This blog post originated from a discussion with physicist Karo Michaelian about his book Thermodynamic dissipation Theory of the Origin and Evolution of Life. The difference between physics and biology is a topic that deserves a blogpost. It will be an informal discussion.
What is the difference between animals, plants, bacteria and viruses on the one hand and stars, volcanos, clouds, rivers, and rainbows on the other hand? If organisms are just physical objects and must obey the laws of physics, what biological laws could exist? Physicists explained the Universe. Physicists have finally arrived at The Theory of Everything which explains all known physical phenomena in the universe from the smallest to the most massive things. And organisms are in between. If organisms are physical objects, they are also explained by The Theory of Everything. They should also obey physical laws. But then, do we need Darwin? Do we need Mendel? Do we need Watson & Crick? Could the biology department be subsumed in the Physics department and send biologists home? Let's listen to a physicist:
" ...the biologists simply are not trained to think in terms of symmetries and fundamental laws, as physicists are. (...) Biologist want simple answers that can be written out in a single paragraph, with learning as little mathematics as possible, and they found one in the perspective of Darwin (and, of course it is a perspective and nothing more). It works as a nice description for some things, but it is only a poor description of reality and misses completely at understanding the fundamental function of life. The physicist wants to know what is behind this Darwinian description and this thermodynamic view opens a completely new paradigm with a much richer and profound understanding." Karo Michaelian, August 12, 2020
No wonder that physicists –in possession of the Theory of Everything– want to invade and occupy the territory of biology. As if it were a war. There is only one real science. The profitability of mathematics is easily explained. Physics deals with dead things. Dead things behave rather predictably. Newton! The movements of the planets! However, because they study only dead things, they don't understand what makes life different.
There is an important difference between physics and biology: complexity. There are only 118 chemical elements, but millions of biological species. The chemical elements do not vary, except radioisotopes which behave predictably. Humans have DNA with 3.5 billion bases. All humans differ genetically. There are 67.3 million single-nucleotide polymorphisms in the human population . A human body has millions of cells, each cell contains in total 42 million protein molecules. The majority of proteins exist within a narrow range - between 1000 and 10,000 molecules. Some are outstandingly plentiful at more than half a million copies, while others exist in fewer than 10 molecules in a cell . And these are only proteins. Physics has no laws for this huge amount of complexity. Physics studies dead and simple things.
A hot cup of tea (source)
A mouse (Apodemus sylvaticus) ©GK
Most importantly, physicists don't understand the difference between a mouse and a cup of tea. A mouse maintains a temperature difference between its body and the environment. A cup of tea also has a higher temperature than its environment. But what happens with the cup of tea? The temperature difference has gone within an hour. Just obeying the laws of physics. The mouse maintains the temperature difference all its life. Physical laws don't explain the difference in behaviour between a cup of tea and a mouse. Physics cannot explain how the physical object called 'mouse' maintains its temperature. This example alone suffices to suggest that we need a separate science. It's called biology, the science of the living things.
Does a mouse maximize heat loss? Being naked would help! It would very likely maximize heat loss . Heat loss may be a driving force in the abiotic and pre-biotic world. But
living organisms have subsystems that control energy uptake, energy
production, energy use, energy storage, and heat loss . Those systems by-pass physical laws without violating them. Just as birds and air-planes do not violate the law
In the living world, energy management is under control, it is regulated: thermo-regulation. Because it is under control, pure physical laws cannot be applied. Therefore, physical laws cannot be the driving force of evolution.
Yes, physical laws constrain the properties of living organisms, but within those
constrains there is freedom to shape organisms. And what a shapes there are!
Endless forms most beautiful! Heat loss occurs in living organisms, but it is
not a driving force, certainly not the driving force. Energy management is one
of the fundamental differences between biological and physical systems. This
is under genetic control. Genetics is information . The control of
chemical and physical processes is the main difference between living and
physical systems , . It is part of the definition of life.
I add two important reasons why organisms have energy control systems:
1) without energy control they die.
2) organisms can produce more offspring if they use energy more efficiently. That's the evolutionary reason.
Organisms that are less energy efficient waste energy and cannot invest as much energy in reproduction because that's an energetically very costly process. In general: energy efficient organisms out-compete less energy efficient organisms. Energy efficient organisms are winners, energy wasters are losers . Warm-blooded animals have fat, fur or feathers to prevent heat loss. Whales, dolphins, seals and other marine mammals can generate their own heat and maintain a stable body temperature despite fluctuating environmental conditions. But these animals take thermoregulation to an extreme, enduring water temperatures as low as –2 degrees Celsius and air temperatures reaching –40 degrees C . They have biological inventions that oppose heat loss. That's against the Thermodynamic dissipation Theory. Life is a successful fight against the Second Law of Thermodynamics. There is certainly no attempt to lose as much heat as possible. That would be insane.
|Dead Weasel Mustela nivalis ©GK|
Even a dead weasel is not quite a dead physical object as can be seen on the
picture above. It is teeming with life. Flies are the first organisms to occupy the unfortunate animal.
Many follow, including bacteria, worms, beetles, fungi, maybe a fox or a raven. .
So, if physicists are blind and deaf for the differences between living and dead
objects, no useful exchange of ideas between physicists and biologists will happen. Arrogance and ignorance will be deadly for any communication. Only as equal partners in science we will understand life.
- A cell holds 42 million protein molecules, Science daily January 17, 2018
- I wrote about that in my review part 2 of Thermodynamic dissipation Theory.
- See further 'Not Wasting Energy' in my review part 2. 16 May 2018.
- For more details see: Open Questions / Genetic variation in this review.
- 'Processes in living systems must be regulated and controlled' is one of 5 Real (absolute) life criteria. See my Ganti review.
- Information is the difference between life and matter, A review of Hubert Yockey's 'Information theory and molecular biology'. Yockey is a physicist!
- How do marine mammals avoid freezing to death? Scientific American, 13 May 2009.
- Thousands of unexpected microbes break down our bodies after death, Science, Dec. 10, 2015
- If not maximize and not minimize heat loss (minimize heat loss is against TDT), than anything goes? Any value would be compatible with the Thermodynamic Dissipation Theory? But then it would be unfalsifiable! The theory would not forbid anything. It would not predict anything. It would not say one thing about the world. It would make the TDT non-empirical and theory-less. Worst of all: no mathematics involved! That's a serious matter. 14 Aug 2020 15:09
Ernst Mayr (2004) What makes Biology Unique? Considerations on the autonomy of scientific discipline. (a defence of the autonomy of biology). See my summary.