A Barcode of Life

A Barcode of Life

Barcodes are commonly used for the identification of items. Many standards exist but, in general, barcodes must be universal, unique, and easy to process. The standardization of barcodes grants great benefits, not only for everyday shopping: A unique identifier facilitates and simplifies the ordering and processing of goods all over the world.

Similarly, the distinct identification of organisms and their relationships is one of the major goals in the life sciences. What would be more suited than a barcode – a barcode of life?

Many genetic regions have been proposed for the use of being such a barcode. For eukaryotic species, the 18S gene is most commonly used today; a rather short fragment of ribosomal RNA that is evolving slowly and allows the reliable identification of most species. It is surrounded by highly conserved sequence regions that simplify the sequencing process. By this, the analysis of 18S RNA from the environment delivers a comprehensive overview of all present species, equivalent to scanning a barcode of all organisms.

Egyptian Geese

Egyptian Geese

I regularly visit our local lake and another park with two small ponds. What do they have in common? All year long they are both inhabited by at least one couple of Egyptian Geese, which are normally endemic to the southern half of Africa. So what brings them up here?

Egyptian Geese have been hold captive in Europe since the eighteen hundreds and individuals were set free or escaped from time to time, resulting in a small group of wild individuals. Starting in 1970, a fast expansion of these animals occurred along the river Rhine, which also led to a well-maintained population in Germany. Even more so, they continue to spread around Europe and take over urban areas. They can be rather aggressive, especially towards mallard ducks, and seem to have found an environment that favors their species. Sometimes they even displace larger birds from their nests and breed there themselves.

One couple in our city just had its second litter this year, which seems rather odd given that temperatures are dropping rapidly. Maybe the warm autumn mislead their instinct.

Review: Fujinon XF 80 mm F2.8 R LM OIS WR Macro

Review: Fujinon XF 80 mm F2.8 R LM OIS WR Macro

I’ve warned you: There will be different stuff on this blog. For example, this post right here; a review about one of my absolutely favorite lenses for the Fujifilm X system.

All pictures are shown in reduced resolution (3000 px on the long side). There is (much) more detail in the full-sized versions.

Fujifilm X-T30, Fujinon XF 80 mm Macro, ISO 250, f 2.8, 1/640 s


There are quite some reviews about the XF 80 mm Macro out there. So, why am I writing another one?

I regularly check out reviews on lenses I think about buying or that I am interested in. And, universally, they lack the most essential content: Good pictures. Pictures I can relate to, pictures I am hoping to shoot, or pictures I can marvel at. Mostly, because most reviews seem to be written after only a few hours of use.

This review is about the pictures. About the capabilities this lens provides and how it might help you to fulfill your artistic dreams. From two years of intensive use. And hopefully, for some rare visitors, this selection of pictures fills the void in between the soulless reviews for this wonderful lens and awakens the urge to go out and create yourself.

Fujifilm X-T30, Fujinon XF 80 mm Macro, ISO 80, f 2.8, 1/320 s

As all my photography gear, I’ve bought this lens from an online second-hand platform. If you’re not already doing it, I can only recommend to buy used gear. It’s not only cheaper, but also saves resources of our precious planet. All detailed stats for this lens can be easily found online. So far, I’ve used the lens exclusively on the X-T30 body.

Fujifilm X-T30, Fujinon XF 80 mm Macro, ISO 500, f 6.4, 1/500 s, stitched from multiple exposures


The lens is a delight to use. As for most Fuji lenses, it has an aperture control ring that allows the smooth control from f2.8 up to f16. When turned to the very end, it switches to automatic aperture mode. Furthermore, it has two switches: The first one controls whether the optical image stabilization (OIS) is turned on or off. The second one controls the ‘focus range’ – this determines where the lens attempts to find a focal point (either close, far, or anywhere). The lens comes with a lens hood which always stays attached to my lens during use: In my experience, it not only protects the glass from scratches and rain drops, but it also helps to quickly assess how close you may move to your subject while maintaining focus.

The lens is of very high build quality, feels sturdy, and is weather sealed. While these qualities add to its weight, they are also beneficial when you go out in harsh weather (and you should because rain drops are wonderful in Macro photos). I’ve used this lens without any problems whatsoever in minus 23 degrees Celcius, in heavy rain, in scorching heat, at the salty sea, and at sandy beaches. It has never failed on me and still looks like new.

