Dr's Casebook: Reason why Christmas tree is a symbol of hope

Dr Keith Souter writes: If you have a cut Christmas tree it may surprise you to know that each of its cells has seven times more DNA than a human cell. Why it should have so much DNA puzzled scientists for decades until they began to work out the genomes of conifers.

It is a fact that coniferous trees dominated major parts of the world for hundreds of millions of years. Some 300 million years ago they developed a genetic code, hence so much DNA, that allowed them to survive first a major geological disaster and then the meteorite impact that caused the extinction event that wiped out the dinosaurs.

The genome is the name given to all of the genetic information of an organism, which is contained in every one of its cells. The genomes of conifers are of immense importance in ecology as we grapple with the problems of climate change. This is why the science of genomics is so important.

Study of the human genome is opening up a whole new era in medical science. Genomics is the study of a person’s DNA, their genes and how they are expressed and interact to influence the growth, development and the working of the body. Genomic medicine has the potential to offer a greater understanding of how our genetic makeup impacts on our health and the response to treatments.

It has incredible potential since it involves using genomic information about an individual as part of their clinical care. For example, for diagnosis, making decisions about their treatments. It suggests that tailored medicine will be possible.

Genomic medicine has been of inestimable value during the Covid-19 pandemic. Continuous genomic surveillance across the countries of the globe has permitted sequencing of the Covid-19 genome so it is possible to see how it has been evolving.

Genomics is unravelling amazing things about Christmas trees, humans and the

viruses that infect us and gives us hope amid the gloom. Enjoy your Christmas.