Now It's Transitional Turtle Fossils

BBC News - How the turtle got its unique hard shell



What an appalling day for Creationists!



What with pebbles on Mars showing how Mars is very old and the 'Goldilocks zone' is much wider that they like to pretend, transitional fossils showing how cretaceous amphibians evolved, the discovery of rapid recent evolution in Brazilian palm trees and news that scientists at CERN are getting closer to explaining why matter exists, the news of the discovery of a transitional turtle fossil must be devastating.



If they don't adopt their normal method of coping with the cognitive dissonance and simply covering their eyes until it goes away, that is.

Summary

The origin of the turtle shell has perplexed biologists for more than two centuries. It was not until Odontochelys semitestacea was discovered, however, that the fossil and developmental data could be synthesized into a model of shell assembly that makes predictions for the as-yet unestablished history of the turtle stem group. We build on this model by integrating novel data for Eunotosaurus africanus—a Late Guadalupian (∼260 mya) Permian reptile inferred to be an early stem turtle. Eunotosaurus expresses a number of relevant characters, including a reduced number of elongate trunk vertebrae (nine), nine pairs of T-shaped ribs, inferred loss of intercostal muscles, reorganization of respiratory muscles to the ventral side of the ribs, (sub)dermal outgrowth of bone from the developing perichondral collar of the ribs, and paired gastralia that lack both lateral and median elements. These features conform to the predicted sequence of character acquisition and provide further support that E. africanus, O. semitestacea, and Proganochelys quenstedti represent successive divergences from the turtle stem lineage. The initial transformations of the model thus occurred by the Middle Permian, which is congruent with molecular-based divergence estimates for the lineage, and remain viable whether turtles originated inside or outside crown Diapsida.

Evolutionary Origin of the Turtle Shell

Tyler R. Lyson, Gabe S. Bever, Torsten M. Scheyer, Allison Y. Hsiang, Jacques A. Gauthier

Current Biology - 30 May 2013

Lead author, Dr Lyson, of the Smithsonian Institute and Yale University, described the fossil thus:

Eunotosaurus is a good transitional fossil which bridges the morphological gap between turtles and other reptiles. [My emphasis]

I hope any Creationists who have lasted this far noted that description. If so, they won't now in all honesty be able to use the traditional Creationist argument that there are no transitional fossils.

The turtle shell is considered an evolutionary novelty, which means that there are no closely analogous structures in related animals.



That leads to the notion that such things cannot occur through normal evolutionary processes. But, when you examine it in detail, you can see the series of steps, each of them explainable through small changes that gradually add up to the novel structure.

Judith Cebra-Thomas, assistant professor from the department of biology at Millersville University in Pennsylvania.

(Quoted by Melissa Hogenboom, Science Reporter BBC News)

There we have as good a description of Darwinian evolution as you'll find anywhere - "[a] series of steps, each of them explainable through small changes that gradually add up to the novel structure". And the whole is, of course, what Creationist 'scientists' like Michael Behe and the professional liars of the Discovery Institute would describe as 'irreducibly complex' and therefore evidence of their current under-cover version of biblical literalism, 'Intelligent Design'.



It has been a very bad day indeed for these frauds.



Reference:

Evolutionary Origin of the Turtle Shell; Tyler R. Lyson, Gabe S. Bever, Torsten M. Scheyer, Allison Y. Hsiang, Jacques A. Gauthier; Current Biology - 30 May 2013



How the turtle got its unique hard shell; Melissa Hogenboom, Science reporter, BBC News, 31-May-2013

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CERN - Unweaving Reality. No Gods Found.

Scientists find clues to why everything exists - ComputerworldUK.com



Scientists using the Large Hadron Collider (LHC) at CERN are getting closer to understanding why there is matter in the Universe. So far, they have not detected any gods, nor found any need to include them in any hypotheses.



We have long known that pairs of virtual particles arise spontaneously (that is, unpredictably and without cause) inside a quantum vacuum. These pairs always consist of matter-antimatter pairs which exist for a fraction of a second and then mutually annihilate, releasing energy.

We're reaching into the fabric of the Universe at a level we've never done before. We've kind of completed one particle's story. ... Now we're way out on the edge of a new exploration. This could be the only part of the story that's left, or we could open a whole new realm of discovery.

Professor Joe Incandela, University of California at Santa Barbara

This can be demonstrated with the Casimir Effect where a pair of uncharged metal plated placed a few micrometers apart in a vacuum can exhibit attraction or repulsion depending on their arrangement. This is explained by virtual particles spontaneously forming between the plates.



Incidentally, the spontaneous generation of these particle/antiparticle pairs is an example of an uncaused event, so giving the lie to the Cosmological Argument beloved of religious apologists, that everything that begins to exists must have a cause. This is demonstrably not so with quantum events such as this - and the Big Bang was a quantum event.



But the mystery was why, if there were equal numbers of matter and antimatter particles formed in the initial instant of the Big Bang, why they didn't all annihilate one another almost instantaneously, leaving nothing behind but energy. In other words, why was there an apparent surplus of matter over antimatter when there should have been perfect symmetry.



Now scientists at CERN are beginning to unravel that conundrum. As PC Computerworld US's Sharon Gaudin reports:

CERN reported that when scientists there smashed protons together inside the underground collider, they have been able to create conditions similar to the period soon after the Big Bang. That means they have seen some anti-matter particles.



CERN said they discovered a subatomic particle, dubbed BOs, which decays unevenly into matter and anti-matter. The anti-matter part decays faster than the matter.



It is only the fourth subatomic particle known to exhibit such behavior, scientists noted.



"By studying subtle differences in the behavior of particle and antiparticles, experiments at the [Large Hadron Collider] are seeking to cast light on this dominance of matter over antimatter," CERN reported on Wednesday. "The results are based on the analysis of data collected by the experiment in 2011."

Sharon Gaudin, PC Computerworld UK

This comes close on a report last month that equipment attached to the International Space Station may have detected particles that could be the building blocks of dark matter which is thought to make up about one quarter of the Universe's mass but which is almost undetectable other than by observing the gravity its mass exerts because it is made of of particles which interact only weakly, if at all, with other particles.



Very gradually, methodically, and without fuss, science is unweaving reality and find no trace of gods or supernatural entities. In fact they have found not the slightest trace, either directly or implicitly, of a supernatural realm at all.



But then, no scientific progress was ever made by anyone who gave up looking and declared it must have been the locally popular deity which did it. Science long ago abandoned Bronze-Age guesswork and declaration of truth by fiat. The result is the modern world which can build such machines as the LHC at CERN.



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Creationism Refuted - By Newts!

Tiny but feisty prehistoric wesserpeton amphibian discovered - Nature - Environment - The Independent.



Can it get any worse for Creationists? The last couple of weeks have seen evidence of a transitional species between chimpanzees and humans in the earliest known human ancestor, evidence lining up the fossil record with the molecular evidence of a split between apes and monkeys in Africa about 26-27 million years ago, and evidence that humans were establishes in South American by at least 20,000 BCE. Now comes news that another transitional fossil has been found, this time transitional between two early groups of amphibians.



