Tal­mu­dic Ques­tion #100

The birth of Charles Dar­win.

Maybe sort of a de­ci­sion of the first cell(s) rather than an event: to stay in con­tact with the "Ur­suppe" and its own sib­lings via mat­ter (genes, phages, plas­mids) and sig­nals (quo­rum sens­ing, sig­nal cas­cades etc.). With­out this, the yin-yang in­ter­play of com­mu­ni­ca­tion and com­pe­ti­tion would prob­a­bly not have led to us, study­ing evo­lu­tion.

ac­tu­ally, say­ing 'first cell' is i think too vague, be­cause it en­cap­su­lates many dis­tinct fan­tas­tic dis­cov­er­ies... in terms of evo­lu­tion it­self, the fact of dis­cretely dif­fer­ent forms (2million++ spp) is what amazes me, be­yond the ba­sic life processes them­selves. one could try to sep­a­rate out some prop­er­ties:
1) the ba­sic ma­chin­ery that al­lows a chem­i­cal process to feed off of en­ergy flow and hold its form (flames and BZ re­ac­tion do this)
2) feed­back loops to search for and main­tain the process in a flow of en­ergy (like sim­ple bac­te­r­ial chemo-taxis) (ac­tu­ally in­volves pos­i­tive feed­back ex­ploratory be­hav­ior (ran­dom in­put) and neg­a­tive feed­back loops to zero in on what is found
3) re­pro­duc­tion (a form of pos­i­tive feed­back so the life processes can con­tinue to seek out new en­vi­ron­ments so a small patch of life doesn't bite the dust in a cat­a­strophic event)
none of these to me so far seems to re­quire dis­crete cells or dis­crete forms... and flames ALMOST do all of these...
4) sporu­la­tion of a spring loaded chem­i­cal mech­a­nism that can hole up un­der ad­verse con­di­tions and re-sprout when new con­di­tions ar­rive. this might have been a stu­pen­dous dis­cov­ery early on that en­abled life to sur­vive the early chaotic earth, and en­abled life to spread com­pletely across the planet?
5) at this point i can imag­ine life as an ho­moge­nous green goo that can cover the planet and does these things, so the next step is the BEGINNING of Dar­win­ian evo­lu­tion: en­cap­su­la­tion of dis­crete her­i­ta­ble forms.
now the ge­netic ap­pa­ra­tus cer­tainly en­abled this and is what has cat­a­pulted life into its 2million++ amaz­ing forms, but i'm not cer­tain whether chem­istry even with­out en­cap­su­lat­ing mem­branes couldn't do this with­out the DNA/RNA/Ribosome thingy (well, cer­tainly the lush rain­for­est of frogs tou­cans cen­tipedes 600,000 bee­tles needs the DNA ap­pa­ra­tus!). It is one of the ar­eas of chemistry/mathematics that i am cur­rently ex­plor­ing: what kinds of chem­i­cal sys­tems can elab­o­rate into dis­crete forms
>>now your ques­tion was event in evo­lu­tion, and none of these processes might have been a prod­uct of Dar­win­ian evo­lu­tion, though a fas­ci­nat­ing ques­tion is how much heredity/selection could have oc­curred in sim­ple non ge­netic chem­i­cal sys­tems, i.e. pro­posed auto-cat­alytic nets even with­out mem­brane bound­aries? but they fit in the broad mean­ing of evo­lu­tion.
6) al­lied with this con­cept then, would be eu­kary­otes' propen­sity to not share so much DNA as do bac­te­ria and en­hance spe­ci­a­tion be­yond what bac­te­ria seem to me to have done.
7) per­haps some of our ram­pant spe­ci­a­tion (500spp of drosophila in the Hawai­ian is­lands? 600,000++ bee­tles?) is due to sex­ual se­lec­tion and al­lied mech­a­nisms of re­pro­duc­tive iso­la­tion.
8) Homo sapiens/rocket ships to re­pro­duce plan­ets

Ge­nomic tools for deal­ing with viruses and other mo­bile el­e­ments, and even bet­ter, for us­ing their DNA as a source of ge­netic vari­a­tion for evo­lu­tion. Or maybe mu­sic ... hard choice 🙂
Glad to see a Tal­mu­dic ques­tion again. Thanks.

The first DNA re­com­bi­na­tion event, whether it be phage me­di­ated or some type of other mo­bile el­e­ment i.e. a trans­po­son.

Elio, I so ad­mire these Tal­mu­dic Ques­tions. We just talked about this in my Mi­cro­bi­ol­ogy course. Even though I urge (well, hec­tor) stu­dents about fol­low­ing STC, I don't be­lieve they do. But I am de­lighted to re­port that the stu­dents' dis­cus­sion of this TQ in class was in­sight­ful and in­ter­est­ing. The de­f­i­n­i­tion of a "cell"—and pos­si­ble alternatives—was par­tic­u­larly fun. I hon­estly think an en­tire sem­i­nar course (or a fun book) could be de­vel­oped from these won­der­ful ques­tions. Thank you as al­ways.