by John Lloyd
Tidal effects are at their strongest when the sun and moon are on the same side of the earth (new moon), or on the opposite side (full moon), and their gravitational pulls combine to create the strong ‘spring’ tides (‘spring’ in the sense of ‘powerful forward movement’, not the season).
The Phoenicians founded Gabes in about 800 bc. Pliny the Elder first noted its unusually large tides in AD 77 in his Natural History. He also recorded that Gabes was second only to Tyre in the production of the expensive purple dye made from murex shells, which the Phoenicians discovered (hence the Greek for purple, phoinikeos), and which was highly prized by the Romans: the toga purpurea was worn only by kings, generals in triumph and emperors.
The Mediterranean is bigger than you might think. At 2,500 square kilometres (965 square miles) it covers the same area as Sudan, the largest country in Africa, and would comfortably swallow Western Europe (France, Spain, Germany, Italy, Greece, Britain, the Netherlands, Belgium, Switzerland and Austria combined). Its coastline stretches for 46,000 kilometres (28,000 miles) or about twice the length of the coastline of Africa. Nor is it particularly shallow: its average depth is over 1½ kilometres (about a mile) while the North Sea’s is a mere 94 metres (310 feet) and, at its deepest point, in the Ionian Sea, it reaches down nearly 5 kilometres (over 3 miles), substantially deeper than the average depth of the Atlantic.
Six million years ago, the Mediterranean dried out completely in the so-called Messinian Salinity Crisis. This created the largest salt basin that ever existed and raised the sea level of the rest of the world by 10 metres (33 feet). Three hundred thousand years later, the rock barrier at the Straits of Gibraltar gave way – in a cataclysm called the Zanclean Flood – producing the world’s largest-ever waterfall and refilling the whole of the Mediterranean in as little as two years. The tide would have risen 10 metres every day. But it wouldn’t have gone out again.
STEPHEN The Mediterranean was once the biggest dry lake in the world. In the late Miocene era.
ALAN The water came rushing in over the Strait of Gibraltar.
STEPHEN You’re quite right. Six million years ago.
ALAN I know this because I saw it in the Plymouth Aquarium.
JIMMY CARR That must have been fabulous for all the towns around Spain and Portugal that rely on tourism. When that came in, they went: ‘This is fantastic. Finally these jet-skis are going to get an outing.’
Which birds inspired Darwin’s theory of evolution?
Many smart people would answer ‘finches’, but actually it was mockingbirds.
The great passion of the young Charles Darwin (1809–82) was killing wildlife. As a student at Cambridge, when the shooting season started, his hands shook so much with excitement he could hardly load his gun. Though studying medicine and divinity to please his father, he dismissed lectures as ‘cold, breakfastless hours, listening to discourses on the properties of rhubarb’.
But he was also an enthusiastic amateur biologist and fossil-hunter and was keen to see the tropics, so he signed on as a ‘gentleman naturalist’ for HMS Beagle’s second survey expedition (1831–6). He almost didn’t get the job: the captain was keen on physiognomy and thought that Darwin’s nose indicated laziness. Charles later noted that ‘I think he was afterwards well satisfied that my nose had spoken falsely’.
The story goes that, during the voyage, Darwin noticed that finches on different islands in the Galapagos had distinctive beaks, which led him to guess that each type had adapted for a specific habitat and evolved from a common ancestor. It’s true that Darwin’s theory of evolution by natural selection originated aboard the Beagle, but it had nothing to do with finches. Though Darwin did collect finch specimens from the Galapagos, he showed very little interest in them until years later. He was no ornithologist in those days and wasn’t even aware that the finches were of different species. It wouldn’t have helped much if he had been, because he didn’t label them to show where they’d been caught. He mentioned them only in passing in his journals and they are not mentioned once in On the Origin of Species (1859).
The mockingbirds were a different matter. Intrigued by the variations between the populations on two nearby islands, Darwin took careful note of every mockingbird he encountered. Gradually, as his journals show, he began to realise that species were not immutable: they could change over time. Out of that insight all his subsequent theories on evolution grew.
