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First Complete Lizard Genome Sequenced
iamrmani writes with an article in the International Business Times about the recent gene sequencing of a lizard. From the article: "Researchers have managed to sequence the genes of the green anole lizard, which is the first non-bird species of reptile to have its genome sequenced and assembled. The findings, which researchers have obtained after assembling and analyzing more than 20 mammalian genomes, may go a long way in understanding the evolution of animals and humans."
Lounges across the world have become that must less mysterious.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
The first non-bird species of reptile? I've heard that it is also the first non-mammal species of reptile to have its genome sequenced. Seriously though, the Slashdot summary may sound stupid (shocking, I know) but the story is actually quite interesting. Of course this is not something to read about in the International Business Times! There is a much better article in Scientific American: Lizard Genome Unveiled: First non-avian reptile sequence helps explain vertebrate evolution by Lee Sweetlove. Highly recommended reading. I also recommend this article on PhysOrg: First lizard genome sequenced by Haley Bridger. Ths story is particularly remarkable that when we have successfully sequenced the genomes of the entire line of the fish - reptile - bird - mammal evolution then we will finally be able to prove the theory even beyond any reasonable doubt of intelligent designers. Hopefully this breakthrough will start an interesting discussion in the world of science about the exact details of the natural selection in general and the speciation in particular.
Karma: Positive (probably because of superiour intellect)
Dinos are reptiles, birds are dinos
http://en.wikipedia.org/wiki/Phylogenetics
http://evolution.berkeley.edu/evolibrary/article/phylogenetics_04
https://secure.wikimedia.org/wikipedia/en/wiki/File:Phylogenetic-Groups.svg
However, mammals are not reptiles (but reptiles and mammals are both amniotes)
Climate Progress - Hell and High Water
Too much overload today, eh?
About 160 million years ago. Slashdot should be covering the story some time next week.
Palm trees and 8
TFA discusses how having this genome may help us better understand evolution by getting a better picture of how different reptile species diverged and how exactly they diverged from mammals. One of the neatest aspect of this research are the discovery of a large number of transposons. http://en.wikipedia.org/wiki/Transposon. These are segments of DNA which can jump around the genome inserting themselves where they please. They can be disruptive or helpful or just do weird things (in fact they were initially discovered in corn when Barbara McClinctock was trying to figure out what controlled the very strange behavior of corn coloration) . As TFA discusses, some of the same transposons in the lizard genome also exist in humans but many have been tamed and put to productive use.
Too bad they aren't taking requests for which lizards to sequence. I'd be very interesting in the sequencing of the New Mexico whiptail http://en.wikipedia.org/wiki/New_Mexico_whiptail in the hope that its weird reproductive behavior might be better understood. The whiptail has evolved to be an all female species. The females reproduce in a way that does shuffle their own genes so that children aren't complete clones. But one really neat detail is that they need to engage in mock sexual behavior in order to reproduce. If they don't hump each other they won't produce eggs. This is has earned them the nickname "lesbian lizards". They are not the only species that has adopted this sort of process but it is very rare, and the whiptail is one of the better understood examples. I would hope that having the full genome might give us more insight into how/why this sort of thing can evolve.
More pessimistically, there's been very little direct benefit from finding species complete genomes. While the human genome project has provided some benefits most of those benefits have been fairly subtle. It seems that the human genome project has been helpful but not nearly as much as some people predicted. Some of the modern genetic work uses techniques developed during the genome project but much doesn't seem to actually use the human genome project data itself.
That is how it goes in a second grade level explanation or evolution.
That's the problem with second grade. It's a simplification to make the data accessible to second graders. It doesn't take into account more complex knowledge that we have acquired since then.
Oh, and by the way, atoms aren't small collection of beads orbiting each other. That's also a school-science simplification that fails to take into account wave functions and all such wonders.
All these is what some name "lies-to-children"
Don't get me wrong: There's nothing inherently bad in using simplification. You just have to keep in mind that they are model. And as with any model in since, it has its domain of application. (You can use newtonian physics for everyday motions, you only need to whip out Einstein's models for bigger speeds).
Your second grade teacher didn't make a mistake by teaching this, but made a mistake by failing to specify that this is a coarse model and pupils with special interests are encourage to study more details if they wish.
BUT BIRDS ARE NOT REPTILES reptiles do not have feathers, are cold blooded and have a three chambered heart.
If you use that over-simplified definition yes.
Except that, since then, people have also looked on evolution markers. Apparitions of small characteristics, small anatomical differences, physiology, mutation in DNA, and much more.
What arises there is that Mammals split apart from reptiles pretty early one.
Reptiles split further later on, with avians emerging quite late.
In fact, there are much less difference between avians and some reptiles, as there is difference between reptiles.
If you want to lump turtles, crocodiles and lizards in the same "reptile" class, you end up with a definition so broad of "reptiles", and a position so early in the evolution tree, that you need to lump dinosaurs and birds in the same class too (and only miss lumping mammals too by a hairbreadth. We split appart a tiny little bit earlier).
That's why the lizard is defined as a non-avian reptile.
- It's also a "reptile" according to these new evolutionary biology discoveries. But due to how broad this definition has become, it could also mean "birds" or "avian reptiles". And we already have several genomes of those (turkey was sequenced for research because of its agricultural significance, for exemple)
- They have to specify "non-avian reptile" to what people commonly refer as "reptile" (using simplified 2nd grade biology) : lizards, turtles, and the like.
So the phrase makes perfectly sense to anyone using more complex models of phylogeny, and only sounds silly to someone using simplified 2nd grader models.
The 2nd grader explanation rely only on a few big characteristics, and might lump together things that remotely look alike but in fact aren't that related.
Case in point : the number of heart chambers.
On might be quick to separate bird and mammals on one side, and non-avian reptiles on the other as the former have 4 chambers and the later only 3 (mostly). Well, turns out there are several different way to "invent" a 4 chambered hearts. The fact that both birds and mammals have them isn't due to common ancestry, but due to convergent evolution: Once you have a 3-chambered hearth, the next best step in improving the oxygen pumping efficiency is to evolve 4 chambers to separate oxygenate and non-oxygenated blood.
But "birds" got their "4-chamber heart" in a slightly different way. In fact their hearts are assembled "the other way arround" when you look into some details: our left aorta pumps fresh blood to the body. In birds it's the right. When we created walls to separate the two circulations (lungs and body), we didn't do it the same way around. Proof that our hearts were invented by evolution at separate points of time.
So number of hearth chambers might work as a quick rule of the thumb. But starts to fall apart when you need more details. And when you start looking into the exact DNA text, oh boy you what a detailed model you need.
By the way: Crocodiles have 4 chambered hearth too.
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