I’m a Tetrachromat – And Other Tales of Bad Science

I have some wonderful news, readers – my amazing skill at being able to see both colours in the dress is down to the fact I’m a tetrachromat – a marketer says so.

Firstly I’ve always known I was special. When everyone else said I had poor colour vision, I just knew I was discerning subtle differences in colours that they couldn’t even perceive. When people said how much they loved spring green, I knew how tasteless they truly were. When nobody believed in me, I would look at the glorious colours that surrounded me and quietly comforted myself in their glory.

A rainbow of colour nuances . . . apparently

 

The LinkedIn article discusses some truly groundbreaking new research. View the above rainbow, seemingly created by Professor Diana Derval who’s an expert in neuromarketing. Crazily enough, she uses something very like Articulate Storyline to build her website – we are clearly bound by fate! Derval asks you to count how many colour nuances you see in this rainbow. I see 36 on this screen, 38 on my phone and 34 on my screen at work. Let’s take an average of 36.

If you see less than 20 colours, Derval suggests you are a dichromat, like dogs, which would be red-green colour blind typically. You would struggle to see the ’57’ in this image.

If you see between 21 and 32 colours, Derval suggests you at trichromat, like . . .well . . . the majority of humans.

If you see between 33 and 39 colors, Derval calls you a tetrachromat. Still not as cool as a mantis shrimp, but apparently you’re more able to see purple (?) and you’ll be irritated by yellow. I’m irritated by spring green tinged yellows, and lemon yellows wash out my skin tone, but a golden yellows are everywhere in my wardrobe because I fricking love yellow.

In her article, Derval points to a paper by Jameson et al (2001) which investigated the genes linked to tetrachromaticity and colour perception in 64 people (38 women and 26 men, all based in California if that influences your thinking any).

First Jameson et al investigate the genetic sequence that’s responsible for the light-sensitive parts inside our eyes. First for a short physics lesson: the rainbow is made up of what we call a spectrum of light, and each colour has its own wavelength. We say humans are trichromats because we have cells in our eyes that can pick up three broad wavelength bands: red, green and blue. Because light is a wave (at least for the purposes of this blog post)  – we can see the rainbow as its the overlapping wavelengths. We can see orange because it sits in the overlap of red and green.

 

The parts of the human genetic code that make all the light sensitive parts of the eyes are complicated. Our genetics hold more possibilities than our eyes actually come out with – which makes figuring out how people see very complicated!

If a human has two different amino acids  (amino acids are basically important things the help the body do its body stuff) coded on a particular gene – there’s a possibility they could be tetrachromat. That is to say that as well as the three light wave frequencies ‘normal’ humans can see, they have another which is sensitive to a fourth.

Of the 64 subjects they had 23 women had these two amino acids on the gene (possibly genetically tetrachromat), 37 people who were trichromats (or ‘normally’ sighted), and 4 men who were dichromat (or red-green colourblind).

After checking the genes, the researchers investigated what these 64 people saw. To do this, they didn’t use a computer screen. Instead they shone a light through a prism, like the old school experiment, and asked the subjects to draw lines demarking where they saw ‘colour partitions’.

What’s different between this methodology and the LinkedIn article? Firstly – no computer screens, or monitors of any type. The subjects were looking at pure light – light scattered through a prism – which is different from a computer attempting to display colours based on RGB numbers (or worse, html). The computer also has to be told what colours to display, there are only 39 colours in Derval’s rainbow (each one a fixed width apart so we ‘know’ where a colour demarkation should be, even if we observe it as a broader band. This is very poor design as well, you could at least randomise colour band width to stop people from assuming they should see a colour difference. For the record, I’m positive this is why I’m scoring so highly because my colour vision really is poor), and so we’re not really choosing what colours we see – not like the subjects were in Jameson’s experiment.

