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I've always liked frogs. I remember, when I was probably around 4 years old, being fascinated by the tadpoles that Dad brought home in a big jar from a farm pond. Mum explained about how they'd gradually metamorphose (thought I doubt she used that word!) & we watched their legs slowly grow & their tails disappear as they swam around in an old tub, until the point where they became frogs.

Frogs are amphibians, along with newts & mud-puppies & axolotls and the legless caecilians (which look like a cross between an eel and an earthworm). As a group, frogs are much younger - in geological terms - than the others: most fossil frogs date back only about 50 million years, although the earliest-known frog-like creature, Triadobatrachus, lived about 250 mya in the early Triassic.

Like almost all terrestrial amphibians, adult frogs use not only lungs for gas exchange, but also their skin and the membranous lining of their mouths. (Lungless salamanders are an exception - as the name suggests, they must rely on their skin alone, which is very convenient for those researching amphibian gas exchange.) This reliance on transcutaneous respiration has meant that amphibians are very susceptible to harm due to to chytrid fungus infection, which severely damages the skin and markedly reduces the animals' ability to exchange O2 & CO2 with the atmosphere.

In addition, using your skin as a gas exchange surface means that you have to keep it moist. This means that we'd expect to find frogs only in environments that are humid and damp year-round, & in general that's the case. But there are always exceptions. and the desert rain frog is one of them. Breviceps macrops lives in one of the most inhospitable environments there is, a dry coastal strip of land in Namibia & South Africa. Hardly a place for a frog! It spends most of its time in burrows dug deep enough to reach into moist sand, but comes out at night when the air is cooler & more humid. While there's very little actual rain, moisture-bearing sea fogs roll in from the ocean on at least 100 nights each year, bringing some water to the habitat as the fogs condense onto dunes & vegetation - enough to allow these little amphibians to survive. (There's no actual tadpole stage in their life cycle; little froglets develop directly from eggs in the burrows.)

And like other amphibians, they vocalise to advertise their presence. I hesitate to say the sound is a croak. In fact, it drove my dog to distraction when I played the following clip.

I give you - 'the sonorous war cry of a very angry frog'.


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This was first posted over on Talking Teaching.

I’m always looking for interesting ideas that might spark student engagement. A couple of days ago this rap video popped up on the ScienceAlert FB page:

As you can see, it’s a fun post with a serious message & – I think – an excellent piece of science communication.

Anyway, then this happened:

BIOL102 chat re rap on FB

I’m really hoping that we can make this happen. It would be an excellent way to enhance interactions between undergraduate and grad students, and also with academics if they would like to be involved (& I’d hope at least some would!) It would give the grad students (& staff) an opportunity to communicate with a wider audience about the nature & significance of their work, and the undergrads who take part would gain some of the capabilities that they need in the world beyond university.

Here’s hoping!

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Today I heard that one of my favourite authors, Sir Terry Pratchett, had died (at the relatively young age of 66). And I cried. In his Discworld novels he created a world full of the most amazing characters, and while their voices - and through them his - will continue to speak to us, their adventures are done. I almost want to ask if anyone's checked for the sign that Granny Weatherwax used when she went 'travelling': I ate'nt dead.

Pratchett's books provided a compassionate, witty, literate & at times downright hilarious commentary on our own world: war, politics, racism, greed, kindness, cruelty, love, science, academia (his take on my own profession rang very true at times), and Death - who always spoke IN CAPITALS. 

In recent years Pratchett, who was living with (& I suspect enormously frustrated by) the effects of early-onset Alzheimers, had become an advocate for euthanasia. He wrote passionately & with great compassion on the subject. And he would probably have agreed with Death's opinion: that in his (to us untimely) death he was simply leaving early to beat the rush.

As he said himself (in Reaper Man):

No-one is actually dead until the ripples they cause in the world die away...

Rest in peace, Sir Terry, and may the ripples of your words continue to spread outwards for many years to come. 