Because the finches are a perfect example of Darwin’s theories in action, later scientists assumed that they must have been the birds that inspired him. One of these was the evolutionary biologist David Lack (1910–73) whose 1947 book, Darwin’s Finches, fixed the idea (and the term) in the popular consciousness.
Darwin’s book on the voyage of the Beagle was an immediate best-seller, and the trip made the captain’s name too. Robert Fitzroy (1805–65) went on to become a vice-admiral, Governor General of New Zealand and the inventor of weather forecasting – one of the sea areas in the Shipping Forecast is named after him.
The finches got famous, too, as we know. The fifteen species of Geospizinae are still popularly known today as Darwin’s Finches – although it turns out they’re not finches at all, but a different kind of bird called a tanager.
Where’s the most convenient place to discover a new species?
In your own back garden.
You can cancel that expensive (and possibly dangerous) trip up the Amazon.
In 1972 an ecologist called Jennifer Owen started to note down all the wildlife in her garden in Humberstone, a suburb of Leicester. After fifteen years she wrote a book about it. She had counted 422 species of plant and 1,757 species of animal, including 533 species of parasitic Ichneumon wasp. Fifteen of these had never been recorded in Britain, and four were completely new to science.
Suburban gardens cover 433,000 hectares (well over a million acres) of England and Wales. If so many new species can be found in just one of them, this must be true of others. Between 2000 and 2007, the Biodiversity in Urban Gardens in Sheffield project (BUGS) repeated Dr Owen’s work on a bigger scale. Domestic gardens account for some 23 per cent of urban Sheffield, including 25,000 ponds, 45,000 nest boxes, 50,000 compost heaps and 360,000 trees. These present, as Professor Kevin Gaston, BUGS’ chief investigator, put it ‘175,000 separate conservation opportunities’. One of BUGS’ discoveries was what may be a new, minuscule species of lichen, found in the moss on an ordinary tarmac path.
To more or less guarantee discovering a new species, all you need is a garden, a lot of time and patience, and a lot of expertise. In the words of the eighteenth-century naturalist Gilbert White (1720–93), ‘In zoology as it is in botany: all nature is so full, that that district produces the greatest variety which is the most examined.’ In 2010 London’s Natural History Museum found a new species of insect in its own garden. They are baffled by what it is, as it doesn’t match any of the more than 28 million specimens inside the museum itself.
Part of the fun of discovering a new species is that you get the chance to choose what it’s called. A recently discovered beetle with legs resembling overdeveloped human biceps was named Agra schwarzeneggeri; a fossilized trilobite with an hourglass-shaped shell was called Norasaphus monroeae after Marilyn Monroe; and Orectochilus orbisonorum is a whirligig beetle dedicated to singer Ray Orbison because it looks like it’s wearing a tuxedo. In 1982 Ferdinando Boero, now a professor at Lecce University in Italy, but then a researcher at Genoa, had a more underhand motive in naming the jellyfish he discovered Phialella zappai – it was a cunning plan to persuade his hero Frank Zappa to meet him. It worked: they remained friends for the rest of the musician’s life.
British-born astrobiologist Paul Davies of Arizona State University urges us all to search for new unknown forms of life. ‘It could be right in front of our noses – or even in our noses,’ he says.
The one thing you don’t want to find in your nose is an Ichneumon wasp. These unpleasant insects caused Darwin to lose his re
ligious faith. ‘I cannot persuade myself’, he wrote, ‘that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars.’
What kind of bird is Puffinus puffinus?
Before you answer, bear in mind that Rattus rattus is a rat, Gerbillus gerbillus is a gerbil, Oriolus oriolus is an oriole, Iguana iguana is an iguana, Conger conger is a conger eel and Gorilla gorilla gorilla is emphatically a gorilla.
And Puffinus puffinus?
Bad luck, that’s the Manx shearwater. It’s unrelated to the puffin.
