Dear Readers, what, you may ask, is this tiny little orange guy doing? He looks rather like Atlas carrying the world on his shoulders. Well, this week I have mostly been doing Cell Biology for my Open University degree, and in particular we’ve been studying the ways in which ‘stuff’ is moved about inside the cell. I had never really thought about what goes on in our cells, but of course each is a tiny world which is constantly demanding molecules from outside the cell, transporting stuff out into our bloodstream and moving all kinds of things around within the cell itself.
You might think (as I did) that they inside of the cell is just a mass of cytoplasm with things floating about in it, and indeed for the simplest organisms, such as bacteria, that’s pretty much what happens. However, in more complex cells (such as ours) there is a whole matrix of filaments and microtubules known as the cytoskeleton that helps the cell keep its shape, and provides ‘roads’ for the transport of different materials.
Enter the motor proteins. By a complex series of chemical reactions (you might remember Adenosine Triphosphate from your GCSE Biology? Well, here it is again), the proteins literally ‘walk’ along the cytoskeleton, carrying their load. Sometimes they’re carrying a vesicle (like the one in the illustration above), which is a kind of balloon full of whatever the cell needs or wants to get rid of. Sometimes, it’s an organelle like a mitochondria that needs to be somewhere else. Each motor protein only moves in one direction, so there are different kinds according to whether they’re coming or going.
Motor proteins are also responsible for the contraction of our muscles, including our gut during peristalsis, and our hearts. They only stop when their supply of ATP runs out, because part of the process of contraction is knowing when to stop, and ATP helps the motor proteins to relax. In the absence of ATP they just continue to contract, and this, dear Readers, is why rigor mortis occurs after death.
When scientists watch mitochondria moving, they seem to do it in little jumps as a result of each of the ‘steps’ made by the motor protein – this is known as saltatory movement, from the Latin saltare – to jump.
Several scientists have made animations of the process. While it’s clear that this is not an exact vision of what happens in a cell, I think it’s close enough. It looks like a cross between Blade Runner and a tired old cartoon character. And to think that this is happening in my cells as I sit here typing away, contracting my finger muscles and using up ATP, feels truly astonishing.
Dear Readers, since 7 a.m. this morning (and yes, it is Saturday as I write) I have been hunched like a vulture over my second Biology of Survival assignment for my Open University degree. What a palaver! I am nearly there, but I am very frustrated that my cyber-rats aren’t doing what I expected them to do. And you can tell me all you like that a failed experiment provides just as much interesting data as one that comes up with the answers that you’re expecting, but it just isn’t as satisfying as when everything falls into place. I suspect that the problem is my sample size – we only have five ‘rats’, and one of mine is the smallest rat I’ve ever seen, even in cyberspace – he or she is barely mouse-sized and I suspect that that is skewing my results. Oh well. At least I’ve nearly caught up now, after not being well before Christmas.
And in other news, I heard the first tentative croaking of a frog in the pond this afternoon, so I stood there in the rain hoping I could see him and capture his portrait. Alas, he was too shy, not a problem that he and the rest of his little friends will have in a few days time when the ladeez turn up and the testosterone gets working. But for now, it was just the demurest of sounds, almost as if Mr Frog was clearing his throat, or trying out his voice after a long winter spent in the mud. I wish him luck, especially as I’ve noticed several cats gazing intently into the water over the past few days. Cats do love to play ‘whackamole’ with the frogs, though they seldom eat them (presumably they’ve learned that frog skin has a rather nasty toxin in it). Let’s see how things shape up over next week – I actually have a couple of days off, so I can keep an eye open.
Oh, and there seems to be a fly hatching from the water. Let’s hope the frog doesn’t spot it.
