Modern Snake With Legs, and Primitive Snake With Feathers

This is just to post the picture - read and respond to the NEXT post below on Dinosaurs and Birds!

Birds DID evolve from Dinosaurs!

Scientists have long debated the evolutionary ancestry of birds. During the past decade, evidence has emerged that birds evolved from dinosaurs. This past month, scientists in China discovered an amazingly well preserved fossil that seems to finally put the question to rest.

Xing Xu of the Chinese Academy of Science in Beijing has discovered the remains of a "four-winged" dinosaur that seems to confirm that birds owe their ancestry to dinosaurs living millions of years ago. The "dino-bird", called Anchiornis huxleyi.
Until now, incomplete fossils suggested that A. huxleyi was a fully transitioned primitive bird. The fossil is clearly transitional and dinosaur-like - providing almost indisputable evidence that proves birds descended from dinosaurs.

Xu and his team discovered a dinosaur with long feathers covering its arms, tail as well as its feet. This is an arrangement of a "four-winged" dinosaur does not prove that the creature could fly. It also had long lower legs that suggest it was a good runner. But the well-preserved fossilized feathers do show a "transitional species" that illustrates how bird-like dinosaurs developed features enabling them to fly.

The astounding fossil comes from in Daxishan, in Jianchang county in northeastern China. It was found in rock dated to the early part of the Late Jurassic period, about 160 million years ago. This date means that A. huxleyi is not a true bird, but rather a a late member of the Troodontidae, a category of dinosaurs closely related to birds, Xu said.

Xu concludes that his discovery proves once and for all that dinosaurs and bird-like creatures did exist at the same time, and that the family of modern avians descended and evolved from reptilian ancestry.

As for the reptiles themselves, I only remind you of the other discovery I mentioned in passing this week - a rare snake with fully developed legs. Discovered - again - in China.

What does this modern mutant suggest to you?

A STRANGE NEW FISH? OR AN OLD KNOWN ONE?

New organisms are being discovered all the time. But sometimes, what appears new, turns out to be known.

This bizarre looking creature was caught off of the coast of Brazil this past week. About 100 pounds, and 6 feet in length, you would think that it couldn't be missed. Yet it lives in the ocean depths, and is seldom seen near the surface. Its body is highly gelatinous (jelly-like) making it less than desirable as seafood (probably a good thing, given the arguments of last week's post!). Scientists know it by it's gelatinous, bulbous "nose" at the front of its head. Hence its name: the Jellynose.

The Jelly-like body is due to the fact that the fish has an extremely high fat content in its body. This probably allows it to store energy, as food is hard to find at the depths where it lives - about 1,000 feet below the surface. Unlike most other fish, the Jellyfish body does not have scales. Nor does it have true bones. Instead, like rays and sharks, it has cartilage. Overall, their body form and function (and DNA) places them firmly in true "bony" fish family - teleosts - rather than the family of cartilaginous sharks and rays, Chondrichthyes. Jellynoses appear to be a true anomaly.

There are 30,000 known fish species in the world. Who knows how many more species have yet to be discovered. Some scientists think hundreds. But many more scientists believe that the number could go into the thousands.

Little else is known about the Jellynose family.

Seeing something like this always makes me feel humbled once again, by the great diversity of life on Earth.

AQUACULTURE

Aquaculture. No, it’s not a typo. Instead of farming cultivated plant foods we’re farming fish. And this year, we’ve reached a tipping point of sorts. The Washington Post reports that now, over ½ the fish consumed in the world will have been raised in pens, rather than caught. The implications are enormous.

Several years ago, I began the marine biology course that I taught at TA with a graph that showed the projected decline in ocean fish. The numbers of fish had been declining for several decades, but the frightening part was the projection out to the year 2050. The endpoint for this graph suggested that the oceans would be depleted of all fish. In other words, while a few species might survive in unique niches, fish - from the sharks to the scavengers – would disappear from our oceans. The oceans in a sense would become relatively lifeless pools of flooded sand.

The predator prey relationships of the past have been permanently altered given the huge increase in human population (from 1 billion to the current 6 billion in about 150 years). That increase, coupled with a commensurate increase in the world’s taste for seafood has lead to some drastic over fishing. Cheap, smaller fish are also being caught in massive numbers to be ground up into fish meal, to be fed to poultry, pigs, and ironically – farmed fish. In other words, fish are being hunted and caught to feed people. And fish.

Another article this past week discussed the imminent demise of the large blue fin tuna, a magnificent half-ton beast that is capable of swimming 3000 miles without stopping. Tuna, it seems, is about to become a victim of the global sushi craze. Tuna can’t be farmed. They are too large, too energetic, and they require too much space.

But other species can be grown from “egg-to-plate” as they say. Salmon are probably the best known and most popular of the farm-raised fish. Once considered a delicacy, salmon has literally become the “chicken of the sea”. I remember salmon selling for about $10/pound in the 1970s – that’s probably something like $25/pound today. Now, I see it selling for as little as $3.95 locally. Salmon, and now other fish, are becoming cheap and plentiful because they are being farmed, raised in huge circular pens like the one pictured above.

The fish are born into the tanks. They are raised on a diet of unused poultry trimmings from the millions of chickens that are raised in dark boxes, corn meal, and antibiotic powders. Not being free to swim the oceans, the fish also accumulate more body fat than a free, “wild” fish. This trait is particularly noticeable in farm-raised salmon. Genetically chosen for hardiness, and the ability to live in these conditions, the fish that you are eating are different from the fish your grandparents ate.

