Tuesday, June 28, 2005

Green little men?

In many science fiction movies and books the aliens and the men of the far future are always depicted the same way: short, slim, green or blue -often pale-skin, bald and with big head and eyes.
This image is in fact the extension of the "evolution" process that separates us from the other primates: we are slimmer than the gorillas, we have less hair and our head -brain- is supposedly more developed, thus the man of the future should follow the same path, or not?
The big question here is, are we still under selection? Are we still evolving genetically?
The answer is no.
Selection means that different phenotypes have more probability of leaving descendants than others. This process leads to stronger lions, faster cheetas, smarter monkeys but it does nothing to human beings because our society-our mind child- was projected to erase all the effects of selection and the laws in mot modern countries states clearly that every man is equal.
The truth is that in our society, being bigger, faster or stronger makes no difference since the "fitness" and status are defined by the capacity of acumulating money.
Does this should mean that the man of the future will be a yuppie?
The answer is no.
Even the wealthiest men on earth have in average 2-3 children, some only one. Most middle-class families in rich countries in Europe and USA are composed only by the husband and wife, they have no kids (double income no kids: dinks) what is a lot less compared to the families in poor and miserable countries where the number of children can't be counted on the fingers of the two hands.
This process will indeed lead to a future where most of the humans will be decendants of the poor people of the countries under development today and since poverty is not a genetic trait but a historical condition, mankind shall remain the same yet for a long time.

Sunday, June 12, 2005

Shakespeare Monkeys

Once I read in a book about theoretical computer science that if we had a room of infinte size with an infinite number of chairs and in front of them an infinite number of typewriters it would be enough to put an infinite number of monkeys in front of them and after some time (maybe an infinite amount of time that could be shortened by increasing the quantity of monkeys or by replacing the type writers by voice activate system adapted to monkey cries) they would end up by writing Shakespeare complete collection of books.

The other day I heard a colleague say that if we had no computing power limitations we could solve most of the genetics problems we have nowadays (philogenetic analysis, protein 3D structure prediction,etc.). This comment really reminded me of the monkeys playing with type writers and made me wonder that if we really had an infinite computational power we wouldn't even need to care about creating smart algorithms since we would just need to test all the possible solutions in a very simple program, everything would be reduced to brute-force search.

To conclude, the main reason for writing this text: the more I study genetics and gene regulatory systems the bigger my impression that evolution has a lot to do with monkeys and typewriters, however since we didn't dispose on an infinite amount of time (neither of monkeys and type writers) we are far from William's elegance. A close look into our cells would show a great crowd of molecules shouting orders to one another in an environment that would remind Wall Street's NYSE in a hot market day.

I wonder how we are still here and how far the evolution will take us based on this principle of mutation/ natural selection / genetic drift. Even more, I wonder how could this text come out of an entity organized in such a chaotic way, maybe what we believe is rational thinking is nothing but the sound of monkeys typing endlessly...

Thursday, June 09, 2005

On ageing and on death

Ageing and death due to ageing is a characteristic that is not mandatory in all life forms. In fact bacteria and other living entities who reproduce symmetrically do not age since the "mother" entity splits into two twin entities that can't be identified as the mother and the child. This means that these basic life forms must ensure they do not age and thus once they duplicate they are as viable as they were when they were born from a previous duplication.
Mammals and other higher forms that developed the capacity of creating multi-cellular organisms do age and this is not a problem since the degradation affects only the mother, the children are born with their "age counter" at zero.

The interesting points here is why do we have to die and what would happen if we didn't.

We must die because pluricellular organisms are immune to mutation and thus to natural selection, only our species can evolve but the individuals do not. Unlike unicellular organisms, mutations on higher organisms will happen only in one cell, one tiny piece of ourselves and this mutation will not propagate to the rest of the being. This means that once we are born our species has bet on us and counts on us to have as many descendents as possible, prove the fitness of our genes and then die, leaving behing our progeny to continue the evolution/selection process.

If you consider two species of mammals, one living indefinitely and the other with a limited life span (probably fine-tuned by natural selection) a computer simulation will show that the limited-life span species will have a faster response to evolution and thus will more quickly adapt to changes in environment as well as double cross the other species in competition.
The other species, the one with immortal individuals will face two problems: the first is that since the elders do not die and they have more experience/resources than the youngsters they will keep the monopoly of the habitat's resourses and will kill the youngsters by hunger. The second point is that their presence will delay the evolution of the species since archaic genomes will continue to mix with newer ones generated by mutation and meiosis crossing.

In the next article we'll talk about why this process created by natural selection is useless in human beings and we'll also trace a link between cancer, development and ageing.

Saturday, June 04, 2005

In the beginning...

My first contact with genetics came when a friend of mine lent me Nobel winner's James Watson book "The Double Helix" and I finally learned how a 22 year old guy and his colleague Francis Crick established the basis of what we now know of DNA.

My second contact with genetics was thorugh the book "Molecular Biology of the Cell" that's a great compendium of what we now understand and suppose about the cellular functioning. I first got puzzled to see a book with more than 1000 pages dedicated only to the cell's itnernals but after I started reading it I realized I was entering a totally new world I had never conceived before.

Many say the 21st century will be the beginning of the genetic revlution, that many diseases will be cured and people will live a lot longer and better, however even though we have better technology and more money for investigation than ever before, the advances of biotechnology is threatened by a new Dark Age of inquisition and ignorance.

This is the Brave New World we live in and I intend to do my part to make the difference. If you also believe you're here to do something and leave your marks on this planet then you're more than welcome.

Best regards,