Science Buddies: "Ask an Expert"

Hello, I am doing a project on the maximum amount of DNA that can be contained inside a cell's nucleus. (Project Title: How much DNA can you pack into a cell?)
Would you mind answering a few questions for me?

-Why is DNA measured in weight?
-Is the complexity of organisms limited by the amount of DNA that can be contained by its cells?
-If humans are going to evolve into a super complex species, will our cells either have to grow in size or evolve a new genetic material?

Thank you for your time. I appreciate it!

~Kris & Daniel
ありがとうございます！

Hi,

Those are great questions, good luck with your project

-Why is DNA measured in weight? It's a convenient way to measure it. Sometimes we do list the measurement in kb (kilobases) - which is more like a length measure.

-Is the complexity of organisms limited by the amount of DNA that can be contained by its cells? Not necessarily. Some smaller, seemingly less complex, animals have pretty big genomes. We are finding that the old idea of 1 gene = 1 protein = 1 function is NOT true. The DNA can be very short, but encode a variety of proteins, each with multiple functions, due to alternative splicing and modifications. It's amazing, and VERY efficient.

-If humans are going to evolve into a super complex species, will our cells either have to grow in size or evolve a new genetic material? It is not likely we will gain larger cells - because the surface to volume ratio has an optimal value, and it seems we are in that range of optimal. What types of attributes are you looking for in an advanced species? i think of advanced brain power, so I think the mutations leading to that would be around super-fast signal transduction in the brain, so maybe longer neurons or something like that?


Tonya

Thank you for answering our questions!!