This news comes from two researchers at the University of Southampton, England, Steven C. Sweetman and James D. Gardner, who have been studying numerous specimens of wesserpeton, a tiny newt-like amphibian whose fossils are found on the Isle of Wight, just off the south coast of England. The Isle of Wight is famous for it's fossils of dinosaurs and forms part of the so-called 'Cambrian Coast' which includes the cliffs at Lyme Regis, Dorset, where the first complete ichthyosaur fossil was found by Mary Anning. The Isle of Wight has been nicknamed 'Dinosaur Island' because of the abundance of these fossils in the chalk and limestone deposits of which it is composed.



As reporter, Ben Mitchell of The Independent said:

The discovery of the wesserpeton fills a gap in the evolutionary history of a now-extinct group, the albanerpetontids, according to researchers at the University of Portsmouth.



The amphibian, nicknamed "Wessie", was about the size of a small, modern-day newt and unlike most amphibians, albanerpetontids had a scaly skin and eyelids, showing that they spent most of their time on land. Details of the skeleton also suggest that they were well adapted to burrowing.



The creature lived on the Isle of Wight, which has gained the nickname Dinosaur Island because of the number of fossils found there, about 130 million years ago during the early cretaceous period, at the same time as dinosaurs such as neovenator, iguanodon and giant, long-necked sauropods.



The researchers believe that broken but healed jaws among the bones suggest Wessie was a feisty creature. Like some modern-day salamanders, it probably engaged in fierce battles for mates and territory and sharp chisel-like teeth indicate that it was a predator.



Steve Sweetman, of the university's School of Earth and Environmental Sciences, said: "When I started looking for the little animals that lived with the dinosaurs, a Wessie jaw was the first thing I found and I can still remember how excited I was. I also remember thinking that 'albanerpetontid' was a heck of a mouthful for such a tiny creature.



"Of the 50 or so new four-legged animals I have now found, Wessie bones are the most common and it was clearly well adapted to the ancient floodplain environment in which it lived."



The researchers have no complete skeletons of Wessie but they have a large number of isolated bones representing almost all parts of the animal.



Dr Sweetman and his co-author, Jim Gardner of the Royal Tyrrell Museum of Palaeontology, Canada, named the animal wesserpeton because its bones come from rocks known as the Wessex Formation.



The discovery of Wessie neatly fills an evolutionary gap. Albanerpetontids are first found in rocks of middle jurassic age and their last occurrence is in the late pliocene.



During this period of more than 165 million years, skull bones known as frontals gradually changed from bell-shaped to triangular. Until now, part of this transition was missing from the fossil record.



Dr Sweetman said: "Until the discovery of wesserpeton, there appeared to be an abrupt transition from the more primitive elongated and bell-shaped frontals of the early albanerpetontids to the triangle-shaped frontals of later forms. The frontals of wesserpeton are elongated but they are also triangular, neatly filling the gap between the two."

Source: The Independent; Ben Mitchell, 29-May-2013

So here we have a new 'transitional' fossil to add to the list, much to the chagrin of Creationists no doubt. I wonder how their pseudo-scientists are going to explain this one away, assuming they don't do the usual hand-over-the-eyes approach to evidence and ignore it altogether, knowing full well that most of their target market will be doing likewise.



Reference:

A new albanerpetontid amphibian from the Barremian (Early Cretaceous) Wessex Formation of the Isle of Wight, southern England; Steven C. Sweetman and James D. Gardner

Acta Palaeontologica Polonica 58 (2), 2013: 295-324 doi: http://dx.doi.org/10.4202/app.2011.0109

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Rapid Evolution in Brazil

Functional Extinction of Birds Drives Rapid Evolutionary Changes in Seed Size



Yet another example of observed rapid evolution is published in this week's Science. This time it is rapid evolution in Brazilian palm trees due to human activity with no evidence whatsoever of any intelligence being involved in the process, nor of any being required.

Abstract

Local extinctions have cascading effects on ecosystem functions, yet little is known about the potential for the rapid evolutionary change of species in human-modified scenarios. We show that the functional extinction of large-gape seed dispersers in the Brazilian Atlantic forest is associated with the consistent reduction of the seed size of a keystone palm species. Among 22 palm populations, areas deprived of large avian frugivores for several decades present smaller seeds than nondefaunated forests, with negative consequences for palm regeneration. Coalescence and phenotypic selection models indicate that seed size reduction most likely occurred within the past 100 years, associated with human-driven fragmentation. The fast-paced defaunation of large vertebrates is most likely causing unprecedented changes in the evolutionary trajectories and community composition of tropical forests.

Functional Extinction of Birds Drives Rapid Evolutionary Changes in Seed Size; Mauro Galetti, et al.

Science 31 May 2013: 340 (6136), 1086-1090. [DOI:10.1126/science.1233774]

This is a lovely example of how evolutionary change will occur without any new mutation arising simply because the environment has changed. I have shown before how it is not necessarily the information contained in the genome which needs to change but the meaning of that information as determined in the context of the environment in which it finds itself. See Evolution - The Meaning of Information and Rapid Human Evolution.



Over time, these Brazilian palms had evolved to have their seeds dispersed by a range of bird species by being eaten by them and excreted some distance away (neatly giving the seed a little fresh fertiliser to start in on its way in the process). Larger seeds obviously produce larger seedlings and so will have been favoured in areas where 'large-gape' birds were present because these birds could swallow large seeds whole, but, with other bird species present, which could disperse smaller seeds, there would have been little pressure on palms towards producing only large seeds; instead they produce a range of seed sizes.



But, in several areas, under human pressure in the last 100 years or so, many of these large-gape bird species have become locally extinct making it impossible for palms with larger seeds to get dispersed. Not surprisingly, in these areas, as this paper has demonstrated, palms have evolved to produce smaller seeds. With this human-induced environmental change, the relative frequency of alleles of genes favouring smaller seeds in these Brazilian palm trees has shifted - and that is all evolution is.



This reminds me of a similar though more drastic example of how humans can disturb a balanced ecosystem from the Indian Ocean island of Mauritius where several large frugivores (fruit eaters), including the Dodo and a species of giant tortoise have been exterminated by man, resulting in the near-extinction of several plants that depended on them. One such example was the relationship between the tambalacoque (Sideroxylon grandiflorum) or 'Dodo Tree' which was reported in 1973 as being near extinct with only 13 specimens having germinated since the Dodo went extinct 300 years earlier. This was an over-simplification and exaggerated the problem but never-the-less it serves to illustrate the point:

In 1973, the tambalacoque, also known as the "Dodo tree", was thought to be dying out on Mauritus, to which it is endemic. There were supposedly only 13 specimens left, all estimated to be about 300 years old. Stanley Temple hypothesised that it depended on the Dodo for its propagation, and that its seeds would germinate only after passing through the bird's digestive tract. He claimed that the tambalacoque was now nearly coextinct because of the disappearance of the Dodo. Temple overlooked reports from the 1940s that found that tambalacoque seeds germinated, albeit very rarely, without being abraded during digestion. Others have contested his hypothesis and suggested that the decline of the tree was exaggerated, or seeds were also distributed by other extinct animals such as Cylindraspis tortoises, fruit bats or the Broad-billed Parrot. According to Wendy Strahm and Anthony Cheke, two experts in the ecology of the Mascarene Islands, the tree, while rare, has germinated since the demise of the Dodo and numbers several hundred, not 13 as claimed by Temple, hence discrediting Temple's view as to the Dodo and the tree's sole survival relationship.