So what were the results? The genetic tetrachromat women (n = 23) saw on average 10 spectral delineations, the 15 trichromat women saw 7.6 on average. This was significantly different at the P<0.01 level, though it’s very important to recognise the small sample sizes and also that the tetrachromat women were very variable (e.g. one tetrachromat woman might see 7, another might see 13). The trichromat people in general (n=37) saw 7.3 delineations on average, and dichromat men (n=4) saw 5.3. This was also significantly different.

Jameson et al concluded these results demonstrated that their rainbow test was a good, non invasive indicator of whether someone is tetrachromat or trichromat. They also suggested that we aren’t very good at detecting tetrachromats with our traditional colour testing, which I more than agree with.

I disagree, strongly, that Derval’s method has any chance of trying to identify who these people are. The methodology is not sufficient. But more than anything else, Derval suggests that tetrachromats are not tricked by the dress. This tells me that not only is a professor of marketing cashing in on a phenomenon to plug her book (and more power to her – I use search engine optimisation to do the exact same thing), but that she doesn’t understand how the Dress illusion works because it has nothing to do with how good your colour vision and everything to do with how your brain is primed to interpret images.

These kind of internet tests are fun – but for heavens’ sakes, don’t trust them! They are as precious as the paper they’re printed on.

 

And I promise I will stop talking about the dress.

And Baby Makes Three

The UK looks like it will be the first country to allow babies with the genetic material of three parents, with our MPs voting for the bill on Tuesday.

Now in the UK we also have a House of Lords, who also must approve the bill at a later date, and there’s no guarantee they will, but given the large majority of parliament members (382 to 182) it’s likely they will. It also has to be approved by the Human Fertilisation and Embryology Authority, a UK governmental organisation.

On Tuesday morning I was listening to Morning Call on Radio Scotland. It’s a fairly simple show, where people call in to give their opinions on any given subject. That, combined with the online reaction today, has had me and my colleagues thumping our foreheads against the desks repeatedly.

Buzzfeed has a great “Six Things You Should Know...” list that I won’t repeat here, but there are a few things we have to discuss …

 

Three Parent Babies is a Bit of a Stretch

Yes, this is a classic case of a catchy headline. The mitochondria, which you probably remember from high school biology, is essentially the battery of a cell. Long, long ago in our evolutionary past, back when we were simple collections of cells, mitochondria were simple single cell organisms capable of doing things our little cells weren’t. Namely powering things. So they were captured and made a part of larger cellular organism that was us. And the rest, as they say, is history.

But it’s because of this that mitochondria have slightly interesting and unique DNA, a separate part of our genome that codes for our mitochondria. Some organisms have managed to get rid of all of the mitochondrial DNA, and others have got weird mutations in there, we’ll come back to that later.

The important thing to note is that ‘three parent baby’ simply takes the mitochondrial DNA from one genome, and the rest of the DNA in the traditional method (for a given definition of ‘traditional’, in a test tube, under the stars, wearing leather, wearing lace . . . ) comes from the two parents.

 

A Gateway To Eugenics

One of the strangest comments I’ve heard in relation to this news is that it means we’re a step closer to eugenics. This is, in some ways, deeply insulting to the families of those who are suffering from mitochondrial diseases. To want to be free of disease does not equate to eugenics.

In humans, mitochondria are inherited directly from the mother. You’ve heard of Mitochondrial Eve? The reason we have her is because our mitochondrial DNA doesn’t get recombined and altered in the same way as the rest of our genome. Like the Y chromosome, it is an excellent way of doing forensic genetics. Both of them remain greatly unchanged throughout our evolutionary history, and we can track back to a conceptual Mitochondrial Eve and Y Chromosome Adam. However, I’ll point out that these aren’t real people. They’re simply the earliest ancestor we’re all related to – which changes as our population changes over time.

But it’s this phenomenon, the conservation of this DNA, that allows us to swap them out in this fashion. The DNA inside the mitochondria is so useless to the rest of the body they can be exchanged very easily. So you see, we’re still many, many years and innovations away from selecting the genes we want and engineering our babies. This procedure is feasible, and safe, because mitochondrial DNA is so protected, and usually inconsequential in a genome.