Shellfish too, are being farmed. Scientists report that some Chinese bays are so congested with nets, traps, and pens that they have become un-navigable. Lest you think this is an “Asian problem”, let me assure you that New England is one of the fastest growing fish farm regions in the country.

This is an unsustainable practice. As we deplete the oceans of its largest fish, and its small foraging fish, we are decimating the two ends of the oceanic food chain. Krill too – the small shrimp-like plankton that lays the foundation for the oceanic food web is also being sieved out of the Antarctic waters at alarming rates. Such over-fishing can lead to an environmental chain reaction of sorts. In the 1970s and again in the 1990s Peru exploited its anchovy population. Anchovies are small foraging fish. Not only did fish stocks decline, but so did local sea bird populations that depended on the small fish for their food. It took a change in government in 2006 to place restraints on fishing. Restraints that have lead to a recovery of the ecosystem.

That was the experience of a small, regional ecosystem. What happens when we deplete an ocean? What happens if the chain reaction truly starts, and species begin to disappear at an accelerating rate? What happens if the projections are correct, and the oceans do become dead zones in the next few years? What does it mean if the earth no longer has seafood?

What will happen to our poultry industry? What will happen to us?

Maybe we're the chickens who have lost their heads.

ZOOMING IN ON A LEAF

This 3 minute video is really cool, despite the corny voice-over narration. This is one leaf - what does this suggest about the biological detail found in a complete plant? Or in a tree?

Watch the video, and provide your thoughts and comments. (Again, you may have to cut and paste the link if it does not appear live on your computer)

www.scienceblogs.com/grrlscientist/2009/09/zoom_into_a_leaf.php

WHERE HAVE ALL THE FLOWERS COME FROM?

This initial post addresses what Darwin called an abominable mystery - the origin of flowers.

We have seen how most of our modern garden flowers originated in China, and have even seen images of what could possibly have been the "First Flower". But was it actually the first? Scientists are continuing their work in this field - literally and figuratively. Scientists are fairly certain that Amborella, pictured above, is the oldest lineage of flowering plant. It appers to be an ancient species going back millions of years.

For the rest of the story, click on the link below (or cut and paste the link into your address bar if the hyperlink does not work on your computer) and read the article that appeared in the New York Times yesterday on this very topic. Type up your first response, as we discussed in class, and you're on your way!

What is it that flowers provided that their predecessors, the "naked seed" plants, did not?

www.nytimes.com/2009/09/08/science/08flower.html?8dpc

LET YOUR MIND DANCE.....

TA faculty have been spending much of our meeting time this past year writing, and reviewing standards. As I've thought about the standard on Reflection, I've found my own self reflecting on the phrase "let your mind dance", some words that came to mind while writing a Zoobot post earlier this year. This morning, as I was doing my usual Sunday morning web surfing, I came across an article in The New Republic about President Obama's Secretary Of Energy, Steven Chu that starts with a great example of this:

"In the winter of 1984, a young scientist named Steven Chu was working as the new head of the quantum electronics division at AT&T's Bell Labs in Holmdel, New Jersey. For months, he'd been struggling to find ways to trap atoms with light so that he could hold them in place and study them better. It was an idea he'd picked up from an older colleague, Arthur Ashkin, who had wrangled with the problem all through the 1970s before finally being told to shut the project down--which he did, until Chu came along. ("I was this new, young person who he could corrupt," Chu later joked.) Now Chu, too, had hit an impasse until, one night, a fierce snowstorm swirled through New Jersey. Everyone at Bell had left early except for Chu, who lived nearby and decided to stay a bit longer. As he watched the snow drift outside, he realized they'd been approaching the problem incorrectly: He first needed to cool the atoms, so that they were moving only as fast as ants, rather than fighter jets; only then could he predict their movements and trap them with lasers. It was a key insight, and Chu's subsequent work on cooling atoms eventually earned him a share of the Nobel Prize in physics. While it may sound inevitable in retrospect, big breakthroughs like that don't come along too often."

This anecdote captures perfectly the idea of letting your mind dance. Sometimes we face problems, assignments, situations, or blog responses not knowing how to start. Whether its a paper or a painting, what is the first word or brushstroke to put on the paper or canvass. This anecdote emphasizes the importance of non-active thinking. Letting the mind wander. Looking out the window. Giving yourself the opportunity to relax enough to allow your mind to forge some natural connection between what you already know and what it is you are trying to grasp - that elusive idea that lies just beyond your reach.

I emphasized the final sentence in the New Republic piece, because it too raises an important aspect of letting your mind dance. Very often the outcome - that big breakthrough - seems inevitable when it becomes explicit. I'm sure that every Chem 1 student would know that atomic motion slows down as temperature decreases. But it took a moment of wonder (yes, and a pretty smart guy) to experience the epiphany that this simple fact could be applied in an entirely new way in order to achieve an elusive research goal.

Let your mind dance on this last thought for the semester: Current studies indicate that the Silverback Gorilla will be extinct in 30-50 years. Ishmael’s epitaph includes the statement: “With the Gorilla gone, will there hope for man”? Reflect on this statement. Dance around some of the information you gleaned from reading The Sixth Extinction article several weeks ago on the library’s lawn a couple of weeks ago. Share your thoughts.

My summer wish for all of you is that you allow yourselves the opportunity, nay - that you make multiple opportunities - to relax and let your minds dance.

Peace- out.


Posted by Gary at 4:16 AM 0 comments