Have there been any experiments observing DNA changing into new forms of DNA?
Not just adaptations of DNA, like for a beak to get longer, necks lengthening, or colours changing, but of something NEW developing that did not exist before.
Evidence that a species can change from one species to another, which happens over such a long period we can’t observe it, but on molecular levels surely we can observe evolution happening, right?
I’m not a scientist, and was challenged by a friend who thought evolution couldn’t be proved.
Thanks for your help!
Posted: October 19th 2008
SmartLX www
There are many ways to reply to your friend, but let’s go with your idea of an example. I think the following is exactly what you’re looking for.
Biologist Richard Lenski has been running an ongoing experiment for 20 years. He farms a population of E.coli bacteria (yes, the deadly one). He feeds it, lets it breed over and over and periodically freezes a sample of it for archival. Since frozen samples can be thawed and revived, it’s like having real living fossils from everywhere on the timeline.
Lenski and his team split up the bacteria into isolated groups and monitor each for signs of mutation. What they’re really looking for are signs of beneficial mutations, which creationists often argue are impossible.
There were various changes over the years, but they hit the jackpot in 2008. One population developed the ability to metabolise (eat) citrate as well as the usual diet of glucose.
E.coli isn’t supposed to be able to get citrate in through its cell walls, and its usual inability to consume the stuff is a defining characteristic. It’s like a human suddenly being able to live on dirt, but considering how relatively simple E.coli is, it requires an even greater physical change. That’s evolution, baby.
Not surprisingly, there is an ongoing campaign by creationists and in particular by Conservapedia to discredit the experiment. Research the issue yourself and you will find that any related controversy exists entirely in the realm of the public creation-evolution conflict, and not in the realm of science.
Posted: October 21st 2008
Eric_PK
Anti-evolutionists like to say that “micro-evolution” can happen, but that there are no cases of “macro-evolution”.
But that’s a distinction that has no basis in fact. Take two populations of the same species, put them in two different and separate environments (so they don’t interbreed), and they will start to evolve differently, through small changes. Over time, those changes will accumulate, and if there is sufficient evolutionary pressure, over time they will become sufficiently different for them to be unable to interbreed.
You now have separate species.
Ask your friend that if small changes are possible, what keeps those small changes from accumulating?
There is no mechanism to keep that from happening, and that’s why the whole macro/micro evolution distinction is a farce.
As for something “new” developing, ask your friend for an example of something “new” that he/she thinks is not explainable by evolution. Once you get into specifics there are great resources you can read to find out how evolutionary theorists explain it.
Posted: October 21st 2008
logicel
Excerpted from talkorigins.org.
The five propositions below seem to be the most common misconceptions based on a Creationist straw-man version of evolution. If you hear anyone making any of them, chances are excellent that they don’t know enough about the real theory of evolution to make informed opinions about it.
1) Evolution has never been observed.
2) Evolution violates the 2nd law of thermodynamics.
3) There are no transitional fossils.
4) The theory of evolution says that life originated, and evolution proceeds, by random chance.
5) Evolution is only a theory; it hasn’t been proved.
As you can see your friend has both the first and last misconceptions about evolution. Hence, to paraphrase, your friend most likely does not know enough about the real theory of evolution to make informed opinions about it.
In the link, you will find another link delineating some examples of observed speciation.
There is an impressive body of information supporting evolution, including DNA (buttressing common descent). The scientific theory and FACT of evolution does not rely on just one aspect like DNA or observation of speciation, but on a substantial interlocking matrix of details, scientific disciplines, research, experiments, etc.
Posted: October 21st 2008