Showing posts with label Evolution. Show all posts
Showing posts with label Evolution. Show all posts
Tuesday, February 12, 2013
Happy Darwin day! Ze Frank's True Facts about the Katydid
Posted by: zefrank1
If I were better at planning posts for the site, had a different work schedule, or hadn't just spent the better part of the past four hours fighting with my internet connection, I would have prepared something of substance for Darwin day. Instead, here's my admittedly anemic, and just barely on time/on topic offering, in the form of yet another true fact video from ze Frank. This time around, evolution checks in on the Katydid. All in all, things seem to be going well for the creature... except for where the monkeys are concerned.
-CAINE-
Sunday, November 18, 2012
Scientist Denied Use of "Hobbit" In Title of Lecture on Hobbits (Homo Floresiensis)
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| Homo Floresiensis, by Peter Schouten |
So this isn't a particularly big deal, and it's not as if the rulers of middle Earth called in the lawyers on the guy or anything. And to be fair, the Tolkien estate says it was not approached concerning Alloway's lecture. But, c'mon. There isn't a single person in the Middle Earth camp that thought, "Hey, someone wants to use our movie to promote actual science. SURE! Why not?" I mean, it seems to me that there's a fairly heavy overlap between LOTR fans, and the kind of people who might get excited to check out a scientific Lecture. And since New Zealand is practically turning itself into a living Hobbit theme park; what with putting Gandalf and friends on it's legal currency, and planning to rename the capital of Wellington "The Middle of Middle-earth" for three weeks before and after the premiere of the next Hobbit movie. So why not let the man use the damn word to promote his lecture? I mean, it is a word in the oxford English dictionary. Plus, the lecture in question is free. So why does it matter?
Also, I hate Hobbit movies. Which isn't really relevant to the story, I just wanted you to know.
That is all.
-CAINE-
SOURCE: the guardian
IMAGE CREDIT: Homo Floresiensis-Peter Schouten-
Hobbit Feet Slippers- Think Geek
Friday, November 16, 2012
On The Origin of Species, As Read by Richard Dawkins
Posted by YouTube user: 957Chatterton
Now seems as good a time as any to share this.
-CAINE-
VIA: Left Hemispheres
Sunday, May 13, 2012
Creationsm vs Evolution: Watching Evolution Go
But first, a quick reset.
In case I wasn't clear before, there is no question amongst scientists as to weather or not evolution took place, either in our own genetic past, or that of every other living thing on the planet. We know this because, contrary to creationists arguments, fossil records alone -though certainly not "complete*"- are enough to confirm that evolution is a real process responsible for the forming of all species, and almost certainly life itself. Modern genetic studies have gone even farther in mapping, not only the relation of all species to one another, but the points at which specific biological mutations led to their diversification; the point at which one genetic makeup changes (evolves) enough to become another. But in the monkey bill entry, I brought up the idea that evolution was not only a scientific reality of our biological past, but that it was still an ongoing process in the world today. One of the things that makes this, as well as the idea of evolution in general a hard fact for may people to accept, is that evolution happens too slowly in complex, long living organisms, to be observed in real time. But that doesn't mean it can't be observed at all.
Because of their rudimentary genetic makeup and brief lifespans, which can allow for the passage of thousands of generations in a relatively short amount of time, single celled organisms like bacteria, are invaluable in the study of evolution. The E. coli bacteria in particular, has played an integral role in it's study.
Arguably one of the most definitive and direct observations of evolution ever made, was published in the 2009, result of a research experiment conducted at Michigan State University. The experiment was conducted by Professor Richard Lenski, on a sum total of 40,000 generations of E. coli bacteria, grown over the course of 20 years. By the 20,000-generation midpoint, researchers discovered 45 mutations among surviving cells. Mutations, which, in accordance with the theory of Darwinian evolution, afforded those generations of the bacteria distinct survival advantages over their ancestors. One of the the most dramatic examples of the evolution of the bacterial colonies in Lenski's experiment, was one population of bacterias development of the ability to utilize a carbon source other generations and populations could not.
