Rip:20

How is the mosaic modular nature of enzyme evolution convergent? Also, if you read the article the changes in non-coding regions are the opposite of useless since they altered phenotype. That's the whole point of the study, that non-coding regions have important regulatory and expression effects. Evolution works across the genome on much more than just composition of protein coding regions (genes).

Hehe. They're struggling in the rocket dept. too. Fail

Well if it's biotic then you should check the autoclave setup. 250 C, high pressure, 30 minutes should get everything. Tin foil top, keep it covered. Why are you storing at 60 C. That's flippin hot! Try the fridge.

LOL. I have certainly sustained some damages to my psychological mind. Otherwise, the question of virus origin is truly fascinating because it stretches the canonical definition of life for me. Unlike cellular life, viruses (and virus-like particles) lack a set of conserved genes with which we could infer past evolutionary relationships from. Plus that virus-like behavior can be derived from DNA or RNA with or without proteins, or proteins with out nucleic acids, says to me that it is perhaps an intrinsic property of both protein and nucleic acid polymers above a certain size, and that the extant lineages of viruses (and VLPs) have multiple evolutionary origins. Think about that for a minute. This contrasts with our view of cellular life, all of which appears to have a shared common ancestor. This is legendary. +45

Yup. The stuff I see used to meet the NSF's somewhat new "broader impacts" evaluation criteria are often pretty funny post hoc add ons. A common easy cop out is that the grant will enable training opportunities for students. Not that that's not an admirable goal, but it's actually good to come out of our strange obsessions sometimes and think this stuff through. Although there might not be a directly visible route to an application, you can still use your imagination to come up with stuff that at least meshes with your hypotheses a bit more directly.

It only works if you have a pure culture of bacteria and only about 5% or so of bacterial "species" can be (have been) isolated into cultures. Furthermore, absence/presence of an outer lipopolysaccharide layer is not a monophyletic trait. (Nor is chlorophyl +/- in Euks either for that matter). So while Gram staining is a good tool for instructional microlabs, it's utility in current research science is extremely limited. But of course you can do whatever you want, which is a part of what makes science great. As of 2007 we are up to 30 phyla with cultured representatives and 70 phyla defined solely by culture independent techniques for Bacteria. (Based on 16s rRNA sequence space.) Using metagenomics and metaproteomics (among other techniques, like good old fashion culturing) we are just beginning to scratch the surface of the accompanying phenotypic/metabolic diversity. It's both an overwhelming and exciting time to be a microbiologist.

This is akin to saying there are two types of Eukaryotes: chlorophyll positive and chlorophyll negative. Although not incorrect, it's a superficial delineation based on a characteristic that's very easy to measure but provides limited biological insight. Same with gram staining, it was once an important method for describing bacteria (couple of decades ago), but has since been replaced with more descriptive measures.

Requires hours of autoclaving to destroy? How about Methanopyrus kandlari, which actually grows in an autoclave. Yup, grows in 121 C water. Native to deep sea thermal vents. My link

Intelligence, although it's a difficult term to define, is simply not a requisite for evolution to occur, as you claim in your original post. Memory (or information storage) is required for both evolution and intelligence. Since Griffith's work in the early part of the last century, we've known that strings of DNA are the information storage system for all cellular life. Most of the points you make only support evolution, rather then call it into question. The issue you bring up about oxygenic photosynthesis seeming to be in balance with aerobic respiration is just one of many successful cyclical systems life has evolved.

Exactly. ^^ Also, to the OP: cellular memory = DNA. But memory ≠ intelligence. A book is a form of memory, but you would not call it intelligence. DNA is a form of information storage, but not intelligence.

This is a great topic that is often misunderstood. I'll put my vote in with the bacteria (being a microbiologist), mainly due to the awesomeness of HGT. I want to point out that the Archaea have the shortest branch length (slowest changing), followed by bacteria, with Euks having the longest branches in the ribosomal tree of life. I would also like to say that sometimes evolution works by not changing (purifying selection).

