Alan Turing is considered by many to be the father of computer science. In his 1936 paper on computable numbers he wrote that – It is possible to invent a single machine which can be used to compute any computable sequence. Back then many would not have believed in that statement. But today around 1.4 billion people on the planet have a computable machine (smart phone) in their pocket.
Using the statement made by Alan Turing, I created a text file called generation1.txt. Then I wrote a script in Python which will randomly pick an alphabet from generation1.txt and replace it with another random alphabet and stored the result in a new file called generation2.txt. Both these files differs by a single alphabet as shown below.
On the next run the script picked up a random alphabet from the file generation2.txt and replaced it with another random alphabet and stored the result in a new file called generation3.txt. The files generation1.txt and generation3.txt differs by two characters as shown below.
I automated the script to do this for 100 generations. The difference between generation1 and other higher generations are shown below.
Why am I talking about a Python program in a post related to evolution? The example that I gave above is an analogy for understanding evolution. As the author of this excellent post tells that analogies are fuzzy, not 100% accurate, and yet astoundingly useful. They’re a raft to get across the river, and leave behind once you’ve crossed. Spend sometime to go through the similarities between the python program and evolution.
I tried explaining the concept of evolution to some of my friends and relatives. But many don’t understand. They advised me to stop reading fiction books. I always wondered why they find evolution very hard to understand. After some thinking I was able to come up with the reasons which are given below.
(1) Take a look at the pictures given below. The one on the left hand side was taken when I was 3 years old. And the one on the right hand side was taken when I was 38 years old. The difference between the two is like night and day. These changes happened very slowly over 35 years by tweaking proteins one gene at a time. And in spite of me watching the mirror everyday, I never noticed this change on a day-to-day basis. Why is that? This is because human brain and senses works on a contrast scale and not on an absolute scale. This was demonstrated by a psychologist named Cialdini by using three buckets of water.
Each student takes a turn sitting in front of three pails of water – one cold, one at room temperature and one hot. After placing one hand in the cold water and one in the hot water, the student is told to place both in the lukewarm water simultaneously. The look of amused bewilderment that immediately registers tells the story: Even though both hands are in the same bucket, the hand that has been in the cold water feels as if it is now in hot water, while the hand that was in hot water feels as if is is now in cold water. – Influence; Cialdini
(2) Time is an abstract concept. We humans understand time by relating it with something we already know. Take for instance the SI unit of time, which is second. What does one second mean? One second is the interval of time taken to complete 9,192,631,770 oscillations of the cesium 133 atom. We are generally good in understanding time if the duration is short. For instance when someone tells me 100 years, I equate it to how long human beings can possible live. What about 200 years back? From the year 2015 I go back to the year 1815 and I know that Charles Darwin was born around that time. What about 10,000 years back? I roughly know that’s when humans invented agriculture. Beyond that my time sense fades away. Why bother about 10,000 years when people don’t know how to hold securities for more than few days?
The way I see it, day traders considered themselves successful if they bought a stock at $10 and sold at $11, bought it back the next week at $24 and sold at $25, and bought it a week later at $39 and sold at $40. If you can’t see the flaw in this — that the trader made $3 in a stock that appreciated by $30 — you probably shouldn’t read the rest of this book. – Howard Marks
(3) We are very good in understanding linear systems. For example two stones feel twice as heavy as one stone. And it takes three times as much food to feed three times as many people. But in our world not everything follows linear pattern. This concept is beautifully explained by the neuroscientist V.S.Ramachandran.
Imagine you have block of ice in front of you and you are gradually warming it up: 20 degrees Fahrenheit… 21 degrees… 22 degrees… Most of the time, heating the ice up by one more degree doesn’t have any interesting effect: all you have that you didn’t have a minute ago is a slightly warmer block of ice. But then you come to 32 degrees Fahrenheit. As soon as you reach this critical temperature , you see an abrupt, dramatic change… Nature is full of phase transitions. Frozen water to liquid water is one. Liquid water to gaseous water (steam) is another. But they are not confined to chemistry examples. They can occur in social systems, for example, where millions of individual decisions or attitudes can interact to rapidly shift the entire system into a new balance. Phase transitions are afoot during speculative bubbles, stock market crashes, and spontaneous traffic jams. On a more positive note, they were on display in the breakup of the Soviet Bloc and the exponential rise of the Internet. – The Tell-Tale Brain
Evolution happened very slowly over billions of years. And evolution is not a linear system but a complex system where the whole is greater than the sum of its parts. It has all three properties discussed above which inhibit many us of from understanding it. What do we do when we don’t understand something? In order to avoid cognitive dissonance we promptly shun the idea. In the paragraph given below, Ramachandran succinctly summarizes the algorithm of evolution.
I would even suggest that phase transitions may apply to human origins. Over the millions of years that led up to Homo sapiens, natural selection continued to tinker with the brains of our ancestors in the normal evolutionary fashion— which is to say, gradual and piecemeal: a dime-sized expansion of the cortex here, a 5 percent thickening of the fiber tract connecting two structures there, and so on for countless generations. With each new generation, the results of these slight neural improvements were apes who were slightly better at various things: slightly defter at wielding sticks and stones; slightly cleverer at social scheming, wheeling and dealing; slightly more foresightful about the behaviors of game or the portents of weather and season; slightly better at remembering the distant past and seeing connections to the present. Then sometime about a hundred and fifty thousand years ago there was an explosive development of certain key brain structures and functions whose fortuitous combinations resulted in the mental abilities that make us special in the sense that I am arguing for. We went through a mental phase transition. All the same old parts were there, but they started working together in new ways that were far more than the sum of their parts. This transition brought us things like full-fledged human language, artistic and religious sensibilities, and consciousness and self-awareness.– The Tell-Tale Brain