The Michigan state experiment is just one of the many examples of E.coli in particular, being used to directly study and observe the evolutionary process as it takes place, and there are countless other examples of similar experiments to choose from. A recent favorite of mine -What? How could you not know by now that I'd be the kind of guy who'd have a list of favorite scientific experiments?- was a result published just this year.
In an experiment lead by researchers Travisano and William Ratcliff , brewers yeast was successfully coaxed into evolving into a multi-cellular organism. The yeast was grown in flasks of nutrient rich broth. Those flasks were shaken once a day, and the yeast which sank to the bottom of the flasks was removed, leaving the free-floating yeasts behind. After just 60 days, the yeasts which clumped together had grown into permanent clumps of individual yeast cells, displaying all the tendencies associated with “higher” forms of life, including: a division of labor between specialized cells, juvenile and adult life stages, and multi-cellular offspring. Now, because the yeast was exposed to artificial pressures to grow larger, including artificial selection at the hand of the researchers involved, it could be argued that this was not a "natural" evolutionary process. But it does show that seemingly complex traits like multicellularity, can actually develop astonishingly quickly under the right conditions.
But let's be honest, all the bacterial experiments in the world, no matter how unambiguous the result, aren't about to convince the hardcore evolution denier; which is the only proper way to describe someone who chooses to ignore the factual reality of evolution, in case you disagree with my usage of the term.
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* The incomplete fossil record is something of a logical fallacy. Not only because most creationists choose to ignore the existence of transitional fossils, but because it implies 1) That all the steps in the evolutionary process from point A to point B, have been identified. And 2) That such a thing could even exist, since, given that many creatures would not have left any physical evidence behind, it could not.
Thursday, May 10, 2012
Creationism by Lewis Black
More to come tomorrow...
-CAINE-
Monday, April 30, 2012
Creationism/Intelligent Design and The Tennessee Monkey Bill
One of the many things I missed commenting on during my latest hiatus from the web, was the passage of the so-called "Monkey Bill" in Tennessee. This bill grants teachers in the state the right to teach the "strengths and weaknesses" of scientific theories like, climate change, human cloning, and evolution, with little fear of repercussion. The idea of allowing individual teachers to promote their own
personal agenda under the guise of
teaching any subject is so obviously flawed a concept, it seems
utterly insane that anyone would even suggest it. That is, of course, unless personal agendas, not academic freedom or even truth, are what you actually care about, as is the case with the supporters of this bills, and others like it. Then it starts making sense. The "strength and weaknesses" argument, or the idea that teachers should be allowed to "teach the controversy" of certain scientific theories -specifically, evolution- is a tired, but growingly successful tactic employed by religious creationists. The group adopted the strategy as part of a pseudo-scientific makeover the organization underwent, following their defeat at the hands of a1987 supreme court ruling, which rightly deemed the teaching of their religiously based fiction in public schools to be a violation of church and state. In response to this defeat, Creationists manufactured a completely non-existent scientific controversy (more on that in a minute), relabeled their efforts a struggle for academic freedom, adopted the, extra sciency-sounding moniker: "Intelligent Design", and went back to lobbying for their cause: Undermining the teaching of science and circumventing the separation of church and state, in order to infect public education with religion.
But just for fun, let's pretend the creationist agenda really is about education (which it isn't) and not about promoting a religious agenda through pseudo-science (which it is). So what about the scientific controversy surrounding the validity of Darwinian Evolution? I mean, if science isn't even sure evolution is real, isn't that something children should know about?
It certainly would be, if it were true. But it isn't.
There is NO scientific controversy as to weather or not evolution is true, NONE. To science, evolution is as much a fact of reality, as gravity; which is also absolutely true, and also "just a theory". Yes, there's an ongoing effort to fully understand the specific mechanisms which drive the phenomena of evolution, and to complete the paths it has taken to drive all species on the planet to their current states; because that's how science works. But there is NO question as to weather or not evolution has taken place, or that it continues to take place today.
As for Creationism/Intelligent Design, on the other hand. The lack of scientific evidence supporting the handful of quantifiable claims they're willing to make, is equally definitive. IN other words, there isn't any. Which is the problem with trying to label your religious fantasy a testable, provable science; people will try and test it, and then end up disproving it.