This is awesome. Where did you come up with this? I'm requesting more details.

But sometimes evolution does select for simplicity. Think of the genome reduction in Pelagibacter ubique, or your own example of loss of unused traits in parasites (could be drift in some cases, could be positive selection to reduce waste). The point is there is no one direction or plan that evolution follows for all life forms. In terms of Eukaryotes v.s. Bacteria, yes the bacterial domain has far more metabolic diversity in total, and some members are massively versatile (i.g. large genome pseudomonads), but no one individual bacteria rivals a crown Euk (i.g. human) in terms of differential multicellularity, or even total protein diversity.

The disconnect is that not all life has followed the pattern of evolving from simpler forms into complex multi-cellular forms. So the premise of the article you site is not a generalizable principle of evolution. My counter-example was bacteria, but there are many others too. The bacterial lineage is just as old as our own Eukaryota, it's just gone a very different, but highly successful direction. Sometimes evolution selects for simplicity.

Nice story you just made up. Thanks for providing zero science to the science forum.

Short of returning a sample from Mars, or where ever, to earth for culturing tests, and detailed biochemical analysis, how can we really "prove" the existence of microbial life anywhere using remote sensing or data from landers/probes? Life inherently harnesses favorable reactions which can occur abioticaly, so microscopes and mass specs aboard landers would be my guess, but I don't know much about what you can fit on landers. I've heard rumblings about the methane plumes on Mars, and searching O2 using spectrometry. Other ideas? It could be a long time before we can confidently say microbes exist off plant, even if they are close by. Think about this idea for a bit: http://en.wikipedia.org/wiki/Panspermia Merged post follows: Consecutive posts mergedhttp://www.sciencedaily.com/releases/2010/06/100606103125.htm Cool stuff. Titan. The Russian project to drill into lake Vostok has almost penetrated, I'm really looking forward to any results from that too.

Ha. True true.

Methanogensis is restricted to the Archaea, no bacteria have been found to have this metabolic capacity so far.

A further twist on the avocado is that it was probably humans who drove the seed's disperser, the giant ground sloth, to extinction through hunting.

No thanks I don't need any more iron in my knee cap thank you very much, my user name is a play on clock time, which can change. Unconventional and confusing yes, insular inside joke, of course, rooted in a typo at some point, perhaps, having anything to do with math and irony, not really. --Rip:00

+1 HGT for the win. And this is not the first time HGT has been found in multicellular Euks as mentioned in the article. Aphids got their carotenoid genes from fungi and bdelloid rotifers pick up all kinds of DNA during their repair process from desiccation (may or may not be expressed).

When you think about natural selection on each generation from the species point of view, it does seem there is no "long-term view". You need to think about the broader gene pool (outside of the arbitrary species delineation). Once you start thinking about survival of individual genes within larger clades then you can see how enormous diversity can be used to buffer against changes in the fitness landscape. One reason that there are so many forms of life is a result of how all (most) fitness landscapes always change though time. But old adaptations that are suboptimal in the current fitness selection arena are not just historical relics that are doomed for extinction, they can be reshaped or re-appropriated to be useful in future environments. Your example of the avocado is pretty funny b/c although yes, the megafauna are gone , now humans have decided that the avo fruit is delicious and have extended the plant's range via cultivation. I have one growing in my office here in Colorado. Serendipitous evolution for the avo tree, no? --Rip:45

This is for animals only. As the authors point out, bacteria are some of the most successful organisms on earth and yet remain single celled (mostly). By successful they mean most diverse in terms of "species", and probably largest total bio mass.

Ya, don't pick a clade unless you really can't stand to do anything else and just LOVE clade X. Some people are like this and there is always room in a field if you are one of the best at what you do. That said, if you are interested in it from a more pragmatic POV, think more about broad skill sets and knowledge bases that can be used to explain more widely shared phenomena. For example, I choose to study patterns of evolution, and analytical techniques used to discern such patterns, because it is the rules of evolution that drive the astounding diversification of life, from which you and me can't seem to pick favorites from.