Anand CV Mallaya

Science and rebirth?

In math, science, spirituality on November 30, 2012 at 2:32 pm

I was little worried that I am becoming a pseudo-scientist  This feeling of guilt was burning inside my mind for sometime and wanted to do really scientific approaches in problem solving.

On the cold morning today, I had this interesting thought on rebirth. Normally I will delve in to thoughts for a few hours and then it will remain as a common religious belief. So this time I wanted to do an exercise on this to improve my scientific problem solving skills.

The problem:

Is rebirth scientifically possible?


Let us look at definition of rebirth here. Rebirth is defined here as having the same appearance of a person died before.

Now science tells us that the characteristics of body of a person is defined by mostly the genes. But this is not the only thing that shapes a body. It depends on the environment the person lives. This include the food, the climate etc. To simplify we will define a person as a set of genes. So rebirth in this context is having exactly the same sets of genes that of a previously dead person.


The number of variation or mutation in genes  are vary small. That is if we consider genes as a set of playing cards, the deck of cards are  unchanged. Each individual gets a shuffled set of cards.


This problem can be done only statistically. Let us start some number crunching

Total initial population, P0 = 10000
(Note: there is a hypothesis that entire population today are coming from a small population which survived a global catastrophe in Africa)
Reference : The Human Journey: Migration Routes (

Total genes per person, Gi = ~20600

Maximum genetic difference in the population (assuming all genes of the population are different) Gp=  Gi*P0 = 206,000,000

Total population ever lived till date Pt = 108,000,000,000

Assuming the variation in the gene pool through mutation is negligible over time, total possible unique individuals = Pt/Gp = ~524

So if there is no gene variations happening  there must have existed around 524 exact copies of every individual.

Now if we consider the rate of mutation in human genome in to consideration,
Rate of mutation = ~1.1×10^−8 to  3 × 10^−8 per site per generation

Reference :
1. Analysis of Genetic Inheritance in a Family Quartet by Whole-Genome Sequencing (

2. Page on ( , Estimate of the Mutation Rate per Nucleotide in Humans (
3. Mutation rate (

Avg. Max rate of mutation Ra= 2.6 X 10^-8

Tootal nucleotides in human genome N =  2,846,445,372

Time of origin of population = 70000 BC
Total years since the beginning of population = ~72000

Total number of generations since the initial population(assuming 25 year for a generation) K = 72000/25 = 2880

Total mutations occurred Mp = Ra*N*K = 213142

Total different unique genes now Gpm= Gp+Mp= 43907216867804

total possible unique individuals = Pt/Gpm = 0.0024

So if we consider mutations, there is no single of rebirth occurred.

Correct me if I am wrong 🙂

  1. Try metaphysics perhaps? 🙂

  2. An interesting approach. But perhaps you might ask why the question of rebirth even makes sense to ponder. It seems a fairly improbable notion. Without a good reason to suspect it, I don’t think the question is really worthy of analysis (based on Occam’s razor).

    However, I do see that you are really looking at the idea of genetic variability. Perhaps you should consider it a question of ‘twinning’ rather than rebirth (which makes the question seem more spiritual than I think you mean it to be).

    A very cool, thought.

    • Jack,
      Thanks for stopping by and giving your comment.
      Rebirth is a catchy word, which will be interesting to the average reader. For a more advanced reader, I have kept a better definition which is simplify the process in to minimum criteria for two individuals to have the possibility to become identical.

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