The simple fact is, the "theory" that we live in a universe that's 6,000 to 12,000 years old; that all the organisms on the planet were either designed as they exist today, or, after escaping extinction by taking refuge from a world-wide flood on the deck of mythical boat, underwent some ridiculous, made up, hyperactive version of evolution in order to diverge into all of the species on the planet today- simply does not fit with reality. Evolution on the other hand, like climate change (sorry, it's real too. But we'll deal with that another day), does. And the only place any controversy about evolution exits, is in the mind of creationists.
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Learn more about creationism and what you can do to help keep this, and other fantasies, out of the science classroom! Go to: ncse.com ( The National Center for Science Education)
Sunday, September 18, 2011
Dinosaur Feathers in Amber
Earlier this week, a paper published in the Journal Science described a collection of dinosaur feathers suspended in amber. The 11 samples described in the paper were found amongst a collection of some 4,000 amber deposits held in various museums in Alberta, Canada. These ancient feathers were trapped in amber (fossilized tree resin) around 70-80 million years ago, sometime during the late Cretaceous period.
According to the paper's abstract, the structure of the protofeathers found in the deposits, demonstrate several different evolutionary adaptations of the feather, including those used in flight, as well as underwater diving. And because of their preservation inside amber, these specimens also reveal the actual pigmentation of the feathers; which range in color from brown to black.
For those of you who haven't kept up with your paleontology or evolutionary biology very well over the years, and find all this talk of dinosaurs and feathers a bit confusing; and because it's been a while since I indulged myself with a lengthy science entry, I offer the following:
The dominant view in science today is that modern birds are in fact, dinosaurs. More specifically, birds are considered by most scientists to be modern examples of a family of dinosaurs known as theropods, which evolved during the Mesozoic era ( 250 to 65 million years ago). This idea, or at least the idea that modern birds were descended from dinosaurs, was first proposed shortly after the publication of Charles Darwin's origin of species in 1859, by British biologist Thomas H Huxley.
Huxley came to believe in the dinosaur's ancestry to birds, after comparing the anatomy of the "first bird" fossil, Archaeopteryx Lithographica, with that of a small theropod dinosaur called Comsognathus, which he noted were -aside from Archaeopteryx's feathers and hands- extremely similar to one another. Huxley made his case for the link between the two animals, and their likely ancestry to modern birds in, "On the Animals which are most nearly intermediate between Birds and Reptiles" , published in "The Annals and Magazine of Natural History", in 1868.At the time of Huxley's research the popular consensus was that dinosaurs had not developed into birds, but that birds -like every other modern species- had their own lineage; one which had arisen completely independently from dinosaurs. Archaeopteryx, therefore, represented the first primitive form of the species now known as birds, rather than a transition between dinosaur and bird, as Huxley had asserted. As a result of this opposition to the Darwinian notion of transmutation, Huxley's theory faded from interest, and the belief that birds and dinosaurs had evolved separately, remained the most popular scientific view for nearly the next hundred years.
But Interest in Huxley's theory would finally be fully revived in 1964, when American paleontologist John H. Ostrom, conducted his own anatomical comparisons of modern birds and dinosaurs. In the years which followed, others began to conduct similar comparative analysis, and by the late 1970's, many had not only come to accept the relationship of birds to ancient theropods, but some had also begun to speculate that early theropods might also have had feathers. By the mid 1990's, the notion that modern birds were, in fact, living dinosaurs, had largely become accepted fact, and the assertion that their ancient counter-parts had most likely been feathered as well, was also widely believed. But this belief was still a speculative one at this point, as little to no fossil evidence of feathered dinosaurs had yet been found.
But in the past twenty years, dozens of new fossils and various other major finds have also been added to the list of evidence in the case for feathered theropods. From simple impressions found around fossil remains, to quill knobs (the anchor point for wing feathers) found on the forelimb of certain fossilized specimens. In 2010, researchers even managed to determine the color of some of these feathers, by analyzing fossilized melanosomes, found in the fossils of birds and dinosaurs from northeastern China.
