Here are some BRILLIANT scientists who came up with fascinating LIFE facts and theories.

ROBERT BROWN was a botanist from Scotland. After working in England, he went on an expedition to Australia in 1801 and collected 4,000 different plants to examine. Five years later he returned and spent several more years sorting out all the plants he’d brought with him!

While examining the cells of different plants under a microscope, he noticed that he could divide them into groups based on similarities and differences. He also discovered that living cells usually have a lump inside them, which he called the NUCLEUS.

Robert Brown made another important discovery in 1827. He was looking through a microscope at what happens to pollen grains when they are mixed in water. He noticed that the grains were continuously moving. At first, he thought it must be because the particles were living. He decided to prove this by testing different types of both living and non living particles in water to see what would happen.

Through his microscope, he observed that exactly the same thing occurred every time - all the particles, both living and non-living, moved around without stopping.

This erratic movement of particles in liquids or gases is known as the BROWNIAN MOTION, although at the time Robert Brown didn’t have a clue what caused this movement!

CHARLES DARWIN was a British Naturalist. While studying the South American and Pacific coasts in 1831, he noticed that there were many different species of birds and animals in each area. He thought it was very unlikely that God had created each species individually and therefore all living things - including humans must have evolved to suit their surroundings.

This was not a new idea, but Darwin was the first person to write everything down properly. In fact, he spent more than 20 years gathering evidence to prove his THEORY OF EVOLUTION!

Basically, he believed that species would change - or ‘evolve’ - over time as different characteristics emerged to encourage their survival. As an example, animals living in cold countries would develop warmer coats to keep them warm and human beings from hot countries would develop darker skin to withstand the sun.

Until this time, people had believed that God created every living thing, just as it says in the Bible. Darwin was saying that, even if God existed, the story of creation must be incorrect. He even said that human beings could have evolved from apes! The Church strongly disagreed with his views, yet it was difficult to find fault with his carefully recorded observations.

But there was one thing that Darwin failed to explain. He assumed that parents passed on equal mixtures of characteristics. Yet this would mean ‘useful’ traits would be quickly weakened when mixed with the ‘unnecessary’ traits. This question was answered some years after Darwin died by …

An Austrian monk called GREGOR MENDEL wanted to learn about inherited characteristics, now known as GENES, so he spent many years breeding pea plants and recording his results.

He realised that the new plants were not usually simply a mixture of the ‘parents’, but some characteristics tended to be ‘dominant’. This means that most of the new plants inherit these characteristics.

The same thing happens in human beings. If one parent’s eyes are brown and the other has blue eyes, there is a greater chance of a baby developing brown eyes because we know that the ‘brown eye gene’ is stronger than the ‘blue eye gene’. There is still a chance of the baby having blue eyes, as the genes from both parents are passed on, but it is not so likely. The same is true with plants.

So, if some characteristics are dominant, after many years the less dominant characteristics will weaken until they have no visible effect on the species. This explains Darwin’s Theory of Evolution.

Unfortunately, both Charles Darwin and Gregor Mendel had died before the significance of GENETICS was recognised.

So we know that different characteristics are passed on. But how?

It’s all in the CELLS!

Do you remember Robert Brown discovered cells contain something he called a NUCLEUS? Well, parents’ characteristics are held within the nucleus of every cell in every living thing. And all this information is stored within something called DNA. This stands for Deoxyribonucleic Acid.

DNA was first discovered in the nineteenth century, but it was a bit of a scientific mystery. In fact, scientists didn’t really understand its purpose until 1943! Many people tried to discover the meaning of DNA, including Rosalind Franklin and Francis Crick.

It was Francis Crick, working with a man called James Watson, who eventually uncovered DNA’s secret. Each DNA molecule contains two strands of special chemical code, which are connected in a spiral shape known as a double-helix. When reproduction takes place, the strands from one parent’s DNA join with DNA strands from the other parent and form a new chemical code combining the genetic history of each parent.

When Robert Brown was sorting out his plants and discovering the Nucleus, I bet he didn’t imagine how much we would learn about cells!