Thursday, 31 July 2014

Origins Of The Exodus Myth

With so many to choose from, it's difficult to decide which of the various folk tales, invented 'histories' and origin myths that have found themselves bound up in the same book and presented as the inerrant word of an omnipotent god is the silliest, but one of them has to be the tale of Hebrew enslavement in Egypt and subsequent escape.

It was obviously written by someone who knew little or nothing of the geography or politics of the time and place the tale was set, so we have the idiotic notion of the 'Israelites' escaping from Egypt by crossing the Red Sea to Sinai - which was also in Egypt. That's like 'escaping' from the USA by crossing the Hudson River from New Jersey to Manhattan or escaping from the UK by crossing the Bristol channel from England to Wales. The author also has the 'slaves' building the Egyptian city of Raamses - which wasn't started until some 120 after the traditional date of the Exodus.

Killer Sperms Reinforce the Species Barrier

Killer sperm ravages internal organs of luckless worms - life - 30 July 2014 - New Scientist

I've mentioned before how, as two diverging nascent species each evolve specialisation, hybrids will often be at a disadvantage being good an neither of their parent's specialities. As isolated and diverged populations of finches came back together, at the end of the last Ice Age for example, one might have evolved a long thin beak for eating small seeds and the other a short stout beak for eating large hard seeds. A hybrid with a long stout beak or a short thin one would find feeding difficult so it would be in the interests of both sets of genes to set up barriers to interbreeding.

The very fact that they are diverging accelerates the process of speciation, not as an end in itself but to protect the advantageous genes from being wasted on hybrids which have a lower probability of passing them on (see Why Species?, Creationist's Macro-Evolution Lie and More Mimetic Evolution).

We now have a rather surprising, even shocking example of one such barrier in closely related nematode worms.

More Evolved Mimicry

This is my last blog for a while on the fascinating topic of mimicry in animals and plants. Previously I wrote about Batesian and Müllerian mimicry in Copycat Evolution and More Mimetic Evolution where a harmless species comes to resemble a harmful one and so gains protection from a predator which has learned to avoid the harmful one (Batesian), or two harmful species come to resemble one another and so gain from the evolutionary 'spade-work' of the other (Müllerian).

Now I'm going to look at another form of mimicry where (usually) a plant deceives another species into thinking it's something else, not to repel or avoid it, but to attract it.

Tuesday, 29 July 2014

Murmuring Starlings Do It Naturally.

Decisions ripple through flocks of birds like a wave - physics-math - 27 July 2014 - New Scientist

One of the most spectacular sites in nature in Britain is a winter 'murmuration' of starlings, and I'm fortunate enough to live just a short drive from the open stretch of moorland north of Oxford known as the Otmoor, now a wonderful RSPB-owned nature reserve and important inland wetland site, where this spectacle can be seen most winter evenings at sunset in suitable weather.

Watch these videos first, then I'll discuss them. The first was filmed over Otmoor, the second at Gretna in Scotland.

Monday, 28 July 2014

More Mimetic Evolution

Having blogged a couple of days ago about the role of mimicry in evolution I decided to look more closely at the subject, especially the widespread mimicry found in butterflies. The results are fascinating.

But before I get on to that I'll just deal quickly with another aspect to evolution - speciation - following on from something I mentioned in the same blog. I pointed out how mimicry involved a two species both of which are prey to the same predator and where at least one of them is toxic or harmful to the predator.

I mentioned that the selection pressure for one species to become more and more like the harmful one depends on the presence of the predator in the local environment but the species range may well include areas with different predators, different comimics or indeed the absence of one or both. In this case, and in that part of the range there may be no selection pressure and no particular advantage in adopting the colour pattern of the toxic or harmful species, and there may even be a disadvantage because a different predator may not have any aversion to the mimicked colour.

Sunday, 27 July 2014

Recent Evolution - That Old Chestnut

Horse chestnut leaves infested with Cameraria ohridella lavae.
If you live in Southern England, for an example of very recent evolution you probably only need walk to your nearest horse chestnut tree. I took this photograph near Sunningwell, Oxfordshire earlier on Saturday when we went out for a last distant look at Didcot Power Station, which is probably England's best-loved 'eyesore' but which is due to disappear in a cloud of dust in a few hours time. The chances are that by now your nearest horse chestnut tree will be becoming infested with the leaf-miner caterpillars of a moth which was unknown before 1985 when the first outbreak was recorded in Macedonia, Greece.

