Autocatalytic sets are self-sustaining chemical reaction networks which are believed to have played an important role in the origin of life, and to be an underlying principle of living systems in general. They have been studied in great detail both mathematically and with computer simulations, and actual experimental examples have been constructed in the lab. However, so far these experimental examples were of a limited complexity (so-called “elementary” autocatalytic sets). Recently, though, a group of researchers have constructed and studied the first experimental example of a more complex (“non-elementary”) autocatalytic set.
Standard economic theory assumes that humans behave fully rationally and are able to objectively calculate the value (or cost) of the different choices they are presented with. In fact, we pride ourselves on our rationality. Different from the animals, we humans have the unique capacity for logical thought and rational decision making. Or do we?
Read the full piece on This View of Life…
With on average more than 180 days with rain annually (that’s roughly every other day!), and a total of more than 800mm of rainfall every year, one certainly would not expect to find a desert in The Netherlands. However, there are actually several areas in the country where you can walk through perfect white-sand landscapes. Interestingly, the cause of this goes back several ice ages.
Schumann resonances (SR) are global electromagnetic resonances generated by lightning in the cavity between the Earth’s surface and the ionosphere. Their existence was predicted mathematically in 1952. However, it took another decade before they could be reliably measured and verified. Given that Schumann resonances occur in the same electromagnetic frequency spectrum as human brain waves, it has been suggested that extreme fluctuations in these resonances could affect human behavior and health.
Read the full story at Plus magazine.
A particular mathematical relationship known as a power law has been observed in many day-to-day situations, from word use frequencies in natural languages to the connectivity distribution in Facebook friendship networks. As it turns out, though, such a power law can also be found in snooker statistics. And if the amazing Ronnie O’Sullivan produces yet a few more centuries, the mathematical correspondence will be even better! Read more
A year ago I published an article in Plus magazine debunking claims buzzing around the internet about a supposed recent increase in earthquakes and volcanic eruptions and so on. In that article I showed in detail how anyone can analyze publicly available data to put such claims to the test. In the current post, I present a brief update on earthquake statistics, showing that there still is no need to worry.
The theory of evolution has helped biologists and ecologists to understand more about the natural world in general, and psychologists and social scientists to understand more about ourselves in particular. However, it has also taught a thing or two to computer scientists.
Read the full story on This View of Life…
Some problems are fundamentally hard, not only for humans, but even for computers. We may know how to solve these hard problems in theory, but in practice it might take billions of years to actually do so, even for the fastest supercomputer.
Read the full story on Plus magazine…
Around 1620 the Flemish chemist Jan Baptist van Helmont, often considered the father of pneumatic chemistry (the chemistry of gases), wrote the following:
“If you press a piece of underwear soiled with sweat together with some wheat in an open mouth jar, after about 21 days the odor changes and the ferment coming out of the underwear and penetrating through the husks of the wheat, changes the wheat into mice.”
This reflected the commonly held belief at that time, even among many scientists, of spontaneous generation. Life was assumed to arise spontaneously and continuously: mice from wheat, maggots from meat, frogs from mud, and so on.
Read the full story on TVOL.
Earlier this year, the inaugural workshop of the EES Project was held at the Konrad Lorenz Institute (KLI) in Austria. The KLI is a private and independent research institute with a focus on the development and evolution of biological and cultural complexity. Housed in a beautiful baroque building in the medieval town of Klosterneuburg, it offers a place to think outside the box, escape the usual academic constraints, and work on unconventional ideas.
Read the full story on the EES blog…
Recently I went on a day trip to Brno, Czech Republic, to visit the Mendel Museum. This small museum is located in the original Augustinian abbey where Mendel lived and worked for most of his life. The museum was founded in 2007 in an effort to promote the legacy of this “humble genius”, who is considered the father of genetics. However, Mendel was known for much more than his experiments in plant breeding. For several years he was the actual Abbot of the monastery, and also conducted many experiments in for example meteorology and bee keeping, about which he published as well.
Our ability to learn, use, and process language is something that sets us apart from other animals. Language is used for effective communication, but also allows us to express our creativity through literature, poetry, and song. However, our use of language follows strict mathematical principles as well. One of the best known of these is Zipf’s law.
Read the full story in Plus magazine…
“Most scientific explanations are causal. This is also the case in evolutionary biology, where the primary goals are to explain the diversity of life and the adaptive fit between organisms and their surroundings. Yet, the nature of causation in evolutionary biology is contentious.” So starts the description of a workshop on Cause and Process in Evolution, organized by Kevin Laland and Tobias Uller. It brought together an eclectic mix of evolutionary biologists, developmental biologists, and philosophers of biology, with the aim of addressing this contention. I sat in on this workshop, like a fly on the wall, in the hope of learning a bit about the latest research and debates in evolutionary biology.
In this day and age of the internet, where anyone can post anything, it is often difficult to know what is true and what is not. One person claims one thing, while another states the exact opposite. Who to believe among all this (sometimes deliberate) confusion? The upside, also thanks to the internet, is that you don’t need to be a professional scientist to find out at least some of the truth for yourself. With the increasing availability of public online databases and easy-to-use software, “citizen science” can go a long way at countering unsubstantiated claims.
Read the full story on Plus magazine…
We’ve heard it all too many times: animal and plant species are currently going extinct at a rate that is higher than ever before. Climate change, over-pollution, and urban and agricultural encroachment all contribute to the rapid decline of our planet’s biodiversity. So much so, that there is a real danger that even within the next few decades, several major ecosystems worldwide (such as mangrove, alpine, and polar regions) will be seriously disrupted, with major consequences for us humans as well.