It has also been suggested that the Broad-billed Parrot may have depended on Dodos and Cylindraspis tortoises to eat palm fruits and excrete their seeds, which became food for the parrots. Anodorhynchus macaws depended on now-extinct South American megafauna in the same way, but now rely on domesticated cattle for this service.



Just another example of evolution in progress, driven as always by the environment selecting for fitness to survive in that environment and environmental change producing a change in allele frequency. If the Brazilian palms in question had not existed in the presence of a range of frugivorous birds but had been forced down an evolutionary path dictated by a single, or small number of, large-gaped species of birds, we would now be looking at impending local extinctions of these trees.



All in all, no evidence there of intelligent design, and all of it easily explained by Darwinian Evolution.

Source: Wikipedia - Dodo, diet

Reference:

Functional Extinction of Birds Drives Rapid Evolutionary Changes in Seed Size

Mauro Galetti, Roger Guevara, Marina C. Côrtes, Rodrigo Fadini, Sandro Von Matter, Abraão B. Leite, Fábio Labecca, Thiago Ribeiro, Carolina S. Carvalho, Rosane G. Collevatti, Mathias M. Pires, Paulo R. Guimarães Jr., Pedro H. Brancalion, Milton C. Ribeiro, and Pedro Jordano

Science 31 May 2013: 340 (6136), 1086-1090. [DOI:10.1126/science.1233774]

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Creationists Hit By Pebbles From Mars

Martian Fluvial Conglomerates at Gale Crater



Fascinating observations from Mars reported in this weeks edition of Science

Abstract

Observations by the Mars Science Laboratory Mast Camera (Mastcam) in Gale crater reveal isolated outcrops of cemented pebbles (2 to 40 millimeters in diameter) and sand grains with textures typical of fluvial sedimentary conglomerates. Rounded pebbles in the conglomerates indicate substantial fluvial abrasion. ChemCam emission spectra at one outcrop show a predominantly feldspathic composition, consistent with minimal aqueous alteration of sediments. Sediment was mobilized in ancient water flows that likely exceeded the threshold conditions (depth 0.03 to 0.9 meter, average velocity 0.20 to 0.75 meter per second) required to transport the pebbles. Climate conditions at the time sediment was transported must have differed substantially from the cold, hyper-arid modern environment to permit aqueous flows across several kilometers.

Martian Fluvial Conglomerates at Gale Crater; R. M. E. Williams, et al.

Science 31 May 2013: 340 (6136), 1068-1072. [DOI:10.1126/science.1237317]

What this means is that at some point in its history, Mars had flowing water with enough power to transport rocks and turn them into pebbles. Pebbles are formed as rocks rolling along in water knock against each other wear away any irregularities on their surface to make them smooth and rounded.



The pebbles on Mars have been there long enough to have become incorporated into concretions formed over time from the sand particles they were deposited in.



This has major implications for young-earth creationists who desperately cling to the biblical myth that Earth was created simultaneously with the rest of the Universe between six and ten thousand years ago and everything in the Universe was created exactly as we see it today.



One of their favourite claims is the Earth must have been specially and intelligently designed because it occupies the 'Goldilocks zone' around the Sun where water can exist in each of its three physical states - solid (ice), liquid (water) and gas (water vapour). Creationists claim that the probability of Earth occupying just this 'narrow' band around the Sun is vastly unlikely. This of course ignores the fact that life has evolved on Earth because Earth has the conditions for it to have evolved, and that it fits the conditions on Earth like a hand in a glove because that's what evolution by natural selection causes, as is explained by the Theory of Evolution.



Flowing water on Mars means these conditions existed there at some time too, so widening the 'Goldilocks zone' to include the orbit of Mars and so giving the lie to Creation pseudo-scientist calculations that the 'Goldilocks zone' is very narrow. In fact, the occurance of water in its three physical states on Earth are largely because of Earth's geology and meteorology - mass/gravity, atmosphere, atmospheric pressure, etc - just as when they existed on Mars it was due largely to Mars's geology and meteorology not Mars's distance from the Sun.



The existence of pebbles, which do not form over night, and, more importantly their inclusion in concretions of sand particles, formed with "minimal aqueous alteration" (i.e. after the water had either evaporated due to Mars's low gravity and thin atmosphere, or had become locked up in subterranean permafrost, speaks of a very old Mars, and certainly one more than a few thousand years old. This evidence for liquid water also raises the possibility of the Creationists' nightmare scenario of simple life having evolved on Mars. The search for that continues...



Creationists try to explain away deposits such as these on Earth as due to the Noachin Flood, sent by their god in a fit of temper, to kill all living things because of their 'wickedness'. Do they suppose a similar flood once killed all living things on Mars too, but their god didn't tell a Martian to build an Ark?



Or maybe the Flood reached up higher than the highest mountain on Earth and deluged the inner planets too, but avoiding the Moon which shows no such signs of flowing water.



I dare say one of their 'brilliant scientists' can explain it all...



Don't laugh. It isn't nice.



Reference:

Martian Fluvial Conglomerates at Gale Crater

R. M. E. Williams, J. P. Grotzinger, W. E. Dietrich, S. Gupta, D. Y. Sumner, R. C. Wiens, N. Mangold, M. C. Malin, K. S. Edgett, S. Maurice, O. Forni, O. Gasnault, A. Ollila, H. E. Newsom, G. Dromart, M. C. Palucis, R. A. Yingst, R. B. Anderson, K. E. Herkenhoff, S. Le Mouélic, W. Goetz, M. B. Madsen, A. Koefoed, J. K. Jensen, J. C. Bridges, S. P. Schwenzer, K. W. Lewis, K. M. Stack, D. Rubin, L. C. Kah, J. F. Bell III, J. D. Farmer, R. Sullivan, T. Van Beek, D. L. Blaney, O. Pariser, R. G. Deen, and MSL Science Team

Science 31 May 2013: 340 (6136), 1068-1072. [DOI:10.1126/science.1237317]



Life's a Beach: Rover Finds Mars Pebbles; Ian O'Neill, 31-May-2013.

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Another Victory For Human Decency

BBC News - Six Bosnian Croat ex-leaders convicted of war crimes



Hard on the heels of a victory for human rights in the European Court yesterday, when it was confirmed that being a Christian does not excuse abusing others and denying them human rights, comes confirmation that war crimes, even when committed in the name of religion, are not to be accepted in civilised societies.



The War Crimes Tribunal in The Hague today handed down sentences of between 10 and 25 years to six Bosnian Croat Orthodox Christians who had been convicted of war crimes against Bosniaks (Bosnian Muslims) and others in the former Yugoslav republic of Croatia during a series of conflicts following the breakup of Yugoslavia. The plan had been to 'ethnically cleanse' a mini state in Croatia in preparation for its incorporation into a 'Greater Bosnia'.