Since then, Cameraria ohridella has spread at an average of 60 Km per year across western Europe reaching England in 2002, where it is now widespread, causing the leaves of horse chestnut trees (Aesculus hippocastanum) to turn brown, wither and fall off by late summer. Devastating though this attack appears, the general health of the trees seems not to be unduly affected since they come back into leaf and grown normally the following spring.

Although this moth was a newly-discovered species in 1985, specimens of it were accidentally collected and pressed in botanical specimens as early as 1879 only to be rediscovered when a team of researchers carried out a systematic search of specimens stored in herbaria.

Abstract
Determining the native geographic range or origin of alien invasive species is crucial to developing invasive species management strategies.

Friday, 25 July 2014

Copycat Evolution

Which ones would you pick up?
A friend asked me the other day to explain how mimicry can play a role in evolution. This is my attempt to do so.

There are in fact two main types of mimicry recognised by biologists, although the distinction is quite technical and is blurred anyway. For all practical purposes, they can both be regarded as forms of the same thing. They are known to biology as:

  • Batesian mimicry. Named after the English naturalist Henry Walter Bates. This is where a harmless species evolves to resemble a harmful species if it and the harmful species share a common predator.
  • Müllerian mimicry. Named after the German biologist Fritz Müller. This is where two harmful species evolve to resemble one another if they both share a common predator.

Thursday, 24 July 2014

Evolution Arms Race - Moose Spit Detox

Ungulate saliva inhibits a grass–endophyte mutualism

A fascinating example of both evolutionary cooperation and an evolutionary arms race was published in Royal Society Biology Letters yesterday.

Abstract*

Fungal endophytes modify plant–herbivore interactions by producing toxic alkaloids that deter herbivory. However, studies have neglected the direct effects herbivores may have on endophytes. Antifungal properties and signalling effectors in herbivore saliva suggest that evolutionary pressures may select for animals

Wednesday, 23 July 2014

Around the Bend with Ken Ham

2 January 2013: Astronomers have determined that the Milky Way may contain as many as 400 billion exoplanets, with almost every star hosting at least one planet.
"We'll find a new earth within 20 years" | Around the World with Ken Ham

Signs that Ken Ham may be beginning to panic at the thought that science could soon find evidence of life on another planet emerged recently with this desperate attempt to harness his fundamentalist audience in a bid to stop NASA looking for it, dismissing it as a waste of money which is bound to fail. His panic can be gauged from the horrible muddle he gets into with his argument where he inadvertently 'proves' that there isn't non-human life on Earth either.

He also showed his traditional propensity for making things up, even about the Bible, and relying on his ignorant audience not checking.

Monday, 21 July 2014

The Sacred Conclusion

Most theists will deny that they do it but it's usually easy to demonstrate that religious beliefs are not based an objective assessment of the evidence but on a received conclusion which is then protected and reinforced by highly selective cherry-picking of the evidence which is often heavily weighted whilst contradictory evidence is minimised, ignored or dismissed on spurious grounds.

'Evidence' can even include assumed evidence such as that 'list of eyewitnesses of the life of Jesus', 'all those fulfilled prophecies in the Bible which have been independently verified', or, in the case in point, 'all the historical names, places and events' mentioned in the Bible.

Nothing wrong with these as examples of evidence, of course, apart from just one thing - they are all false. There are no authenticated eyewitness of the life of Jesus; there are no fulfilled prophecies in the Bible which can be independently verified and there are no historical names, places or events in the Bible which give it an authenticity as a holy book.

Thursday, 17 July 2014

No Bread of Heaven for Creationism

Fiendish wheat genome reveals grain's history : Nature News & Comment

It's been another bad week for the Intelligent Design industry. No wonder their secretive five year 'Wedge Strategy' is now well into it's sixteenth year, during which the number of non-believers in the USA has gone up from about 4% to about 20%, conservative Christianity has become the preserve of the white right fringe and court after court has thrown out their attempts to subvert the Constitution and smuggle fundamentalist Christian extremism into the US public school system disguised as science.

Clearing Up the Unintelligent Designer's Mistakes

Hamilton O. Smith. (Photo: Jane Gitschier ©PLoS Genetics)
I'm homing in on the genetic essence of life - opinion - 14 July 2014 - New Scientist

In an interview published in New Scientist a few days ago, 1978 Nobel Laureate and synthetic biologist Hamilton O. Smith said:

The other thing we want to know is... how much can we rearrange the genes? Evolution has sloppily put them together. A lot of the cell's processes are scattered around. We're putting them together into one neat form.