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I've just spent an entertaining 10 minutes or so clearing out my spam folder. I don't go there often, but a student had asked why I hadn't answered their email & since I hadn't actually received one in the in-box, I thought I'd best check spam. (And there it was. General hint to students: really idiosyncratic email addresses will land you in spam, from time to time. Also, they can look a bit unprofessional on a CV.)

Apart from the amazing offers of money (if I'd only send a little money - a 419 scam - or alternatively my bank account details, plus PIN, I could be a millionaire! And retire to travel the world!!!), and people trying to sell me pipes and ball bearings, there seem to be an awful lot of people who are starved of social interactions and, dare I say it, romance? How else to explain the pitiful cries of Olga and Anna, who are 'nice girls' from Russia, just wanting a little companionship? They seem (from the subject lines of their emails) to be quite hurt that I haven't responded to their earlier pleas for the chance to get to know me better.

But it's slightly creepy to see so many people with such an interest in the quality of my love life!

And to those who asked (so many of you!) if I am the caring, tender gentleman of their dreams - ladies (if ladies you are), how wrong you are!

But more seriously, the sad thing is that someone, somewhere, will be responding to these scammers, and probably losing money - and equally worrying, potentially becoming subject to identity theft as well. A good rule of thumb here is, if it sounds too good to be true, it probably is! The next time you get one of these emails, check what has to say on the subject, or visit the 419Eater archive.

But don't send money, your bank details, your photo. Because you won't find love, or money. You'll just make some nasty unscrupulous people even better off than they already are.

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Back in 2010 I wrote a post about bananas, following on from a Schol Bio question the previous year. As well as looking at the genotypes of modern bananas, I highlighted the fact that the original wild banana was not a particularly appetising object, with little flesh and a lot of large, hard seeds. Selective breeding for the win!!!

Anyway, it seems like at least one anti-GMO Facebook group has got a case of the vapours about 'GMO bananas', this being the only explanation some of its members could think of for the fibres that you'll often see in the skin of a not-completely-ripe banana when you twist & pull the stalk end. Kevin Folta picked this up in a blog post, noting the lack of knowledge of some of the commenters there (I haven't quite decided if the one about Morgellon's is a poe...) - but as Robert Sacerich notes, one of those commenters is giving an object lesson in how NOT to do science communication, & doesn't help the cause. 

And no, we have no GM bananas - at the moment. Sacerich points out that there's work in progress on developing GM plants that are resistant to the major threats to banana production (Black Sigatoka disease, Banana Bunchy Top virus, and bacterial infections). So such plants may well become a reality in the relatively near future.

But that will have nothing to do with the fibres that so concerned those anti-GMO commenters; they've always been with us & were apparently used in cloth production in Japan as early as the 1200s, a practice that's seen something of a recent resurgence. (I didn't know that! You learn something new every day.)

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And oh, how I wish I could say it was me who came up with that title!

But it wasn't; it was the BBC, headlining a fascinating article about how octopuses get it on.

It seems it's rather difficult to be a male octopus with mating on his mind. Like a female spider, his prospective partner may end up dining on him. 

In octopuses (& their relatives, squid, cuttlefish, & nautilus), males don't have a penis. Instead, they produce packets of sperm - spermatophores - which they must then pass the female using a specialised arm called a hectocotylus (which does contain erectile tissue). 

Squid practice a form of drive-by mating, slapping a spermatophore onto the outside of the female's body. It's pretty indiscriminate. In fact there was a report last year of a woman who ended up with squid spermatophores embedded inside her mouth, through eating parboiled squid - the hectocotylus still had some life in it.

Male octopuses, on the other hand, use that specialised arm to place their sperm packet well inside the female's mantle cavity, close to her ovaries. As you can imagine, this generally requires a certain amount of close contact, which is when things may get downright risky and in some species an unlucky male may finish his days as his beloved's meal. In one recorded incident

A female [Wonderpus photogenicus] used constricting as a form of fatal aggression to asphyxiate a male as part of apparent sexual cannibalism.

This image by Pierangelo Pirak is from the BBC article, and shows what's involved in octopode sex.

