The Origins of DNA and Its Evolution Over Time

10 Apr The Origins of DNA and Its Evolution Over Time

It’s astonishing that every human is made up of the same stuff – yet tiny differences at the microscopic level create profound differences in our physical composition; how we look, feel, and function.

What’s behind these tiny yet powerful differences? DNA – Deoxyribonucleic Acid. But what exactly is DNA? Where did it come from? When was it discovered? And can it really be read like a manual? Let’s dive in.

What is DNA anyway?

Let’s imagine DNA as a cookbook. It contains all the recipes and ingredients needed to build and keep organisms alive. The DNA molecule is the book itself stored in every cell that contains the instructions (genes) that create everything needed for life. The book’s chapters are the chromosomes, each containing specific instructions.

Genes can be seen as recipes with even more specific instructions on making proteins the same way you’d make a dish. Every recipe has ingredients.

• These ingredients are the nucleotides A, T, C, and G. A (Adenine) pairs with T (Thymine), like peanut butter and jam. C (Cytosine) pairs with G (Guanine) like salt and pepper.
• Together, these form genetic codes and ensure the recipe is copied correctly every time.

Now, a chef often copies a recipe for certain dishes from cookbooks onto a notepad. In your cells, the messenger RNA (mRNA) is the notepad that copies the instructions from DNA and carries them to the cell’s “kitchen”, the ribosome.

Like a chef, the ribosome reads the mRNA instructions for cooking up proteins by adding the ingredients together, including amino acids that keep the body functioning optimally.

This is part of DNA replication, which ensures that each new cell gets a complete set of instructions. Therefore, every gene must be copied exactly, much like making another copy of the cookbook. But first, what are the origins of DNA?

What are the origins of DNA?

The origins of DNA date back billions of years.

• RNA is widely hypothesised to be the first genetic material. It is able to both store genetic information and catalyse chemical reactions.
• DNA evolved roughly 5 million years later from RNA, as DNA-based life was more chemically stable. Therefore, it was a better long-term genetic storage molecule.

You might be familiar with prokaryotic cells, which are a type of bacteria.

• They were the first cells to store their genetic material within their cytoplasm in a circular form.

Natural selection, as we know, favours efficiency and the ability to repair, so prokaryotic cells continued their evolution.

• Just over 1 billion years later, eukaryotic cells evolved. These cells contained a nucleus as well as mitochondria and chloroplasts.

This allowed for DNA to organise itself linearly, which meant more complex regulation of genes.

• From then on, multicellular life formed, along with genetic mutations, which led to new species and traits.

Read about which DNA test is best, UK?

When was DNA First Discovered?

DNA was first identified in 1869 by a Swiss scientist, Friedrich Miescher. He noticed a strange substance within white blood cells, which he called “nuclein”. Nuclein was later known as DNA.

Surely you’re familiar with the names Rosalind Franklin, James Watson, and Francis Crick.

• Using x-ray images from Rosalind Franklin, Watson and Crick found that DNA has a double helix structure.
• In the 60s and 70s, scientists cracked the code of the sequences of A, T, G, and C, as well as their link to amino acids and their role in building proteins.

Since then, numerous breakthroughs followed, such as the human genome project, where all 20 000+ human genes were identified and mapped, meaning we have the manual to read our DNA!

As a result of this, Dolly the Sheep was successfully cloned.

• Today, technology such as CRISPR allows gene editing, which has already been used to correct a genetic disorder, sickle cell anaemia.

The future is wide open with possibilities of what we can do with and to DNA. For example, custom medicine can be formulated for your DNA, treating diseases before you have symptoms. Or reviving extinct species, such as the woolly mammoth, by reconstructing their DNA.

3 Interesting facts about DNA

• If you uncoiled all your DNA in your body, it would stretch to Pluto and back; that’s roughly over 10 billion kilometres!
• 9% of our human DNA is identical to one another. That means that only 0.1% is unique.
• Identical twins have the same DNA, but their fingerprints are what sets them apart. This is due to the environmental factors that impact their development.

A Roadmap Worth Following

Your DNA is the blueprint of your body—past, present, and future. It never changes, but your understanding of it can. A DNA test can unlock the secrets to working with your body, not against it, so you can live a healthier, happier life. Click here to discover your unique DNA insights today.