Part 4

Return of the king In August 1485, King Richard III of England was killed at the Battle of Bosworth and buried in Grey Friars Church near Leicester. The church was later demolished and the area eventually became a parking lot. In 2012, archeologists dug up a skeleton in the parking lot, which they suspected might belong to the missing king. Examining the evidence As with any missing person's case, the investigators brought together lots of strands of evidence to come to a conclusion. It was calculated that there was a 99.999 percent chance that the skeleton was that of Richard III. He was later reburied in Leicester Cathedral. CONSPIRACY! Many people believe that Richard III killed his two nephews in the Tower of London so that he could become king instead of his older brother's sons. The skeleton has a curved spine, as Richard was described as having. WHAT WE NOW KNOW ABOUT RICHARD III FROM HIS DNA » There's a 96 percent probability that Richard had blue eyes. » There's a 77 percent chance that he had blond hair (which darkened in adulthood). » The most accurate portrait of Richard is the one we've shown on the opposite page, from the Society of Antiquaries in London. Mitochondrial DNA Mitochondrial DNA is special because it only gets passed on through your mother. Therefore, it is identical between siblings. Richard's mitochondrial DNA was passed on by his sister to her daughters and granddaughters through the female line—for 19 generations! The skeleton showed signs of injuries suffered on the battlefield where Richard died. Geneticists compared the mitochondrial DNA sequences and found that they were identical, proving that the skeleton was that of Richard III. Mitochondrial DNA was found in the skeleton after more than 500 years! Mike and Wendy By tracing the family tree, researchers found two living relatives, Mike and Wendy. They had the same mitochondrial DNA sequence as King Richard's skeleton.

Can we fix genes? A genetic disorder can be caused by a mutation in just one gene. If we can fix this mutation in the cells that use the gene, then we can cure the disease. This is called gene therapy. Gene therapy There are two possible types of gene therapy. Somatic gene therapy only treats the patient's diseased cells, but germ line gene therapy changes all the cells in the body, including the ones that will be passed on to the next generation. 1 Faulty cells whose DNA needs to be edited are taken from the patient. 2 In the lab, a virus is altered genetically so that it can't make you sick. 3 The healthy version of the gene that has gone wrong in the patient's cells is inserted into the altered virus. 4 The altered virus containing the healthy DNA "infects" the cells that were removed from the patient. 5 The cells start to use the gene from the virus to make a healthy protein. 6 The altered cells are put back into the patient, and the healthy protein helps cure the disease. Changing DNA in your eggs or sperm means that the change will be passed on forever! BABY IN A BUBBLE Gene therapy can cure babies born with a weak immune system. These children can't fight off infections, so they must be kept inside germ-free "bubbles." Now, their cells can be genetically altered to give them an immune system that works, so they can live normally.

Should we change genes? Who gets access to this technology? Is it only going to be for very rich people? Intelligence could be improved? If everyone were as intelligent as Albert Einstein, what would life be like? Human disease could be cured? You might pass this on to your children. People could be more "beautiful"? If everyone were changed to be the same, a new disease might evolve that could wipe us all out! People could be more athletic? What do you think? Now that we are finding new ways of altering our genes and those of other organisms, we don't need to wait for natural selection anymore. This means that we can think about making changes for ourselves. But, is it always a good idea to tinker with genes? Disease- resistant crops? Would it taste as nice? Crops could be altered to make more food from the same number of plants? Would we end up growing fewer varieties of fruits and vegetables? Bacteria could eat plastic? Will the change spread into wild populations of the altered species? Plants could cope with drought? Will it interfere with other plants and animals that live in the same place? Fruits and vegetables could last longer in stores?

Let's clone plants! Plants are special because every single cell can grow into a new plant that is a clone of the first plant. You can try cloning lavender yourself! We're indentical! 1 Take a cutting Cut a fresh, green stem with no flowers from a healthy lavender plant. Remove the leaves at the bottom of the stem so that they don't rot in the soil. 2 Plant the cutting Fill a small plant pot with free-draining compost or soil and plant the lavender cutting firmly in the middle. 3 Keep moist Water the plant well and secure a clear plastic bag over the top of the pot to keep the soil moist. Place it somewhere warm and light. Rise of the clones! Cloning is the process of producing genetically identical individuals, with exactly the same DNA. Sometimes this happens naturally, as with identical twins. Farmers clone fruit trees to make sure they produce the same tasty fruit, such as apples. Flowers Flowers make seeds when they are fertilized by other plants. Plants grown from seeds will not be clones. CLONING THEMSELVES A few, very unusual, animals can reproduce by cloning themselves. These female aphids are able to have babies without a male. They produce daughters that are all genetically identical to the mother. Cloning animals In 1996, Dolly the sheep was born. Scientists made her by transferring the DNA-containing nucleus of an udder cell into an egg without a nucleus. Dolly was a clone of the mother who gave the nucleus. A whole new sheep was made from an udder cell! 4 Enjoy the flowers After a few weeks, you will see new leaves at the top of your new plant, and eventually flowers. You have created a clone of your original plant! Egg cell The egg cell has had its nucleus destroyed to remove its own DNA. Needle A tiny needle injects the udder cell nucleus into the egg cell.

How would this work? To re-create a woolly mammoth, genes from preserved remains of mammoths would be put into the DNA of the Asian elephant—the mammoth's closest living relative. The mammoth genes would give the baby traits such as shaggy hair. This would make an "elemoth"—an elephant-mammoth hybrid. Gene splicing The mammoth genes would be inserted, or spliced, into the chromosomes of an Asian elephant. Asian elephant The new DNA would be put into an elephant egg and the elemoth baby would grow in a surrogate Asian elephant mother. Return of the mammoths? Since 2015, scientists at Harvard University have been looking into bringing the woolly mammoth back from extinction. They hope to achieve this by using new technology to replace elephant genes with woolly mammoth genes. In 2012, an important woolly mammoth specimen was discovered in Russia—by an 11-year-old child! Mammoth remains Scientists are currently extracting DNA from woolly mammoth remains. They would then need to identify different genes and match them up with the elephant genes. LOST FOREVER? These are some other animal species that have become extinct, but that scientists could potentially bring back to life. Do you think this would be a good idea? Dinosaurs Dinosaurs are the ancestors of birds, so we could look at bird DNA to try and figure out how to re-create a dinosaur. Dodo The dodo became extinct hundreds of years ago. Some of its DNA has been discovered in remains.

Human diversity The chance of finding two people—who are not identical twins—with an identical DNA sequence is about the same as tossing a coin and getting heads six million times in a row. Try it! The human family Despite the variety, a huge amount of the human genome is the same across the world—99.9 percent of it! May contain Neanderthal! Most of us contain around 2 percent Neanderthal DNA from our extinct, ancient cousins. Variety is the spice of life! Individuals of every species of animal, plant, or microbe all have slightly different DNA sequences. This variation is called the gene pool. Larger gene pools make species better at surviving change. There are about 3,000,000 differences in the DNA sequences of any two people. Our genetic history DNA analysis can be used to trace human origins back to Africa. Diversity is great! If we were all the same, our species would be much less healthy! GENE POOLS Cheetahs are vulnerable to disease because they have a very small gene pool. About 12,000 years ago, they nearly died out. Only a few individuals survived, and a lot of genetic diversity was lost. Conservation programs run by zoos and other wildlife organizations try to preserve and expand the gene pools of threatened species.