Thankfully, efforts are underway to try and curb some of these negative influences. But without knowing better what exactly their consequences are, it is almost like driving in the dark without the headlights on. Is there a way to estimate more accurately what the biodiversity consequences are of, e.g., a two-degree increase in global temperature? It turns out the answer is yes (at least to some extent), thanks to mathematics and computers.
Read the full story on The Naked Scientists…
As part of a workshop at the Wissenschaftskolleg zu Berlin (Wiko), we had the pleasure of being taken on a backstage tour at the Natural History Museum in Berlin. Our private and extremely knowledgeable guide Brandon Kilbourne turned out to be a walking encyclopedia on the evolution of mammals, so we were in for a special treat. This 2.5hr tour provided many wonderful insights into amazing adaptations over millions of years of mammalian evolution, with as cherry on the cake some unique dinosaur skeletons to marvel at.
In a post just over a year ago, I presented data on earth activity (in particular earthquakes, volcanic eruptions, and tropical storms). Given all the buzz on the internet about an increased earth activity over the past several years, I was curious to see this for myself, so I downloaded and analyzed some publicly available data. Surprisingly, though, the data showed no such increase at all. In the current post, I present the updated data for up until the end of 2016, which still shows no sign of any unusual behavior. Judge the plots below for yourself…
Spirals are common in nature. We’ve all admired the beautiful spirals that occur on sea shells, we can find spirals in plants, and even in the arms of galaxies or weather patterns. There are also situations in which spirals aren’t a result of slow growth, but occur spontaneously in biological or chemical systems. A famous example from chemistry is the Belousov-Zhabotinsky (BZ) reaction: when several chemicals are mixed together in a petri dish, the resulting solution forms changing spiral patterns. In biology a particular slime mould, called dictyostelium discoideum, gives rise to similar patterns. Spontaneous spiral wave formation in such systems can be reproduced and studied with simple mathematical models known as cellular automata.
Read the full story on Plus magazine…
Charles Darwin’s theory of evolution by natural selection is one of the most profound scientific theories to have ever been developed. However, there were several questions about evolution that Darwin himself could not answer. Not that he wasn’t smart enough (in fact, his intuition often pointed in the right direction), but the answers to those questions required sophisticated mathematical insights that were not developed far enough, or even available yet, in Darwin’s time. One such problem was the evolution of altruism. If evolution by natural selection is all about competition and survival of the fittest, how can altruistic behaviour (which, by definition, lowers the altruist’s fitness and increases the receiver’s fitness) ever evolve?
Read the full story on Plus magazine.
Evolution is still all too often (but wrongly) downplayed as “just a theory” in public discussions. This is partly due to an unfortunate misunderstanding of what a theory means in science, as opposed to its common language meaning. Evolution by natural selection is much more than just a hypothesis, and is as much a valid and well-accepted scientific theory as the theory of gravitation. What Darwin did for biology is on par with what Newton did for physics — and mathematics plays an important role in both theories.
Read the full article in Plus magazine…
I’ve made a short movie showing autocatalytic sets arising in a dynamical simulation of a simple polymer model. It shows how autocatalytic subsets appear, one after another, and then grow in concentration. This provides a nice visual and dynamical example of our usually more graph-theoretical analyses. Read more
A key result of last year’s UN climate change conference in Paris is that we now have a new international deal to curb climate change. However, it seems primarily focused on reducing greenhouse gas emissions to limit global warming. A significant step forward, no doubt, but it does not address the more difficult, and perhaps also more relevant question of how to deal with the inevitable consequences of climate change. Are we able at all to predict what those consequences will be? And, more importantly, will we be able to do something to reduce, or even prevent, some of these consequences? When it comes to biodiversity and the distribution of species, some researchers believe this is indeed possible.
Read the full story on Plus magazine.
“Please hold the line, your call is important to us.” It’s a sentence we’re all frustratingly familiar with. Just as familiar as we are with standing in line at the supermarket or post office, with the other queues seeming to move much faster than the one we happen to be in. Thankfully, mathematics can help. Queueing theory studies such situations mathematically, and tries to find solutions that minimise the average customer waiting time while also limiting the average time a queue server remains idle. This double constraint makes the problem a difficult one. An additional source of difficulty is the randomness involved. Customers usually do not arrive at regular intervals, but their arrival times are what is called a stochastic process. Coming up with a general formula that provides a solution for such stochastic problems is generally difficult, and sometimes even impossible. Recently my uncle Arie Hordijk and I studied such a queueing problem, and came up with a solution based on the movements of a ball on a billiard table…
Read the full story on Plus magazine.
What is life? This question is still much debated in science. After the discovery of the structure of DNA by Watson and Crick in 1953, and the more recent advances in DNA sequencing technology, living organisms have become primarily viewed as being defined by their genes. However, there is more to life than genetics alone. In fact, a more “holistic” view is emerging in which the essence of life is considered to reside in the complex collection of chemical reactions that enable an organism to grow, repair, and reproduce itself. In other words, life as a network of self-sustaining chemical reactions. This alternative view could have important consequences for many areas of science, for example the way we might treat diseases like cancer, search for possible life on other planets or grow artificial donor organs. And now there is mathematical evidence that at least one particular living organism (the well-studied bacterium E. coli) is indeed such a self-sustaining reaction network, thus formally supporting this alternative view of life.
Read the full article on The Naked Scientists.
The internet is buzzing with claims that there has been a significant recent increase in seismic, volcanic, and atmospheric activity on our planet, and there seems to be a specific emphasis on the years 2012 and beyond. Suggested causes for such an increase include global warming having an effect on these earth activities, deliberate geo-engineering, changes in solar activity and/or cosmic radiation, and an as yet unknown or undisclosed disturbance within our solar system. However, a simple analysis of relevant and publicly available data provides surprisingly little support for such claims. [Last update: 29 Dec 2015]