Monday, September 24, 2007

Why our cells are unlikely to evolve

Bacteria evolve right before our eyes. Hospital acquired diseases are a very good example. Overexpose bacteria to some antibiotic, toxins, metals etc...they will change in a matter of days, adapting to their new environment. Unicellular organisms have absolute freedom to change because their own evolution, as individuals, can only benefit the population. If they fail to adapt, some individuals will be eliminated BUT those who are successful will become the ancestors of a resistant colony.

Why is it that this principle can not be applied to our own cells? Simply put, because the fate of our own cells is interconnected, a small change in the genome could mean disaster for the other ones. The reason why our own cells do not evolve in our lifetime (under normal circumstances) is discussed in an article by Pepper et al., soon to be published in PLoS computational biology. An article on the Nature website (september 21, 2007)explain why evolution within our own cells is unlikely and not desirable. Our tissues simply DO NOT evolve!

It is known that epithelial tissues have a rather high turnover...old cells are replaced on a constant basis. The speed at which they grow could suggest that these cells are more prone to mutations. This is not the case. As Philip Ball explains in its news feature (Nature): "Why a person doesn't evolve in one lifetime" epithelial cells take a long walk on the way to differentiation. Epithelial stem cells divide just a little before they commit to their final state. Mutations can occur within these cells but since they do not compete against each other because these mutations make differentiation of these stem cells more difficult.

On the other hand, the immune system is made to evolve, it has to adapt to new pathogens every single day but there is a price we pay for this: a higher incidence for cancer!

This blog post has also been posted on my other blog site:

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Thursday, September 20, 2007

Nomenclature or moneyclature ?

By tradition, the person who discovers something new is free to name it whatever he/she's one of the perks of being a scientist. Sometimes it can be quite funny. Take for example the protein "Sonic hedgehog", named after a popular video game (Sonic the Hedgehog by Sega). Another interesting example...three round fungus beetles, Agathidium bushi, Agathidium cheneyi and Agathidium rumsfeldi and were named by entomologists Quentin Wheeler and Kelly Miller in honor of President Bush, Dick Cheney and Donald Rumsfeld. Personnaly I could have come up with better names...but it's their right...they found those beetles they get to name them! By the way, they got a call from George W. for this.... (!)

A better example right here on Vancouver Island. Malaspinanema goateri, Cordonical gibsoni and Hammerschidtiella hochi are all parasites living in the gut of cockroaches and were named by Aaron Jex in honor of his Malaspina professors: Tim Goater, Allan Gibson and Matthew Hoch...cute story! Unfortunately, there is a way of naming new species that disturbs auctioning.

Last saturday I was sitting in my kitchen, with my morning coffee and the Vancouver sun (this is where I got the idea for this blog post). It struck really can buy anything! On Thursday, September 20th in Monaco there will be an auction, The Blue Auction, and the highest bidders will be naming new species such as this one (opening bid: $400,000) and this one (opening bid $100,000). Honestly, I do not agree with that. I think science is about passion, about dedication and about patience. Science is not about pride and narcissic's about finding the truth. Buying a name for a new species has, to my humble opinion, more to do with marketing. What if Coca-Cola, Apple or Volkswagen buys the name? Is that impossible? Not at all....The Golden Palace Casino (online gambling) bought the rights ($650,000) to name a new primate: Callicebus aureipalatii (Golden Palace in latin)'s now some kind of mascot and total disrespect for nature! They even called it the "Golden Palace monkey..."

Please bring back science to the people and the scientists who share a real concern about the species they discover and education....Frankly, I do not care about the silly names...they make a nice story...

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