He was explaining how his synthetic and bioengineering group at the J. Craig Venter Institute in La Jolla, California, USA is using the genome of a bacterium Mycoplasma mycoides to investigate the minimum number of genes needed to function as a viable, living organism.

Their greatest challenge is to work out exactly what DNA is junk, i.e., which has been included over billions of years but which now doesn't serve any purpose. Hamilton Smith estimates that it only needs 400-450 genes to make an organism viable. The other task is to rearrange these genes more efficiently instead of being scattered around the genome in the haphazard and 'sloppy' way they are in M. mycoides.

Wednesday, 16 July 2014

Altruism and Tits

Long-tailed Tit (Aegithalos caudatus)
Browsing through my Royal Society for the Protection of Birds (RSPB) magazine, Nature's Home, just now I came across a reader's letter asking about something he had seen with nesting long-tailed tits recently. He had noticed that several adults were helping to feed the young in addition to the parents and wondered if this was normal.

It is. It is a lovely example of altruism in one of my favourite birds.

The so-called long-tailed tit - it's actually closer to the warbler family than the tits - is one of the UK's smallest bird. Were it not for it's long tail it would actually equal the size of our smallest two, the

Tuesday, 15 July 2014

A Message From 270 Million Years Ago

Amphibians' swim stroke has lasted 270 million years - life - 15 July 2014 - New Scientist

Fascinating pictures of 270 million year-old fossils tracks from the Alps were published today, sadly most of them behind a paywall. They show the tracks laid down, probably by a salamander, as it paddled across a shelving patch of mud from shallow into deeper water and eventually taking to swimming. This is the first recorded instance of the transition from walking to swimming.

Abstract
Exceptionally preserved Early Permian tetrapod trackways from the Orobic Basin (Central–Western Southern Alps) offer a unique opportunity to investigate in detail locomotion in fossil vertebrates that lived on continental European landmasses. Herein are reported the results of a study on several tetrapod trackways that display a large variety of behavioral, gait and substrate related extramorphologies. They clearly document the transition from terrestrial–underwater walking to swimming and are assigned to the compound ichnotaxon Batrachichnus C Lunichnium. The use of the “C” symbol is here introduced for the first time as nomenclatural indication of a Compound trace. Producers were probably small-sized temnospondyl

Christmas Tree Tease for Creationists

The Norway spruce genome sequence and conifer genome evolution : Nature : Nature Publishing Group

Here's a fascinating piece of research from Sweden which is enough to give any self-respecting creationist pseudo-scientists a split personality. It shows how and why a Norwegian spruce (Picea abies a Christmas tree) has a much more extensive and complex genome than humans. I'll get to why it's a problem for creationists in a moment. Incidentally, thanks to Helmer von Helvete, a friend from Google+, for bringing this to my attention.

Abstract
Conifers have dominated forests for more than 200 million years and are of huge ecological and

Sunday, 13 July 2014

Catholic Church "Untrustworthy"

The Catholic Church in Germany is witnessing an astonishing collapse in public trust and is haemorrhaging members at an unprecedented rate. According to a Forsa poll recently 65% of Germans said they found the Catholic Church untrustworthy.

This trend has been linked to the 'bling bishop' scandal in which Catholic Bishop Franz-Peter Tebartz-van Elst was found to have spent millions of euros of church money on his own private house. He later 'resigned'. Once again ordinary Catholics had to endure the embarrassment of yet another Catholic cleric abusing the power and trust his position gave him.

In Germany, a tax is levied on church members by the

Friday, 11 July 2014

Of Mice and Men and Evolution

Source: Iakes Ezkurdia, et. al., Multiple evidence strands suggest that there may be as few as 19 000 human protein-coding genes*
Size of the human genome reduced to 19,000 genes - ScienceDaily

Just how close to other mammals are we? The answer is much closer than most people think and of course far closer than creationists will admit and which more sensible religious people like to imagine.

A detailed study led by Alfonso Valencia, Vice-Director of Basic Research at the Centro Nacional de Investigaciones Oncologicas (National Cancer Research Centre - CNIO) in Spain, and published in the journal Human Molecular Genetic found that about 90 percent of protein-coding genes found in humans are common to the earliest metazoans (multicellular organisms), that 99 percent of them pre-dated the emergence of the primates 50 million years ago.

