On Radiolab’s latest podcast, Asking for Another Friend, Pat Walters and I kick off a discussion about massive genomes and why some organisms have them. The coast redwood is about 8 times larger than the human genome, an indication that lots of extra DNA has crept into the redwood genome over millions of years. Is it unfortunate evolutionary baggage or is it actually an insurance policy for the future?
Any organism’s genome is made up of long sequences of DNA – some that codes for important genes that keep us alive, but a lot of the DNA seems to code for nothing or at least doesn’t provide an obvious advantage today. The thing is, could some of this seemingly junk DNA actually be advantageous in the future as conditions change? On the podcast, Pat describes his own storage closet with mysterious items that he isn’t convinced he needs to keep…but what if he does need them some day!
This is the perfect analogy for genomic conservation – we need to protect as much genomic diversity as possible for species so that they have every possible chance to survive in the future as a population. If we protect many different redwood trees in a forest, then we can keep that reservoir of DNA that just might be needed in the future. By sequencing the redwood genome, we will be able to inventory genomic diversity across the landscape and design conservation and restoration practices that promote native diversity to help future redwood forests.
Tune into the podcast around minute 42 to hear the discussion.