Life Hacked Time
There is Darwinian theory of organisms’ evolution, which tells us story about rare radical mutations (evolutionary jumps) and gradual (or continuous) mutations “improving” organisms. And ruthless selection decides whether some mutation is advantageous for species or not. But nowadays scientists have become aware of extremely complex molecular machines running living cells, and some of such machines are of “irreducible complexity”, meaning they are comprised of various parts, and without any part such machine has no use. That casted a shadow on Darwinian-like explanation on such machines being built gradually in evolution. Alternative theory called “Intelligent Design” arose, stating that cells and other life creatures “somehow” target certain functionalities as their evolutionary goals and “somehow” can see over dysfunctional gap from no functionality to functionality, so that functionality is achieved. They get the machine blueprint “somehow”. Such features/machines are recorded in DNA once they are built, and to appear as result of random DNA mutations, it will require, for example for ribosome creation, 10⁷⁴ mutations in DNA, and that is a big number: “bigger than number of atoms in Universe, and it would take more time than Earth has existed, or even more than 14B years from Big Bang”.
By now we know that there was no Big Bang, and there should be no reasonable way of counting atoms in Universe, but we can do better than that — we’ll show that life figured out a way to produce unimaginable number of mutations in a reasonable time. Let’s start far away from a test I got during one financial job interview:
Having $10K and 1 hour, find a person who gets all heads in row on 10 tosses of a coin. Result should be reproducible: within another hour and with $10K you should find another person getting all heads in row on 10 tosses.
There are two known solutions at least, one uses group of 10,000 people, but that is an unreasonable number of people to gather in one hour. Another solution, which is reasonable, starts with collecting a group of 1000 people. Game plan: each person is asked to toss a coin, and if he/she gets tails — then he/she leaves the group, but does not go away; and if he/she gets heads — then he/she tosses coin again … and so on, up to 10 attempts. Person is paid $1 for each coin he/she tosses. Let’s see what happens in average:
1) 1000 tosses, ~500 heads — stay, ~500 tails — leave
2) 500 tosses, ~250 heads — stay, ~250 tails — leave
3) …
9) 4 tosses, ~ 2 heads — stay, ~2 tails — leave
10) 2 tosses, ~ 1 heads!
Total number of tosses ~ 1000+500+250+…+4+2 = ~2000 when results are evenly distributed between heads and tails. But at steps 9 and 10, when number of tosses is small, results could be distributed very unevenly. Probability of failing the game (at step 10 all tails) is ~1/4. Cost of the whole (1–10) game is ~$2K. Having $10K, we can run such game 5 times. Because of these 5 rounds we asked all losers not to go away — to participate in next rounds. Probability of failing all 5 rounds is
~ 1/4 * 1/4 * 1/4 * 1/4 * 1/4 = 1/2¹⁰ = 0.001
Meaning, we will win a round with 1–0.001 = 99.9% probability. Thus, we will have at least one winner with the probability of 99.9%.
If think back, this problem was about time actually — we have to find our winner in one hour. If we go with ~10,000 players, we will fail to gather them in one hour. If we go with one person tossing a coin ~10,000 times and waiting when 10 heads happen in row, we will fail again, as it is improbable for a person to make even 1,000 tosses in an hour (with checking results). So, we used a reasonable size group of 1000 players and translated 1-hour game into ~1000 hours of players’ combined time. We hacked the time — we “made the time”.
Life has figured out that mechanism long time ago — by cell division (replication). At a single person lifetime, a bacterium that divides once in a few days, will divide 2¹⁰ ⁰⁰⁰ times (10,000 power comes from number of days). It is approximately 1000¹⁰⁰⁰ — a number difficult for us to comprehend (we know 1000⁴ as a trillion). But there should be enough food and space for a big population of this bacteria family. And ruthless and relentless selection shoots this number down as well. But anyway, such bacterium converts a time period we get used to into unimaginably big combined time, and probability of mutation 1 of 10⁷⁴ does not sound improbable compared to 1000¹⁰⁰⁰. In the nutshell,
Darwinian life = solving problems, even without identifying them. Compared to Intelligent Design life = identifying problems and solving them.
Last one definitely comes from human speculation and sounds like definition of intelligence.
Lifehack that we described, works for cellular organisms (replicating often). But even for complicated organisms, like us, 99.99% of problems were solved at the time when single cell organisms evolved, and solutions were inherited and scaled up in multicellular species. Check please https://www.youtube.com/watch?v=3Cu-g4LgnWs&t=781s — is it giraffe or just a cell?
We — people still solve many problems even not noticing them and not identifying them as problems — most of them were solved and solutions are wired in us through our ancestors, a long time ago. Some really new problems that we come across and solve do not require 10⁷⁴ mutations. But if we decide to grow wings, then mutations will kill us probably. Rarer than rare scenarios and environments described in chapter 5 aftermath — perhaps life appeared then and there, but evolved/adjusted on Earth.
Or … Let’s explore the possibility of ribosome creation on Earth. Did we make a mistake in assuming that the possibility of ribosome random creation is 1 of 10⁷⁴? Let’s take into account the Survivorship bias — a good example of how probability of event could be dramatically misinterpreted, though it seems right for an observer of the result. Although the probability of getting a particular ribosome, which we observe now, is 1 of 10⁷⁴, let’s change our perspective to the functional:
“Ribosomes are macromolecular machines, found within all cells, that perform biological protein synthesis.”
And if we ask
“Is the probability of creating a molecular machine that perform biological protein synthesis 1 of 10⁷⁴?”
and if we consider that we know at least two very different ribosomes in prokaryotic and eukaryotic cells, then we understand that variety of such machines should be great, but very few have survived the selection. And if there could be, let’s say, 10⁴⁰ variations of protein-synthesizing machines, where some of them are very efficient and some of them are inefficient, then the probability of such machine creation is more like 10⁴⁰ of 10⁷⁴, that is 1 of 10³⁴, and that number can be supported by enough nucleotides on Earth for replications and mutations, considering that this process was distributed in millions or billions of years (that is ~10¹⁰ days or something like that). And if you remember from school Avogadro number, that is 6×10²³ molecules in 22.4 liters of ideal gas, then with life probability we are getting to very realistic numbers.
If you have not read WHAT HAPPENED 65 MILLION YEARS AGO? — check it out.
P.S. Check recent research on proto-ribosome - maybe ribosome complexity is reducible and it has evolved after all.
