Photo from here.
We tend to think of DNA as set in stone: immutable instructions the body follows from birth through life until death. In truth, DNA is dynamic throughout life and even subject to outside influence from the environment. It’s one of the raddest things in biology. The above article from phys.org summarizes it perfectly so I’ll just quote:
“DNA is the rulebook or manual for life, the genome. It is divided into different sections. Some cells will only use instructions in specific sections. Environmental factors, such as light, temperature, stress or even famine, control what chapters will be used at different times of life. The bookmarks in this rulebook—guiding how the rules are read and what adaptations happen in response to the changes—are the epigenetic markers. “
And now scientists at Florida International University (FIU) are using those markers to determine the age of dolphins, which before required literal pulling of teeth. Knowing the age structure of a population – how many are young, old, and in between – is crucial for conservation, management, and pretty much any other science you can name. This is huge for bottlenose dolphins, but expanding it to other species like FIU is planning to with sharks would be a game-changer. R.A.D. EPIC-genetics!