Tuesday, 30 April 2019

Homeostasis and Complexity

Biomolecules such as RNA,DNA,amino acids etc, arose in a sea of interacting molecules in a  primordial soup. This was followed by compartmentalization to separate out the biomolecules from their environment. This resulted in homeostasis i.e. regulated exchange of matter between systems and surroundings.

According to wikipedia- "In biologyhomeostasis is the state of steady internal physical and chemical conditions maintained by living systems.[1] This dynamic state of equilibrium is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodiumpotassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity."

Why did complexity arise then ? To provide more and more regulation for a system in varying environments. This complexity , arose perhaps through phase transition.

Homeostasis regulation may be compared to an analog knob with different possible states of being.
With a fluctuating environment, this knob has to be regulated and complexity is the hand that regulates the knob by fine-tuning to the environment.

Breakdown of regulated complexity , results in breakdown of homeostasis as in diseases like cancer. In cancer regulated multicellular organization breaks down due to mutations in genes and perturbations in environment. How do mutations  in genes occur ? Probably , mutations occur denovo and get selected for survival. But why so ? Its a mystery. The cancer seems to survive at the expense of the host.
Alternatively, environmental pertubations can cause mutations to occur in DNA resulting in higher risk for cancer.
https://www.pnas.org/content/99/25/15904

Increase in complexity results in highly evolved nervous systems. Probably these nervous systems evolved to regulate homeostasis. After a period of meditation (concentrated focus on a sound or words) I feel at calm and more relaxed. Probably meditation, by concentrating the mind, results in slowing the body metabolism resulting in greater regulation of homeostasis i.e. greater calm , lesser disturbed feelings.
https://www.ncbi.nlm.nih.gov/pubmed/25620166

Post meditation, one tends to observe things and processes through the lens of a calm , non-agitated mind.

Regulation and maintenance of homeostasis seems to me , one of the biggest drivers of evolution.



Homeostasis

Yesterday I heard Dr.  Damasio on the mindscape podcast hosted by Prof. Sean Carroll.
https://www.preposterousuniverse.com/podcast/2019/04/29/episode-44-antonio-damasio-on-feelings-thoughts-and-the-evolution-of-humanity/

 It was a fascinating, insightful conversation.

The observation that "feelings" drive culture was new to me. From experience, I can say that feelings, along with thought do drive my choices.

Affect i.e. emotions and feelings play an important role in shaping societies. The hypothesis drawn  is that , homeostasis is a necessary pre-requisite to maintaining life , and homeostatic mechanisms result in feelings as adaptations to the environment.

Nervous systems could have evolved to regulate homeostasis. This is a strong argument from the evolutionary biology point of view, because the questions being asked today are-what are the environmental selection pressures that drive evolution.

Exchange of substances occur between the living organism and the environment to maintain homeostasis. Regulation of this process resulted in the evolution of nervous systems.

The conversation with Dr. Damasio compels me to read his book-"The Strange Order of Things".

Energy Barrier

Is the directional arrow of time due to an energy barrier ?  Analogy: Uncatalyzed reaction. May be a catalyst-like invention could revers...