Fishy Fossil Monogamy

Coelacanths give birth to live young
Image: Peter Shunula

Zoologger: The fossil fish that's a serial monogamist - life - 20 September 2013 - New Scientist

Following close on my blog about so-called 'living fossils', our closest living fishy relative, the Coelacanth, is back in the news once again, with this New Scientist article by Andy Coghlan. As so often with science, the answer to one question leads to a couple more questions.

Female coelacanths give birth to a large number of large live young after a gestation lasting three years. This represents an enormous investment for the female, so we would expect her to use a spread bet strategy and mate with several males rather than risk all on a small number of mates. However, DNA analysis of two pregnant Latimeria chalumnae females caught in 1991 and 2007 respectively by Kathrin Lampert and colleagues of Ruhr University Bochum in Germany, showed that all the young had the same male parent.

Coelacanths are carnivorous and live mainly on squid and small fish. The reason for a long gestation and live birth of relatively large young could be because, living together in caves would put small young at risk of being quickly eaten by parents and other coelacanths. Being large and immediately independent would give them a fighting chance of escaping.

So, we now know that females are monogamous, admittedly based on just two examples, but that raises a couple of questions:

1. Why monogamy when polygamy would be expected?
2. How does internal mating occur when males don't appear to have the necessary apparatus for penetration?

These massive fish - up to 1.5 meters (nearly five feet) long - live in deep ocean volcanic caves in what are believed to be colonies of a few individuals. It is believed that there are only a few hundred coelacanths still alive, so it could be that males are in short supply. It could also be the mating is a prolonged process, maybe involving mating rituals intended to bring the male and female cloaca into the right alignment for sperm transfer to occur.

But the real answer is that we don't yet know and can only hazard educated guesses.

I wonder if one of my keen creationist readers could suggest an 'Intelligent' Design explanation for males not have the required equipment for internal fertilisation and why females put all their eggs in one basket as a mating strategy. Could it be that a slow lingering extinction is what the benevolent Intelligent Designer had in mind all along when he created coelacanths?

'via Blog this'

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Recent Evolution Underground

Culex pipens taking a meal

If you travel on the London Underground you might consider using a good insect repellent. We have a newly-evolved species of mosquito living there and it is a voracious blood-sucker. It has been classified by taxonomists as Culex pipiens f. molestus. It lives off the blood of rats, mice and especially humans, unlike the birds it's parent species lives off.

It has evolved very recently, certainly since the London Underground was built, starting in 1863, almost certainly from a population of C. pipens, and made life miserable for those who took shelter in London Underground stations during the blitz of WWII, as though Hitler wasn't making it miserable enough. The fact that hybrids between it and C. pipens are usually sterile suggests that speciation has occurred and the subterranean variety should more properly be classified as a new species rather than a variety or subspecies of C. pipens.

The evidence for this mosquito being a different species from C. pipiens comes from research by Kate Byrne and Richard Nichols. The species have very different behaviours, are extremely difficult to mate, and with different allele frequencies consistent with genetic drift during a founder event. More specifically, this mosquito, C. p. f. molestus, breeds all-year round, is cold intolerant, and bites rats, mice, and humans, in contrast to the above-ground species, which is cold tolerant, hibernates in the winter, and bites only birds. When the two varieties were cross-bred, the eggs were infertile, suggesting reproductive isolation.

Source: Wikipedia - London Underground mosquito

I'd love a liar for Jesus/money/power from the Discovery Institute, Answers in Genesis, or any other pseudo-science creationist scam site to come here and explain to my readers how this fits with their infantile 'Intelligent (sic) Design' model. Why would a benevolent creator god suddenly come up with a subterranean mosquito in the last 150 years which seems to exist solely to make more mosquitos and for making the life of travellers, staff and maintenance workers on the London Underground a little less pleasant, unless he was on Hitler's side in WWII and was doing his bit to help by being an irritating little nuisance and has just left his secret weapon hanging around?

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To A Mouse

I had a brief encounter with a mouse the other day. Not one quite so dramatic as Burns' - it's a long while now since I followed a horse-drawn plough. In fact, to be strictly accurate, it's a long while now since I saw a horse-drawn plough. They even had them-there tractor things when I was a child.

No. My encounter was a lot more mundane.

Every morning I feed my birdies - a flock of (mostly) wood-pigeons, collared doves, starlings, house sparrows and other assorted birds in season - at the bird table and various feeders we have in the back garden. I buy the mixed birdseed in 20 Kg. sacks along with bags of dried meal worms and peanuts and store it in our garden shed.