Rarely, I’ve also attached the 1.4x TC, however, it doesn’t bring much benefits as far as I’m concerned.

Fujifilm X-T30, Fujinon XF 80 mm Macro, ISO 320, f 6.4, 1/180 s

Macro: Insects and Flowers

When shooting Macro I predominantly use the camera hand-held with low aperture values and OIS turned on. For a very limited number of times I’ve required focus stacking; for this, I turn off the OIS and use a tripod. However, in most instances, my Macro subjects are moving (either by themselves or in the wind), which makes it difficult to use a tripod and/or stacking anyway. Also I find that shooting hand-held is way more fun and enables you to quickly react to changes in light or the environment. On rare occasions I also removed the lens hood; for example when photographing butterflies close up as they are easily scared from the approaching lens or its shadow.

In the beginning, I often had the urge to move as close to the subjects as possible (it’s a Macro lens after all, isn’ it?). However, you should be aware that the depth of field gets very shallow when being close to your subject. For example, getting the eyes of a dragonfly into focus when being at the minimal focus range requires an aperture of at least f8. Getting a whole insect into focus (without stacking) is only possible when moving further away from your subject. I also found that moving further away often improves the possibilities for creative and appealing compositions significantly.

Fujifilm X-T30, Fujinon XF 80 mm Macro, ISO 500, f 2.8, 1/1000 s

Shooting people, animals, nature, abstracts, and creative imagery

The lens is also excellent at shooting portraits. However, I will not share any because I’ve mainly photographed my family. While I also own the 56 mm f1.2, I still sometimes prefer the 80 mm for people when shooting outside during hikes as the 80 mm gives a lot of flexibility. Somewhere I’ve read that the lens is too sharp for portraits. While it’s definitively the sharpest Fuji lens I own, it still works wonders for portraits; at least for my taste.

I’ve also shot birds, cows, deer, and some other wildlife with this lens. While I would normally go for the 100-400 mm in these cases, the sharpness of the Macro lens also allows for marvelous pictures of animals within the landscape. In the case of the goose I was lucky enough to get close without disturbing them; additionally, the sharpness of the lens allows a generous crop.

Besides, I’ve used the lens a ton on a tripod on f8 for abstract patterns in nature or landscapes; likewise, I sometimes whirl it around for some ICM photography – if you’re into this, I also recommend to play around with turning the OIS on and off: it makes a significant difference in the resulting patterns.


In most cases, buying new lenses won’t help you to take better pictures. But in this rare instance, it felt like it did work for me. Not only because of the capabilities of the lens itself, but also because it is such a delight to use, and because it motivated me to go outside and play with it, no matter the conditions and weather.

All pictures from this post:



Sometimes, it feels like I am already experiencing symptoms of an aging body and mind: I am getting more conservative, my back often hurts, recovery from sports takes longer, and suddenly I appreciate trees. And flowers. And birds.

In my younger days, I was convinced that birdwatching is boring; but it has grown on me. Birds are adorable. From the smallest goldcrest to the great bustard (hopefully I’ll see one someday), every type of bird is so unique and fascinating and there is so much to learn: about their behaviour, calls, appearance, and migration patterns. Depending on the employed definition, there are between 10,000 and 20,000 bird species on earth. In Scotland we saw at least 63, many of which I have never seen before. I was a real treat to experience the puffins, razorbills, and guillemots at the coast. On our last day alone we spotted a spoonbill, a barnowl, sedge warblers, and a gannet, none of which I had ever seen before.

But again, the climate is changing everything: The spoonbill populations are slowly shifting north due to the increasing temperature. We got told that it was only the second time that an individual was spotted at the small lake where we parked over night. It is estimated that 15% of all species might go extinct soon (in evolutionary timescales) because they cannot cope with the rapid changes of the climate. Around our hometown some bird populations even increase, but the majority declines. Especially endangered are those that breed on farming grounds because of the streamlined agriculture occupying large amounts of space, often with monocultures. On the bright side: At least around here there are also increasing amounts of ‘Blühstreifen’, strips of wild herbs and flowers that are incorporated into the conventional agriculture and run along all the fields of wheat and corn. And if it doesn’t work out for the birds, my personal contingency plan is to just see all 10,000 species soon enough.

