The alien of the deep

QUESTION Which animal has evolved least over the longest period of time?

When Charles Darwin published On The Origin Of Species in 1859, the book in which he first detailed the theory of evolution, he introduced the term ‘living fossil’.

In one section, he discussed the platypus and the lungfish, writing that: ‘These anomalous forms may almost be called living fossils; they have endured to the present day, from having inhabited a confined area, and from having thus been exposed to less severe competition.’

There are several species that might be considered living fossils. One well-known example is the goblin shark, order

Mitsukurinidae, sometimes called ‘the alien of the deep’ for its strange looks, which include its pink flesh, protruding teats and dagger-like head, which appear to have changed very little over the past 125 million years.

Tadpole shrimps, or notostracans, have a shield-shaped body, ending in a forked pair of filaments — a shape that makes them almost indistinguishable from their ancestors in the Triassic period 265million years ago. That means they survived the Permian extinction, often known as the Great Dying, which wiped out almost every other animal species.

Another great survivor is the horseshoe crab, order Xiphosura, whose fossil record dates back 450million years. Coelacanth have roots that stretch back 390million years. They are large, bottom-dwelling fish that can grow up to 2 metres long.

Because of their fleshy limbs, they were once considered the transitional form between marine and terrestrial life.

While these animals have not physically changed much over millions of years, it would be very wrong to say they have stopped evolving. Many researchers believe we should do away with the term ‘living fossil’ altogether.

every so-called living fossil has turned out to be very different from the fossils that they apparently resemble, either at a genetic level or through subtle physical changes. For example, a 2013 study of coelocanth demonstrated a fundamental change in their DnA and morphology.

It demonstrated a physical transformation in their skeletons, a second dorsal fin had transformed from spiny to lobed, and they had lost bones around the rim of the mouth and around their scales.

The truth is that genes are always mutating and being reshuffled by sex,

Living fossil: The goblin shark and all animals are constantly evolving, though their changes may not be immediately visible.

DrIanSmith,Cambridge.

QUESTION In the final episode of Downton Abbey, a character was diagnosed with pernicious anaemia and was preparing to die. At what time was vitamin B12 treatment discovered and used for this condition?

PERNICIOUS anaemia is an auto-immune disorder characterised by a dangerously low red blood cell count. It occurs when the body can’t absorb enough vitamin B12, essential in the manufacture of red blood cells.

Its progress is very slow; early symptoms include weakness, headache, chest pain and weight loss. Later symptoms include loss of balance, spasticity, peripheral neuropathy, numbness in the arms and legs, progressive lesions of the spinal cord and severe memory loss.

The symptoms were first described in 1822 by Dr James Scarth Combe of edinburgh. In 1871, German physician Michael Anton Biermer coined the term ‘progressive pernicious anaemia’ — ‘pernicious’ as it was invariably deadly.

By the early Twenties, 6,000 lives a year were lost to pernicious anaemia. In 1923, Dr George r. Minot of Massachusetts General hospital joined forces with young harvard graduate Dr William P. Murphy in a quest to cure the disease. The pair realised that the work of George Whipple, Professor and Chairman of Pathology at the university of rochester, was significant.

Whipple bled dogs to make them anaemic, then determined which foods restored their red blood cells, demonstrating that raw liver was the best treatment.

Minot and Murphy began administering half a pound of liver to their patients each day. The pair were hampered by scepticism from the medical community — as well as their patients’ natural disgust at swallowing enormous quantities of the raw offal.

But the treatment worked, and in 1926 their research results were presented at a medical meeting in Atlantic City. By that time, Minot and Murphy had successfully treated 45 patients, in which ‘clinical improvement had been obvious, usually within two weeks’.

The final episode of Downton Abbey was set during Christmas 1925. So when Lord Merton, or richard ‘Dickie’ Grey, was diagnosed with pernicious anaemia, it would still have been considered fatal — just. happily, it emerged that Dickie only had common anaemia, so it did not ruin Lady edith’s wedding.

In 1928, edwin Cohn, a harvard physical chemist, condensed and purified a liver extract so it could be eaten or injected into a muscle. This extract was between 50 and 100 times as potent as liver. It wasn’t until 1948 that pure vitamin B12 was isolated and used directly to treat patients.

Dr Minot, Dr Murphy and Professor Whipple shared the nobel Prize for Physiology or Medicine in 1934.

ColinHall,Kidderminster,Worcs.

QUESTION Roy Keane recently caused a stir by saying: ‘If Ashley Young is a Man United player, then I’m a Chinaman.’ My dad used this phrase. What other phrases have gone out of fashion?

FURTHER to earlier answers, when I was young, a small child was described as being knee-height to a grasshopper, or knee-high to a kerbstone. Also, they were described as ‘good as gold and twice as precious’.

If you wanted someone to shut up, you said: ‘Put a sock in it!’ Someone looking under the weather was described as looking like ‘a dying duck in a thunderstorm’.

A clumsy person was ‘as clumsy as a cow on a bicycle’. Someone who felt very well indeed said he felt he could throw a bus into the middle of next week.

MrsJ.M.Perrot,LondonW3.

When my old nanny was trying to cut something with a blunt knife, she would say: ‘You could ride to London on this and not tear your breeches’.

DeanaBarber,Hythe.

QUESTION Why did Virgil keep a pet fly?

FURTHER to the earlier answer, another piece of the Virgil myth is a poem known as Culex or The Gnat, purportedly written by the great poet. It tells the story of a shepherd who is awakened by a gnat sting which saves him from a marauding snake.

The shepherd eventually builds a marble monument in the gnat’s honour:

‘O tiny gnat, the keeper of the flocksDoth pay to thee, deserving suchathing,Thedutyofaceremonialtomb,Inpaymentforthegiftoflifetohim.’ The similarities with the fly story are clear.

GeorgeWells,StAlbans,Herts.