Horizontal gene transfer: active in gut bacteria (Introduction)

by David Turell , Friday, February 04, 2022, 15:40 (813 days ago) @ dhw

QUOTES: "By forming a 'temporary union' with another bacterium in our gut, a microbe can therefore transfer its genes to another – it doesn't even have to be the same species.

"All the microbe has to do is stick out a tube, called a pilus, and attach itself to another cell, shooting off a transferable package of DNA called a mobile genetic element when it's ready."

"The discovery of bacterial sex was made over 70 years ago, when scientists realized this horizontal gene transfer was how microbes were sharing resistance genes for certain antibiotics, thereby spreading antibiotic resistance.”

dhw: Wow! This is a real eye-opener for me, though obviously not for people in the field. I’ve always thought that sexual reproduction was an astonishing leap forward in evolution, but the basic principle was already established by bacteria through horizontal gene transfer! For me, this provides a crucial link in the chain of common descent. Many thanks to David for this “revelation”!

QUOTE: “The horizontal gene exchange among microbes is likely used for anything that increases their ability to survive.”

dhw: Yes indeed, all these steps in life’s history are likely to be motivated by the quest to improve chances of survival.

Yes, organisms must survive long enough for the next stage of evolution to develop.