Natural Selection in action

Evolution Albino turtle

Albino baby turtle (Eretmochelys imbricata) from east Bangkok. Photo via Reuters/Chaiwat Subparasom

We’ve discussed the mechanisms by which species arise, given enough time and environmental circumstances. These mechanisms account for the means by which evolution occurs–in other words: natural selection. Would nature select for or against the albino turtle? How would this selection take place? What can be said about the trait that results in albinism?

Memes as Genes, Genes as Memes: a Strange Loop of Information

"A diagram showing the spread of the "No one should" meme on Facebook. Each node represents a different version, and each edge connects a version to the most likely ancestor variant. Nodes are colored by timing prompt: rest of the day (blue), next 24 hours (red), or other (purple), showing that mutations in the timing prompt are preserved along the branches of the tree. Credit: Lada Adamic."--Via

“A diagram showing the spread of the “No one should” meme on Facebook. Each node represents a different version, and each edge connects a version to the most likely ancestor variant. Nodes are colored by timing prompt: rest of the day (blue), next 24 hours (red), or other (purple), showing that mutations in the timing prompt are preserved along the branches of the tree. Credit: Lada Adamic.”–Via

Consider the following statement: We are human beings, product of emergent mutations and natural selection. We’ve asked & answered questions about the cosmos; using animism, magic, religion, philosophy, and, more recently, science–

we are the universe aware of itself.

The patterns that resemble networks in our brains–galaxies are organized, as long as they are close enough, as networks; neurons are organized in networks; the Internet is one huge network–, are a big part of what makes us human. If we want to get a better grasp on what makes us human, to account for the relationship we have with the current technological context is a good way to start. Thus, nowadays, subjects as neuroscience, information theory, and consciousness research (a very tricky subject), are powerful tools when dealing with questions that have been with us for millennia…

How is humanity dealing with these questions in the 21st Century?

If you thought about heredity and the Internet as possible approaches to these questions, you are correct. Genetics and information theory (via biotechnology and infographics) can be put to use in interesting and interdisciplinary ways. Richard Dawkins–biologist–came up with the idea that cultural units (music, art, words, etc.) behave in ways that resemble genetic variation:

“Dawkins made his own jump from the evolution of genes to the evolution of ideas. For him the starring role belongs to the replicator (a DNA molecule, human consciousness), and it scarcely matters whether replicators were made of nucleic acid. His rule is “All life evolves by the differential survival of replicating entities.” Wherever there is life, there must be replicators. Perhaps on other worlds replicators could arise in a silicon-based chemistry—or in no chemistry at all.

What would it mean for a replicator to exist without chemistry? “I think that a new kind of replicator has recently emerged on this very planet,” Dawkins proclaimed near the end of his first book, The Selfish Gene, in 1976. “It is staring us in the face. It is still in its infancy, still drifting clumsily about in its primeval soup, but already it is achieving evolutionary change at a rate that leaves the old gene panting far behind.” That “soup” is human culture; the vector of transmission is language, and the spawning ground is the brain.

For this bodiless replicator itself, Dawkins proposed a name. He called it the meme, and it became his most memorable invention, far more influential than his selfish genes or his later proselytizing against religiosity. Memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation,” he wrote. They compete with one another for limited resources: brain time or bandwidth. They compete most of all for attention.”

Mutations are a common occurrence in both scenarios: the digital and the organic (for more information on what memes are, you can click here). The following quote, taken from the article Facebook memes can evolve like genesgives us some insight into what parallels are drawn between genes and memes:

“In many ways memes shape the culture and communities through which they move,” said Eytan Adar, an assistant professor in the U-M School of Information and the Department of Electrical Engineering and Computer Science. “The thing we really wanted to understand was how the cultures shaped the memes. This work has implications for understanding how people communicate and influence each other, and let’s us measure people’s beliefs, desires, values, and even what entertains and amuses them.”

Tools like the Yule-Simon distribution were used in this interdisciplinary research. Knowing this, do you think that concepts discussed in class, such as allele, mutation, selection, etc., are applicable to their findings? What examples taken from the article could you give that resemble concepts related to genetics and evolution?*

*If you answer these questions, you’ll be awarded a 5 point bonus in the Genetics exam (Feb 25, 10H; Feb 26, AP Bio).

Charles Darwin explains Natural Selection

Darwin worm

“Caricature of Darwin’s theory in the Punch almanac for 1882, published at the end of 1881 when Charles Darwin had recently published his last book, The Formation of Vegetable Mould Through the Action of Worms.–Via Wikipedia.

After more than 150 years of its publication, Charles Darwin’s The Origin of Species draws a lot of debate. More often than not these debates are unfortunate; many of them should not even exist, especially if we take into account that Darwin cleared many of its nuances in a few passages at the beginning of his now classic book. The following is a short passage that accounts for Darwin’s response to the remarks that were very common in regards to his theory; remarks that are still common today, and show an utter disregard to scientific literacy:

“This preservation of favourable individual differences and variations, and the destruction of those which are injurious, I have called Natural Selection, or the Survival of the Fittest. Variations neither useful nor injurious would not be affected by natural selection, and would be left either a fluctuating element, as perhaps we see in certain polymorphic species, or would ultimately become fixed, owing to the nature of the organisms and the nature of the conditions.

Several writers have misapprehended or objected to the term Natural Selection. Some have even imagined that natural selection induces variability, whereas it implies only the preservation of such variations as arise and are beneficial to the being under its conditions of life. No one objects to agriculturists speaking of the potent effects of man’s selection; and in this case the individual differences given by nature, which man for some object selects, must of first necessity occur. Others have objected that the term selection implies conscious choice in the animals which become modified; and it has even been urged that,as plants have no volition, natural selection is not applicable to them! In the literal sense of the word, no doubt, natural selection is a false term; but whoever objected to chemists speaking of the elective affinities of the various elements?–and yet an acid cannot strictly be said to elect the base with which it in preference combines. It has been said that I speak of natural selection as an active power or Deity; but who objects to an author speaking of the attraction of gravity as as ruling the movements of the planets? Everyone knows what is meant and is implied by such metaphorical expressions; and they are almost necessary for brevity. So again it is difficult to avoid personifying the word Nature, only the aggregate  action and product of many natural laws, and by laws the sequence of events as ascertained by us. With a little familiarity such superficial objections will be forgotten.”–[Pages 94-95 of The Origin of Species by Means of Natural Selection or the Preservation of Favoured Races in the Struggle for Life]