Communicating Science

Communicating Science

I’ve been at a scientific meeting recently and (again) was surprised of the disconnect that sometimes occurred between a speaker and the audience. If the listener (me) does not understand a complex subject that is explained, it is not solely on me! Don’t blame me that I could not follow your cluttered slides and your jumbled train of thought! Sure, sometimes I will be uninformed or not smart enough. But sometimes it is on you, dear speaker.

Explaining an easy concept complicatedly is easy. Explaining a complex concept concisely is artistry. And while I’ve set through many talks cluelessly, I admired the few speakers who mastered the art: The ones that make you feel clever just by listening. The ones that explain intricate science so well that you think you designed the experiments yourself. The ones that let you rediscover what they did and make it seem like what they are doing isn’t difficult after all.

Giving a good talk boils down to the same things that are important in photography: The subject needs to be clear. Leading lines are necessary to guide the viewer. Help them navigate the frame. Unimportant stuff is left out (and there is a lot of unimportant stuff). And everything left in has to support the main subject. Tell a story.

The following pictures do not follow these rules at all, but I hope my own talk did at least…

A Short Reading List

A Short Reading List

A brief list of some of the books I read during the last year, thanks to Fräulein Klitzeklein. The first draft of this post is already from last Winter but only now I came around to finishing it. It is mainly intended for myself: to remember which books I read, what they taught me and how they affected me, as well as what I wanted to take away.

Der Buchspazierer, by Carsten Henn

The mundane, the monotonous, the every day rhythm. This book is about those things. And how they are among the ones that matter most in life. It matters what you make out of it. It matters with whom you persevere through it. It’s the daily interactions with people around, however small they might be, that make it worth it. An easy-going story, yet scratching to the bones, about passion to detail, about finding unexpected friends, and about loyalty.

Der Gesang der Flusskrebse / Where the crawdads sing, by Delia Owens

This one invigorated my passion for nature and science as it elegantly intertwines both within a complicated story of a complicated life. It features a deep appreciation for the nature and its inhabitants. Never give up, stand up for yourself, and life can be unfair. I finished the second half in a single day, something that hasn’t happened for quite a while.

Die Bücherdiebin / The book thief, by Markus Zusak

I never would have picked this one up myself. All the more, I am fortunate that it got forced upon me: Probably the most impactful read for me so far. Deeply moving, cleverly narrated, a story of genuine humanity. Where heroes are inconspicuous, but never have been more important. Where the profound joy and all inexpressible horror of life cling to each other like there is no tomorrow. Where the smallest childhood memories become something larger than themselves. A story of innocence and trust, of apples and daunting terror, of the power of words and how they shape our world.

Zugvögel / Migrations, by Charlotte McConaghy

Nobody is flawless: There is always good and bad, even though it can be difficult to perceive it. Do not judge others, especially if you cannot relate to their experiences. Sometimes they are more similar to you as you might think. Attaining redemption is a journey, as our life, without goals other than the ones we define ourselves. And no one is prepared for the abruptness of the end as it might arrive every second of your life.

Das Flüstern der Bäume / Greenwood, by Michael Christie

An entertaining novel narrated cleverly to blend a multitude of time frames to illustrate the larger picture of our society, our history, and our planet. Has a bit of everything, and thus, a bit of nothing.

Der Circle / The Circle, by Dave Eggers

Exhausting read and quite demanding. Balances on the uncomfortable gap between surreal fiction and actual reality that keeps bouncing in your head for quite a while after. A constant warning of where humanity currently is and which direction we might be heading in a digitized world, paired with deep-reaching questions about our individual purpose of life. About the phenomenal benefit and destructive power of data, as well as societies inability to grasp the impact of what they create.

Was man von hier aus sehen kann / What You Can See from Here, by Mariana Leky

A wonderful story of love, life, death, family, and nature from the eyes of a growing human. It charms with wonderful characters that are narrated so well that you’re sure you’ve met them in real life. And even after closing the book, they occupy your mind and keep lingering there with their struggles, their joy, and their words of wisdom. This book shows how to embrace triviality, how to cope with setbacks, and how a village community manages to navigate life.

Looking for Alaska, by John Green

Several of my friends read John Greens books during high school. I never did. Maybe I am pleased with this fact. It’s like listening to good music for the first time: It’s something special; you should find the right time and place and embrace it because it’s your only chance to experience it in this way. This book has power, no matter your age. It leaves marks.

