Cells Talk and Help One Another via Tiny Tube Networks
quantamagazine.org
quantamagazine.org
Vesicles are like a message in a bottle, thrown out into the "sea" of our atmosphere. Or an email, and viruses are spam. Here, it's like cells create point-to-point communication - like using lasers to send ship-to-ship communications in space science fiction - to upload their vesicle-wrapped RNA messages securely from client to server. Or server to client, as immune cells show:
> How exactly did the engineered stem cells rescue the mouse? First, they differentiated into immune cells called macrophages and traveled to the injured kidney tissues. Once there, the macrophages formed TNTs with injured cells and transferred lysosomes — tiny packages full of healthy enzymes — to the diseased cells, Cherqui explained. The diseased cells also sent their defective lysosomes back to the macrophages through the same channels.
This supports an economic cellular theory wherein not every cell in the body can create all of the molecular structures and components it needs to survive - but each cell can create some components in excess, so cells trade RNA and proteins as they need.
Previously on HN:
Cells Talk in a Language That Looks Like Viruses. [0]
800 million viruses fall onto every square meter of Earth every day. They kill 20% of bacterial life every day. [1]
Video simulation of HIV infecting a cell and reproducing. [2]
[0] https://news.ycombinator.com/item?id=17005810
[1] https://news.ycombinator.com/item?id=16839636
[2] https://news.ycombinator.com/item?id=16982396It's also another example of why I'm in the panspermia camp. I don't think all this crazy shit could evolve in the amount of time that Earth has been hospitable to life. It just feels too complex.
This doesn't explain where the "very first cell" comes from, but I find the theory fascinating anyway. Unfortunately those who share this view are not very vocal about it (who wants to be called a crackpot? :)
To your point, the idea of a monolithic 'I' that represents the ~50 trillion cells in my body is kind of ridiculous, particularly when roughly half of them don't even share my DNA. In that same vein, it has always weirded me out that we don't intuitively know how our bodies work...to the point that I even began thinking of the human consciousness as kind of virus that infected the germ line of primates with this extra meat in the noggin that intercepts the senses and controls the body.
Anyway I just need to learn more about all of this stuff before I put any real stock into my harebrained ideas.
You may wish to compute an estimate of the parallelism available over said amount of time and compare it to the rate of individual contemporary examples of simple evolutionary steps instead of relying on a “feel”ing. :-)
Here’s a summary: https://news.ycombinator.com/item?id=17125348
The Bacteriophage MS2 encodes only 4 genes (4 proteins, in about 4000 basepairs). That puts us down to 1067 orders of magnitude instead of 349236.
Since we know that meteorites carried water and basic prebiotic compounds we can increase the chance that a random functional RNA organism forms.
For very basic life to form, you don't need cell walls luckily. warm A puddle with the right compounds and RNA with self-replicating capabilities is sufficient for this.
Additionally it should be noted that mutation and biogenesis aren't fully random processes. Things get tried and evolved or discarded.
We didn't get to humans by randomly attaching hairy arms to a fish, rather, at some point a fish got better at breathing surface air than the others and obtained a survival advantage from it. And then this random "minor but useful advantage" mutation process continues for every generation since about 4.5 billion years ago. If you took a picture of every child and parent, you will never find a picture where you can clearly call "inbetween here we went from ape to human".
Are you thinking there is only ~1/8.7e349236 viable solutions? There is no reason to expect you need to exhaust even a tiny fraction of the space to get something reasonable.
I’m obviously missing wide swaths of useful information and understanding. But I’ve looked at this for a little bit and haven’t had the epiphany I need for this to click.
The space of possible configurations can be simply huge, but still you can usually find a reasonable (not optimal) one after only a dozen or hundred attempts.
>"single ionization events can kill a cell’s ability to reproduce (or worse)"
Maybe I don't know what you mean by single ionization event, if it is mutating a single basepair then I doubt it.
I think your other point is probably related to sparsity of viable vs. non-viable configurations and the steps needed to get between them. Of course that's complicated by the contextual interdependecies (are you in a mammal's womb or a submerged egg sac) but to your point you don't need to climb mount everest in a single step. Just get from one solution to another and the viable ones will tend to outweigh the less viable.
Appreciate the help reframing it a bit. I'm still thinking it's too complex but at least there's light at the end of the tunnel. :P