Dear Readers, I know that you have been positively agog to hear the latest on my bird food preference experiment for my Open University course, so here is an update (try to contain your excitement please 🙂 )
I have pretty much got the birds coming to feed on my ultra-nutritious minimally-coloured dough balls now. But what birds? Well, these guys…
Yep, a pair of magpies. I know when they’re around because they rat-a-tat-tat at one another like a bunch of plastic machine guns. They are very shy for such big bolshie birds, which means that I can’t just sit in the kitchen and make notes. Instead, I have to listen for them, and sneak out to my back bedroom which overlooks the garden.
What we have to do is to present them with 45 red dough balls and 5 yellow dough balls. Then, we have to do a count while there are still between 35 and 15 balls left. This is trickier than it sounds as a hungry magpie can wolf down the lot in about five minutes flat, which would mean that I’d have to start again. This performance has to happen ten times with mainly red dough balls, and ten times with mainly yellow ones, so just as well I started the experiment itself a week before I was meant to, as results have to be in by the end of November.
The aim is to see if the birds prefer one colour of balls to another, and if so if it’s statistically significant (which means some antsy-fancy maths). Before I started the experiment proper, I would have anecdotally said that they seemed to prefer the red ones, but on my first trial yesterday they ate 4 out of the 5 yellow ones, which points the other way. This is the trouble with real life, it’s never quite as neat as the textbooks. Anyway, let’s see how we get on as the weeks go by, and the data is gathered. It certainly makes for a lot of getting up and down to check on progress, which can only be good for my back. Too much sitting is bad for one, as we know. And it’s fun to do some real science! All I need now is a white coat and I’ll be in business.
Dear Readers, as I mentioned last week I have just started my second year at the Open University, and for this module we actually get to do some science stuff. This week we are looking at different kinds of rocks, and, believe it or not, you can simulate what happens when volcanoes throw out lava and igneous rocks are created simply by looking at the effects of cooling on different solutions.
Another aspect of our work this year has been that we will be collaborating with one another on our results, so we all got different experiments to do. I fear that I might have drawn the short straw this time, because I had different solutions of bicarbonate of soda to work with, and I fear that they don’t do anything interesting at the temperature of a household freezer. Alas, if only I’d had the kind of freezer that we used to have when I was a student, with an icebox – these have an average temperature of -12 degrees Centigrade, and I suspect that this would have produced some more interesting results. My freezer runs at -18 degrees Centigrade and what I ended up with was three ‘ice’ cubes that looked identical, in spite of the different concentrations, plus one standard ice cube as a control.
The ‘ice’ cubes containing bicarbonate of soda were all interesting in one way, however. They had all gone white (the solutions were clear when they went in), and they were all extremely fragile, breaking into shards when I extracted them, so clearly something has happened. Alas, in the groups who used sugar and salt solutions, I imagine there might have been some crystals – when the molten rock is thrown out of a volcano it can cool to produce all sorts of effects, depending on the speed at which it cools. For example, two different samples of magma that cool at different rates can produce two very different rocks. Granite is normally the result of magma that has cooled slowly deep within the earth, allowing lots of different kinds of crystals to grow to a perceptible size. No wonder it’s so popular for kitchen work surfaces.
Granite with lots of different mineral crystals that have developed as the magma cooled slowly (Photo One)
This is a sample with exactly the same mineral composition, but where the lava cooled so quickly that crystals didn’t have a chance to form – not surprisingly, this kind of rock is created where the magma is exposed suddenly to air or to water, lowering its temperature swiftly. Those who watched Game of Thrones might recognise this as obsidian, and it is completely clear, with no visible crystals at all.
Obsidian (Photo Two)
And so, in our experiment we wanted to see what would happen to our mineral solutions when they were cooled to a set temperature, just as would happen if some volcano shot out some magma (not likely in East Finchley but you can never tell!) Later, we will pool our results, and I’m sure that some people would have had more interesting results. Maybe I’ll cheekily have a go at one of the other experiments later on in the week just to see what happens. Until then, I’m off to find out about metamorphic and sedimentary rocks.
