Daily Archives: June 3, 2017

1 : one of a set of prescribed movements

2a : a process of change in a certain direction : unfoldingb : the action or an instance of forming and giving something off : emissionc (1) : a process of continuous change from a lower, simpler, or worse to a higher, more complex, or better state : growth (2) : a process of gradual and relatively peaceful social, political, and economic advanced : something evolved

3 : the process of working out or developing

4a : descent with modification from preexisting species : cumulative inherited change in a population of organisms through time leading to the appearance of new forms : the process by which new species or populations of living things develop from preexisting forms through successive generations Evolution is a process of continuous branching and diversification from common trunks. This pattern of irreversible separation gives life's history its basic directionality. Stephen Jay Gould; also : the scientific theory explaining the appearance of new species and varieties through the action of various biological mechanisms (such as natural selection, genetic mutation or drift, and hybridization) Since 1950, developments in molecular biology have had a growing influence on the theory of evolution. Nature In Darwinian evolution, the basic mechanism is genetic mutation, followed by selection of the organisms most likely to survive. Pamela Weintraubb : the historical development of a biological group (such as a race or species) : phylogeny

5 : the extraction of a mathematical root

6 : a process in which the whole universe is a progression of interrelated phenomena

Visit link:

Evolution | Definition of Evolution by Merriam-Webster

Our May Insights puzzle was inspired by recent discoveries of some rare, intriguing patterns of inheritance that hark back to Jean-Baptiste Lamarcks theory of evolution and its emphasis on the inheritance of acquired characteristics. Elementary textbooks often present Lamarcks theory as a failed 19th-century rival to Charles Darwins theory of evolution by natural selection. But reality, as usual, is far more complicated. There is indeed a great deal of evidence that most acquired characteristics are not inherited, but as the new findings have shown, this proscription is not absolute. The famous verkalix study, for example, showed that men who were exposed to a poor food supply between the ages of 9 and 12 were found, two generations later, to have conferred a measurably lower risk of diabetes and cardiovascular death to their grandchildren. Adaptive Lamarckian inheritance does seem to be possible, and epigenetic mechanisms for it have been found. These mechanisms modify DNA in ways that differ from those of heredity.

But at a deeper level this kind of inheritance can be naturally selected for in the traditional Darwinian way, provided certain environmental conditions are satisfied. So Darwinian natural selection remains the fundamental basis of evolution and can produce Lamarckian inheritance: The theories are not rivals after all! Using simple models, our puzzles show how natural selection can sustain Lamarckian inheritance. The requirement is that environmental conditions, such as famines, follow patterns that persist across several generations and are repeated over long stretches of evolutionary time.

Imagine there exists an animal that has a new generation every year. Every normal individual has an average of 1.6 surviving offspring in a normal year, which can be defined as the animals fitness (lets call itf), after which the animal dies. During a famine year,ffalls to 1.3.Now suppose there are a bunch of smaller individuals whosefvalues are 1.5 in normal years but 1.35 in famine years: Their smaller food requirement helps them survive famines better. How long would a famine have to last for the small individuals to do better than normal ones? How many famine years before small individuals make up 90 percent of the population?

The basic mathematics of natural selection is simple. For every group, you just multiply the fitness numbers across multiple generations. You then find the ratio between the numbers you obtain for the different groups. This gives you their relative populations, assuming that the initial numbers were the same. (Note that these numbers dont signify the actual populations of each group, but they indicate their relative success. If f is larger than 1, then the product may grow extremely large after many generations. In the real world, there are many checks on the population of a species, so at equilibrium, the population is actually stable. What does change are the relative ratios between the populations of the different groups, which are accurately reflected in the above calculation.)

For Question 1, assuming we start from a normal year, we have to find a positive integer n such that 1.5 x 1.35n > 1.6 x 1.3n. You can do this analytically using logarithms or by setting up a spreadsheet and reading off the values. After two years of famine, the smaller individuals already have a population over 50 percent. (If you want to bookend the famine with normal years on either side, then it requires four years of famine for the small individuals to be ahead of the normal ones a year after the famine is over.)

As Ty Rex noted, for smalls to make up more than 90 percent of the population, the number of famine years needs to be greater than [log(9) + log(1.6/1.5)]/log(1.35/1.3) ~ 59.9. So, 60 famine years are needed for smalls to make up 90 percent of the population.

Suppose there exists an initially normal mutant group of individuals called Epi2s, whose germ cells are affected by a year of famine in such a way that their progeny changes to the small type for two generations before they revert back to normal in the third generation, through epigenetic mechanisms. Consider a 13-year period that starts and ends with normal years but has a one-year famine, two two-year famines and a three-year famine in between. Which of the three groups (normals, smalls, Epi2s) will be most successful? Are there famine patterns in which Epi2s overwhelm the other two groups over the very long term?

