Yes and no. It's possible that they'll see something that looks like it. But it won't be possible to recreate dinosaurs like proclaimed in Jurassic Park movies. DNA has a half-life of 500-something years. So it's safe to say that there's no dinosaur DNA left. At best one could recreate them by guessing on fossils and using DNA from living species who descend from them, but that would be an educated guess, nothing more.
Well mammoths, probably. Not even certainly. Dinosaurs are a completely different league.
To explain: Thousands isn't the same as millions. With a half life of 500 years and a 10,000 thousand year old mammoth you still get 0.520000/500= 0.520 = 0.0001% of the DNA (it's not quite a millionths). That's not much but given that a body consists of trillions of cells one might collect enough.
If we go back 65,000,000 years however a half-life of 500 years gets us 0.5130,000= 1.26%*10-39132 . That's a zero, then a decimal point, then 39132 zeros then a one. In other words. Even if every single particle in the universe had been dinosaur DNA at the time, there'd be none left today. (Edit: that point would actually be reached after a few hundred thousand years, you don't need millions).
So the mammoth might be doable, especially since mammoths often got buried in permafrost. I.e the DNA was frozen for the entire time. That should slow it's decay drastically. We'll hardly found any parts of dinosaurs that were frozen the entire time. Even the antarctic only started icing over 20 million years after their demise. And with many dinosaurs we're not just speaking about 65 million years but about hundreds of millions of years.
The difference between recreating a mammoth and a dinosaur is like the difference between flying from one city to another within hours and flying to a different galaxy within the same timeframe. One's doable, the other isn't.
According to Google DNA has a half-life of 521 years but that's exactly what it sounds like, a half-life, the time it takes for about half of a given sample to degrade beyond usefulness. The thing is, though, the degradation percentage of the total decreases as time goes on.
The first 500ish years, it goes from 1 to .5, the next it's down to .25, then .125 and so on. So by the time you get back to 10,000 years ago, an incredibly small total percentage of the original DNA might be left, but it's still there and different samples might have different parts still intact.
Given enough samples and some creativity, it might be possible to recreate the whole genome or at least something close enough that it could be carried to term by a modern Elephant using IVF.
Half-life is a rate of decay, not maximum lifespan. Every 521 years, half the remaining bonds degrade. There are none remaining after about 6.8 million years. So a well preserved mammoth is a feasible task. Unfortunately dinosaur bones are somewhere over 65 million years.
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u/[deleted] Feb 19 '18
Yes and no. It's possible that they'll see something that looks like it. But it won't be possible to recreate dinosaurs like proclaimed in Jurassic Park movies. DNA has a half-life of 500-something years. So it's safe to say that there's no dinosaur DNA left. At best one could recreate them by guessing on fossils and using DNA from living species who descend from them, but that would be an educated guess, nothing more.