 

Why Do We Need It?

Because mitochondrial diseases are horrific things. The mitochondrial DNA is special, yes, separate from the rest of the DNA, yes. But it also mutates, as all DNA does, and it doesn’t have much of a way of repairing itself or realising that its damaging its body. Symptoms include Multiple Sclerosis style diseases, loss of eyesight, loss of hearing, dementia, neurological problems, an inability to exercise, diabetes, poor growth, heart disease, gastrointestinal disorders . . . and each one of these things are a SYMPTOM of the disease, not the disease itself.

We can eradicate this disease, easily, while maintaining a person’s right to reproduce. If you fear that because you’ve seen one too many B movies about Frankenstein . . . you just show me how much work I have to do.

 

 

Finally I have to say something about the “Science has gone too far” style comments, and “humans have evolved to their current state, we shouldn’t meddle”. In so many cases, comics can communicate more about science than any of my blogs. To those people I say . . .

Thag no! You go too far! 

Could Deoxyribonucleic Acid Be in Your Food?

My colleague Arjan, who’s much wittier than I am, suggested the label go something like this:

Product may contain trace amounts of DNA; DNA has been linked with cancers and other disorders; There is a high probability pregnant mothers will pass DNA to their unborn children

It’s almost too good to be true, and certainly a gift for any science communication blogger out there . . . can it be?

80% of Americans support mandatory labelling of food containing DNA. 

My colleague Arjan, who’s much wittier than I am, suggested the label go something like this:

Product may contain trace amounts of DNA; DNA has been linked with cancers and other disorders; There is a high probability pregnant mothers will pass DNA to their unborn children

The Department of Agricultural Economics at Oklahoma State University has a project called the Food Demand Survey which surveys Americans regarding their attitudes and sentiments to their food. Before we’re even going to address this claim about DNA, let’s think about the methodology.

The information comes from Volume 2: Issue 9 (January 2015) of their self-published online reports. So the first point to make is that this methodology is not peer reviewed. However we can glean some of the methodology from Lusk and Murray (2014). The survey has been running since May 2013 and goes out each month online to survey at least 1000 people, but no word on what their response rate is like. Each month they add an ad hoc question which doesn’t follow the basic survey layout and the DNA result comes out of the question.

So the question this month was:

Do you support or oppose the following government policies?

  • A tax on sugared sodas (39% Supported)
  • A ban on the sale of marijuana (47% Supported)
  • A ban on the sale of food products made with transfat (56% Supported)
  • A ban on the sale of raw, unpasteurised milk (59% Supported)
  • Calorie limits for school lunches (64% Supported)
  • Mandatory calorie labels on restaurant menus (69% Supported)
  • Mandatory labels on foods containing DNA (80% Supported)
  • Mandatory labels on food produced with genetic engineering (82% Supported)
  • A requirement that school lunches contain two servings of fruit and veg (84% Supported)
  • Mandatory country of origin labels for meat (87% Supported)

Really, without further methodology questions all we can really say is more of these particular Americans (a number we know is less than 1000) want mandatory labelling on foods containing DNA than a tax on sugared sodas. Without sample size data we have no idea whether that difference is significant or not (although if they surveyed 100 people, and 80% want DNA labelling, then that is significantly different from a random 50:50 distribution).

But here’s the thing: regardless of methodology, the idea that there are any people in a survey that aims to be informative who are concerned about DNA being in their food is very concerning indeed.

In the title of this post, I used an old journalistic trick by using DNA’s more formal name which is long, hard to pronounce and contains the scary ‘acid’ word. It’s the kind of question that we’d laugh about if it caught out our most hated politician. But the survey appeared to ask about DNA. I can only conclude this is a sample of people who have never even watched Jurassic Park, never mind the one respondent who said they’d read the bible as an agricultural text (this led me to the best site ever – Biblical Research Reports: Farming).

