PZ has been live-blogging the new “Evolve” series on the History Channel since it began a few weeks ago. This week’s episode is on the evolution of jaws, and should be a good one. Alas, none of the Minions will be able to live-blog the program, but I will post an ‘Evolve’ open thread in time for the East Coast airing at 10 PM Tuesday night, in case anyone is interested in commenting as they watch.
Danio, for the collective.
Posted by LisaJ
Now this is a super cool new Science story. Have you ever wanted to make yourself invisible? Ever said “man, I wish I could just run away or hide and make everyone go away”? Maybe as a young 8 year old, trying to hide from those bullies on the playground. Or perhaps you’d like to saunter into mass inconspicuously one Sunday morning to grab one of those delicious wafers without starting a riot. Well, if this sounds like you, then your lucky day is (almost) here. Dr. Xiang Zhang and his group from the University of California have reportedly “created a material that could render people and objects invisible”. They are announcing this week, in a pair of articles to be published in Nature and Science, their generation of a 3D metamaterial that exhibits a negative refractive index (thanks negentropyeater). ‘Metamaterials’ are apparently a manmade mixture of metal and ceramic or Teflon like materials (anyone who knows anything about this field is welcome to clarify this!) that function to bend visible light waves quite aptly. These researchers have harnessed this unusual property of the metamaterial they have created to redirect light around 3D objects to effectively disguise or ‘cloak’ them.
This new study represents a major progression in the field, as previously this technology could only be used to cloak very thin 2D objects. Now I’m assuming that the 3D objects they effectively made invisible in these studies were probably pretty small too, we’ll have to wait until the end of the week to find out, but this is a big step closer to allowing humans to obtain their own invisibility cloaks.
This article explains that this ‘new work moves scientists a step closer to hiding people and objects from visible light, which could have broad applications, including military ones. ‘ Which is a pretty cool application, I guess (but also a very frightening one when you think about it). I think it’s pretty obvious what the greatest potential of this new technology really is: to make millions of Harry Potter fans very, very happy. You make a real invisibility cloak and you’ve hit a goldmine with that fanbase.
Now I am by no means a mechanical engineer, materials scientist, or an expert in this particular field. So if anyone would like to add any additional info on how this technology works it would be much appreciated. It sounds very cool, and I’d like to learn more.
Hi all! This is LisaJ, and I’ll also be guestblogging here on Pharyngula for the next 10 days or so. I’m very much looking forward to the opportunity to chat it up with you fine folks here on Pharyngula, and I hope I can do my part to keep everyone stimulated and satisfied.
I would first like to echo MAJeff and Danio’s sentiment and send a big thanks to PZ for inviting me to participate as a guestblogger. I too was very surprised and flattered to be asked. What a nice guy that PZ is! Just to briefly introduce myself: I’m a 3rd year PhD student studying novel functions for the pRb/E2F tumour suppressor pathway in nervous system development. Although this is my favourite protein pathway, largely because it takes up most of my waking thoughts and, you know, these proteins are just so awesome and multifunctional, I will likely be contributing various Science related posts during my time here, among other topics that will just come as I go!
I’m also a pretty proud Canadian girl, currently living in Ottawa, our beautiful capital city. Since alot of the posts here on Pharyngula center around the news, politics, crazy christian crusades, etc, going on in PZ’s fine country, the US of A, I thought that for my first post I would lead a little discussion on what makes its Northern neighbour such a special place… but also, not really that different at all in some respects.
MAJeff here, and I’ll be one of your guestbloggers for the next several days. I’d first like to thank PZ for asking me to do this. I was more than a little surprised to get an email the other day inviting me, and I hope I can keep up the quality people have come to expect from the place.
I’m not sure of everything I’ll be posting about yet. But, I’ll probably be doing some of what I do when I teach, and that is asking questions. Y’all are a chatty bunch, so I probably won’t need to do much asking. Sometimes, though, I just like to get to know folks better, to move beyond argument and talk. As a sociologist, I study people. I don’t always understand them, but I do find them fascinating. Opportunities to get to know what drives folks are never to be turned down.
So, here goes: What is it about science that so enthuses all of you?
My brief answer–it’s not Boobies; not that there’s anything wrong with that, w00t–is below the fold….
[Read more…]
I was sent this lovely bit of poetic biology, by someone who said it was written by a colleague at the Salk…maybe she’ll give full credit in the comments. Consider yourself a knowledgeable cell biologist if you get all the allusions.