The Fault in our Stars, by John Green

An absolute masterpiece. Utterly moving. Possibly life changing. Who would’ve thought that a romantic journey of high school students can be told with such intensity. An honest, melancholic, and moving experience. See also That which remains.

Umwege des Lebens / The Book of Two Ways, by Jodi Picoult

My first one from Jodi Picoult and presumably not the last one (and I am told there are way better ones). A potpourri of topics mingled into a love story in our contemporary world. By this, it aims to please many, which comes at the cost of some tiring sections. Besides exploring complicated relationships and lifelong dreams, it focuses around the process of dying.



Spreading from a common body, reaching out in search of light, intertwined but solitary, a mutual goal but separate journeys. All supporting a common trunk to be alive, to support a life, to stay alive.

Long-term deep emission reductions, including the reduction of emissions to net-zero, is best achieved through institutions and governance that nurture new mitigation policies, while at the same time reconsidering existing policies that support continued emission of GHGs (high confidence).


It’s all there. A multitude of pathways to reduce emissions. Many branches, a common goal: Keep the planet habitable. It requires systematic change in all sectors: energy, housing, transport, industry, land use, food production. All of the pathways that limit warming to ‘acceptable’ limits have one thing in common: they require change right now. Or to be more precise – the required change should have begun 2 years ago, or 10 years ago, or 20 years ago. But still, nothing changes. Since this last report has been released, several countries have released their new plans to drill for even more oil and gas. Business as usual; the trees will get chopped down, leaving limbs scattered around the corpses.



One of the last exercises in an introductory course to programming I teach is to implement a straight-forward approach for modeling population growth over discrete time steps with a logistic growth function: The population x of a species at time t+1 is determined as x(t+1) = r * x(t) * (1-x(t)) where x(t) is the population at time t, and r is a fixed reproduction parameter. The choice of r influences the long term behaviour of the resulting time series – thus, the growth of the species population; for example, for r < 1, the series tends towards zero – the species goes extinct. However, for r > 3 the series oscillates – it exhibits a periodic behaviour (for some values of r the series even becomes seemingly random without a fixed period, see e.g. here). The length of the period depends upon r, but it never reaches an equilibrium; like a pendulum, swinging around its only stable position in the middle. Like life pulsating between non-steady positions, but never reaching a balanced state.

Oscillations are present constantly. The term (1-x(t)) models the environmental restrictions that prohibit unlimited growth. Restrictions which prevent us to come to a rest. The fantasy of a steady state is a futile one. There are times where a stable position seems in reach; until external restraints pull us back into another direction. At the moment, it’s the direction of work; and hence, photography and blog posts are somewhat neglected. Winter already fades again, making way for summer. Left are only some solitary pictures of oscillating camera movements and colorless nature.

The Inevitability of Triviality

The Inevitability of Triviality

Triviale Maschinen haben nur einen Zustand: Sie liefern auf denselben Input immer den gleichen Output.

Heinz von Förster

The quote could be vaguely transcribed as ‘Trivial machines have a single state: Given the same input, they always produce the same output.’ In contrast, for non-trivial systems the output not only depends on the input but additionally on an inner, possibly unknown, state of the system. This inner state evolves with every given input and, thus, the same input can lead to different output. In other words: the output may seem random to an observer as it also relies on the complete history of inputs processed by the system, reflected by its internal state.

Using this bipolar framework to describe actual systems can be challenging: When I type 2+2 in my calculator it will always yield 4. It’s apparently trivial – until the environment acts upon it and the batteries run out, the circuit board becomes corrupt, or the display breaks. If my bike would always give the same output when I start pedaling, I would be much more satisfied and my local bike shop would go out of business. If computers really were trivial, a whole lot of IT assistants could look for a new job right now. Systems decay over time, they are error prone, they are subjected to the very same universe we are.

Another approach might be to not consider it as a binary decision, but a continuous scale of triviality where systems are ranked based on their robustness. In a probabilistic sense, the calculator is rather trivial as it gives the predicted output in a quantifiably large majority of cases. In contrast, living systems are on the other end of the scale and highly non-trivial since they exhibit wildly different behaviour in seemingly similar situations.