DNA has been one of the most amazing discoveries in science, and has been so completely misunderstood by the respondents of this survey that it’s unbelievable. And yet these consumers, by the same survey, place the highest value on the safety and nutrition of their food. Instead of laughing at them, it’s my role as a self-professed science communicator to give them the tools and understanding to interpret the information they need to achieve those values.

In America, it’s just a particularly obese mountain to climb.

Fluffy Friday – Visualising Risk

Happy Hogmanay my lovelies!

I am, as you read this, most likely still recovering as in Scotland we take two public holiday days to get over the Hogmanay celebrations. Myself and Athena are probably both curled up on the sofa hoping someone will clear up around us.

But I did spot this great little article in the New York Times that I’d like to share – just because it’s a great example of visualising risk, and in a situation that many of us are frighteningly familiar with . . .

How likely is it your birth control will fail?

In brief, Fluffy Friday form, here’s what I love about it:

  • It describes the relationship with time, showing how risk is not always a linear relationship. Indeed in some cases it levels off with time.
  • It shows the difference between typical use and perfect use, on the same graph, and sometimes this is quite startling! (Honestly, what happens with Depo-Provera?)
  • It describes the actual risk – e.g. failure resulting in pregnancy, out of a 100 women.
  • My choice comes out on top – yay for progesterone only implants! Who knew migraines were good for something.

 

The Fashionable Scientist

Science, being the awesome beast it is, recently landed a ten year old probe on a comet. My laptop is three years old and it’s already beginning to groan and whine.

But you’ve probably heard and seen the commotion over one of the scientist’s shirt, which was a gaudy, loud, and featured many half clad ladies on it. On Twitter, a wit said this:

 

And thus began a Twitter storm of epic proportions as ever. On the one side, those who (rightly) feel that the posit03ion of women in STEM fields is a tenuous one and needs direct action, the other those who (rightly) feel that what a scientist wears has little to do with their achievements or even their attitudes to other people.

I was asked by some of my friends what I felt about the issue being both a scientist and a dyed in the wool feminist.

Before I commit my words to the internet it’s important to recognise that my opinions on this are based on my own ethics, my own experiences and they might not necessarily reflect that of all feminists, all women or all scientists – but I also believe my opinion is the right one, hence the fact it’s mine (hey – this is pretty much exactly like animal welfare ethics!)

I think it’s a storm in a teacup. The guy wore a dumb shirt, a woman rolled her eyes, and suddenly we’re onto the death threats. Why is this the default position of the internet? I think it’s sad that the guy was reduced to tears in his apology, I think it’s horrific the tweeter’s life was threatened for pointing out a very real problem. It is frankly ridiculous to say that a shirt overshadowed the accomplishment of the human race. Humans are more than capable of carrying two or more issues in their heads at one time.

Really the only person who address this with any degree of clarity was my guiding light, Hadley Freeman. In her style column she says:

There are so many signifiers of sexism in the world and the science world that to attack a man for his shirt feels a little bit like fussing at a leaky tap when the whole house is under a tidal wave . . .  There is a difference – and I concede, the difference may be fuzzy in some cases – between enjoying the weird fantasy-world depiction of women, and seeing actual women as sex objects. Taylor has the right to wear whatever pig-ugly shirt he likes, and people have the right to be outraged by it. But when that outrage leads to a grown man weeping on TV, perhaps we all need to ask if this outrage is proportionate. My God, I’m a fashion bitch and even I don’t want to make anyone cry over my comments about their clothes.

 

But as it’s the run up to Christmas, there is a silver lining. My wonderful STEM field compatriot has her HauteDog Couture shop on Etsy. We’ve decided at our next meet up we’ll wear dresses made of that shirt material. HauteDog Couture is amazing. Check it out.

Value

I like when current events in the media combine to illustrate animal welfare in our society. This week’s blog post was impossible to resist.