To a Mouse

(Written by Robert Burns in Gallowegian dialect supposedly after he had turned over the nest of a field mouse with his plough. This poem illustrates Burns' tolerance to all creatures and his innate humanity.)

Wee, sleekit, cowran, tim'rous beastie,
O, what a panic's in thy breastie!
Thou need na start awa sae hasty,
Wi' bickering brattle!
I wad be laith to rin an' chase thee,
Wi' murd'ring pattle!

I'm truly sorry Man's dominion
Has broken Nature's social union,
An' justifies that ill opinion,
Which makes thee startle,
At me, thy poor, earth-born companion,
An' fellow-mortal!

I doubt na, whyles, but thou may thieve;
What then? poor beastie, thou maun live!
A daimen-icker in a thrave 'S a sma' request:
I'll get a blessin wi' the lave,
An' never miss't!

Thy wee-bit housie, too, in ruin!
It's silly wa's the win's are strewin!
An' naething, now, to big a new ane,
O' foggage green!
An' bleak December's winds ensuin,
Baith snell an' keen!

Thou saw the fields laid bare an' wast,
An' weary Winter comin fast,
An' cozie here, beneath the blast,
Thou thought to dwell,
Till crash! the cruel coulter past
Out thro' thy cell.

That wee-bit heap o' leaves an' stibble,
Has cost thee monie a weary nibble!
Now thou's turn'd out, for a' thy trouble,
But house or hald.
To thole the Winter's sleety dribble,
An' cranreuch cauld!

But Mousie, thou are no thy-lane,
In proving foresight may be vain:
The best laid schemes o' Mice an' Men,
Gang aft agley,
An' lea'e us nought but grief an' pain,
For promis'd joy!

Still, thou art blest, compar'd wi' me!
The present only toucheth thee:
But Och! I backward cast my e'e,
On prospects drear!
An' forward, tho' I canna see,
I guess an' fear!

Robert Burns, 1785

I used to just stand the sacks of seed in the shed and fill a small container to take to the bird table until a family of mice set up home in the shed and learned to chew holes in the sacks, so I bought a plastic dustbin with a clip-on lid in which I also keep a plastic bucket to take seed, mealworms, peanuts and scoop to the garden in. Initially I felt a little bad about locking their food away and use to put a little seed and a few peanuts out for the mice but I decided it was best to wean them off their increasing welfare dependency and encourage them to earn an honest living.

A couple of days ago though, one little mouse had decided to use its entrepreneurial initiative and, when my back was turned and the lid was off, had had jumped or fallen into the deep plastic bin - with smooth sides.

My initial surprise was to discover that there were still mice in the shed. The mouse's initial surprise was to see the bottom of a large, black plastic bucket begin to descend, followed quickly by a large pair of eye and a human voice saying, "Hello! Okay! Let's see you get yourself out of there then!"

Isn't it interesting how quickly mice get over that initial panic and, after running round the perimeter of the bin three times, stop, look up, sit back on their haunches and wash their face.

So, what to do now then? In times gone by I would have thought nothing of picking it up by the tail and giving its head a quick flick against a wall then chucking it to the nearest cat or onto the compost heap. Maybe I'm getting soft or maybe I just appreciate living things a little better. Whatever, I decided to let nature take its course and do a little experiment. How would the mouse get itself out of an impossible situation?

Maybe it didn't appreciate the situation fully but my little mouse just picked up a sunflower seed and proceeded to take out the kernel and eat it. Maybe it needed some energy.

Of course, given a practically unlimited supply of food in comparison to its size, and not needing water beyond what they can get from their food, even dry seeds, the mouse wasn't actually in any real danger. It could have lived its entire life in that bin so maybe its risk assessment was a little different to what mine would have been. Never-the-less, my little mouse did try to climb up the sides a few times, then it tried jumping - as though its ability to jump about four inches was going to be enough to get to the top, about 30 inches away. But it was obviously worth a try - yer gets owt for nowt!

So I thought, let's see how intelligent you are. How quickly can you learn to climb a piece of garden string?

So I pulled out a length of string from one of those balls of green garden twine which was standing on the rack next to the food bin, and let it hang loosely down to the surface of the seed.