Those convicted were:

• Jadranko Prlic - leader of the self-proclaimed state of Herceg-Bosna - 25 years in jail.


• Bruno Stojic - former defence minister of the breakaway Herceg-Bosna - 20 years.


• Slobodan Praljak - former militia head - 20 years.


• Milivoj Petkovic - former militia head - 20 years.


• Valentin Coric - former commander of Bosnian Croat military police - 16 years.


• Berislav Pusic - ex-head of prisoner exchanges and detention facilities - 10 years.

As BBC Reporter Anna Holligan reports:

The judges ruled that murders, persecutions, rape and torture of Muslims "were not committed in a random manner by a few undisciplined soldiers" but were part of the plan to remove Muslims from the self-proclaimed Herceg-Bosna state in 1993-94.



They also said it was a religiously-motivated campaign, describing how mosques were blown up and Muslim prisoners were forced to recite Christian prayers.



Referring to the forcible expulsion of the Muslim population from the eastern part of the city of Mostar, the panel said: "Muslims were woken up in the middle of the night, beaten and forced to leave their apartments, often still in their pyjamas. Many women, including a girl of 16, were raped by HVO (Croatian Defence Council) soldiers".

The trial, which began in 2006, is the War Crimes Tribunal's longest running case. It represents yet another example of how religion is quickly losing its privileged position in Europe and abuses in its name will no longer be tolerated. The Humanist position, that all people deserve to be treated with respect and dignity by virtue of the simple fact that they are human beings, is quickly becoming the social norm and accepted as the only basis for a civilised society.



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Christianity Is No Excuse - ECHR

European Court of Human Rights refuses to hear appeals in three ‘Christian persecution’ cases » British Humanist Association:



Congratulations to the European Court of Human Rights (ECHR) on confirming that even Christians can't deny basic human rights to others, at least in signatory countries to the European Human Rights Convention (EHRC). This will no doubt come as a great shock to many of them who still take for granted their former privileged place in Western society and who still assume their 'faith' gives them the right to persecute and oppress those with whom they disagree.



It get really Byzantine, so bear with me:



The (refused) appeal was by three Christians who lost their original case in the ECHR when they claimed it infringed their human rights to deny them the right to deny services to others on the grounds that they are Christians. They have previously claimed for unfair dismissal when they were sacked for refusing to treat people equally in the provision of services, and had lost in the English Courts. Britons have the right to take their case to the ECHR if they feel their human rights, as outlined in the EHRC, have been infringed. The ECHR is the final court of appeal for signatory countries.



This refusal effectively brings the case to a close and confirms the strong movement away from deference to religions and towards the principle that religion is no longer the excuse for antisocial behaviour, victimisation and bullying that is was in times gone by.

All Things Bright And Beautiful



The rich man in his castle,

The poor man at his gate,

God made them high and lowly,

And ordered their estate.

Anglican Hymn

Stand by for more whinging and claims of persecution from people like former Archbishop of Canterbury, Lord Carey from his unelected, privileged position as a member of the UK Parliament's upper chamber, the House of Lords.



It is rulings like this, which are extending human rights throughout much of Europe, which is infuriating the political right in Britain, led by the racist, xenophobic, homophobic and misogynistic UKIP and the 'swivel-eyed loons' in the Conservative Party who are interchangeable with UKIP, who see Christian supremacy, social stratification, and denial of basic human rights to the lower orders and minorities as right and proper, and their God-given birthright.



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Human Gene-Meme Co-Evolution

In an article in this week's Science Journal, scientists Simon E. Fisher and Matt Ridley make a case for some aspects of human genetic evolution in the last 200,000 years to be the consequence of cultural evolution rather than, as is generally assumed, cultural evolution to be the consequence of genetic mutation.

Abstract

State-of-the-art DNA sequencing is providing ever more detailed insights into the genomes of humans, extant apes, and even extinct hominins (1–3), offering unprecedented opportunities to uncover the molecular variants that make us human. A common assumption is that the emergence of behaviorally modern humans after 200,000 years ago required—and followed—a specific biological change triggered by one or more genetic mutations. For example, Klein has argued that the dawn of human culture stemmed from a single genetic change that “fostered the uniquely modern ability to adapt to a remarkable range of natural and social circumstance” (4). But are evolutionary changes in our genome a cause or a consequence of cultural innovation.

Culture, Genes, and the Human Revolution; Simon E. Fisher and Matt Ridley

They cite examples such as Richard Wrangham's study showing how the discovery of cooking led to a change in the size of the human gut, the spread of the lactase-persistence gene facilitated by the availability of cattle milk as a consequence of cattle-herding about which I have previously blogged in Lacatose Tolerance and Creation 'Science' and higher alcohol tolerance among Europeans as a result of greater alcohol consumption in Europe, as compared to Asians.



The authors suggest that the "human revolution", when humans developed a range of abilities, mostly cultural, which distinguish us most radically from other animals, even our closest relatives, may have been led by cultural changes rather than, as is normally assumed, caused by genetic evolution. They point out how this shows the difficulty in distinguishing between cause and effect in human evolution.



But is this dispute between culture-led and gene-led evolution more than a storm in a teacup? Is it not in fact exactly what we would expect?



Ever since Richard Dawkins proposed the idea of 'memes' - memory genes or units of cultural inheritance - being inherited replicators subject to imperfect replication, just like genes, and so being the subject of Darwinian evolution, people have speculated on human gene-meme co-evolution. Dawkins himself pointed out how genes form alliances with other genes when they are mutually beneficial and how genes have no concern for the nature of the replicators with which they form these alliances. There is no intent involved; the alliances are merely consequences of groups of replicators being more successful in the presence of certain other replicators. In fact, there is no mechanism for distinguishing between memetic and genetic replicators. What ever works to produce more descendants will produce more descendants with those replicators.



In several blogs I have pointed out how the information in genes only has meaning in the context of the environment in which they find themselves, and it is the meaning which matters. In the presence of a surplus of cattle milk, humans were able to sustain a larger population, and have more babies due to earlier cessation of breast feeding (which acts as a natural contraceptive) if they carried the lactase-persistence mutation, whereas, in the absence of cattle milk (due to tsetse fly making cattle-herding non-viable, for example) there was an advantage in weaning babies at about 18 months, when lactose intolerance normally develops. The meme or memeplex of cattle-herding created an environment in which the lactase-persistence mutation produced more descendants.



There are several more examples of cultural change facilitating genetic evolution in humans, such as the movement of Han Chinese onto the Tibetan plateau leading to genetic changes associated with living in a high altitude, and the evolution of the ability to tolerate alcohol, leading to the Asian facial 'flush' which followed the spread of rice farming between 7-10,000 years ago.



The "Human revolution" seems to have been the evolution of the ability to adapt to new situations and to form corresponding cultures and the ability to learn and pass on these cultures in the form of memes. In other words, the "Human revolution" of about 200,000 years ago appears to have been the evolution of memes, or rather the evolution of the ability to pass on and inherit memes, arising out of the need of early humans to work together as cooperative groups.



As with the evolution of anything involving multiple replicators, it's immaterial and only of academic interest which one in particular led the change. Just so when those replicators include memes in a gene-meme complex.



