An open letter to all the kids I work with

I am an outreach science communicator. My full-time job is to pack a van full of science shows and exhibits and set off to schools all over Scotland, from the borders to the highlands and islands. I love my job, and one of my favourite aspects of it is interacting with the kids during the exhibit sessions or after a show, who can be anywhere between 5 and 16 years old. We ask teachers to fill out feedback forms in order to justify and secure our funding and to assure we are hitting all the right spots as far as the curriculum is concerned, but for me direct face-to-face interaction with the pupils themselves is the best measure of our impact, and I don’t care if it’s difficult to measure quantitatively or that it does not cut it with the funders. The children and young people I work with are the reason I do the job I do, and this is an open letter to them.

Dear Primary School pupils,

You guys are brilliant. I will never stop envying your energy, enthusiasm and endless curiosity about the world, and I think all adults could learn a lot from you.  You lot are all little scientists already and I hope you continue to enjoy the subject all the way through your lives, even if you don’t want to be a scientist, because it is all of you who will be the doctors, vets, astronauts, and teachers of the future! Thank you for all your questions which always challenge me, make me think and often make me smile (“Why is poo brown?” is a favourite). Never stop asking “why?” and “what if…?”, no matter how crazy it drives your teachers and parents.

Dear High School pupils,

I love talking one-to-one to you guys, not only because I can talk to you like adults and we usually have really good conversations, but also because you are not afraid to tell me the truth and ask really thought-provoking questions that often I do not know the answer to (admittedly I hate that almost all of you tower waaay over me). I’d like to take this opportunity to remind you that you are not stupid. I hear this all the time from you guys, and it is a downright lie. (See also: “I caaaan’t!”, my other pet hate. You can.) You know who you are, the ones who say you enjoy the show or workshop but when I ask you how you feel about science at school, your reply is often “oh I’m not good at it, I’m not that clever!” Anyway, you don’t necessarily need to be uber-intelligent to be good at science (this seems to be a common misconception). The most important thing is to never stop questioning everything around you – remember when you were little and you would ask “why?” constantly? Try to get back into that habit. But now that you’re older, try working the answer out for yourself, either on your own or by carrying out research! You guys literally have a world of knowledge at your fingertips, the internet. You can find out absolutely anything you want to – be your own teacher. I learn from all of you as much as you (hopefully!) learn from me, so thank you for being so receptive and interested in the world around you.

Lauren

Happy Valentine’s day! Testicle size and mating systems

I really despise Valentine’s day because I do not appreciate society telling me when I should feel romantic and loved-up and when I should not. HOWEVER as a bit of fun, I thought I would write a post about love, romance and sex but most importantly SCIENCE!

And testes*.

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Testicles are funny things, and almost all healthy male vertebrates boast two of them. In many mammals, including ourselves, they hang from the body in a scrotum because the valuable sperm they contain are mighty fussy, and mammalian body temperature tends to be just a little too hot for them. So natural selection kindly began dangling the sperm of males from two sacs between the rear legs, nice work evolution. But it turns out that we can tell a lot about a species’ mating system (i.e. how monogamous or promiscuous they are) just from looking at the size of the male testis. The diagram below is both hilarious and helpful:

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Here you can see the gonad size of various primate species in relation to body size. The top row are the males – the big circle represents their body size, the arrow is the penis and the balls are, well, the balls. (No laughing at the gorilla and yes guys, your penis is quite large compared to our primate cousins). The bottom row shows the female sexual organs of the same species – I can’t help but giggle at the human female. MASSIVE BOOBIES!

So the size of the testes can tell us a lot of information about the mating system adopted by various species. We have to remember that although in our culture monogamy is often (rightly or wrongly) seen as the norm, this is far from the case in most other mammalian species. There are lots of different mating systems: monogamy (one male one female), polygyny (one male, several females), polyandry (one female, several males) and promiscuity (basically a free-for-all orgy where it is completely acceptable for anyone to have sex with anyone).

Males of species with promiscuous mating systems (such as chimpanzees) tend to have the largest testes, and this makes sense because of something called sperm competition. In a promiscuous mating system, lots of males are having sex with lots of females, and everyone wants a good shot at fathering the most offspring, because this means passing on your genetic material and is a big fat evolutionary WIN. So for this reason it is advantageous to have a lot of sperm, and big old testes to store the little guys in.

However, the males of species with polygynous mating systems (e.g. gorillas)  tend to have smaller testes, because a single male has almost guaranteed access to at least a couple of females. So there is no need to waste extra energy on producing lots and lots of sperm in giant testicles, because his chances of impregnating a female is pretty high and he has no competition to wane off.