1. Mouse finds string and starts to climb. String is loose and stretches out so mouse makes no progress and gives up.
2. Mouse tries again and pulls string to make it tight then starts to climb it. Falls off.
3. Mouse tries again and climbs string until it can reach the rim of the smooth plastic bin with its front feet. Lets go with its hind feet but loses grip and slips back into the bin.
4. Mouse climbs up above the rim of the bin so its hind feet can stand on it. Walks round the rim of the bin a short distance then hops onto the rack, washes its face, and disappears.

In four steps the mouse had learned progressively by trial and error, and had got itself out of the bin.

What we had there was an interesting interaction in terms of genes and memes.

The mouse found itself in a predicament brought about because it exists in an environment in which I exist and in which the meme for enjoying nature and wanting to attract birds into my garden exists. The mouse genes had produced an animal which needs to feed and which actively looks for food, using a whole range of senses and abilities, not least of which is curiosity and an ability to discover by trial and error.

It survived because I have a mixture of memes and genes which make me interested in wildlife and an appreciation that they, like us, are the end-products of an incredible evolutionary process in which every one of our ancestors survived, that to end that gene-line would bring to a halt a process which started three and a half billion years ago and which has never yet failed, and an understanding that the simple fact of sharing our history and having ancestors in common with all living things gives us a connectedness and a kinship with it which is truly inspiring and deeply spiritual.

And the mouse had genes which allowed it to make an intelligent assessment of its situation, plan an escape strategy and improve its technique by trial and error whilst learning from its mistakes and keeping its objective in sight. With a little help from its friend.

And I spent a magical twenty minutes or so enjoying an interaction with a wee, sleekit, cowran, tim'rous beastie.

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Evolution in Progress - A Tale Of Three Sparrows

Italian sparrow, Passer italiae

While sitting enjoying the shade in a very hot Villa Borghese Park in Rome the other day [sniff!] I noticed all the male sparrows were different to our 'normal' house sparrow that we see in Britain and most of the rest of Europe. They all have chestnut coloured heads whereas the usual house sparrow males have grey heads. Their backs looked a little brighter too. The females are indistinguishable (to me) from the usual female house sparrows. I have seen these 'Italian sparrows' before, in Switzerland on the south side of the Alps just a few miles from the Italian border. It's the kind of small difference that makes you think, "there's something different about that bird!" Most people who have no interest in wildlife probably wouldn't even notice it.

How Birds Lost Their Penises

How did the cockerel lose its penis?

BBC News - Study reveals how birds lost their penises.

One of the great mysteries in bird evolution is why the males in all but about three percent of species have lost their penises during their evolution, even though fertilisation takes place internally. What makes this a little more of a puzzle is why a few species, such as ducks, geese, ostriches and rhea have retained one - and we now know that it has been retained rather than having evolved independently.

In the majority of bird species sperm is transferred to the female during a 'cloacal kiss' when the single openings for the digestive, urinary and genital tract, the cloaca, of the mating pair are pressed together. Mating for most birds lasts just a second or two and is often performed frequently during the breeding season.

One theory, which requires a lot more work to

Evolution Of A Plague of Locusts

Magicicada adults and final stage nymphs.

Photo credit: 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.

Ear Worm Crosses The Species Barrier

Outside near my garden right now is a male Blackbird in a beech tree announcing to the blackbird world, and particularly to any spare females, that this is his territory and he is available. He has been there every day for about two weeks or more singing variations of his repertoire of musical phrases and cadences and competing with the Gold finch's babbling silver trickle of notes and Great tit's piping in the same tree. (A typical Blackbird song on this RSPB site).

European Blackbirds are noted for incorporating musical phrases into their song and extemporising on them. This particular one seems to have a snatch of a song by Robert Burns called Ye Banks and Braes which is ironic really because the phrase it keeps singing is the tune to the lines "Thou'll break my heart, thou warbling bird, That wantons thro' the flowering thorn!"

Ye Banks and Braes

Ye banks and braes o' bonnie Doon,

How can ye bloom sae fresh and fair?
How can ye chant, ye little birds,
And I sae weary, fu' o' care!
Thou'll break my heart, thou warbling bird,
That wantons thro' the flowering thorn!
Thou minds me o' departed joys,
Departed, never to return.
Aft hae I rov'd by bonnie Doon

To see the rose and woodbine twine;
And ilka bird sang o' its luve,
And fondly sae did I o' mine;
Wi' lightsome heart I pu'd a rose,
Fu' sweet upon its thorny tree!
And my fause luver stole my rose -
But, ah! he left the thorn wi' me.

Robert Burns

Maybe it's just a coincidence and that it my brain's ability to recognise patterns which is working, but what we have here is an example of a meme or ear worm. It's something every successful pop tune writer tries to achieve - a phrase you keep playing over and over in your mind.