Scientific names for animals are usually composed of two words: the genus comes first, followed by the species. The species of a living thing is defined as that group with which it can reproduce. Its genus is analogous to its tribe: a group of species that are clearly related to each other. When the names of an animal’s genus and its species are the same that’s called a tautonym (from the Greek tautos ‘same’ and onoma ‘name’). For example, the bogue fish is Boops boops and Mops mops is the Malayan Free-tailed bat.
Where there is a third part to the name of a species, it is used to indicate a subspecies. So the triple tautonym Gorilla gorilla gorilla (the Western Lowland gorilla) is a subspecies of Gorilla gorilla (the Western gorilla). The Tiger beetle subspecies Megacephala (Megacephala) megacephala has a name that translates as ‘bighead (bighead) bighead’. Sometimes a subgenus is also given in brackets such as Bison (Bison) bison bison, which (for the avoidance of doubt) is a kind of bison.
Tautonyms for animals are not uncommon, but are strictly forbidden for plants under the International Code of Botanical Nomenclature.
There are three species of puffin and they belong to the genus Fratercula, Latin for ‘little brother’, because their plumage resembles monastic robes.
There are about thirty species of shearwater, all of which share the genus name Puffinus, which comes from an Anglo-Norman word meaning ‘fatling’. This refers to the chubbiness of the young birds, and hints at their culinary uses. They were eaten both fresh and pickled and, because they swim so well under water, were for a long time thought to be half fish, which allowed Catholics to eat them on Fridays and during Lent. Shearwater chicks are easily mistaken for puffins: which probably explains the confusion over the name. Puffins (and particularly their hearts) are a national delicacy in Iceland.
The oldest living bird ever recorded in Britain was a Manx Shearwater. It was found by chance in 2002 by the staff of the bird observatory on Bardsey Island in North Wales. They were delighted to discover that ornithologists had ringed it in 1957, when it must already have been at least five years old. It’s reckoned to have covered around 8 million kilometres (5 million miles) over more than half a century, flying to South America in the winter and back again to Britain for the Puffinus puffinus breeding season.
JEREMY CLARKSON You don’t want to listen to this, but I once had some whale. And they said to me: ‘Would you like me to grate some puffin on that?’
Can you name three species of British mouse?
Two points each for Harvest mouse, House mouse, Field mouse and Wood mouse – and four points for Yellow-necked mouse – but minus ten for dormouse.
The dormouse is more of a squirrel than a mouse.
Admittedly, it does look rather mouse-like – except for its tail, which is furry. (Mice have scaly tales.) It also has fur inside its ears – which mice don’t. In fact, the dormouse is generally furrier all round. This to keep it warm in winter: it’s the only British rodent that hibernates.
The ‘dorm-’ part of its name means ‘sleepy’ and sleeping is what it’s best at. The golden-coloured Common (or Hazel) dormouse can spend three-quarters of its life asleep. It’s also known as the ‘seven-sleeper’ because it regularly spends seven months of the year dormant, though warmer winters now mean its hibernation lasts five and a half weeks less than it did twenty years ago.
If you want to get involved with dormice, you’ll need to go on a Dormouse Handling Course and apply for a government dormouse licence. The British dormouse population has fallen by 70 per cent in the last quarter century and it is now strictly illegal to disturb, let alone kill, this rarely seen nocturnal creature.
The much larger Edible (or Fat) dormouse (Glis glis) is even less common in Britain than the Common dormouse (Muscardinus avellanarius). It’s grey and white and could easily be mistaken for a small squirrel with big ears. It was introduced to Britain in 1902 by Lord Rothschild, as part of his wildlife collection in Tring Park, Hertfordshire – since when escapees have spread across the Chilterns. They can be a serious pest in lofts and outbuildings and can cause fatal damage to young trees. It’s legal to shoot them.
The Romans were very keen on eating Edible dormice, though there’s no evidence that they brought them to Britain. They kept them in earthenware pots called dolia, fattening them up on a diet of walnuts and currants, and storing the pots in special dormouse gardens or glisaria. Recipes included roast stuffed dormouse and honey-glazed dormouse with poppy seeds.