A beginner's guide to octopus sex (Credit: Pierangelo Pirak)

In some species the risk is minimised by having very long arms, and even by mating while the female is distracted, and in the blanket octopus the male simply detaches his hectocotylus & leaves it with his mate: an entirely reasonable tactic given the huge difference in size between male and female.

I was intrigued to hear that in some species there are 'sneaker males' - smaller individuals who may even hide that specialised mating arm in order to sneak in & mate with someone else's partner. This does not always end well either

The smaller males wait until a larger guarding male has left the den, then covertly mate with the female. As a result, they are called "sneaker" males. They have even been known to disguise themselves as females, hiding their hectocotylus to make a less threatening approach to a guarded female.

This sly tactic can occasionally backfire, as it did in an instance caught on film by Huffard. A sneaker male approached a burrow where he seemingly sensed a female was hiding. As he reached an arm in, an octopus emerged. But it was not the female: it was her guarding male. Unsurprisingly, this big male was not impressed by the sneaker male's attempt to insert a hectocotylus into his mantle.

And a somewhat mind-boggling fact to end on: the spermatophore of a male Pacific octopus is almost a metre long, and may take an hour to transfer to the female. I think it goes without saying that this must be one of the 'friendlier' species!

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So, which is it? A mantis? Or a fly?

(Image by kind permission of Daniel Llavaneras)

In fact, the creature shown in this gorgeous image by Daniel Llavaneras is neither mantis nor true (Dipteran) fly, although its common name is 'mantisfly'. Instead, it belongs to the insect family Mantispidae (a group that includes lacewings and antlions). Like real praying mantids, matisflies walk on 4 legs, with the front pair folded as shown, and the head is somewhat mantis-like. The adults hunt as mantids do, shooting out those raptorial front legs to catch small insects, while the larval diets vary: some are also active predators, while others consume wasp & beetle larve, or spider eggs (later pupating in the spider's egg sac). In adult form & behaviour, the mantisflies are an excellent example of convergent evolution.

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Seeing this image of a fish with 2 mouths reminded me that I needed to finish writing about Frankenlouie, a janus-headed (diprosopic) cat. It's funny how the mind works, because the fish definitely isn't a janus-fish: that would require the mouths to be side-by-side rather than one above the other. (While this is a rather unsightly mutation, the fish seems to have survived in the wild until a fisherman hauled it out.)

Two-mouthed bream

Photo: Garry Warrick)

So - on to Frank'n'Louie. 

Frank'n'Louie was (were?) described as a 'janus cat' because he had two faces that looked in different directions, like the Roman god Janus (as opposed to that fish, which has two mouths one atop the other). Many people would have found him rather hard to look at, as he had 3 eyes, the middle one of which was blind; two noses; two mouths; and but a single brain. The fact of that single brain means, I suppose, that this really was one, strange-looking, individual cat, rather than the two distinct individuals seen in dicephalic parapagous conjoined twins such as the Hensel sisters. Despite being expected to die soon after birth, Frank'n'Louie attained the ripe old age of 15 years before succumbing to cancer in 2014.

R.I.P.: 'Frankenlouie', the world's oldest Janus cat - a feline with two faces - died at the age of 15 on Thursday, Dec. 4, 2014. The Guinness World Record holder passed away at the Cummings School of Veterinary Medicine at Tuft's University in Grafton, Mass. according to owner Martha "Marty" Stevens of Worcester, Mass. (AP Photo/Worcester Telegram & Gazette, Jim Collins)

Frankenlouie's features are the result of craniofacial duplication, or diprosopus: an individual with a single body and normal limbs, but a greater or lesser degree of duplication of the face. (He was lucky to survive so long as many janus individuals also have neural tube defects, including - at their most severe - anencephaly, or the absence of a brain, and die very young). When I first saw a picture of this cat I wondered if his features had something to do with conjoined twinning, and apparently that's often put down as the underlying cause if the organism has two complete faces.

However, another possible cause is a mutation in the gene responsible for the Sonic Hedgehog protein (SHH), which among other roles is involved in the control of craniofacial development. Too much of that protein (overexpression of the mutant form of the gene) results in craniofacial duplication; too little can cause cyclopia, where there is just a single eye. (Infants with cyclopia die soon after birth as the condition is associated with severe brain abnormalities, so the Cyclops of the Ulysses stories would not have been modelled on an actual adult with the condition.)