This Blackbird has pulled off the neat trick of passing a meme across the species barrier so my mind now keeps singing "Thou'll break my heart, though warbling bird...". A meme is of course a unit of cultural inheritance; in this case a musical phrase which interprets in the context of my British cultural background and my personal development as a song by Burns, complete with the Galawegian Scottish dialect words with phrases like "And I sae weary, fu' o' care!" and "And ilka bird sang o' its luve, And fondly sae did I o' mine; Wi' lightsome heart I pu'd a rose, Fu' sweet upon its thorny tree!"

In the context of the Blackbird's culture of course, that same meme has a totally different meaning understood only truly by another Blackbird.

This is the exact analogy of how genes only have meaning in the context of the environment in which they are expressed and by which the information in them is translated into meanings. This is a point which Creationist pseudo-scientists either don't understand or deliberately obscure when they claim that no new information can arise from mutation (which is nonsensical anyway) when what is important is not the information but what that information means in the context of the environment in which it expresses. Even with no change in information, an environmental change can produce a change in the meaning if that information and so an evolutionary change in the species carrying it.

The importance of the cultural context of memes is also illustrated in a blog I wrote a few days ago about cultural bias in which I presented some common 'proofs' of the existence of the locally popular god and the truth of different holy books with 'proofs' which only work on people with a pre-exiting belief in those gods and holy books. To people from other cultures, the fallacy of those 'proofs' is laughably obvious because it is quite simply devoid of an rational meaning.

It is because the interaction between the genotype and the environment produces the phenotype and the environment selects in favour of fitness to survive in that environment, that species look as though they were made for that environment. They were. They were made by the environment itself.

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Fundamentalists Should Have Sex Like Rabbits

Moment of Ovulation

Creationists really have got their knickers in a knot over sex, especially when they insist the only purpose of sex is procreation and that doing it for pleasure or as a social activity is somehow sinful, something to be ashamed of, and not what their assumed intelligent designer designed us for.

If this were so, and if we had been intelligently designed, there would be a link between ovulation (egg production) in women and intercourse, and not to an almost complete disconnect between sexual activity and ovulation. As it is, women ovulate every 28-30 days on average whether or not that have had sex. Even virgins and sexually inactive women produce a monthly egg or two. Unless they are pregnant or breast-feeding a baby, healthy women normally ovulate every month from the age of puberty until the menopause, usually between forty-five and fifty-five years of age - some thirty to forty years.

Whether or not they become pregnant will depend entirely on if and when they have sex and if a live sperm happens to come across a viable egg in the right place in her reproductive plumbing.

An intelligent designer who intended sex to be only for procreation would have designed this process so that women only had sex when they were sure to get pregnant and that every instance of intercourse resulted in pregnancy. It's not as though such a system hasn't been designed. If you believe in this intelligent designer you will believe it designed the process so I'm afraid you are hooked on your own logic here.

Ironically, one of the best examples of sexual activity being designed to ensure pregnancy, thus ensuring its purpose is exactly what religious people insist sex is for, is to be found in the very mammal frequently cited as an example of promiscuity - the rabbit.

My first job as a school-leaver many years ago was as a laboratory technician in Prof Geoffrey Harris's Neuroendocrinology Research Unit in Oxford. One of the things we were investigating was hormonal control of ovulation, using rabbits. Prof. Harris had discovered that the hormone which causes the ovary to shed its eggs is produced by the pituitary gland in response to 'releasing factors' (we were trying to find out exactly what they were) which are produced by special nerves in the stalk attaching the pituitary to the brain. These 'releasing factors' are transported to the pituitary gland in blood by a microscopic 'portal system' of small blood vessels which ensures they are concentrated and delivered to the front lobe of the pituitary where they cause the pituitary to produce 'lutenising hormone' into the blood, which, when it reaches the ovaries, causes an egg to ripen and be shed.

One drawback to using rabbits is that you have to be careful how you pick them up, otherwise you can induce them to ovulate - which is not what we wanted as we were trying to induce this with hormones.

The reason we were using rabbits is because they are spontaneous ovulators, that is, they don't have an oestrus cycle but ovulate when mated. In rabbits, there is a simple reflex system which is initiated by mating, either by direct stimulation of the vagina, or even by a male mounting and attempting to mate - and this is where we needed to be careful. If you stroke a female rabbit's back, or her hind quarters, you can simulate the act of a male mounting her and cause her to ovulate, so you need to pick them up by the scruff of the neck and keep contact to a minimum.

