Quickies
Quickies: Missing link found in deep ocean, a real-life replicator, and stop calling women nice
- Under the sea, a missing link in the evolution of complex cells – “Scientists estimate that the first eukaryotes evolved about 2 billion years ago, in one of the greatest transitions in the history of life. But there is little evidence of this momentous event, no missing link that helps researchers trace the evolution of life from bacteria to eukaryotes.”
- Real-life Star Trek replicator prepares meals in 30 seconds – From CriticalDragon1177.
- World of Wonder: Sea pig – “This translucent little cutie can fit in the palm of your hand and eats “marine snow”—that tasty bit o’ sea life dander and detritus that sloooowly trickles down to the very bottom of the ocean floor.”
- Editor of Science: Stop calling women ‘nice’ – “In an editorial in top scientific journal Science, Editor-in-Chief Marcia McNutt recalls her astonishment at seeing terms like “nice” and “kind” find their way into recommendation letters for students applying for research grants—but only when those students were women.”
- Cute Animal Friday! Rock hyraxes have the best faces.
Those hydraxes looks so unimpressed.
“Yeah, I see you looking. What do you want?”
I shared the same article on Facebook. I said something like, “This is HUGE. Actually, it’s really small, but this discovery will have an enormous impact on our knowledge about the origins of life.”
Take that, Fundamentalists! There are no transitional forms? Maybe you can get away with that in Louisiana and the other states that have “teach the controversy” laws. There is no controversy in the scientific community! Maybe they should be giving equal time to flat earthers in geography class, too. I love that they claim those laws foster critical thinking. Ignorance is strength!
It will? You’re sure? Have a crystal ball there?
There are few things more entertaining that a self-professed skeptic who admits that her knowledge is provisional, taking a stand upon that provisional knowledge and declaring someone else in error.
You don’t know your enemy. Here’s a few clues: geography is observable by the eye. Origins, not so much.
Debate does foster thinking. Teaching that you can’t question dries up debate. Conflict and debate lead to a better, more complete understanding — or that’s the way it’s supposed to operate. I fail to see the harm in teaching that a theory is a theory. I am very leery of the state decreeing what I must believe, as should you, if you’re going to quote 1984. (That irony I found quite delicious.)
Make sure you understand how “science” is constructed, with grants (who determines what should be studied?), intense peer pressure among faculty, cabals running peer-reviewed journals (see: Climategate), reporters ignorant of science reporting “news”, and so forth. In other words, be skeptical.
Show me a skeptic who doesn’t think Fundamentalists aren’t in error. You should know that theory means something different in the realm of science. It’s not a dumb ass guess or even a hypothesis. Try jumping off a cliff and see if gravity is just a “theory.”
PS: Being a skeptic means you should be able to change your mind when confronted with convincing evidence. That’s something the religious don’t do. When Filias later commented in this thread and explained some of the science of this “discovery” better than the author of the article did, I retracted my comment that this was HUGE. That’s true skepticism.
I’m cautious about the “missing link”-find. Metagenomics seems like a method with results that could have all sorts of interpretation, so until they isolate the actual organism instead of analysing scattered DNA in mud I’m not changing my family tree.
No need to change the tree, the ancestors you have will always be there whether you like it or not. :)
I don’t know about your tree, but mine has a blank spot right before Eukaryote Prime. Not filling it in until the evidence is more conclusive. (Only one line goes that far back, obviously. Most others dead end in the 18th century due to incomplete records.)
Amanda,
Its not really what I think of when I think of Star Trek’s replicator, but its still pretty Awesome. Glad you liked it. It does have potential.
I work in a evolutionary biology, but in data processing/algorithms/computing aspects, so I have some knowledge about this stuff, but not at expert level.
This is just one experiment, although an exciting one. It may well turn out to be a false alarm – exciting results often are. We need to wait until other experts try to pick holes in the result, and for further experiments to (hopefully) confirm this result.
A big problem is that this metagenomics approach doesn’t guarantee that all the DNA you sequence comes from the same critter. Perhaps they have a mixture of eukaryote and archaea DNA. I expect they’ve tried to eliminate this possibility in some way, but it being weekend I don’t have access right now to the paper (and even then I don’t really have the knowledge to criticize this aspect.)
The article says archaea DNA more closely resembles eukaryote DNA than bacteria does. This is true for the core genes to do with DNA processing and protein manufacture. For the metabolic genes (I’ve been told) the eukaryotes and bacteria seem more similar. A popular theory is that a fusion of archea and bacteria was the origin of the eukaryotes. (Some knowledgeable people I respect don’t like this theory. Note that this is a separate earlier fusion than the acquisition of mitochondria, which is not controversial.)
Eukaryotes have multiple cellular compartments, linear chromosomes, and genes with introns (the protein instructions are split into chunks with ‘junk’ DNA between them.) Bacteria and archaea have a single cellular compartment, circular chromosomes and (I think not 100% sure) no introns. As bacteria and archaea are simpler and ‘more primitive’ than eukaryotes, it is often assumed that the last universal common ancestor (LUCA) resembled them (circular genome etc.) however while plausible, this is not a safe assumption.
Very well explained, Filias! I wish the article had discussed the issues you raised. One of the things I love about science is that it’s always provisional. It’s more than a little disappointing to hear rather large caveats to this discovery, if it is indeed a discovery at all. But as a skeptic, you have to be able to accept evidence that what you believe, or would like to believe, is wrong.