Reference:

Culture, Genes, and the Human Revolution

Simon E. Fisher and Matt Ridley

Science 24 May 2013: 340 (6135), 929-930. [DOI:10.1126/science.1236171]

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Building Walls

Robert Frost

(March 26, 1874 – January 29, 1963

Just been helping a neighbour repair a larch-lap fence between our gardens which the winds a few days ago brought down. It made me think of the poem "Mending Walls" by Robert Frost, about how we build walls between us and how acts of unspeakable brutality such as we saw in Woolwich, London last Wednesday are both caused by those walls and act to reinforce and 'mend' them.

Mending Walls

Something there is that doesn't love a wall,

That sends the frozen-ground-swell under it,

And spills the upper boulders in the sun,

And makes gaps even two can pass abreast.

The work of hunters is another thing:

I have come after them and made repair

Where they have left not one stone on a stone,

But they would have the rabbit out of hiding,

To please the yelping dogs. The gaps I mean,

No one has seen them made or heard them made,

But at spring mending-time we find them there.

I let my neighbor know beyond the hill;

And on a day we meet to walk the line

And set the wall between us once again.

We keep the wall between us as we go.

To each the boulders that have fallen to each.

And some are loaves and some so nearly balls

We have to use a spell to make them balance:

'Stay where you are until our backs are turned!'

We wear our fingers rough with handling them.

Oh, just another kind of out-door game,

One on a side. It comes to little more:

There where it is we do not need the wall:

He is all pine and I am apple orchard.

My apple trees will never get across

And eat the cones under his pines, I tell him.

He only says, 'Good fences make good neighbors'.

Spring is the mischief in me, and I wonder

If I could put a notion in his head:

'Why do they make good neighbors? Isn't it

Where there are cows?

But here there are no cows.

Before I built a wall I'd ask to know

What I was walling in or walling out,

And to whom I was like to give offence.

Something there is that doesn't love a wall,

That wants it down.' I could say 'Elves' to him,

But it's not elves exactly, and I'd rather

He said it for himself. I see him there

Bringing a stone grasped firmly by the top

In each hand, like an old-stone savage armed.

He moves in darkness as it seems to me

Not of woods only and the shade of trees.

He will not go behind his father's saying,

And he likes having thought of it so well

He says again, "Good fences make good neighbors."

Robert Frost

What we saw in Woolwich was the result of alienation and disengagement; the result of generations of wall-building between the white and black communities in Britain. In the 1960s, dissafected youths found an outlet in gangs of 'Mods' and 'Rockers' or, with some of us, in extremist politics of the various brands of ultra-left 'Marxist' groups like the Stalinists, Leninists, Trotskyites and Maoists. In the 1930 it had been the Communists and the Fascists, in the 1950's the Teddyboys and the Beatniks.



In Northern Ireland throughout most of the second half of the twentieth century, it had been Nationalism and 'the armed struggle' or Loyalism and Protestant Supremacy. We happily fragmented into Beatles fans, Rolling Stones fans, Bob Dylan fans, Folk, Blues, R&B, Jazz. You name it we could form an exclusive little group around it. Sometimes these were political; sometimes cultural.



Sometimes they ended up with people being killed because we forgot that, despite whatever group we identify with, the group to which we all belong is the Human group.



Human beings form groups. It's what we do. If we hadn't evolved that basic behaviour on the plains of East Africa a few million years ago, very probably before we were even humans, we wouldn't have survived. As lone individuals we would have been leopard food, scraping a living looking for roots and grubs and scavenging scraps from hyena and lion kills - if we were lucky and the vultures didn't beat us to them.



We are motivated to affiliate with like-minded people. We need to belong. (See Whatever Possesses Religious People.) Our affiliative needs come just above our basic needs for shelter, food, safety and security in Maslow's Hierarchy of Needs, cutting across the need for esteem and and friendship.

Human beings have always functioned in groups. The most basic human group is the family, centered around the pairing of a male and female for the purpose of procreation and the raising of children. This pairing forms the nuclear family, which soon becomes linked to other pairs through a network of relationships between siblings through several generations, thus creating an extended family. This group is held together by a strong bond of cohesion referred to as kinship. While kinship is often thought of in relation to blood ties, what is more important is the common sense of identity by which all the individuals are bonded to the group. This sense of identity causes the individual's self-conception to be inseparable from the group. It is a bonding at an emotional and psychological level which is a powerful motivation usually enduring throughout the individual's life. His or her sense of well-being is intimately related to the integrity and status of the group. Betrayal of the group by an individual member is a most unpardonable sin, involving deep feelings of guilt, and the most severe punishments.



Kinship is, therefore, the most powerful of cohesive forces binding the human group together. It has played an essential role throughout human history in enabling human beings to function and, indeed, to survive. This is as true in the twentieth century as it was in prehistorical times. But it is not the only type of group cohesion. It exists in conjunction with other cohesive forms, and some groups are held together without kinship. It is important to realize, however, that groups which lack the kinship bond will not cohere as well, nor are they as likely to endure.



Behavioral expectations within the group are defined by the culture; norms and roles are established over time, usually in response to needs, and challenges of the environment. Tradition and practice strengthen these expectations, religion sanctifies them, and law codifies them. Institutions develop to enforce them. These are all necessary functional responses to the need for the group to operate efficiently. Over time, however, circumstances will change so that the religious, legal, and institutional responses may no longer be functional. It becomes necessary then for the behavioral expectations to be modified, and new emphases be placed in response to the changing situation. This always creates a friction with old expectations and traditional institutions. Much of the conflict in human history revolves about this process of change. In any case, the religion, the law, and the institutions which develop, themselves become cohesive forces holding the group together, and even make it possible for types of groups to form which lack the kinship bond.

Suffolk County Community College, NY, History Course Reading Material (HIS 101) Human Groups in History

An interesting exercise is to write down all the groups you identify as belonging to. One group you will belong to is those who read blogs such as this one. If you are reading this one because you follow me as an Atheist and/or a Humanist, you will also belong to those groups (groups don't need to be formal). If you're reading this because you disagree with me you will probably be a member of a religious group. If you're the latter, although you belong to the group of people who are religious, there are probably stronger walls between you and members of other religious groups than there are between you and me, even though you are also members of the same group.



And of course, we are both almost certainly members of the same English-speaking group, unless you are reading a translation of this blog.



Walls are part of the means by which we define ourselves and our group. Without walls, the other group's cows might stray over and eat our apples.



We maintain these walls by all sorts of means, and we build them from both sides. We build walls to keep the others in and the others build walls to keep us out; and we all end up inside our own bastions convinced those outside are trying to get in.



And we build walls when none are needed and we maintain those which are no longer required. Just like Robert Frost's primitive neighbour, we need the walls to stop our apples trees wandering over and eating his pine cones, but "good fences make good neighbours!".

Ah, when to the heart of man

Was it ever less than a treason

To go with the drift of things,

To yield with a grace to reason,

And bow and accept the end

Of a love or a season?