So, in rabbits, which have sex like rabbits - duh! sex is for procreation and the system ensures a high degree of success, where most sex acts lead to pregnancy.

So, Creationists, if your 'intelligent designer' designed this system in rabbits, why didn't it use the same system in humans where all the components are present and just need to be set up correctly to work the way you claim it intended them to work?

In fact, this system has probably been switched off in humans and in at least our close cousins, the bonobo, because sex for pleasure and for other than procreation is so beneficial in terms of pair-bonding and social interaction and where sexual activity continues well past the menopause where is can have no procreational purpose whatsoever.

Of course, Darwinian Evolution has no problem at all explaining these differences. With both humans and rabbits the respective system used produces more surviving descendants given the long, slow childhood of human children which benefits from a pair-bond between parents, compared to the short period of maturity in rabbits which are independent of their mother in a few weeks, sexually mature and in a few months and in whose nurturing fathers play no part at all.

If the religious views of Creationists were sincere, and they knew what they were talking about, they should be advocating humans behave like rabbits when it comes to sex. At least that might go some way to filling the rows of empty pews most European priests are seeing most Sundays nowadays.

This is of course just one of the problems Christians and Muslims have with trying to shoe-horn reality into the primitive superstitions of misogynistic and sex-obsessed Bronze Age tribal leaders who believed in a flat earth, magic, talking snakes and that rain is water dripping through holes in the canopy over the earth from which the sun and moon are hanging.

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Boring Beetles And Bad Eggs

Xyloborus ferrugineus
Pest and Diseases Image Library, forestryimages.org

Xyleborus ferrugineus is a boring little beetle. So boring in fact that as a juvenile or grub, it spends its time boring into wood. It is a destructive pest in parts of Australia. But at least it lives up to its Latin name, which translates into English as 'rust-coloured wood-borer'.

What makes this interesting though, is the strange and unusual, and maybe unique, way in which these beetles determine their gender.

First a little about gender determination: in most mammals this depends on the X and Y chromosomes and all species are diploid (that is, they all have pairs of chromosomes in their cells, all apart from one set. In female mammals there are always two X chromosomes, paired up like any other set. In males, however, there is one X and one Y chromosome, of which the Y is small.

During egg and sperm production, these pairs of chromosomes are shared out, one of each pair to each egg or sperm respectively so, all eggs, produced by females who only have X chromosomes, will all have just one X chromosome, that is, they are haploid. Sperm produced by males however, will either have an X or a Y chromosome.

During fertilization the chromosomes from a sperm are transferred to the egg to produce the complete normal number of chromosomes again. Depending on whether the sperm had an X or a Y chromosome, the resulting embryo will either be male or female.

For more detail on gender determination, see this article.

So, in mammals and many other animals and plants, gender is determined genetically.

In some insects, plants and animals, however, rather than the presence or absence of one or other of a pair of chromosomes, gender is determined by the presence or absence of a complete set of chromosomes. In many social insects of the hymenoptera order, such as wasps, bees and ants, and in some coleopterans (beetles), all males are haploid (that is they only have one of each chromosome). Females, on the other hand are diploid (that is they have two, in pairs). In these insects, the fertilised female keeps a store of sperms and can 'choose' to fertilise an egg, or not. Unfertilised eggs become males and fertilised eggs become females. This means, of course, that in these species males have no fathers!

Now, where does our boring little beetle fit into all this?

Well, as with several other related beetles, X. ferrugineus gender depends on whether they are haploid or diploid. To produce a diploid female the egg needs to be fertilised by a sperm from a male. However, and this is the magic bit, to produce a male, the egg ALSO needs to be fertilised, though not with a sperm but with a bacterium!

So, male X. ferrugineus all develop from 'bad' eggs and the bacteria live in their developing bodies and are passed to the females along with normal sperm during mating.

So what we have here is an example of parasitism having progressed to symbiosis when both sets of genes have an 'interest' in the same outcome. The genes of both the host and the parasite form a cooperative alliance because both benefit from it. The beetle gets the benefits of sexual reproduction, with gene shuffling, etc, and the bacterium gets a free ride and all the nutrients it wants.

And of course this is possible because, at the basic level, evolution takes place in genes. Where alliances are beneficial to genes, or any other replicators like memes, for that matter, these alliances are to be expected.

