Archive for the ‘Discoveries’ Category

Happy birthday to you, happy birthday to you, happy birthday dear Charles Darwin, happy birthday to you!

Happy Birthday Darwin!

On this day in 1809 Charles Darwin, arguably one of the most important scientists ever, was born in Shropshire. Charles Darwin is famous for his book On the Origin of the Species where he introduced ideas to explain the origin and diversity of all living species via Natural Selection and Evolution. Darwin was interested in most things, and his work as a geologist and naturalist gave him to opportunity to travel around the world on a 5-year voyage aboard the ship HMS Beagle. Keeping careful notes and making copious observations during the expedition, Darwin saw great biodiversity and it allowed to him to begin considering the origin of this. When he returned to England he began to formulate his idea of Natural Selection.

HMS Beagle

What is Natural Selection?

Darwin had noted that nearly all the species he had encountered were perfectly adapted to a variety of different habitats, diets and lifestyles. His visit to the Galapagos Islands (near Ecuador) had allowed him to study a group of birds (now known as Darwin’s Finches). He was amazed at the variety of different beak shapes and sizes, each adapted to a different way of life.

The Galapagos Islands

How did this happen? Natural selection requires three factors. The first is variation (differences) between individuals. The second is competition between organisms (e.g. not enough food to feed every organism) and finally an environmental change.

Darwin postulated that originally a group of finches arrived at the Galapagos islands from mainland Ecuador. There was variation of beak size within this group of finches. Because there were different food sources on the island (seeds, fruit, insects etc) different beak sizes were more suitable for different diets. For example, large beaks would be able to break open seeds that smaller beaks wouldn’t. If there were plentiful seeds, the larger beaked birds would find more food, have more offspring and therefore pass on the genes for the larger beak. This would continue as long as larger beaks gave a survival advantage. Eventually, with successive generations and continued ‘selection’ for a certain feature, the original population of birds diversified into many different species.

Darwin's Finches

Darwin realised that this same process, occuring over millions of years, could explain the diversity of all living (and extinct) species.

The Theory of Evolution has shaped our understanding of diversity, formation of new species and our position in the Tree of Life. So, thanks Darwin, and Happy Birthday!

The Tree of Life


If you were to ask people to name a famous scientist you are likely to hear answers such as Newton or Einstein.  If you were to ask me I would reply Mendeleev.  So why I do I think Mendeleev should be as famous as those other two guys? What did he do that was so important, I hear you cry? Well I will tell you, Mendeleev devised the Periodic Table, the most incredible document in the world of chemistry!

Mendeleev was a chemistry genius, not only did he manage to arrange the 80 or so  known elements of his time into the first ever Periodic Table, he left gaps in his table for elements he knew were yet to be discovered. Even more impressive, he correctly predicted the properties of the still to be discovered elements. If that was not brilliant enough, this was all happening in the days before we knew about atomic structure yet Mendeleev still managed to arrange the elements in order of their atomic number before atomic number even existed…that’s just totally WICKED, some would say INCREDIBLE.

If you look at the Periodic Table below it does not look very much like our modern day version but there are loads of similarities if you know where to look. The pink coloured elements are ones discovered after the death of Mendeleev but he had left the pink gaps to be filled in later. He was a very clever man.

Mendeleev's Early Periodic Table

Dr Frederick Banting - pioneer of insulin treatment

This week marks the 90th anniversary of the discovery and isolation of insulin by Dr Frederick Banting, a discovery that has saved and improved the lives of millions of diabetics.

What is Diabetes?

Diabetes is a serious disease that affects over 250 million people globally, in which the body either doesn’t produce enough insulin (Type 1) or doesn’t respond to the insulin that is produced (Type 2). This leads to a high blood sugar level, and this causes a variety of medical problems if not managed. 90% of cases are Type 2 diabetes.

What is insulin?

Insulin is a hormone produced by the pancreas. It plays a central role in controlling and regulating the amount of glucose in the blood. It does this by causing cells in the liver (and some other cell types) to store the glucose as glycogen. Insulin is injected by Type 1 diabetics as part of their treatment. Type 2 diabetics may sometimes need to inject insulin, but their treatment and management focuses mainly on lifestyle and diet control.

How was insulin discovered?

Before insulin was discovered, diabetes caused death in nearly all cases. The only treatment available was a strict controlled diet and this only gave the patient a few more years. In the 19th century a German medical student called Paul Langerhans had identified a set of cells in the pancreas that didn’t seem to have a function. (These were later identified as beta-cells which produce insulin). A few years later two other German scientists showed that the pancreas was involved in controlling blood-sugar, because they found that dogs that had their pancreas removed developed diabetes.

Location of the pancreas

In 1920 Dr. Frederick Banting, a Canadian surgeon in Toronto, developed a process for isolating a secretion from the pancreas that was shown to prevent diabetes when injected into dogs that had had their pancreas removed. With this isolated secretion now named ‘insulin’, Dr Banting and his team started testing on human subjects, beginning with themselves. They managed to develop the correct dosage and in January 1922 gave insulin to a 14 year old diabetic boy, Leonard Thompson. The insulin worked perfectly, and Leonard recoverd from near-death. In 1923 Banting was awarded a joint Nobel Prize for Physiology or Medicine and a medical company went on to mass produce insulin.

Leonard Thompson - the first person to receive insulin.

Whilst insulin doesn’t cure diabetes, it means diabetics are able to regulate their blood glucose levels and stay alive. Perhaps you’ll agree that the discovery of this treatment is one of the great medical advances of the 20th century.