Wednesday, 9 July 2014

Germ Warfare in Brazil

Credit: Gleison Miranda/FUNAI/Survival
Uncontacted tribe in Brazil ends its isolation | Science/AAAS | News

News that a previously isolated Amazonian tribe has made voluntary contact with a group of Brazilian government scientists from (FUNAI) marks a departure from the Brazilian Department of Indian Affairs' 'no contact' policy but was deemed necessary in this case because there was a serious threat to the welfare of the tribe from other tribes in the ares, following reports of raids on crops and theft of tools.

The reason for the 'no contact' policy is because of the very real threat to isolated people from the viruses we often take for granted such as influenza, measles and mumps. Between 1983 and 1985 some 60% of the

Sunday, 6 July 2014

More Trouble Down Under for Paedo-Protecting Pope

"We will not take one step backward with regards to how we will deal with this problem, and the sanctions that must be imposed. We have to be even stronger".
Pope Francis, 11 April 2014
In stark contrast to Pope Francis' public professions of sorrow and wheedling apologies for the Catholic Church's role in facilitating institutionalised sexual abuse of vulnerable children by it clergy, and his assurances that the Vatican will do everything to bring them to justice, the Vatican has declined to cooperate with an Australian Royal Commission set up to investigate abuses by Catholic priests in Australia.

As reported by Lindy Kerin for ABC News:

The head of the Royal Commission into Institutional Responses to Child Sexual Abuse, Justice Peter McClellan, revealed last month that he had

Saturday, 5 July 2014

Human Evolution - Ringing The Changes In Tibet

Tibetan Family
Tibetan altitude gene came from extinct human species - life - 02 July 2014 - New Scientist

The evidence that archaic, diversifying human populations behaved like a ring species over Europe and Asia just keeps on accumulating.

A couple of years ago I blogged about how a research team led by Rasmus Nielsen of the University of California, Berkeley, USA found that Tibetans differ from the Han Chinese by about thirty genes and most of these genes control how the body responds to altitudes.

This was a case of very rapid human adaptive evolution over a period as short as 3-6,000 years during which the

Consciously Evicting God From Another Gap

Consciousness on-off switch discovered deep in brain - life - 02 July 2014 - New Scientist

One of the favourite arguments used by religious apologists is that somehow materialism can't explain conscious thought and that a 'random' [sic] process like evolution could only ever give rise to random thoughts and not rational arguments.

Of course, this argument is never revised to accommodate developments in science and in our understanding of neurophysiology and the microscopic structure of neurons, so it is identical in form whether used by C.S.Lewis, William Lane Craig or Ken Ham even though our understanding of the science has been transformed immeasurably in the intervening half century.

But then we need to remember that religious apologists are not seeking to make converts but to keep believers believing and thus to ensure their income stream is maintained and the arrogant claims they make to

Friday, 4 July 2014

Green River Exposes Layers of Creationist Lies


Green River Formation varves
One of my favourite creationist pseudo-scientists must be the psychologist with no qualifications in science or record of research in the subject, Dr. Paul D. Ackerman, who supplements his income from teaching psychology as an assistant professor at a minor university by writing bad science books and articles for creationists who also seem to have little knowledge or understanding of science.

He is the notorious author of what must rank as one of the worst 'science' books for creationists ever published (it now has to be given away by the Institute for Creation Research) called It's A Young World After All: Exciting Evidence For Recent Creation. I've already dealt comprehensively with this book in a series of blogs so I won't dwell any more on it here, save to quote Dr Ackerman on what is one of the few nearly true things he said in his book:

Thursday, 3 July 2014

Still Not Yeti!

Genetic analysis of hair samples attributed to yeti, bigfoot and other anomalous primates

Last October I reported on a tentative claim by geneticist Bryan Sykes of the Oxford-Lausanne Collateral Hominid Project that he might have solved the Yeti question, only the Yeti is a descendant of a Paleolithic bear known from a single jawbone from northern Norway. This bear is believed to be ancestral to both the polar bear and the brown bear. His claim was based on a comparison of mitochondrial DNA (mtDNA) from samples of hair claimed to have come from Yetis with those of known species held on the GenBank database, an international database of genetic information.

mtDNA is inherited in mammals from the female line only and, because it doesn't recombine during sexual reproduction, tends to be stable over time, mutating at a more or less constant rate. It thus makes an excellent means of tracing female line populations and evolutionary relationships. The biological significance of this find was not so much that it might have solved the Yeti question but that it might have revealed a living population of this Ice-Age bear in the Himalayas, where it might have taken refuge as the ice retreated.

Now Bryan Sykes has reported on a much more extensive investigation of mtDNA from hair samples of 'Yeti', 'Bigfoot', and
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