Recently there was a bit of hubbub over a group of scientists discovering what they described as … a freaking puppy sized spider (emphasis mine, extra Raid cans also mine).

The scientists released a blog and the media picked it up and ran with it (because it was a freaking puppy sized spider. It wasn’t even chihuahua sized, this is a decent sized puppy we’re talking about. No I’m not linking to a picture. Google that yourself. Go on. Type ‘puppy sized spider’ in there. I dare you).

But here comes the twist in the tale (the puppy sized spider tail . . . wait, that doesn’t really work, does it?). Our intrepid scientist started to receive death threats and abused because he collected a specimen. And ‘collected’ in this sense means in the more Victorian sense. There is one less puppy sized spider in the world.

Piotr, for that is our scientist’s name, has written an excellent blog post describing the necessity of biological sampling, and the danger of assuming that any of us lead a guilt free life. I strongly encourage you to read it, but I’ll include this quote:

We kill thousands of organisms without realizing that we do it. Look into the light fixtures of your house or the grill of your car, they are full of dead insects and spiders. 

It is all but impossible to live a life that does not harm animals in some description, and for the most part (legally, and culturally) we often excuse ourselves by protect vertebrates. I’m really fascinated by the outrage that has come up around a spider.

This week, TV presenter Chris Packham penned an open letter to the presenters Ant and Dec asking them to put a stop to the ‘animal abuse’ in their show ‘I’m a Celebrity Get Me Out of Here’. The show typically features ‘celebrities’ eating live bugs on screen as a challenge, or in one memorable case, a contestant caught, killed and ate a rat. Packham says:

“I can guarantee that some animals are harmed during production, because they are fragile or easily stressed. Or simply killed, as they are in your bushtucker trials.”

Are we heading toward a new age of invertebrate animal protection?

 

I have a visceral reaction to that spider. It makes me feel unwell. Yes, I am an arachnophobe (I’m not fond of any insect really), even the cute ones like the Peacock Spider are only tolerable when they are an image on a screen. When I see a spider the space between my shoulderblades begins to twitch and my heart begins to pump. Fear this, my body tells me, and even when I’m trying to be cool in front of other scientists, I cannot bring myself to approach. I have never held a tarantula, even though I’ve had copious opportunities to do so, because I simply would not be able to control my muscles long enough to do so.

It’s Okay To Be Smart did an interesting vid on this recently, but that’s not the point of this post. The point of this post is to discuss whether we, as a society, think it’s acceptable to harm invertebrates.

I have beliefs about the way you should treat animals. This set of beliefs arises from my experiences, my knowledge, my culture and my society. This is my ethical viewpoint. You can explore the most common ethical viewpoints and how you stack up on the excellent Animal Ethics Dilemma website.

My ethical viewpoint has changed over the years, as has yours no doubt. Our ethics can even be formed by different thought processes. Some people will describe their ethics based on how things make them feel. As a utilitarian, I try to remove my feelings from the process of making an ethical judgement (interestingly, a small study of 38 students showed that the way they reacted to images of humans experiencing injustice and unfairness influenced the way their higher-order ‘computational nodes’ of the brain – in essence it was the logical parts of the brain that react in cases of injustice, Yoder & Decety (2014). It would be fascinating to repeat this with other age groups, and with animal scenarios too. The point being that your desire for social justice does not necessarily have to be based on the emotional centres of your brain). Regardless of how your ethical viewpoint was formed, you believe it to be right. When people act against their ethical values, they can be deeply distressed.

Now some people believe you should harm no animal at all. They believe that animals have an absolute value and that we have no right to use them. To live in such a way that upholds the absolute value of all animals is very difficult. The kingdom ‘Animalia’ (the simplest way to define animals, really) encompasses a huge range of beasts: do the sponge and the jellyfish have the same absolute value as the elephant and the tiger? Every time you swat a fly, uproot a worm, or even tell a dog not to eat the cat’s food you could be violating that absolute value.