For another example of this see my blog Unintelligent Design - Forming Alliances. Plenty of other gene alliances can be found in nature. For example, look how many copies of wild jungle fowl genes can now be found in domestic hens following their alliance with humans. How many sheep would there be now had humans never formed an alliance with them? And what of wheat and other cereal crops which now form vast prairies in some parts of the world?

More pertinent to the human story maybe is to wonder how many humans would there be today had we never formed alliances with wheat, rice, maize, barley, horses, cattle, pigs, etc, etc, etc.

And of course, the wider lesson from nature from the 'selfish gene' is how very often cooperation results in great advantage to both members of the alliance. Indeed, life itself depends on replicators, or genes, forming alliances with other genes even at the simplest prokaryote cell level. At the higher cell level, alliances of prokaryote cells formed eukaryote cells. These in turn formed multicellular organisms which in many cases formed social groups, and societies. And, especially in humans, in alliance with those other replicators, memes, multicellular life formed cooperative groups, social systems, nation states and cooperative national groups like the European Union.

By contrast, competition between genes and especially between alliances of genes, is frequently harmful to both, especially when it results in arms races.

None of this makes any sense as the work of an intelligent designer of course. Why would a single designer come up with so many different ways to determining gender, and why have genders in the first place when parthenogenesis would be so much simpler?

From the perspective of 'selfish' genes, there is no problem at all and no magic involved, though some might find the result magical indeed.

What a wonderful world.

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A Callous And Indifferent God?

Eurasian Wren (Troglodytes troglodytes)

How could a benevolent, all-knowing creator god have created the wren?

Wrens, Troglodytes troglodytes, are one of the smallest British birds, being only marginally larger than our smallest bird, the migratory goldcrest (Regulus regulus). The Eurasian wren inhabits a zone extending from Britain, across Europe and into Iran, Afghanistan and across Central Asia to Japan. Over most of this range, wrens are sedentary.

At the northern extremity of it's range it has to cope with occasional periods of extreme cold such as occurred in Europe and especially Britain in 1963 when our winter weather became Siberian for about 3 months. We are experiencing a period of cold now where the temperature is struggling to get above freezing during the daytime. The wren is one of the smallest warm-blooded animals to survive our winters and yet it doesn't hibernate like some small mammals.

Wrens have a mating ritual which entails males building several nests and then enticing a female to mate and lay eggs in it. She will inspect the nests first and will only choose a mate who has built a nest she finds suitable. Only then is the nest lined and prepared for the brood. She then broods the eggs and tends the young whilst the male goes off to entice another female into another of his nests. This leaves many nests, some of which will not be used for brooding.

So how does the small wren, which because of its small body mass, and consequently a large surface area to mass ratio - meaning it will lose heat very quickly and will need a high metabolic rate to maintain its body temperature - keep warm in these winters?

In normal winters, the old nests from spring and summer are used as roosts. Several wrens will gather together in the same nest, so decreasing their surface area to mass ratio, and so keeping warm.

They do the same thing in these occasional periods of extreme cold. The only problem is that, if too few wrens gather together, or the temperature falls too low, or the nest isn't quite as good an insulator as is needed, very many wrens freeze to death overnight and the population will crash.

As a youngster I lived near the beautiful, and poetically named, River Evenlode in North Oxfordshire, one of the tributaries of the Thames. This river had been diverted at several points when the Oxford to Worcester railway line had been built by the Great Western Railway Company to make it easier to build bridges across it. In one such place in an elm wood, the old river bank was still exposed and formed a sort of shallow over-hang hung with tree roots and wild clematis. I could always guarantee finding several wrens nests under these ledges.

In the summer of 1963, after one of the severest winters on record in the UK, when searching for these nests, I found nest after nest full of mummified bodies of wrens, probably some twenty or thirty dead wrens in all. All of them victims of the winter.

So, how does evolution account for this?

Quite easily. Wrens have evolved a survival strategy which works well enough in most years and which leaves a few survivors even in harsh winters. Even when a local population is wiped out entirely in a single year, as may well have happened in my small elm wood in 1963, sufficient survivors are there in other areas to move into the vacant territory. Wrens also produce several batches consisting of 6-8 eggs in a year so a population can bounce back quickly, especially since food will be plentiful in areas where the population has been reduced.

In this way, the environment and the habits the wren has evolved to cope with it, work well enough together to allow the species (i.e. the wren genes) to survive and to produce more wrens next year. This, of course, takes no account of the suffering and death from cold of the individual wrens. There is no survival value for the genes in evolving mechanism to prevent this altogether, only in as much as it leaves a few gene carriers to carry them into the next generation. Because it works well enough, there is minimal evolutionary pressure to evolve more complicated strategies such as hibernation or a larger body mass.