As a couple of commenters noted, there is an ambiguity here: What happens when Epi2s that have changed to the small type encounter a year of famine? Is their status reset and do they continue to be smalls for another two years, or do they continue on their original timetable and revert to normals two years after the original famine year? Most commenters assumed the former. I had the latter in mind, because otherwise the Epi2s behave very much like smalls in extended famines. In any case, the choice of the assumption does not change the answer to this question. As Ty Rex noted, if we start with equal populations, the ratios between the normals, smalls and Epi2s become 85.5 to 83.8 to 86.1, assuming Epi2s reset, so the Epi2s do best by a small margin. If there are no resets, then Epi2s do even better, their relative ratio going up to 87.4. With no resets, Epi2s are adapted to famines that are three years long, so the pattern NFFFNFFF gives them an even larger advantage over the other two groups. With this pattern, Epi2s will make up 90 percent of an initially evenly divided population in 329 years.

Lets add another type of animal to the above: the Epi1s, which like the Epi2s switch to small progeny after a famine, but in this case the progeny revert back to normal after just one generation. Over a period of 20 years, can you come up with a famine-year schedule such that all four types of animals (normals, smalls, Epi1s and Epi2s) exist in virtual equilibrium over this time period?

For this question, note that the numbers of the normal and the small groups are only affected by the number of famine and nonfamine years and not their temporal arrangement. So we have to find a positive number of nonfamine years n such that 1.6n1.320-n is as close as possible to 1.5n1.3520-n. This happens for seven nonfamine and 13 famine years, which gives a relative ratio of 813 to 845 for normals to smalls. How do the years need to be arranged to equalize the numbers of Epi1s and Epi2s? As noted above, without resets, Epi2s are best adapted to famines that last three years, and similarly, Epi1s are best adapted to famines that last two years. So our 20-year pattern needs to have famines of both these durations. The pattern NFF NFFF NFF NFFF NFF NFN meets all the conditions mentioned and gives relative scores of 809 for Epi1s and 817 for Epi2s on the above scale, which are both within 0.5 percent of the number for normals. This seems to be the best approach to virtual equilibrium.

So what these simple models teach us is that it is possible to come up with environmental conditions that will lead natural selection to favor epigenetic inheritance across generations if the selecting factor (here, famine) occurred frequently enough in an animals evolutionary history in the right pattern. Furthermore, there can be patterns that maintain different groups of the species at relatively constant numbers, ready to take advantage of a change in climate, rendering the species as a whole more stable and prepared for several different eventualities.

As I discussed in the puzzle column, scientists have found molecular mechanisms that can implement these transgenerational changes by suppressing the activity of certain genes through the attachment of methyl groups (DNA methylation) or through changes in the configuration of the protein that packages the DNA (histone modification). Transgenerational inheritance is even easier in small organisms that do not go through a germ cell stage, such as bacteria. These organisms can use even more efficient mechanisms that have allowed the evolution of the spectacular DNA-cutting system called CRISPR, which is currently revolutionizing genetic engineering. This system uses bits of DNA called transposons or jumping genes that can jump around from one location to another in genomes. Its amazing what natural selection can achieve in evolutionary time!

Thanks to all who participated in this Insights puzzle. I enjoyed reading your comments and especially my dialogue with Josh Mitteldorf. The Quanta T-shirt goes to Ty Rex. Congratulations!

Read this article:

Solution: 'Darwinian Evolution Explains Lamarckism' - Quanta Magazine

A couple of weeks ago, a white 22-year-old named Sean Christopher Urbanski was accused of fatally stabbing 23-year-old Richard Collins III, an Army Lt., who was black. The incident took place on the University of Marylands campus, which Urbanski attended.

Urbanskis membership in an alt-right Facebook group has led many to believe this was a racially motivated hate crime, though he hasnt been charged with that yet.

No need to think too much about the reason, though, because the Institute on the Constitutions David Whitney knows why it happened. He explained in a sermon at Cornerstone Evangelical Free Church that the motivation was wait for it the teaching of evolution.

As in all public schools, evolution is inculcated and it teaches that there is no Creator God and that everything in the universe came into existence by chance and mistake, accident and is wholly without purpose and without meaning of any kind, Whitney preached. [Urbanski] was taught that mankind, including himself, was nothing more than a long compilation of mistakes and mutations and chance occurrences.

We should not be surprised then if Sean, with that background and education, concluded that life is meaningless, without any purpose at all, he continued. Or, if there is a purpose in life, it would be to advance and further the process of evolution; a process in which the strong destroy the weak and indeed, ultimately, that is the purpose for existence. Survival of the fittest therefore has some rather dastardly consequences which we see in the murder committed by a secular humanist of a Christian young man.

Evolution is also the basis of racism, [and] many assert that racism played a role in the motivation for this murder, Whitney said. You see, evolution is essentially racist. So where did Sean Urbanski learn racism? He learned it in his classes on evolution at the local public high school that his parents sent him to and his parents funded that school by the payment of their property taxes.