In the years since Huxley first proposed an evolutionary link between dinosaurs and modern birds, countless new discoveries have been made which support his theory. And though now widely accepted as scientific fact, there will always be those who question the evolutionary link between birds and ancient theropods; both legitimately and otherwise. But when confronted with the growing fossil evidence, and now, the feathers themselves; perfectly preserved in amber. It seems undeniable that the answer to the question, " Were there feathered dinosaurs?" at least, is a definitive, yes.Cue the rambling creationist counter-point in...
-CAINE-
Source: Wired Science , The Journal Science, Wikipedia, New World Encylopedia
Saturday, August 20, 2011
Lantern Shark Glows to Become Invisible
While the description may at first sound counter-intuitive, like many deep dwelling sea creatures the Splendid Lantern shark, a rare type of dogfish shark found mostly in the East China Sea and off the coasts of Taiwan and Japan, has evolved bioluminescence as a means of defense from predators.Like the bobtail squid, this small variety of shark, which only grows to around 30 Cm (11.8 inches), uses this ability to replicate the light shining down from the oceans surface on the underside of it’s body, effectively rendering it’s silhouette invisible to predators below.But unlike the bobtail squid, which produces it’s light through a symbiotic relationship with a particular species of bacteria. The splendid lantern shark seems to control it’s photosphores, the organ responsible for producing the light, using nerves and hormones, as well as pigments moving within the organ’s cells. Source: Discovery News
Saturday, August 13, 2011
Some of The Building Blocks of DNA May Have Come From Space
Artist concept credit: NASA's Goddard Space Flight Center/Chris Smith
By grinding up and analyzing samples of twelve carbon-rich meteorites, nine of which were recovered from Antarctica, a research group from NASA's Goddard Space Flight Center, in Greenbelt, Md, found both adenine and guanine; two of the primary nucleobases contained within our DNA, as well as hypoxanthine and xanthine; neither of which are used in the construction of DNA, but are utilized by other biological processes.
In two of the meteorites, the team also discovered for the first time, trace amounts of three molecules related to nucleobases (nucleobase analogues), purine, 2,6-diaminopurine, and 6,8-diaminopurine; two of which rarely appear in biology. According to Dr. Michael Callahan, lead author of a paper on the discovery appearing in Proceedings of the National Academy of Sciences of the United States of America;
"You would not expect to see these nucleobase analogs if contamination from terrestrial life was the source, because they're not used in biology, aside from one report of 2,6-diaminopurinecyanophage S-2L,"
While the presence of molecules not known to commonly appear in biology was a strong indication that the findings were not the result of contamination. Callahan's group further confirmed this fact by analyzing a sample of ice taken from Antarctica, where most of the meteorites in the study were found. The result showed much smaller concentrations of the nucleobases, as well as xanthine and hypoxanthine, all of which appeared in parts per trillion in the ice sample, as oppose to the parts per billion generally found within the samples taken from the meteorites. None of the Nucleobase analogues were discovered in the sample. Analysis of the soil taken from the surrounding area where one of the meteorites used in study fell in Austraila, also failed to detect those analogs.
In one final experiment designed to rule out terrestrial contamination and confirm the extraterrestrial origin of the molecules. Callahan's team was able to successfully generate all of the nucleobases and analogues found within the meteorite samples in a completely non-biological chemical reaction in the lab, using hydrogen cyanide, ammonia, and water. Showing not only that the find was almost certainly not the result of contamination, but more importantly, that chemical processes taking place within certain types of asteroids could potentially produce all of the molecules detected in the study.
If confirmed by further research, the findings of Callahan and his team could be a major step towards understanding the true origins of life on Earth. Particularly when considered along with previous research conducted by the team which detected amino acids, the molecules responsible for building proteins, within similar samples; as well samples taken from the Comet Wild 2 during NASA's stardust mission. All of which, adds to the growing body of evidence supporting the theory that the chemistry taking place within comets and asteroids is capable of generating the basic building blocks of essential biological molecules, and that life may owe it's existence, at least in part, to materials delivered from space via meteorite and comet impacts.