This is a difficult (though not impossible, see Jainism) way to live. But most people begin to take a more centrist position by believing that animals have an intrinsic value. We must justify their use in some way. Some justifications are easier than others. I always find the fish eating vegetarian to be a fascinating example of this. Many species of fish (which is an arbitrary group of animals anyway) have very sophisticated nervous systems and are capable of pain and suffering. Killing them humanely is difficult and catching them humanely even more so. But for many people, their ethical viewpoint can accept the death of a fish, but abhors the death of a chicken. This often comes from a relational viewpoint, where animals are prized for the way we interact with them. Most people have fewer interactions with a fish than they do a chicken or a cow, and the life of a fish is more unimaginable.

And then on the other side, some people believe that animals have an extrinsic value, that we may use them as we wish.This is more common than you might think. The cat owner who takes his cat to the vets to be euthanased because he no longer wants it is assigning its life extrinsic value. When the owner no longer takes value from the animal, the life becomes disposable.

This scale of values exists in conjunction with the various ethical viewpoints we have. I myself am a utilitarian who believes animals have an intrinsic vale. I use animals. I am also rather broad in my description of animals. For example, I’ll eat any animal so long as I can be satisfied of two questions: “Did the animal have a good quality of life/human death?” and “Will eating this animal negatively impact my health or welfare?” Now that doesn’t mean I question every animal product that passes my lips, I am more than sure I have eaten poor welfare meat (as we discussed in our kosher post), but this ethical standpoint and my view of animals’ values guides my actions.

 

However there is an element of the ‘relational’ ethical viewpoint for me. I don’t have good relationships with invertebrates, and I don’t have the same emotional reaction to their injury that I do to a vertebrate’s injury. With that being said, we describe invertebrate harm as ‘cruel’ and ‘worrying’ in several cultural contexts. Imagine the cat playing with the spider, batting it from paw to paw, tearing it limb from limb. We frequently stop our cats from doing this, in part because we are disgusted, but in part because we recognise that must be an unpleasant experience for the spider. Cats are cruel and toy with their prey (probably because they don’t recognise their prey as sentient, but with cats you never know . . .)

And then there is the case of the little boy burning ants. It’s a short hand we use for unthinking cruelty in our media, or to indicate that a character will go on to become cruel. And yet invertebrate experimentation like this is a common experience for many of growing up.

 

What is the difference, ethically speaking, in killing a spider for entertainment (I’m a Celebrity) and killing a spider for science (the puppy sized specimen). In  both cases, a spider dies, surely the ethical line is one drawn in the sand?

Well, no, I don’t think so. It’s often tempting to write off ethics as nebulous and personal, but there are many, many reasons to support both the collection of the puppy sized spider and the banning of invertebrate eating on I’m a Celebrity…

  • The ‘greater good’ of media vs science. How much does the entertainment of seeing people eat spiders benefit society?  Not a huge amount, the trials could be replaced by something equally disgusting and memorable (smelly tofu springs to mind, indeed what one of the previous winners of I’m a Celebrity ate as a vegetarian). Indeed you could argue that the destruction of animals for entertainment is an overall negative for our society, as Packham outlines.
  • By contrast, the ‘greater good’ we get from understanding the physiology of the Goliath spider is a scientific contribution to  our understanding of the world. I prize knowledge over entertainment.
  • Which brings me on to volume – the number of spiders which die for this scientific need is less than the number which die or are fatally injured for this case of entertainment.
  • And this brings me to the method – the method of killing on I’m a Celebrity is one which we might reasonably consider to be a high-stress environment, even for what we know of spider perception. Whereas we  might expect the passionate scientist to have a calmer, more human approach.

At the end of the day, if you feel animals have an extrinsic value, neither of these spider deaths will upset you. If you feel they have absolute value, both these deaths will upset you.

But most of us lie in the middle zone, where intrinsic value must meet the benefit our society gets from either entertainment or knowledge. And it is here that the great ethical debates come in.

Regardless, threatening the scientist is not going to help anyone.