Order in Nature

I wonder how many people I’ll lose after the next sentence. The second law of thermodynamics states that the entropy of a system will increase over time. Don’t stop reading! I promise you—I’ll explain my point.

There is an awful lot of complicated math that goes into proving the 2nd law to explain that unless work (i.e. energy) is put into a system, it will inevitably become disordered.

What does this mean? Well, in everyday speak, it’s like cleaning your house. You clean your house, and over time it becomes progressively more cluttered and dusty. It will continue to do so until you put work (i.e. energy) into fixing it up again.

The 2nd law has more to it than just that entropy is inevitable, but that’s the part I’m thinking of now. While the 2nd law is a fundamental part of physics, it has relevance to all science. (Aside: as may become obvious as I continue to blog, physics is the root of it all.)

As a biologist, I realize that to create order, whether that is the manufacture of a complex molecule such as a protein, a highly organized single cell, or an entire multicellular organism (such as a person) requires a huge amount of energy (hence the fact that we must eat to maintain our system).

So, it is because the nature of nature is to become disordered that I find elegance in things that ARE ordered—especially in nature. The fixed number of petals found on flowers, the regular pattern of shapes on a shell, the periodic table.

The periodic table???!!!

Yup, the symbol of a science geek, mostly attributed to a Russian chemist by the name of Mendeleev in 1869. Think about it. The table represents all of the elements found in our universe. And the elements are constructed such that their atomic numbers can be placed in order, based on the number of protons in the nucleus of their atoms.

Hydrogen (H) has 1 proton, Helium (He) has 2, Lithium (Li) 3, and so on.

In other words, the elements are ordered. The building blocks of nature are ordered. There is elegance in that. And a lot of force goes in to maintaining the structure of the atom. The strong and weak nuclear forces are needed to maintain the atomic structure and keep the atom, with its oppositely charged protons and electrons, together. There is a lot of work involved in maintaining order.

It’s Not Just for Camouflage; It’s to Impress the Ladies!

Remember how you learn about camouflage in nature as a kid? Every teacher brings up chameleons as a perfect example of altering their appearance to blend in a avoid predators that might want to eat the little guys.

Turns out it’s not entirely true!

I just read this article in PLoS Biology by Devi Stuart-Fox and Adnan Moussalli and the accompanying descriptive article for it by Kira E. O'Day. Stuart-Fox and Moussalli studied South African dwarf chameleons (not the type in the picture) in a natural habitat to see what triggered the color changes. It turned out that male chameleons displayed their brightest, most obtrusive color when dealing with other males in the interest of finding a mate.

They still change color to match in with the background when confronted by a predator.

But sure enough the guys are donning their brightest clothes to impress the ladies. And the loser in the chameleon posing promptly dons drab colors and retreats.

The scientists analyzed the variety of background colors the chameleons live with as well as the large capacity of colors both visible and not visible (such as in the UV range that humans can’t see), and they’ve concluded that the evolution of color change in chameleons was actually driven by social signals. In other words, while the chameleons reap the benefit of their color change because of how it can help them hide from predators, what may have actually driven the evolution of the capacity to change color is their social life.

So, guys, think of that the next time you try to decide what to wear when you’re going out clubbing.

It's a Matter of Perspective

Science is all about seeing relationships between things or patterns of behavior. Sometimes living systems that are vastly different can have great similarities if you look at them in the right way. And really, that is all that is needed to see the similarities—a change of perspective.

For example, what are the similarities between a human and a mouse? Well, on the surface, you may say not a whole lot, but let’s look deeper.

1. They’re both mammals who give birth to live young (meaning they don’t lay eggs).
2. They’re both vertebrates.
3. They both contain about 30,000 genes in their DNA.
4. On a precise basis, their DNA sequences (the letter sequences ACGT of DNA) are 85% identical.

So, all that’s needed to see the similarity is perspective.

The genetic and biochemical similarity between humans and mice is one reason that physiological studies done on mice hold some relevance for humans. It’s not a perfect fit, but if something works or holds true in mice, then there is precedent for thinking it might work in humans as well. Hence all the studies done in mice (well, there are other reasons too).

Sometimes I look at a set of data in several different ways to see if there is a pattern. It’s helpful just to look at the SHAPES of curves or trend lines. They can tell you a lot. And seeing numbers in a visual fashion, such as plotting them on a graph, is a great way to discern trends and differences. Therefore, I look at data in many different ways—visually, as numbers in a table, in graph form (bar graphs, line graphs, pie charts)—all to look for the trend that may not be obvious.

Of course, sometimes there is no trend or similarities and you’re actually comparing apples and oranges. Or rodents and hominids.