Thats not how evolution works. Its an explanation, not an excuse. It doesnt mean members of a species just kill each other for the sake of it or that a murder alters the course of how the process works. (Hell, you could make a compelling argument for why evolution promotes altruism and working together, too.)

Furthermore, Whitney never bothers to explain why the rest of us who understand and accept evolution arent running around killing everyone else or why there are so many Christians in jail. Its almost like theres more to an accused murderers mindset that a class he took in high school

But that sort of nuance is too complicated for this guy. Its so much easier to blame anything and everything else for a crime as long as youre not implicated in it.

(via Right Wing Watch)

Here is the original post:

Christian Pastor Blames Evolution for a White Student's Alleged Murder of a Black Student - Patheos (blog)

The marketplace is not unlike nature; both are filled with fierce competition, survival and extinction, tremendous diversity, changes to the environment, and seemingly infinite techniques to thrive.

Nowadays, were seeing species especially hard hit by climate change, like polar bears, or species threatened by changes in habitat, such as tigers and other large predatory mammals. And were seeing the marketplace equivalent with markets moving from brick and mortar to online, like the travel industry for example, and other industries natural habitats, if you will, are shrinking, like Western manufacturing.

John Cambers, chairman of S&P 500-listed company Cisco Systems, predicts that within the next 10 years 40% of all businesses will go extinct unless they modify their business models to incorporate new technologies.

Building on the wildlife metaphor, one finds three distinct species of online companies: great white sharks, piranhas, and swordfish. These digital beasts are the companies which can thrive in their new online environment.

The most obvious are the digital great whites. These are the massive online companies companies often native to their digital environments. Google, Facebook and Amazon, to name a few, are perfect examples of the digital great whites and are characterized by diverse product portfolios and massive assets. And with a substantial market presence, it follows that there tend to be very few of these behemoths, much like their aquatic versions.

Where the great white shark has a tremendous appetite to fit its size, a digital great white like Google has to stay competitive by having a presence in many industries. In entertainment, Google has YouTube and Google Play, the dominant Android app distributor. Google Fonts and Web Designer help Google stay competitive in designing software, an area traditionally dominated by Apple, another digital great white. In order to stay at the top R&D is often made a priority and to that end Google has been expanding their artificial intelligence portfolio of late.

The digital piranhas are the species that a digital David Attenborough might want to keep his or her eye on. Companies like these are small but highly competitive and aggressive towards their prey. BlaBlaCar, Shazam and slack are but a few in this school.

Most of these companies stay heavily focused on their products. Unlike the digital great whites, they stay focused on their specific, sometimes even niche, markets and prioritize specialization over diversification. Their competition is almost exclusively those companies that offer the same products. And like real-world piranhas they need to stay fast and fit to have a chance to dominate the market.

The iGaming industry is a perfect example of the fierce competition and product-centric business models that are so prevalent in this digital species. Online casinos bgo and Mr Green offer customers free spins and matched deposits in order to entice customers and stay competitive. The iGaming industry is further representative of digital piranhas inasmuch as they have yet to reach their maturity. By incentive and specialization they are hoping to corner the market and with such fierce competition their products and development can be some of the quickest.

Somewhere lying between piranhas and great whites are the swordfish. Not quite as agile as the piranha, not yet as diverse as the great white, companies like Airbnb, Netflix or Zalando are big and fast enough that they are rarely threatened.

Their market share means that its unlikely they will disappear anytime soon. While digital piranhas can come and go the chances of an Uber, for example, vanishing overnight is unlikely. Still more numerous than the great whites, a few companies tend to lead the way for whatever industry they are in.

IMG_0407(CC BY 2.0)byswruler9284

Nearly at peak growth, these companies still have a chance of growth, but focus on expanding their models on vertical-specific products. To take an example, as a company which started by posting DVDs, then broadband streaming, Netflix is poised to become a global TV and film producer. With series like Marseille, what would have traditionally been reserved to an exclusively French audience can now be viewed around the world thanks to subtitles. Netflix has come quite a way since those red envelopes.For the digital swordfish its vital that they remain innovative enough to begin branching out into industries complementary to their core competencies.

As it is in the animal kingdom, in the digital marketplace evolution holds a great many surprises and none can immediately say what will or wont succeed.

Image Source: 1, 2

If you liked this article, follow us on Twitter @themerklenews and make sure to subscribe to our newsletter to receive the latest bitcoin, cryptocurrency, and technology news.

Go here to read the rest:

From Piranha to Great White Shark Evolution in the Digital Marketplace - The Merkle

The Hindu

Evolution of mothers in cinema: Mum's the word The Hindu Did screen mothers ever come alive, get real, have a life, in the tiresome days of the Kheer Age? The climax of Johny Mera Naam (1970) is near. Sulochanawhite sari, dishevelled bun, Bombay cinema's widowed mother par excellencehas been ... and more »

See the original post:

Evolution of mothers in cinema: Mum's the word - The Hindu