Hi, Vladimir.
Vladimir writes:
I believe that an abiotic synthesis of proteins, and properties of proteins are studied well enough. If the spontaneous formation of the pump would be possible in principle, it has already happened.
This is a very bold claim, Vladimir. There is just too much we don't know.
Consider the scale. How many experiments have attempted to spontaneously produce proteins under hypothetical prebiotic conditions? Hundreds, maybe? Well, how many "experiments" might have been conducted by Mother Nature on the prebiotic Earth before She succeeded in producing a viable protein? Possibly trillions. It's like rolling the dice 10 times and concluding that '3' is impossible because we haven't seen one yet.
Consider the other options. The pump doesn't necessarily have to suddenly emerge, fully intact: it may begin as a simple protein that bonds to an ion, or a simple protein that intercalates into a membrane, and gradually gains the other functions of a sodium pump via later innovations. This is why RAZD and I proposed protocells that could survive without a sodium pump: because if they could survive without it, then it could have evolved gradually later, and wouldn't have to appear suddenly, spontaneously, fully intact.
These are very real possibilities that you are just dismissing because we believe "proteins are understood well enough." That seems very narrow-minded to me.
Vladimir Matveev writes:
Why the microspheres are able to generate an action potential without fully functional membrane, that is the question.
The microspheres can generate an action potential without a membrane?
Vladimir Matveev writes:
Blue Jay writes:
RAZD proposed that a protocell might simply tolerate changes in turgor and ion gradients, until it evolved a mechanism to regulate ion flux. Do you think this tolerant "spore" state is impossible?
Ion gradients are impossible without pumps
That's not strictly true. Ion concentrations can change in the environment for various reasons, and those changes inevitably create temporary ion gradients. Imagine a protocell (lacking an ion pump) in a pond where the salinity changes. That protocell would need one of two things:
- A mechanism to preserve its internal chemistry against changes in the salinity of the outside environment
- An ability to simply tolerate the change in its internal chemistry as the environment changes.
Is there any evidence that a protocell without an ion pump would perish?
If not, it seems that there is still a perfectly valid and reasonable hypothesis for the evolution of ion pumps in protocells that originally lacked them.
Vladimir Matveev writes:
The ability of proteins to spontaneous synthesis is proved by experiments. But with the pumps we have a problem: we are waiting for their second coming.
This just seems like a restatement of the "tornado in a junkyard making an airplane" argument. I think you're being too quick to dismiss the possibilities based on far too little evidence.
Vladimir Matveev writes:
I go to sleep.
Have a good night! It's lunchtime for me!
-Blue Jay, Ph.D.*
*Yeah, it's real
Darwin loves you.