However, when system are ranked on such a scale of non-triviality, problems arise: How should I work on this very laptop when I assume that it could fail me anytime? If I would admit its non-triviality, I couldn’t work in the first place because it could give any output, independent from the keys I am pressing. This example seems a little daft, but when transferring it to human interactions, the exact same applies: How should I communicate with my colleague about work issues when assuming that the output will be determined by a non-trivial living system? How should I forward instructions if the output is uncertain anyway? How could I coherently speak with my partner about serious topics when my input has potentially little effect on the output?

We constantly trivialize the non-triviality around us. We do so because it is necessary. When I am typing in my calculator I expect a correct result. When I am asking a question to a friend, I expect to get an answer. Not because the answering system is trivial, but because I have to assume it is in order to ask the question in the first place. We trivialize machines, we trivialize humans, the reactions of strangers, friends, and partners. And if the output is unexpected, we don’t blame our foolish assumption of triviality, but we blame the system itself. And the scale isn’t really one that describes the non-triviality of systems, but rather a scale of how much an observer trivializes systems.

Where does this lead? Potentially nowhere; there might be other, potentially more useful, distinctions to draw. But when drawing this distinction, I am wondering in which cases it might be wise to begin to acknowledge the non-triviality of systems.

The Sixth Extinction

The Sixth Extinction

66 million years ago dinosaurs became extinct – an inconceivably long time span. However, they roamed the planet for even longer: astounding 165 million years. Our species has only been around for ~300.000 years now. When the dinosaurs died, three-quarters of all plant and animal species vanished with them, also known as the Cretaceous-Paleogene extinction event. The cause was, to our best knowledge, the impact of an asteroid with devastating effects. The precise number of such large extinction events is under debate, but by many the Cretaceous-Paleogene extinction is regarded as the fifth and latest one.

So, what does the title of this post refer to? It refers to right now: this millennium, this month, this day. Today, a lot of species are dying. Forever. They will be lost for all of the remaining time this planet exists. Estimates vary from 24 up to 150 species every day. It’s neither possible to precisely guess the actual number, nor it’s easy to evaluate how drastic the estimated numbers really are. The question at heart ist: How much larger is this decline of species than the background noise of species extinction that happens naturally? Some people argue it’s 100-1000 as much as it would be without human interference. Others say these numbers are inflated and global mass extinction is, for now, not as drastic as proposed (because the common assumption that decline in habitat area is highly correlated with decline in diversity might not hold true). One of the major hurdles in assessing the severity of the current biodiversity situation is not only that estimates of dying species vary widely, but also that the total number of species that are currently living is still largely unknown.

In 2010, the UN agreed upon 20 major goals for the upcoming decade regarding biodiversity, including specific plans for the conservation of nature and variety of species. The last decade was even termed the ‘United Nations Decade on Biodiversity’. So, how are we doing so far?

Pretty bad! And irregardless of how accurate the estimates on global diversity decline might be, some other numbers are well proven and unambiguous: There is a large decline in animal populations across most domains of life. Since 1970, populations show an average decline of 60%. In south America, due to deforestation of rain forests, the decline in biodiversity is already estimated at 94%. The number of insects in Germany has gone down 70-80% in the last 30 years alone. 25% of all plant, fungi, and animal species are endangered. To quote a rather optimistic assessment: If we presume a total of 8 million species, we will loose at least 1 million by the end of the century. And these effects can mostly be traced back to modern agriculture alone. As soon as climate change really hits (very soon), these numbers are expected to increase significantly again. And even if these changes do not necessarily mean a decline in global biodiversity, the effects of declining local biodiversity are the ones we will pay for.

So the UN agreement from 2010 didn’t turn out well – and by now, I doubt that the Kunming declaration from this year will cause any large-scale systemic change. For me, reading about these events evokes two opposing feelings. First, sadness and helplessness. That we, as a society, are responsible for this undesirable change. That I, as an individual, am responsible for this horrible change. And second, relief. At least five times life has recovered from the most harsh conditions imaginable. And it probably will continue to do so until the heat death of the universe. It’s unclear though whether the species Homo sapiens will survive this next great extinction; by several scientists, this threat is estimated to be even more dangerous than climate change.

Yesterday, the winners of the European Wildlife Photographer of the Year 2021 were announced. Check them out here. Stunning pictures all around! The winning picture of this year also entails a grave background story about our influence on precious nature.