Now I know what you’re thinking. Where do we fit in all of this? Well guys, I have to say, your testicles are classified as “moderate”. Bigger than a gorilla, but shy of a chimp. This actually fits well into the mating system hypothesis – although humans are often socially monogamous, they do participate in moderate levels of non-monogamy (SHOCK HORROR KLAXON)!!

So there you have it. The bigger the balls, the more promiscuous the sexy-times. But smaller testicles aren’t for losers – it just means they don’t have to try so hard! Quality over quantity perhaps? Maybe that just means more time and energy can be spend on post-coital cuddles or, you know, child-rearing.

So whether you have testes or ovaries, and regardless of their size, I wish you all a very happy and sexy V-day.

A bonobo with large testicles chillin’ out.  Source

*I will leave it up to you to guess what type of mating system this squirrel may participate in.

The naked mole rat: More than an ugly face

If you live in the UK, have you been watching the latest BBC Attenborough offering, Africa? If you answered “no”, WHY THE HELL NOT? and if you answered yes, OMIGODHOWGOODISIT??

“Sahara”, the episode that aired last night (30/1/13) has probably my personal highlight so far, not least because it featured one of my favourite funny looking creatures in the world ever: The naked mole rat.

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Despite it’s appearance, this creature is not actually an old wrinkly penis with buck teeth growing from it’s nostrils.The naked mole rat is so ugly it is almost adorable. But not only does it look so goddamn horrendous that it becomes some sort of mythical being that you can’t quite drag your screaming yet sympathetic eyeballs away from, it is also a very interesting little creature, for several really cool reasons. Let’s start with its physical appearance, since we’re all judging it already. DON’T PRETEND YOU’RE NOT.

It’s hard to miss the fact that naked mole rats are, well, naked. But if you look closely you will see that they are not completely hairless, oh no. Natural selection has given them the mole-rat equivalent of a fig leaf and provided them with some lovely long super-sensitive whiskers which help them feel around, which is handy when you live in narrow tunnels under the ground (they can also run backwards just as effectively as forwards, which is also handy for the environment they live in). Because they are perfectly adapted to living in underground burrows, the naked mole rats have practically lost the need for their eyes, which are present but are located underneath their skin and are essentially useless. And who can ignore those gnashers? Like all rodents, the incisor teeth of the naked mole rat never stop growing. They protrude in front of the lips (which are sealed behind the teeth) in order to stop the critters swallowing soil when they are using their wallies to dig through the soil – all of which I’m sure you will agree just adds to their sex appeal. 

A naked mole rat’s reaction to being shown a mirror. [Source]

Although they are mammals, naked mole rats do not regulate their body temperature the same way most mammals (including ourselves) do, through a process called thermoregulation. Sweating, shivering and panting are examples of thermoregulation, whereby an organism keeps it’s core temperature at a stable level, regardless of the temperature surrounding it. Rather, naked mole rats are cold-blooded thermoconformers, meaning that their core body temperature changes depending on how hot or cold their environment is. But because they live underground in the African desert, the habitat of the naked mole rat has a more-or-less constant temperature which is comfortable for them.

Perhaps the most peculiar thing about naked mole rats concerns their social structure, as they are one of the very few mammals which are described as “eusocial”: Eusociality is a hierarchical social structure more commonly found in social insects like ants and bees, wherein each colony (for a naked mole rat this is around 80 individuals) has a reproductive “queen” who produces all the offspring in the group, and all the other individuals are “workers” who are sterile. When the queen rat dies, some of the other females in the colony begin to develop eggs within a week of her death. Older females in the colony develop eggs first, and often fight to the death for the right to become the breeding female.

Hopefully I have convinced you that naked mole rats are more than just a pretty face. But the interesting facts do not end there, oh no. It turns out that these creatures may hold a very important secret which could lead to huge breakthroughs in cancer research: Mole rats are thought to be the only mammals who never develop cancer, and scientists have possibly found out why. Cancer is caused by unregulated cell growth, and the cells of naked mole rats poison and kill themselves when they multiply too much, thus cutting out cancer.

So there you have it. Cold-blooded, eusocial, cancer-resistant, bald mammals. Naked mole rats are awesome.

 

Sources

BBC Nature:
http://www.bbc.co.uk/nature/life/Naked_mole_rat

Wired: Why Blind Mole Rats Don’t Get Cancer:
http://www.wired.com/wiredscience/2012/11/blind-mole-rat-cancer/