What I find extremely interesting, even at this early stage, is how the earth is continually recycling itself – rocks come to the surface, are eroded, deposited and in the fullness of time become other kinds of rocks. I never realised how fascinating geology was! So let me hear your geology stories if you have any – I feel as if I’m entering a whole new world, and am already excited about how rocks, and the things that come from them such as soil and sand, impact on the entire ecosystem.
Dear Readers, part of my assignment for November on my OU Open Science Degree revolves around looking at my personal carbon footprint, and what I can do about it. The average for a UK resident is 14.6 tonnes of CO2e, but mine comes in at 15.86 tonnes. What to do? Plus, even the average is still way above what would be needed to actually keep our projected temperature rise at under 2o going forward.
In some ways, we are in good shape. We don’t own a car, and we are good about recycling, repairing and re-using our goods. I’m not one for fast fashion, and we walk and use public transport for the majority of our journeys. I waste very little food, and we are 99% vegetarian.
That’s where the good news stops, unfortunately.
Our home energy consumption is 2.3 tonnes compared to 2 tonnes on average. One of our problems is that we live in a Victorian house, with original windows, gaps in the floorboards and various howling draughts that come from we know not where. At some point we will undoubtedly have to replace the windows, but I love the glass, some of which dates back to when the house was built. You can get double and even triple-glazed units in timber these days which will echo how the place currently looks, but we will have to save up like crazy because these are far from cheap.
We have had draught-proofing down already, but still the draughts persist. This is not an exact science, as anyone seeing my husband crawling under his desk with a joss stick to see if he could see where a particularly noxious chilly breeze was coming from would attest. The other option would be external cladding, but there are problems with this too – retro-fitting can cause damp and condensation, and the terrible events at Grenfell testify to the fire-risk from some products.
All of these are quality problems to have. However, they really do point up one of the weaknesses of carbon calculators generally, which is that many, many people do not have control over where they live, either because they are renting, because they are sharing a house with other people, or because they simply don’t have the money to even consider new windows or cladding. Various schemes have been used to encourage the uptake of insulation or energy-efficient appliances, such as new boilers and light bulbs, and this must be part of the way forward.
Another big difference is in flying, where we use 2.2 tonnes of carbon compared to the average of only .54. So much for feeling smug about not having a car! This is largely due to our transatlantic flight to Canada every year to see my husband’s mother and his Aunties and friends, but as regular readers will know, there’s often another long flight (such as the one to Borneo earlier this year) and our regular trip to Austria. We can’t do much about the Canada trip, but I foresee a lot more train travel in our future, particularly for our European trips. This will actually be a nice way to get around if and when the pandemic eases and we retire. Again, this is a quality problem, with many people not being able to afford to travel internationally at all. At least with the advent of remote technology I stopped travelling abroad for work a good fifteen years ago.
And then, there’s the chunk for goods and services, where we have 6.39 tonnes of carbon equivalent per year compared to the average of 4.55 tonnes. Try as I might, I couldn’t get this down, largely because the bulk of it relates to your household income. We aren’t rich, but we are both working, and this section assumes that when you earn more, you spend more. Also, even if you squirrel your money away, at the end of the day it contributes to someone else’s expenditure. The richer you are, the larger your carbon footprint, on both a national and international level. I dread to think what the Queen’s footprint looks like.
So, after promising to fit new windows, draught proof the house, fit external cladding and reduce my flying I managed to get my carbon footprint to 14.78 tonnes, still above average but only just. What could I do to actually get anywhere close to a proper saving?
Well, I could stop work. That would lower our household income and automatically our carbon footprint would come down to 12.1 tonnes. Whilst I would probably enjoy swanning about, blogging and observing the bird life, this isn’t going to happen in the short term. It does point up both the strengths and weaknesses of carbon footprint calculators however. There is no doubt that richer people should make larger sacrifices because their standards of living are already higher, but this goes beyond just a bit of tinkering with your house.
