You may have heard that the disease atherosclerosis, which is among the leading causes of death in the western world, is a consequence of high cholesterol. And not just any to them: specifically, bad cholesterol. But what does this actually mean? What are good and bad cholesterol, and how do they differ? Let's find out! Too long; didn't read: Bad cholesterol is a … [Read more...] about What is the difference between good and bad cholesterol?
What are proteins?
I often mention in my articles how the body makes proteins, how proteins transport cholesterol, or how DNA codes for proteins. You also might know from food packaging and sports drink advertisements that proteins are an essential part of your diet and you need them badly. This is all true, but do you know what proteins actually are? Let's zoom in on them. In a … [Read more...] about What are proteins?
What is fitness in evolutionary biology
What is this "fitness" the evolutionary biologists often talk about? When something good occurs to a living being, it gains fitness -- like if it works out at the gym. Indeed, the meaning isn't far from that, because going to the gym undoubtedly can improve fitness. Or lose it if you don't know what you're doing and you injure yourself. But what is it? Loosely defined, … [Read more...] about What is fitness in evolutionary biology
How many genes do you share with your relatives?
It's easy to calculate how many genes you share with your parents, children, siblings, and other relatives. Given the fact that parents pass half of their genes to their children, and siblings share half of their genes, the rest is just math. To determine this, you just have to divide genetic relatedness each time you go up or down a step in a family tree, or sideways. For … [Read more...] about How many genes do you share with your relatives?
Why evolution isn’t perfect and giraffes don’t evolve even longer necks
Evolution has an odd way of appearing to be a perfect process, and with good reason. Many things in the natural world fit like a glove on a hand. Terms like ”natural selection” and “survival of the fittest” imply evolution is a goal-oriented process, with the goal being a perfect adaptation to the environment. But is it? Dinosaurs didn't evolve to be even bigger. Instead, … [Read more...] about Why evolution isn’t perfect and giraffes don’t evolve even longer necks
From where do trees get their mass?
As a kid, I remember, I was fascinated with how a tree can grow from a tiny seed. I wondered where their bodies came from and how trees get their mass if it obviously is not stored in the seed? My assumption at the time was that all that stuff must come from the soil, but damn, I was wrong. Years later, when I studied biology, I learned that Jan Baptist van Helmont, a … [Read more...] about From where do trees get their mass?
What is natural selection and how does it work?
Natural selection is one of the main driving forces of biological evolution. In the first article of my evolution series, you learned that biological evolution occurs mainly due to random mutations when organisms copy DNA. While random mutations should result in random changes, most evolutionary changes are not even close to random due to natural selection. But what is … [Read more...] about What is natural selection and how does it work?
What is a molecular clock and how does it tell evolutionary time?
If you’ve ever wondered how can scientists determine the relatedness of different species and how much time has passed since they diverged, a molecular clock could have come on your radar. What is a molecular clock and how is it used? Let's find out. The molecular clock is a method that can tell how long ago two or more species diverged depending on the degree of … [Read more...] about What is a molecular clock and how does it tell evolutionary time?
What is a species?
Do you think you know what a species is? If you see two different animals, they belong to two different species. Or do they? Is this an “ugly” duckling in the picture, or is it just a different kind of bird? When I talk about species or speciation, I often pause thinking about how deep I should explain it. On the surface, term species appears to be precisely defined. I … [Read more...] about What is a species?
How do viruses evolve and why it happens so quickly
As I write this, there is a large pandemic of coronavirus spreading across. Congratulations if you are lucky enough to read this article several years in the future! I'm a biologist with a special geekiness towards ecology and evolution. What else should I write about if not the evolution of viruses? What are viruses A virus essentially is genetic information in a … [Read more...] about How do viruses evolve and why it happens so quickly