The Standard Genetic Code can Evolve from a Two-Letter GC Code Without Information Loss or Costly Reassignments

It is widely agreed that the standard genetic code must have been preceded by a simpler code that encoded fewer amino acids. How this simpler code could have expanded into the standard genetic code is not well understood because most changes to the code are costly. Taking inspiration from the recently synthesized six-letter code, we propose a novel hypothesis: the initial genetic code consisted of only two letters, G and C, and then expanded the number of available codons via the introduction of an additional pair of letters, A and U. Various lines of evidence, including the relative prebiotic abundance of the earliest assigned amino acids, the balance of their hydrophobicity, and the higher GC content in genome coding regions, indicate that the original two nucleotides were indeed G and C. This process of code expansion probably started with the third base, continued with the second base, and ended up as the standard genetic code when the second pair of letters was introduced into the first base. The proposed process is consistent with the available empirical evidence, and it uniquely avoids the problem of costly code changes by positing instead that the code expanded its capacity via the creation of new codons with extra letters.

 

The Standard Genetic Code can Evolve from a Two-Letter GC Code Without Information Loss or Costly Reassignments

Alejandro Frank, Tom Froese

Origins of Life and Evolution of Biospheres
June 2018, Volume 48, Issue 2, pp 259–272

Source: link.springer.com

Hello World: Being Human in the Age of Algorithms (Hannah Fry)

A look inside the algorithms that are shaping our lives and the dilemmas they bring with them.

If you were accused of a crime, who would you rather decide your sentence―a mathematically consistent algorithm incapable of empathy or a compassionate human judge prone to bias and error? What if you want to buy a driverless car and must choose between one programmed to save as many lives as possible and another that prioritizes the lives of its own passengers? And would you agree to share your family’s full medical history if you were told that it would help researchers find a cure for cancer?

These are just some of the dilemmas that we are beginning to face as we approach the age of the algorithm, when it feels as if the machines reign supreme. Already, these lines of code are telling us what to watch, where to go, whom to date, and even whom to send to jail. But as we rely on algorithms to automate big, important decisions―in crime, justice, healthcare, transportation, and money―they raise questions about what we want our world to look like. What matters most: Helping doctors with diagnosis or preserving privacy? Protecting victims of crime or preventing innocent people being falsely accused?

Hello World takes us on a tour through the good, the bad, and the downright ugly of the algorithms that surround us on a daily basis. Mathematician Hannah Fry reveals their inner workings, showing us how algorithms are written and implemented, and demonstrates the ways in which human bias can literally be written into the code. By weaving in relatable, real world stories with accessible explanations of the underlying mathematics that power algorithms, Hello World helps us to determine their power, expose their limitations, and examine whether they really are improvement on the human systems they replace.

Source: www.amazon.com

Stepping Stones to Synthetic Biology (Sergio Carrà)

This book explores fascinating topics at the edge of life, guiding the reader all the way from the relation of life processes to the second law of thermodynamics and the abundance of complex organic compounds in the universe through to the latest advances in synthetic biology and metabolic engineering. The background to the book is the extraordinary scientific adventures that are being undertaken as progress is made toward the creation of an artificial cell and the control of life processes. This journey involves input from research areas as diverse as genetic engineering, physical chemistry, and information theory. Life is to be thought of not only as a chemical event but also as an information process, with the genome a repository of information gathered over time through evolution. Knowledge of the mechanisms affecting the increase in complexity associated with evolutionary paths is improving, and there appear to be analogies with the evolution of the technologies promoting the development of our society. The book will be of wide interest to students at all levels and to others with an interest in the subject.

Source: www.amazon.com

How History Gets Things Wrong: The Neuroscience of our Addiction to Stories ( Alex Rosenberg)

To understand something, you need to know its history. Right? Wrong, says Alex Rosenberg in How History Gets Things Wrong. Feeling especially well-informed after reading a book of popular history on the best-seller list? Don’t. Narrative history is always, always wrong. It not just incomplete or inaccurate but deeply wrong, as wrong as Ptolemaic astronomy. We no longer believe that the earth is the center of the universe. Why do we still believe in historical narrative? Our attachment to history as a vehicle for understanding has a long Darwinian pedigree and a genetic basis. Our love of stories is hard-wired. Neuroscience reveals that human evolution shaped a tool useful for survival into a defective theory of human nature.

Stories historians tell, Rosenberg continues, are not only wrong but harmful. Israel and Palestine, for example, have dueling narratives of dispossession that prevent one side from compromising with the other. Henry Kissinger applied lessons drawn from the Congress of Vienna to American foreign policy with disastrous results. Human evolution improved primate mind reading―the ability to anticipate the behavior of others, whether predators, prey, or cooperators―to get us to the top of the African food chain. Now, however, this hard-wired capacity makes us think we can understand history―what the Kaiser was thinking in 1914, why Hitler declared war on the United States―by uncovering the narratives of what happened and why. In fact, Rosenberg argues, we will only understand history if we don’t make it into a story.

Source: www.amazon.com

The Formula: The Universal Laws of Success: Albert-László Barabási

Too often, accomplishment does not equate to success. We did the work but didn’t get the promotion; we played hard but weren’t recognized; we had the idea but didn’t get the credit. We’ve always been told that talent and a strong work ethic are the key to getting ahead, but in today’s world these efforts rarely translate into tangible results. Recognizing this disconnect, Laszlo Barabasi, one of the world’s leading experts on the science of networks, uncovers what success really is: a collective phenomenon based on the thoughts and praise of those around you.

In The Formula, Barabasi highlights the vital important of community respect and appreciation when connecting performance to recognition–the elusive link between performance and success. By leveraging the power of big data and historic case studies, Barabasi reveals the unspoken rules behind who truly gets ahead and why, and outlines the twelve laws that govern this phenomenon and how we can use them to our own advantage.

Unveiling the scientific principles that drive success, this trailblazing book offers a new understanding of the very foundation of how people excel in today’s society.

 

The Formula: The Universal Laws of Success
by Albert-László Barabási

November 6, 2018

Source: www.amazon.com