Interestingly, on the point of a larger body mass, the wrens on St Kilda, a remote North Atlantic island, are measurably larger than the mainland population. The differences are enough for this wren to be given sub-specific status, Troglodytes troglodytes hirtensis.

And of course, the northern limit of the Eurasian wren's range will be determined by a line above which there are no survivors over winter, so a dynamic has been created which will fluctuate a little each year and by a larger amount as climate changes over the long term. The northern limit will always be an area of large-scale occasional population crashes and recovery.

No intelligent, compassionate, loving creator would be this callous and indifferent to the suffering of individuals. Quite clearly, the wren, it's range, its reproductive strategy and its winter survival strategy have all been created by a dynamic and selective environment.

No mystery and no magic required. Evolution by natural selection is again the most parsimonious explanation.

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An Evolving Sense Of Self

It's usually taken as given that a measure of high intelligence, in comparative terms between species, is that only the most intelligent species have a sense of self, in other words, it takes a high level of intellect to have self awareness.

A rather nebulous definition of 'self-awareness' is awareness of your own individuality which is about as useful as defining 'impressionist art' as 'art done by impressionists'.

A standard test of self-awareness used by animal psychologists is the mirror test. This test assumes that the more intelligent an animal is the more likely it will be to identify itself in a mirror. Apparently, all of the African apes, the orang utan and three species of gibbon have all passed the mirror test, and so have bottlenose dolphins, killer whales, elephants and European magpies (a bird of the crow family). All of these are known from other tests to be highly intelligent.

But I have long been suspicious that these test have an inbuilt species bias. They test not for intelligence or self-awareness but how similar the subjects are to humans in respect of the thing being tested.

To understand self-awareness you need to understand how our brains model the world around us and map it into a concept which can be projected into the future. We see cars moving in the street and project them forward in our conceptual model to calculate where they will be in a few seconds time and whether we can safely pull out in front of them, start to cross the road, or need to hurry over. We see other people and take verbal and nonverbal clues from them which we then place in our conceptual model to gauge how they might react to us according to what we do or say next.

And, to complete this model, we must include ourselves as an object in it. It is the awareness of how and where we fit in this model which we call self-awareness. It is our ability to include ourselves and to incorporate our own actions and reactions in our model world which makes us self-aware, and the construction and manipulation of this model is what we call 'consciousness'.

I remember standing outside the place where I worked in Oxford, on the edge of a local nature reserve run by the Berkshire, Buckinghamshire and Oxfordshire Wildlife Trust, which I am proud to support, and watching a grey squirrel travel though a small stand of beech trees. It was obvious the squirrel knew where it wanted to get too and had plotted a route which included frequent jumps across gaps, detours up one branch and down another and occasional pauses as it prepared itself for a particularly long jump.

Clearly, this squirrel had a conceptual model of its environment and had plotted a course through it. It was also clear that it had projected itself into that model and placed itself at each stage through that route. More importantly though, it had originally projected itself forward in its model world to where it wanted to be. I have yet to understand how it could have done that without self-awareness, yet our grey squirrel would probably never pass the mirror test and would be regarded as not especially intelligent.

Not every animal needs to navigate a route through the branches of a stand of trees of course, but many animals, especially predators, need to plan, even to chase down their prey. Simply to walk across the ground they need to 'know' where they want to get to. In Corfu I have also watched a snake, which I've never been able to identify as I didn't have a camera with me, hunting along the banks of a small stream, clearly looking for frogs and voles, and very clearly acting with purpose as it swam back and forth, working first one bank then the other and gradually working up the stream. I really don't see how it could have done this without a conscious sense of purpose and without placing itself in a conceptual model of its world, if only to swim across the stream.

During my life-time our idea of intelligence in other animal, especially mammals and birds, has changed. I remember when we took it as read that humans were the only thinking animals - our scientific name Homo sapiens means 'man who thinks' as though nothing else does. This was taken as a sign that we were a special 'creation'; somehow different in a material way to other animals which was, naturally, 'evidence' that we were somewhere between the angels and the rest of 'creation' with no doubt at all that the world was created especially for us.

We were, of course mistaken, as you would expect of an idea based on nothing more substantial than superstitions, which are themselves merely the projection of our anthropocentric arrogance onto our conceptual model of the universe, and of the assumption that the 'self' we include in our model is another entity which lives in our body and watches the world for us through the windows we call eyes; that reification we call a 'soul' which earlier superstitions had mistaken for consciousness.