Reluctance; Robert Frost

Frost recognises the primitive, stupidity of this futile exercise and sees how his neighbour is only doing it because his father did and he is proud of his father's 'wisdom' which he has inherited without "looking beneath it". In other words, the wall is often there for cultural tradition and for no other purpose. How much of the walls we build because of religion are built because we are proud of our father's 'wisdom', and not because they are necessary?



In fact, a better question is, if not for religion and because of the religion we inherited from our fathers why are any of these walls there? And how much are we responsible for the walls we built around the alienated black and Asian kids of today who are looking to Islam, the 'subversive' religion of the West, just as in times gone by, Leninism, Trotskyism and Maoism were the subversive political philosophies of the West, for an outlet and an identity so they can be somebody and have some control over their own destiny?

Don't ever take a fence down until you know why it was put up.

Robert Frost

As Robert Frost observed, this is artificial. There is nothing natural about man-made walls. "Something there is that doesn't love a wall That sends the frozen-ground-swell under it, And spills the upper boulders in the sun, And makes gaps even two can pass abreast".



How hard we work to build up those walls that nothing wants, that serve no purpose other than to honour our dead ancestors and which serve only to spread division, distrust, death and destruction amongst us, as we saw in Woolwich on Wednesday and as we have seen so often in so many places throughout human history.



"But good fences make good neighbours!"

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Circular Reasoning

I'm amazed that anyone needs to explain the logical fallacy of the circular argument but the frequency with which you see it being employed, often in all seriousness by (presumably) otherwise normally functioning adults to defend religion, suggest many people either genuinely don't understand it, or are using in dishonestly, hoping their audience won't understand it.

Circular reasoning (also known as paradoxical thinking or circular logic), is a logical fallacy in which "the reasoner begins with what he or she is trying to end up with". The individual components of a circular argument will sometimes be logically valid because if the premises are true, the conclusion must be true, and will not lack relevance. Circular logic cannot prove a conclusion because, if the conclusion is doubted, the premise which leads to it will also be doubted. Begging the question is a form of circular reasoning.



Circular reasoning is often of the form: "a is true because b is true; b is true because a is true." Circularity can be difficult to detect if it involves a longer chain of propositions. Academic Douglas Walton used the following example of a fallacious circular argument:

Wellington is in New Zealand.

Therefore, Wellington is in New Zealand.

He notes that, although the argument is deductively valid, it cannot prove that Wellington is in New Zealand because it contains no evidence that is distinct from the conclusion. The context – that of an argument – means that the proposition does not meet the requirement of proving the statement, thus it is a fallacy. He proposes that the context of a dialogue determines whether a circular argument is fallacious: if it forms part of an argument, then it is. Citing Cederblom and Paulsen 1986:109) Hugh G. Gauch observes that non-logical facts can be difficult to capture formally:

"Whatever is less dense than water will float, because whatever is less dense than water will float" sounds stupid, but "Whatever is less dense than water will float, because such objects won't sink in water" might pass.

Source: Wikipedia - Circular reasoning

Incidentally, on that last point, not only is it logically suspect, it is technically invalid. Objects less dense than water float because they can't displace their volume of water because they don't have enough weight. This can only be achieved by objects with equal or greater density to water. (Archimedes principle).



Imagine a scientist writing a paper on, say, the aerodynamics of bumblebee flight. Instead of presenting carefully gathered evidence which is then analysed and discussed and a conclusion drawn from it, he or she simply stated that bumblebees can't fly and then cited his claim as evidence, and concluded that bumblebees can't fly.



Even if that got past the peer-review process - which it wouldn't - would you be convinced that bumblebees can't fly based on that paper?



I've had a blog up since October 2011 challenging Christians to say how they know that Satan didn't write the Bible. My followers on Twitter will also know I frequently issue that challenge. I have also made the same challenge to Muslims regarding the authorship of the Qur'an.

@rosarubicondior @godlesspanda33 1Corinthians 2:9

— Harper(@Irishbloke) May 23, 2013

@rosarubicondior @godlesspanda33 Read the bible and you will find the answer :-)

— Harper(@Irishbloke) May 23, 2013

@rosarubicondior @godlesspanda33 John 1:1-4

— Harper(@Irishbloke) May 23, 2013

@rosarubicondior @godlesspanda33 2 Timothy 3:16–17

— Harper(@Irishbloke) May 23, 2013

@rosarubicondior @godlesspanda33 2Peter 1:21

— Harper(@Irishbloke) May 23, 2013

Almost invariably, those few who do attempt an answer quote the Bible or the Qur'an. The panel on the right shows a selection from a 'debate' on Twitter yesterday:



As can be seen, @IrishBloke seems convinced that quoting the Bible proves it can't have been written by Satan. Presumably, asked to proved the Bible was written by his god, he would use the same circular argument, convinced that it proves something. He seemed to get into a vicious circle himself as he replied three times to my last tweet, trying a different verse each time.



But if that logic holds for the Bible or the Qur'an it holds for any other book or written word. All one needs to do is state that everything in it is true, and it becomes true. And truth then becomes anything any writer says it is.



But what if those words were written by a liar? For the case in point, what if they were written by Satan to fool the reader? (Note: Of course I don't believe in Satan but those who believe in the Bible do. If they are trying to convince others to believe in it, don't they at least have a moral obligation to be sure they aren't doing Satan's work, even within their own moral framework? Or is it more important to get people to share your beliefs than what those beliefs actually are?)



Just like our failed scientist trying to validate his own claim by citing his own claim as evidence, no claim can validate itself in the absence of corroborating evidence. In fact, an evidence-free claim can never be the starting point of any logical argument. Elephants can fly because elephants can fly. Convinced?



You may think this is all too obvious, yet circular reasoning is behind almost all religious claims for the simple reason that there is no incontrovertible, definitive evidence for any god - which is why all arguments for all gods bear a remarkable similarity. Admittedly, the circularity is often well hidden, and often designedly so, although some may be due to the limited intellect or over-eager confirmation bias of the proponent. The inability to believe that mummy and daddy could be wrong in their belief seems to be a powerful inhibitor of rational thought in many fundamentalists.



The Cosmological Argument, so beloved of Creationists is nothing more than a circular argument is disguise. It begs the question by presupposing that:

1. The Universe was created.


2. The supernatural creator god being promoted could have been the only possible cause.

Having so begged the question and set up an evidence-free premise, the conclusion is then derived from it. There is, and never was, any evidence that the universe was created nor that any supernatural being pre-existed it, let alone the only one that the premise permits.



The Teleological Argument, or Argument From Design, is yet another. How could conscious designed be the answer to a question without presupposing a conscious designer - in other words, presupposing the desired conclusion?

There must be an intelligent designer because an intelligent designer designed xyz.

Really!? "It's logic Jim, but not as we know it". Actually, it isn't logic at all, it's a conjuring trick; an intellectual sleight of hand intended to trick the gullible.



The Ontological Argument - basically the arrogant notion that, because you can conceive of a perfect god and a necessary quality of of perfection is existence, this god must exist. (No really! Many theologists have no problem with the idea that they can define a god into existence, apparently!)



