Category: Uncategorized

Spot the difference!

We are having rather a busy time of it in the department at the moment with lots of visitors, volunteers and outside activities including the ‘Creatures of the Night!’ late night event that was held at the Museum of the History of Science last Friday evening.
After all the hard work we decided that it was time for something fun so here is a five minute distraction for you whilst you have a cup of tea and a biscuit.

The rather stunningly handsome beetle below is a member of the genus Megaphanaeus. He is complete in the first picture but FIVE things have changed by the time we get to the second photo. See if you can spot them all!

Complete beetle

What’s missing here? Can you spot the five differences?

A little piece of Mars

Over the last couple of weeks, our meteorites had been having a busy time. On Friday 11th May, groups of Oxford University geology students came across to the Museum to have tutorials with Dr Don Porcelli from the Department of Earth Sciences. It’s a great opportunity for them to handle and study ten of our most interesting meteorites, and is always very popular. As one of them, Freya, wrote in the Oxford Undergraduate Prospectus last year, ‘There can’t be many subjects where you are able to hold an actual piece of Mars in a meteorite tutorial!’.

Most meteorites come from the asteroid belt, a band of rocky debris between Mars and Jupiter. The lumps of rock keep colliding, and now and again that sends pieces spinning in the direction of Earth. Tiny fragments burn up as they enter the Earth’s atmosphere, and we see them as meteors – shooting stars. Larger pieces reach the surface of the Earth, and they are known as meteorites. Even bigger pieces hit the Earth with such explosive force, they all but vaporise… but that is another story!

The interesting thing about the asteroid belt meteorites is that they are made of the same planetary debris that the Earth itself was formed from, some 4.5 billion years ago. However as Freya pointed out, one of our meteorites has more exotic origins. The Nakhla meteorite fell at Nakhla, in Alexandria, Egypt on 28^th June 1911. Isotope and trace element analyses have shown that it is almost certainly from Mars. The fall allegedly killed a dog; as one of my students once put it, the only Earthling to be killed by a Martian. Meteorites from Mars are exceptionally rare, and give a very special insight into the rocks that make up another planet.

Last Tuesday, members of the public had a peek behind the scenes on one of our regular Tuesday afternoon tours. The theme was ‘Rocks from Earth and Space’, and leader, Dr Dave Waters, showed them some historic rocks from Greenland and Everest, as well as those meteorites. Just think of all those people saying this week that they’ve just held a little piece of real Mars rock!

Monica Price, Assistant Curator, Mineral Collections

Gynandromorphs

Very occasionally we come across some rather special butterfly specimens. These are gynandromorphs, individuals which are part male and part female. In many species of butterfly males and females have different colour patterns. In these species spectacular gynandromorphs can sometimes arise where one half is male and the other female. The genetic cause of these bilateral gynandromorphs is complex but essentially an X chromosome is lost very early in cell division of the embryo.

The Mocker Swallowtail (Papilio dardanus) showing the female (left), male (right) and gynandromorph (center)

Three specimens of the Common Yellow Glider (Cymothoe egesta). The gynandromorph (center) is slightly asymmetrical as the female half also includes some male cells with the yellow pattern.

Example of a British Brimstone (Gonepteryx rhamni) gynandromorph (center) from the Mark Colvin collection.

Gynandromorphs also occur in other invertebrates, such as this earwig which has one longer male forcep and a short female one.

What’s on the van? – Red fox

This week’s What’s on the van? comes from Malgosia Nowak-Kemp, Collections Manager in the Museum’s Zoological Collections.

The Red Fox, scientific name Vulpes vulpes, is a member of the order Carnivora.  Nowadays you can see foxes not only in the wild, but also in towns and cities. Resourceful, cunning, agile, with an ability to climb, they use varied sources of food to sustain them and their families.

They are unusual in having a golden or amber colour eye instead of green like cats, or brown like most other mammals. Their fur varies from yellowish to reddish with the rump often showing white-tipped hairs. The lower parts of the legs and the back of the ears are usually black.

They are highly vocal with barks, howls or yaps and other distinctive sounds with which they communicate between each other. Foxes breed once a year, and live in family groups consisting of a male (dog), female (vixen) and their cubs, and only occasionally, with one or two non-adult females from previous  litters.  Their cubs are born blind after about 53 days gestation, and open their eyes after 10 to 14 days.The males take an active part in caring for the family, by bringing food for the cubs and their mother. They mostly hunt at night for small mammals like voles and rabbits, but also scavenge and explore the contents of dustbins for anything to eat. In summer they would add beetles, and in the autumn, fruit to their diet.

Foxes moult once a year, in the early summer, and during the late summer and autumn months they grow additional hairs so the fur becomes thicker in preparation for the low temperatures of winter. Foxes rarely live longer than 8 years.