In fact, SHH plays a crucial role in embryonic development, as this description on the National Institutes of Health gene database makes clear:

It has been implicated as the key inductive signal in patterning of the ventral neural tube, the anterior-posterior limb axis, and the ventral somites.

This means that mutations in the gene coding for SHH can have far-reaching impacts on the development of the brain and nerve cord, limbs, and body segments, while a mutation in one of the enhancer regions (an enhancer is a region on a chromosome that affects transcription of a particular DNA sequence) results in duplication of the thumb.

But there's more: Sonic Hedgehog is one of a group of 'evolutionarily conserved' genes (others in this gene family include 'Desert Hedgehog' (!) and Indian Hedgehog) found in vertebrates, so SHH is involved in the patterning of embryo development in all vertebrates, not just in mammals like Frankenlouie. These 'conserved' regions of DNA tend to play crucial roles in development and functioning of an organism, and so are relatively unchanged over time: any significant alterations in their sequence, and so in their products, would probably be subject to strong negative selection.  And Sonic Hedgehog's gene family is in turn related to the hedgehog gene that is involved in proper formation of body segments in Drosophila. So the chromosomal region that's most likely to be implicated in Frankenlouie's particular birth defect is one with a very long evolutionary history indeed, one that extends back beyond the split between invertebrate and vertebrate lineages.

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And if the Stuff story here is correct, then I can understand why parents might choose that route, particularly as they seem to have exhausted other options.

NZ state primary schools can offer 'religious education', and under the Education Act parents have the ability to withdraw their children from those classes. (Personally I think it should be a case of opt-in, with opted-out the default setting, but that's not how the legislation was drafted.) The classes can't actually be offered in school time; this is usually circumvented by 'closing' the school for the 30 or so minutes each session takes.

In the Stuff article it's stated that despite the parents indicating that their daughter was not to attend her state primary school's religious education classes, she was "repeatedly put back in". The whole issue isn't new, either, as this 2012 article in the NZ Herald demonstrates. This surely indicates a failure of process at the school end, and the parents are right to be frustrated by it. 

But wait, there's more. From the article: 

One of the Bible class teachers from Life in Focus Trust1, a volunteer who was not a qualified teacher, said parents did not need to be notified because the classes were "history lessons" as the Bible was factually correct.

Seriously? (There's no evidence for the exodus in contemporary Egyptian documents, for example.)

I think it would be great if students learned about comparative religions (if there's room in the already crowded curriculum). But the fact that a document revered by one particular faith is being presented in this school, at least, as an 'historical document' suggests that other religions aren't getting a look-in - and also raises questions about how the Genesis stories, for example, might be taught. Because those are certainly not 'history' (the comments thread to the Stuff article is quite... .... interesting).

1 Having had a look at the Life in Focus website, I can see that its classes are mapped onto the NZ Curriculum document. Since the various outcomes & attributes the program lists are already intended to be delivered in classrooms I'm not clear on why additional people, not all of whom are qualified teachers, would need to be involved, and why myths and stories from only one faith would be used in developing universal attributes in multicultural classrooms.

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Critical thinking is a necessary tool for understanding the world we live in. And I don't believe we teach it particularly well. I know that students in high school science classes learn how to assess the validity/reliability of a source, for example, and that's great, but on top of that we need to get students really thinking about the information and arguments that they'll come across on pretty much a daily basis.

And for that, something like this (found, as is often the case, via Facebook) would be a useful resource: 

For example, you'll often see someone advocating for science-based medicine described as a 'shill'. (Apparently all of us on Making Sense of Fluoride are shills. All I can say is, if the cheque's in the mail, it's a long time coming.) This is an ad hominem attack that does nothing to address the person's arguments. In fact, I'd add another: the argument from authority eg Prof X says so, therefore it's true. (We get that a lot.) You'll find some more examples of these rules to work by, here.

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