Stories began to emerge from detailed studies of wild chimpanzees that they could make tools and practiced subterfuge - which needs self-awareness AND empathy with other chimps.  It was then recognised that all the great apes had a high level of intelligence and were self-aware.  Then marine biologists discovered that dolphins, including killer whales, were also highly intelligent. Some even claimed they may be MORE intelligent that humans. Certainly they seem to have a complex language which has so far defied human understanding.

Laboratory tests showed that rats can quickly learn their way through a maze, that some birds can solve puzzles and even fashion tools.

When milk started to be delivered to our doorsteps in foil-covered bottles, several species of bird, including blue and great tits, blackbirds, magpies and jackdaws all learned to open them to get the cream. This behaviour was mapped and was found to radiate out from centres where it started, showing that learning by observation was taking place. How can a bird learn if it has no sense of self? Why would it realise that if it does what that other bird is doing, it will get cream, if it had no self-awareness.

In parts of the United States there has been a kind of arms race between householders and raccoons which have learned to open trash cans. As more elaborate methods have been used to keep them out, so raccoons have learned to overcome them. In the UK, if you still put bin-bags out and haven't been wheely-binned yet, don't blame the local dogs, cats and foxes for them being ripped open and the contents scattered; in the summer, it's just as likely to have been hedgehogs! And why not? The contents of pet-food tins and pieces of pizza are just as filling as slugs, snails, earthworms and woodlice.

Look closely!

And so gradually, another cherished myth given to us by religion and which has so badly damaged our view of the natural world and our position within and part of it, has been eroded by science and has now all but gone. Very clearly, other animals have consciousness and a sense of self.

Man is a unique species without doubt, which is why, like all other species, science gives us a unique classification, and so we have features which make us unique, but having consciousness and a sense of self-awareness are not amongst them. Nor is intelligence per se, though we may have an especially well-developed form of it, just as elephants have an especially well-developed nose, though no one would give them semi-divine status because of it, save perhaps a superstitious elephant.

The observable facts once again fail to support the notion that Man is the special creation of a god and not just another evolved mammal. All the evidence supports the theory that man is the product of evolution with common descent and has a body plan which is a 'merely' a variation on the basic mammalian theme.

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Something Fishy About Creationism

East African Lakes

The lakes of East Africa with their diverse populations of a group of related species of cichlid fish provide a superb example of radiating evolution over a very short time scale and so are a major problem for creationism. These fish represent an aquatic version of Darwin's finches, and are, if anything, an even more dramatic example of the way new species arise by evolving into new ecological niches and an example of the very short time-scale over which this can occur. See The root of the East African cichlid radiations.

First a little about the lakes and their geology:

Between 17,000 and 16,000 years ago, towards the end of the last Ice Age, there was a surge of icebergs and glacial meltwater into the North Atlantic which altered ocean currents and changed the weather pattern over the African and Asian monsoon areas, which experienced a resulting mega-drought. Analysis of sediments show that this caused Lake Victoria, Lake Albert and Lake Tana to dry up and disappear.

A similar event 14,000 - 15,000 years ago caused Lake Victoria to dry up again and a subsequent lowering of water levels 5,000 years ago left a small satellite lake, Lake Nabugabo, isolated. So, from this we know how long ago each lake received its founding population of cichlids from their feeder rivers. In the case of Lake Victoria, this was between 14,000 and 15,000 years ago. We also know that the micro-lake, Lake Nabugabo, has been isolated for just 5,000 years. By contrast, nearby Lake Tanganyika is tens of millions of years old and has remained filled for all that time. See AfricaPaleo - FOCUS 1: Lake levels and evolution.

And Let Them Have Dominion... Again

Genesis 1:26 And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth. (KJV Bible)

Photograph Kim Cheung/AP

Seized rhino horns in Hong Kong

Customs officers seized a total of 33 unmanifested rhino horns, 758 ivory chopsticks and 127 ivory bracelets, worth about HK$17m ($2.23m), inside a container shipped from Cape Town, South Africa

Source: The week in wildlife – in pictures (Guardian)

And Let Them Have Dominion...

Genesis 1:26 And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth. (KJV Bible)

Photograph: Martin Harvey/WWF International
The white rhino Ceratotherium simum. Killed by poachers for its horn and fuelled by demand from Vietnam,
rhino poaching in South Africa shows no signs of abating, with a record 341 killed there this year to date.