The circularity here is in presupposing that your conceptions have any bearing on reality, that the only possible god is the one being promoted and, a lesser one, that perfection includes existence, which is merely an assumption, not an established fact. Believe it or not, Anselm, a former Archbishop of Canterbury, was canonised for disguising that circular reasoning as theology.



Because all religious arguments are essentially circular, and different religions always start from different unproven premises, no two religions ever agree on the details of any conclusion, which is why, unlike science which tends to converge on the same answer regardless of the starting point or the cultural background of the scientists, religions tend to fragment and diverge into myriads of conflicting 'truths' all of which can be 'proved' within the unproven axioms of the religion. Mohammed is Allah's profit because Mohammed said so. Belief in Jesus is the only way to Heaven because the Bible says so. Joseph Smith saw an Angel because Joseph Smith said so. Israel belongs to the Jews because the Torah says so, and so on, and so on... All religions have been able to 'prove' their gods and 'prove' that their rituals and prayers are right, and 'prove' their gods did this or that, because they say so.



And yet, as I argued in Gods Come And Go But Truth Remains, when religious belief disappears, there is nothing left by which to rediscover it. All there are are claims that no one now takes seriously because no one falls for the sleight of hand in the original circular reasoning that the priests and apologists used on the people who were pre-conditioned to accept them. No one now believes in Zeus or Wotan or Viracocha. No one believes they must have been real because they were written about by people who said they were real.



And yet on such flimsy and fallacious reasoning, the most grotesque of human rights abuses are perpetrated with zeal, the most intolerant of bigotries are enshrined in law, and children are brainwashed and indoctrinated to mistrust the evidence of their own eyes, to be satisfied with not knowing and grow up full of guilt for something they haven't done and in fear of something that doesn't exist. People are induced and bamboozled to live their lives like a rehearsal, hoping for jam tomorrow, instead of living for life, enjoying the thrill of finding things out, and not putting up with stale bread of squalor, hopelessness, ignorance and poverty today.



[Update 25 May 2013]

The #atheist says, "When I see it, I'll believe it." The #Christian says, "I believe it, hence I see it." (Hebrews 11:1,3) — Jeff Wickwire (@PastorJWick) May 25, 2013

Here is a lovely example of what this blog is about, from a pastor, no less. Apparently, @PastorJWick thinks he's scoring some point or other over Atheists who want reasons to believe anything, by boasting that Christians believe it because it's written in the Bible. Apparently, he thinks this ability of Christians to fool themselves with the intellectually dishonest devices of circular reasoning and confirmation bias is actually something to be proud of!

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Two Emails

Compare and contrast there two emails: one from Conservative MP, Nicola Blackwood; the other from Labour MP, Tom Watson.

Nicola Blackwood, MP; Conservative.

The first is from my MP, Nicola Blackwood, Conservative MP for Oxford West West and Abingdon, in reply to an email from me urging her to vote for the third reading of Marriage (Same Sex Couples) Bill.

Dear ***************,



Thank you for writing to me about the third reading of Marriage (Same Sex Couples) Bill. In the event, I reluctantly voted against the Bill.



I have taken a great deal of time to engage closely with the detail of this Bill and met with constituents on all sides of the argument, including equal rights campaigners, religious leaders and Ministers to discuss concerns about the Bill's drafting and implications before coming to a conclusion about how to vote.



From the beginning my concerns have not centred on the issues surrounding the definition of marriage. As a strong supporter of civil partnerships and opponent of discrimination in all its forms, I have no principled objection to equal marriage in secular institutions. I abstained from voting in the Second Reading because although I support the principle of the Bill, my concerns about details of the legislation meant I felt I could not vote for it before there was a chance to address these concerns through debate and amendments.



Initially I was disappointed that this Bill did not extend civil partnerships to heterosexual couples and that is why I voted for amendments NC16 and NC16(a) which will provide a prompt review of civil partnerships legislation. I am pleased that this compromise has been reached as it gives hope to many couples who are currently excluded from civil partnerships and unprotected by the legal rights it offers. My only remaining concern on this issue is that the timeframe and scope of this review remain unclear at this point.



Unfortunately, however, my other concerns about the detail of the Bill, and its potential unintended consequences, have remained unresolved.



In particular, although I voted for two amendments that sought to ensure protection of religious freedom, these did not pass and were not accepted by the Government. In the light of this, and given the vastly contradictory legal opinions offered by Aidan O'Neil QC and Karon Monaghan QC of Matrix Chambers, two of the most pre-eminent human rights barristers in this country, about the strength of the protections provided to religious institutions by the Bill, I am not convinced that these protections will work if challenged in the ECtHR, as is very likely. If you would like me to send you a copy of these legal opinions I would be delighted to do so.



I voted against the Bill quite simply because I could not be sure that the measures in the Bill for the protection of religious freedom would work in the way the Government intends and because the amendments designed to strengthen these protections were not accepted.



I felt as though this Bill, through poor drafting and rushed consultation, had become a choice between religious freedom and equality. In the end, as a supporter of both, I could not find a way to support a Bill that did not guarantee the protection of both.

I do hope that this helps to explain my position. Please do get back in touch with me if I can be of further assistance on this or any other topic.



Kindest regards

Nicola

Needless to say, I have expressed my disappointment to Nicola Blackwood.

Tom Watson, MP; Labour.

The second is from Tom Watson, MP, sent to me as a Labour Party member.

***********,



It was wonderful to finally see the gay marriage bill pass through the House of Commons last night. I am delighted that we are so close to having equal marriage in our country, and so very proud of our party.



In the spirit of celebration, I wanted to share with you the story of one couple -- Emma and Hannah -- who are now looking forward to their wedding and to married life together. Their story, in their own words, is below.



Today is absolutely a day to celebrate, but we have a long road ahead of us.



Help us continue our fight for a fair, equal, one nation Britain: make a donation to the Labour Party now.



Thank you for all your support and hard work.



Best wishes,



Tom

@tom_watson



--

**********,

It's been eight years since I met my partner Hannah.



Since then, we've had the joy of watching some of our closest friends and family members get married. The one sadness for us was not knowing when -- or even if -- we would ever be able to make that commitment ourselves.



All we have ever wanted is for our relationship to be seen as equal and today we can see a future where we too will be able to get married.



To see the equal marriage legislation pass through the House of Commons yesterday was a huge moment for us, and we are incredibly grateful to all the politicians who supported it.



We know this moment would never have come without the Labour Party's unwavering support for and leadership on gay equality -- from repealing Section 28 to introducing civil partnerships.



We have never been more proud to be members of this party, and we just wanted to say thank you to everyone who's campaigned for and supported this bill.



With thanks,



Emma Norris and Hannah Stoddart



(Emma on the left in the photo, Hannah on the right)

These emails probably illustrate the fundamental differences between the Conservative and Labour Parties on the issue of Human rights and equality before the law.

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Evolution Of A Plague of Locusts

Magicicada adults and final stage nymphs.

Photograph by Arthur D. Guilani

If it hasn't happened already, and you live in the Eastern USA, you are in for a rare treat very soon. Rare, that is if you regard once every 17 years as rare, and a treat if you like fair-sized insects that can make a sound approaching the decibel level of a pneumatic drill.