-CAINE-
Source: NASA
Image credit: NASA's Goddard Space Flight Center/Chris Smith
For a deeper explanation of the Nucleobases and nucleobase analogues, as well as the findings of his research, check out the following video from NASA, featuring Dr. Callahan.
Sunday, May 29, 2011
Cephalopods In Space!
Which is why, amongst the various cargo carried into space by Endeavor on it's final flight, is a sample of juvenile Bobtail squid. These baby cephalopods were sent up by microbiologist Jamie foster, to determine what effect, if any, the environment has on helpful bacteria, like those which give the squid the ability to generate bioluminescence.
Bobtail squid are a tiny variety of cepholopods which have evolved their ability to generate bioluminescence by forming a symbiotic relationship with a particular species of bacteria called Vibiro Fischeri, the juvenile squid are exposed to this bacteria shortly after hatching, which take up residence in the animals light organs. Fed on a solution of sugar and amino acids by the squid, the bacteria in turn helps the animal to avoid predators by matching the amount of light hitting the top of it's mantle, thus helping to hide it's silhouette from predators below. Because the animal is not born with the bacteria in it's system, and because the process only involves a single species, unlike the symbiotic relationships human beings form with the thousands of species of bacteria which inhabit our digestive and immune systems, The Bobtail squid seems an ideal candidate for this sort of test.
Preliminary experiments conducted in simulated microgravity on Earth appear to have shown problems with the uptake of bacteria by the squid. And if the shuttle study shows the same result, it would suggest that astronauts' relationships with their own microbes might also be affected.
-CAINE-
Source: New Scientist.com VIA: GGB on tumblr
Image credit: Jenny Huang
For more about the Bobtail squid, check out this video from Science Nation:
Posted by Youtube user: VideosatNSF
Posted by Youtube user: VideosatNSF
Saturday, December 4, 2010
Matt Ridley and Richard Dawkins on DNA, Extraterrestrial Life and More...
Posted by YouTube user:AtheistMediaBlog
Since we've been discussing astrobiology and genetics over the past few days, now seemed like a good time to share this video of evolutionary biologist Richard Dawkins ( that's right kids, he's more than JUST an atheist) and journalist Matt Ridley discussing Alternative biochemistry, extraterrestrials, DNA, synthetic life, artificial life, and all sorts of other interesting things relating to biology, evolution, and life in general. It's very, very, cool and I think you will enjoy it, so check it out!
-CAINE-
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Tuesday, July 20, 2010
Lucy and Big Man
Discovered in Ethiopia in 1974 by Donald Johansen and Tom Gray, the early hominid fossil known as Lucy was estimated to have lived 3.2 million years ago and for may years represented the oldest and most complete example of an ancient human ancestor. But this 40% complete example of the hominid species Australopithecus afarensis was most significant because her skeleton showed evidence of not only a small skull capacity, but the structure of her pelvis also revealed that she most likely spent the majority of her time walking on two legs. These discoveries helped to confirm, or at least bolster the theory that our ancestors had developed the ability to walk upright before gaining a larger brain capacity rather than after.In 2000 an even more complete example of Australopithecus was discovered in the form of a nearly complete juvenile specimen and now there is a third and even older bipedal ancestor to add to the list "Big man".
Discovered in Ethiopia's Afar region in 2005 Big Man has once again pushed back the time when our ancestors first walked upright by another 400,000 years and though he only stood around 5 to 5-and-a-half feet, he still would have towered over the diminutive Lucy who was only 3ft 6in. New details gleamed from Big Man's remains, in particular the shape of his shoulder blade and the length of his legs, show that he shared more physical characteristics with modern humans rather than chimps, a fact which contradicts traditional thought on the evolution of hominids into modern humans but which follows similar evidence observed in the remains of what is to date the oldest known human ancestor, the fossil known as "Ardi" who lived an estimated 4.4 million years ago.
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Links And Additional Content
Read more about the discovery the Afarensis child in 2000 HERE and for more about Big Man go HERE.
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