more difficult but conclusions are more relevant to real behaviours. My partner’s research for example has just demonstrated that the gluing of PIT tags to field crickets doesn’t affect their longevity in the field, meaning that research on these insects can now be done in a field environment without worrying about the study subjects having lower survival than their unstudied counterparts.
I just urge anyone in behavioural science to go forth with careful consideration of their goals and the ways in which to achieve them in a statistically sound and reasonable way. As I have discovered myself, it is so easy to make a study meaningless by less than careful research design. Avoid that at all costs.