Another way to reduce my carbon footprint would be to live with someone else. Our house isn’t enormous but it’s way bigger than the house that I grew up with, where five of us plus dog, cat, mouse, budgie and hamster lived in a two-up, two-down railway cottage in Stratford. If our household was three instead of two, we would reduce our footprint to 13.47 tonnes. We bought a house that was a little larger than we needed originally because we assumed that friends and family would be staying on a regular basis. Well, ‘family’ for me is now mostly gone, and the pandemic has put paid to visitors, but it is something to think about when things ease.
The third way to reduce my individual footprint would be to reduce my income, but indirectly. For example, an increase of 1% on income tax (to be used to pay for the costs of decarbonisation) would reduce our annual carbon equivalent to 8.6 tonnes. Or, I could voluntarily commit to a decarbonisation offset of 1% on my annual income, and that would reduce my footprint to 10.17 tonnes. The problem with this second idea would be to find decarbonisation schemes that actually make an impact – my experience so far has been with the schemes that are sometimes offered when you book flights so that you don’t have to feel guilty about all the carbon dioxide that you’re pouring into the atmosphere, and I am deeply dubious about whether they actually help. However, a proper accredited scheme might be something to consider, for sure.
All in all this was a fascinating exercise, and it makes me think that the changes that we’ll be required to make if we don’t all want to fry, get washed away or starve will be way beyond what governments are ‘fessing up to at the moment. I heard a climate change activist talking about how he’d been invited to speak on a programme about what would be required for us to become carbon neutral. He sent in his ideas – limits on flying, banning of all petrol-driven cars, heating by hydrogen, an increase in nuclear/wind/solar power – and was told that that wasn’t what they wanted at all. No, what they wanted was for people in the supermarket to know if they were better off buying a mango or a banana.
I think that the climate crisis is rather like a bereavement: as we start to come to terms with the fact that the way that we’re living is not sustainable, there’s all kinds of denial and bargaining going on. For example, China, who plan to become carbon-neutral by 2060, are apparently pinning their hopes on technology which will clean the carbon out of the air, and which doesn’t actually exist yet. On the other hand, I am heartened by Joe Biden’s election this weekend – at least he isn’t an out and out climate change denier like the previous incumbent. We live in interesting times, my friends. It will be fascinating to see how things play out.
Sunset over Sharks Cove, North Shore, Oahu, Hawaii (Photo One)
Dear Readers, the most vulnerable habitats are often those on islands. This is because the flora and fauna there have often evolved in isolation, and so are endemic – they can be found nowhere else. They may be beautifully adapted to their local conditions, and may have lost things that they don’t need – birds may be weak flyers or flightless, for example. Animals may also have lost their wariness and be unafraid of humans. Plus, being on an island tends to limit population size because of food resources or space: there is literally nowhere else for an animal to go. So, many island species were never common, but they survived because there were few predators, or little competition.
An island also doesn’t need to be a literal ‘island’ surrounded by sea – we can think of many isolated valleys and mountain habitats as ‘islands’ too. The places where mountain gorillas live, for example, are virtual ‘islands’ because the animals are isolated in them, with no suitable habitat round about.
Animals and plants that are endemic to islands are often ‘inbred’ by our definition of the term – they have a small population, so have they little choice. But this doesn’t seem to be as much of a problem as you might think: in his book ‘The Song of the Dodo’, David Quammen describes how, over time, any genes that might cause problems have disappeared, because the individuals holding them have either died or been unable to breed. This is very different from the inbreeding that occurs in, for example, some pedigree dog breeds, or when a wild population becomes isolated from other members of its species by roads or other barriers.
In Madagascar, the ringtailed lemurs of the Berenty reserve are now completely cut off from other lemurs by roads and also because there are massive sisal plantations, which they will not cross. Ironically, the sisal is used for, among other things, degradable compost bags for folk in the West to wrap their kitchen waste in. Only time will tell how much of a problem the inbreeding that occurs as a result will be for the lemurs.