The p53rd Psalm
p53 is my shepherd, I shall not cycle
It maketh me to lie down in G1
It leadeth me beside still nucleotide pools
It restoreth my genome
It leadeth me past the restriction point for replication’s sake
Even though I walk through the valley of the shadow of the cobalt irradiator
I shall fear no gamma rays, for thou art Guardian of the Genome
Thy amino and thy carboxy termini, they comfort me
Thou maintainest my genomic stability in the presence of mine enemies
Thou annointest my nucleus with p21/WAF1/Cip1/Sdi1/Pic1
my cyclin dependent kinases overflow
Surely pRb phosphorylation and E2F activation shall follow me
all the cycles of my life
and I shall dwell in a non-tumorigenic state until senescence
And if you want some more literary bioscience, here’s some short fiction I was sent.
I’m wondering how this works. VADLO is a web search engine for biologists, and my first attempts at using it…it worked surprisingly well. I looked up a few techniques I’ve been using, and actually turned up some useful articles.
Every time I mention this developmentally significant molecule, Sonic hedgehog, I get a volley of questions about whether it is really called that, what it does, and why it keeps cropping up in articles about everything from snake fangs to mouse penises to whale fins to worm brains. The time seems appropriate to give a brief introduction to the hedgehog family of signaling molecules.
First, a brief overview of what Sonic hedgehog, or shh, is, which will also give you an idea about why it keeps coming up in these development papers. We often compare the genome to a toolbox — a collection of tools that play various roles in the construction of an organism. If I had to say what tool Sonic hedgehog is most like (keeping in mind that metaphors should not be overstretched), it would be like a tape measure. It’s going to have multiple uses: as a straightedge, as a paperweight to hold down your blueprints, as something to fence with your coworkers on a break, and even to measure distances. It will be pulled out at multiple times during a construction job, and it’s generically useful — you don’t need one tape measure to measure windows, another to measure doors, and yet another to measure countertops. Sonic hedgehog is just like that, getting whipped out multiple times for multiple uses during development, often being used where structures need to be patterned.
Let’s dig into some of the details. I’m using the 2006 review by Ingham and Placzek for most of this summary, so if you really want to get deeper into the literature, I recommend that paper as a starting point.
I keep saying this to everyone: if you want to understand the origin of novel morphological features in multicellular organisms, you have to look at their development. “Everything is the way it is because of how it got that way,” as D’Arcy Thompson said, so comprehending the ontogeny of form is absolutely critical to understanding what processes were sculpted by evolution. Now here’s a lovely piece of work that uses snake embryology to come to some interesting conclusions about how venomous fangs evolved.
Basal snakes, animals like boas, lack venom and specialized fangs altogether; they have relatively simple rows of small sharp teeth. Elapid snakes, like cobras and mambas and coral snakes, are at the other extreme, with prominent fangs at the front of their jaws that act like injection needles to deliver poisons. Then there are the Viperidae, rattlesnakes and pit vipers and copperheads, that also have front fangs, but phylogenetically belong to a distinct lineage from the elapids. And finally there are other snakes like the grass snake that have enlarged fangs at the back of their jaws. It’s a bit confusing: did all of these lineages independently evolve fangs and venom glands, or are there common underpinnings to all of these arrangements?
This story is in the news again, so I’ve reposted my description of the paper from 3½ years ago. This is an account of the discovery of soft organic tissue within a fossilized dinosaur bone; the thought at the time was that this could actually be preserved scraps of Tyrannosaurus flesh. There is now a good alternative explanation: this is an example of bacterial contamination producing a biofilm that has the appearance of animal connective tissue.
Read GrrlScientist’s explanation and Greg Laden’s commentary and Tara Smith’s summary of the recent PLoS paper that tests the idea that it is a biofilm.
Look! A scrap of soft tissue extracted from dinosaur bone:
It has been reported in Science this week that well-preserved soft tissues have been found deep within the bones of a T. rex, and also within some hadrosaur fossils. This is amazing stuff; fine structure has been known to be preserved to this level of detail before, but these specimens also show signs of retaining at least some of their organic composition. What the authors have done is to carefully dissolve away the mineral matrix of the bone, exposing delicate and still flexible scraps of tissue inside.
It’s the much anticipate first episode of a new series, Evolve – Eyes.
They are one of evolution’s most useful and prevalent inventions. Ninety five percent of living species are equipped with eyes and they exist in many different forms. Learn how the ancestors of jellyfish may have been the first to evolve light-sensitive cells. Discover how dinosaur’s evolved eyes that helped them become successful hunters. Finally, learn how primates evolved unique adaptations to their eyes that allowed them to better exploit their new habitat, and how the ability to see colors helped them find food.
I’ve programmed my computer to record it, and I’ll probably live-blog the show as well. Let’s hope I have reason to do more than get snippy!