It’s a taste that survives in many parts of Europe, where dormouse hunting is illegal but often done. In Calabria in southern Italy, where tens of thousands are eaten annually, the Mafia allegedly controls the lucrative dormouse trade.
In 2007 fifteen Calabrian restaurateurs were charged with serving Glis stewed in wine and red pepper. They all denied the allegations. Their defence was that the meat in the casseroles wasn’t dormouse – it was only rat.
How far are you from a rat?
It’s much further than you think.
The idea that you are ‘never more than 6 feet away from a rat’ is wrong by a factor of ten. Of course, it depends where you live: some of us live close to hundred of rats, others live near none. But rats, although they happily live off our rubbish, don’t like to get too close. Rentokil, the pest control company, estimates that the average city dweller is at least 21 metres (70 feet) from the nearest one.
The bad news is that rats in the UK now outnumber people. According to the National Rodent Survey, there are around 70 million rats in the country:10 per cent more than the current human population.
Rats carry seventy or so infectious diseases including salmonella, tuberculosis and Weil’s disease. They are also responsible for consuming a fifth of the world’s food supply each year. Their sharp teeth (which never stop growing) enable them to gnaw through almost anything, causing a quarter of all electric cable breaks and disconnected phone lines in the process.
Plus, they brought the fleas that gave us bubonic plague. And they have those nasty, scaly tails.
It was the Black or Ship rat (Rattus rattus) that brought the plague. It sought out human company because our living conditions were so squalid. Slovenly disposal of food waste causes 35 per cent of rat infestations: broken sewers only 2 per cent.
Today, Rattus rattus is one of the UK’s rarest mammals. Only small clusters remain, around big ports like London and Liverpool and on remote islands like Lundy, where they still are regularly (and legally) culled. The Black rat doesn’t appear on any endangered lists – presumably because it’s a rat.
Any rat you see today is almost certain to be the larger, stronger Brown or Norway rat (Rattus norvegicus), which arrived in the UK less than 300 years ago. They have nothing to do with Norway (they originated in northern China) and they don’t carry plague. In fact, their use in laboratory experiments saves many human lives.
The dreaded rat’s tail is actually a device for regulating body temperature. It acts as a long, thin radiator (rather like an elephant’s ears), which is why it isn’t covered in hair.
ALAN You know, all the rats in England all face the same direction at any given time …
BILL BAILEY ’Cause they’re magnetic, aren’t they, rats?
ROB BRYDON It’s very hard for rat couples who have that, kind of, reversed polarity going on. You know, when you can’t put two magnets together? There are rats who
fall in love, and they are destined to be together, and they can’t kiss.
What kind of animal is ‘Ratty’ from The Wind in the Willows?
You won’t be surprised to hear that he’s not a rat.
The Wind in the Willows by Kenneth Grahame (1859–1932) began as a series of letters to his young son, Alistair (nicknamed ‘Mouse’). After being rejected by several publishers, it came out in book form in 1908 – the same year that Grahame retired after thirty years working at the Bank of England.
Ratty, one of the main characters, is a water vole (Arvicola amphibius), colloquially known as a ‘water rat’. As a child, Kenneth Grahame would have seen plenty of water voles, nesting in the riverbanks near his grandmother’s home at Cookham Dean on the Thames – but today they are one of Britain’s most endangered species. Water voles underwent a catastrophe after the fur trade started farming imported American mink in the 1920s. Unlike native predators, mink can follow voles right into their tunnels. Escaped mink (and their descendants) have been eating vast numbers of voles ever since, wiping them out entirely in many places.
This is bad news for future archaeologists. Voles are the world’s fastest-evolving mammals, dividing into new species up to a hundred times faster than the average vertebrate. This allows archaeologists to use the so-called ‘vole clock’. Carbon dating only works up to about 50,000 years ago. For older digs, the investigators use fossilised vole teeth – tiny things about the size of a fingernail clipping. The ways they have altered at different stages in voles’ evolution are so specific that items found alongside them can be dated with great accuracy.