I'm talking about the emergence of the so-called 17-year locust. Actually, it isn't a locust at all, which is a member of the grass-hopper and cricket family, but a cicada, which is closer to the aphids. The first Europeans in America to witness an emergence had heard of biblical plagues of locusts but had no real idea what a locust was, and assumed they were witnessing a similar biblical plague and called the cicadas locusts.



The 17-year cicada is a member of the Magicicada genus, or periodical cicadas of which there are seven species, three of which have a 17-year life-cycle and four a 13-year cycle.

Magicicada is the genus of the 13-year and 17-year periodical cicadas of eastern North America. Although they are sometimes called "locusts", this is a misnomer as cicadas belong to the taxonomic order Hemiptera, while locusts belong to Orthoptera.

Magicicada spp. spend most of their 13- and 17-year lives underground feeding on xylem fluids from the roots of deciduous forest trees in the eastern United States. After 13 or 17 years, mature cicada nymphs emerge at any given locality, synchronously and in tremendous numbers. After such a prolonged developmental phase, the adults are active for about 4 to 6 weeks. The males aggregate into chorus centers and attract females for mating. Within two months of the original emergence, the life cycle is complete, the eggs have been laid and the adult cicadas are gone for another 13 or 17 years.

Source: Wikipedia - Periodical cicadas

17-year Magicicada sp. Brood XIII, 207.

Photograph by Bruce Marlin

Apart from their synchronised life-cycle, where just about the entire population emerges in the space of a few days after a prolonged development stage as nymphs living in the ground and sucking on roots for a number of years that more than coincidentally is a prime number, periodical cicadas are interesting for their strategy for coping with predation.



Male Magicicadas, the ones which emit the sound by using a pair of tybals on their abdominal wall, have some success detering birds and other predators with a barage of noise but the silent females merely drop to the ground and hide in the undergrowth. Neither of these is very effective however and a whole range of predatory birds, mammals, fish, snakes, even turtles, gorge themselves on cicadas when they emerge, often in millions or billions over a relatively small area. And this is the periodical cicadas' survival strategy, or rather the survival strategy of periodical cicada genes.



The strategy adopted is one of predator satiation. During the few weeks that adult cicadas are active, predators eat their fill and can literally eat no more. In effect, the cicada genes pay a tax in the form of a percentage of their carriers (cicadas) so that enough will survive to produce the next generation of cicada genes.

17-year Magicicada septendicima

This long life-cycle and predator satiation strategy has a beneficial effect for the cicadas. As an entomologist observed in 1898, "The use of the newly emerged and succulent cicadas as an article of human diet has merely a theoretical interest, because, if for no other reason, they occur too rarely to have any real value". The same holds true for non-human predators or course. Predators do not become reliant on cicadas and even if they have a boom in their population following a cicada emergence, by the time of the next emergence, this will be long gone. This is unlike many other predator/prey relationships where a population explosion in, for example, voles, will produce a population explosion in a prey species such as, in the vole example, owls or stoats, which in turn causes a population crash in the prey species followed by a crash in predator numbers.



In fact there seems to be just one predator species which has managed to synchronise with the periodical cicada, in the form of a fungus which lives in the nymphs for the duration of their subterranean existence, producing spoor which remain in the soil as the final nymph matures and leaves the soil to climb a tree to become the winged adult. The spoors then infect the next generation as they burrow down into the soil to start the next subterranean population.



Quite frequently there will be a few straggler emergings of periodical cicadas a year either side of the main emerging but these are usually quickly mopped up by predators because their numbers are never large enough to satiate them, so these rarely breed. In effect, genes favouring early of late emergence, and nascent new species with these periods rapidly go extinct due to predation.



However, due probably to an acceleration in one of the nymph stages facilitated by favourable conditions, an early emergence at 13 years instead of the normal 17 is quite common and often in substantial numbers. Normally, these too produce few breeding successes due to low numbers but very occasionally, and on at least one occasion for each of the 17-year species in the last few million years, this has produced a viable, sustainable population of 13-year cicadas. Hence, for every 17-year species there is a closely similar 13-year species (two in the case of the 'decima' form). These species have names reflecting their periodicity and their relationship.

17-Year Period	13-Year Period
Magicicada septendecim	Magicicada tredecim Magicicada neotredecim
Magicicada septencassini	Magicicada tredecassini
Magicicada septendecula	Magicicada tredecula
Source: Wikipedia - Periodical cicadas

This pattern is also complicated because each species exists as several 'broods', each of which has been given a Roman numeral. Some of these broods populations appear to have gone extinct since this convention as adopted. Broods hatch in different years but the geographical range of broods of the same species rarely, if ever, overlap.



This then is an example of the selfish gene in action. It has suited the survival 'needs' of cicada genes to adopt the predator satiation strategy with no regard for the individual carrier of those genes. All that matters is that the genes survive in the next generation and any strategy which produces more descendants will, well, produce more descendants, so genes producing that strategy will prosper in the species gene-pool.



So, that explains the syncronised emergence of very large numbers and the long life-cycle. What is harder to understand is that the number of years is a prime number.



A clue to this is in the nature of prime numbers. A prime number is a number that is only divisible by itself and 1. This means that any competitor or predator with a long life-cycle can't syncronise with a 13-year or 17-year cicada other than with a 13 or 17-year life-cycle. For example, a two-year life-cycle would only be in sycronisation with the 17-year cicada every 34 years; a three year life-cycle every 51 years.



Sophisticated mathematical models have shown how, given a long life-cycle, a predator satiation survival strategy and populations competing for the same resources, stable populations with a syncronised prime number periodicity will tend to form.



It also means that, once a 13-year form has become established, it will only hatch in the same year as a 17-year form every (13*17) years, or 221 years, so they exist, for the most part as isolated gene-pools. Biologists have long debated whether this makes the 13 and 17-year forms separate species according to a biological definition of non-interbreeding populations. Charles Darwin was of the opinion that this possible interbreeding every 221 years was enough to make these merely forms of the same species. Current thinking, based on genetic evidence, and on the fact that the two forms do not in fact normally interbreed due to different mating rituals, including different sounds made by the males, is that 13 and 17-year forms are in fact distinct biological species.



This is, of course, an example of how the man-made definition of 'species' is not always appropriate. Certainly, nature doesn't read the rule book, making Creationist pontification about micro- and macro-evolution utterly absurd. We can readily see in the 13 and 17-year periodical cicadas how one ancestral species can give rise to two daughter species by the operation of environmental factors acting on genetic variation.



Can any Creationist who has survived this far suggest how this story fits with an intelligent design notion? What is the purpose of producing a super-abundance of food once every 13 or 17 years which, if it makes any difference to bird, mammal, fish, snake or turtle populations in a geographical location, only creates a surplus to starve next year when the cicadas have gone? What is the purpose of cicadas which do little other than feed moles for almost all of their lives, slightly reduce the growth rate of trees and act as hosts for a fungus which does nothing other than produce fungi?



If you live in the Eastern USA, go outside any day soon to be reminded of how evolution works and enjoy the results of a perfectly natural process producing one of the great spectacles of the natural world.



Further reading:

The University of Michigan Museum - Periodical Cicada Page.

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