Ringtailed lemurs in Berenty, Madagascar (Photo Two)
So, in Hawaii and Galapagos, Madagascar and Mauritius, New Zealand and Australia, there are unique populations of animals who have evolved in isolation and who are superbly adapted to their original environment, but very vulnerable to change.
I guess we can all see where this is going.
My course book concentrates particularly on Hawaii, the most isolated group of islands in the world. Polynesians arrived there about 2000 years ago, and started to change the landscape – they brought up to 30 new crops, including coconuts, bananas and sugar cane, and animals such as pigs, goats and dogs. However, the population was never enormous, and although some land was cleared for agriculture there doesn’t seem to have been a major impact on the ecosystem. This has largely occurred in the past two hundred years, after European colonisers arrived, creating sugar plantations, taking over an entire island for the growth of pineapples, logging the forests for sandalwood and bringing in other new crops such as coffee and macadamia nuts.
The two greatest dangers to island populations are habitat degradation and the introduction of alien species that outcompete the indigenous flora and fauna. Hawaii has had both.
The scientist and author Richard Fortey writes about a walk in the forests of Hawaii in his book ‘The Earth – An Intimate History‘. Here is what he has to say.
‘Almost none of the plants that climb up the massive trees along the path are a native of O’ahu or the Hawaiian islands. Indeed, neither are the trees themselves. They are interlopers, brought to this remote place by humans. These plants settled in the tropics and thrived, displacing most of the native vegetation. The resemblance of the climbers decking the trees to pot plants is no coincidence: some of them are the same species that can be bought in a supermarket in Norfolk […} as commonplace in their way as tomato ketchup. Even the sweet-smelling ginger plant that looks so at home by the pathside is an aggressive coloniser. This place is not so much Paradise Lost as Paradise Replaced – a paradise of aliens dressed up to look as if they belong. The massive assurance of the trees is play acting. ‘
Hawaiian Rail, extinct by 1788 (Public Domain)
Hawaii has only one two-thousandth of the area of the United States as a whole, but it accounts for 70% of all recorded extinctions in the US and for 75% of all animals listed as endangered in the USA. 40% of 70 of Hawaii’s endemic bird species are extinct. The Hawaiian Rail (above) was flightless, and was probably exterminated by the black rats which came with the first Polynesian settlers. Other birds were killed when mongooses, brought in to deal with the rats in the sugar plantations, turned out to be ineffective against the rodents because they were diurnal, and the rats only emerged at night. Instead, the hungry mongooses turned to the nestlings and eggs of birds, with the result that only Kauai, which didn’t introduce the mongooses, still has a ground-nesting bird population.
The Kauai Elepaio (Chasiempis sclateri) (Photo Three)
And so habitat destruction and introduced species have played, and continue to play, havoc with island species around the world. Conservation organisations fight an uphill battle with invasive plants, entrenched interests and the need to balance the economic needs of what are often very poor countries with the need to preserve unique ecosystems. Every island group has extraordinary individuals who are working to preserve what’s left of their habitats, and they give me a lot of hope. It does seem sometimes as if the extraordinary short-termism of human beings could cause the end of everything, but I prefer to remember the determination and guts of people that I’ve met who are dedicated to make sure that something survives and thrives. It’s too late for the Hawaiian honeycreepers, but it might not be too late for the Kakapo.
The Kakapo is the only flightless parrot in the world, and was saved from extinction by a combination of moving it to a predator-free island, supplementary feeding and intense monitoring. Even today there are only a couple of hundred individuals, but the population is growing slowly. However, in its heyday the kakapo was found throughout New Zealand, and seems to have retreated to forest habitats because of introduced predators. It is a remarkable bird, the only parrot where the males get together and display to the females on a ‘lek’. Without the eradication of predators, however, I foresee it living out its years on the islands to which it has been introduced, under the watchful eye of humans.
Sirocco the kakapo (Photo Four)
And for those of you who have never seen Sirocco ‘in action’ with BBC presenters Mark Carwardine and Stephen Fry, you might want to have a look at the clip below, which is absolute television gold…