Tuesday, May 19, 2015

Prokaryotic Microbes with Eukaryote-like Genes Found

Jack Kruse sent me this link:

Archaea with eukaryotic genes

For those working through Nick Lanes latest book will realise (if you hadn't already!) that there is an energetic cost to everything. The ability to change shape at will, with a view to phagocytosis, is both an essential to the development of the eukaryotes and is energetically very costly.

In the absence of mitochondria the only place this appears to have been discovered is the deep sea alkaline hydrothermal vents, in this case at Loki's Castle. This is the environment where geothermal sources generate the electrochemical disequilibrium which probably got life started using the "free lunch" of CO2/CO plus R-SH giving acetyl-S-R, gateway to metabolism. It is still an energy rich environment.

Phagocytosis is costly.

The alpha proteobacterial precursor of our mitochondria had to get inside the archaeal host. This is an interesting discovery relating to how that might have happened. The phenomenon of archea performing ingestion may well have remained confined to the vents if it was too energetically costly in the open ocean. Unless that archaea was carrying little mitochondrial powerhouses, in which case it was pretty well already eukaryotic. Far from equilibrium environments make for interesting developments.

Looks like you can develop eating only if you already have a free lunch!



raphi said...

Life Ascending (audiobook) was fantastic! Highly recommended. I can't wait to read his new one but have to work through some diabetes & cancer readings-writings first.

If only the diet/medical world had more steeping in the 'how did life evolve' question, I think we'd be far better off.

It'd be nice for docs to start incorporating more evolutionary biology in their thinking rather than ignoring it simply because the paleo social movement is its popular representative.

Jack Kruse said...

Lane's recent book and Jim Al Khalili last book are great reads.