Sunday, May 1, 2011

Carnivorous Plants

Carnivorous Plants
By Alea DelleCave

I. intro:
Carnivores have roamed the planet for centuries, but lately researchers have been gathering information on the carnivores that cant plants for example. Some plants have the ability to hunt and kill without actually moving. Some have sticky petals, thorns, or snapping traps, they gain all of their nutrients from consuming animals, mostly insects or small crawlers. Carnivorous plants appear adapted to grow in places where the soil is thin or poor in nutrients, especially nitrogen, such as acidic bogs and rock outcroppings. Charles Darwin wrote Insectivorous Plants, the first well-known treatise on carnivorous plants, in 1875. True carnivore's were thought to have evolved independently six times in five different orders of flowering plants, and these are now represented by more than a dozen genera. These include about 630 species that attract and trap prey, produce digestive enzymes, and absorb the resulting available nutrients. Additionally, over 300 protocarnivorous plant species in several genera show some but not all these characteristics.

II. discovery: 
Pc1. A grasshopper caught in the Venus
Fly Trap
Venus Fly Traps: the ultimate Snap Trap
Venus Fly Traps are the most well known carnivorous plant, famous for their quickly closing "jaw" they can trap trey and slowly devour it. It has the ability to sense by having three 'trigger hairs" on the north and south parts of the lobes. When a trigger hair is bent, stretch-gated ion channels in the membranes of the cells at the base of the trigger hairs open up, generating on action potential that propagates to cells in the mid rib. The cells respond by pumping more ions out, which can cause water to flow by osmosis, collapsing the cells within the midrib, or cause rapid acid growth, which paralyzes and kills the animal. How this is done is still debated, but still ends in the same result: a quick flash and a snap of the jaw. This whole process takes less then a second. The more the insect struggles the tighter the jaw becomes. The jaw then transforms into a stomach and digestion occurs over a period of 2 weeks. 

The Sundew: Beauty and Bite

Pc2. A sundew 

Sundews are beautiful structures that are characterised by the glandular tentacles, topped with sticky secretions, that cover their laminae. The trapping and digestion mechanism usually employs two types of glands: stalked glands that secrete sweet mucilage to attract insects and enzymes to digest them, and sessile glands absorb the resulting "nutrient soup".Upon touching the sticky dew, the prey becomes entrapped by sticky mucilage which prevents their progress or escape. Eventually, the prey either succumb to death through exhaustion or through asphyxiation as it envelops them and suffocates them. Death usually occurs within one quarter of an hour. The plant them sends out enzymes to both dissolve the insect and free the contained nutrients. The nutrient soup is then absorbed through the leaf surface and can then be used to help fuel plant growth.
Pc3. A Sundew Captures his prey
All species of sundew are able to move their tentacles in response to contact with digestible prey. The tentacles are extremely sensitive and will bend toward the center of the leaf in order to bring the insect into contact with as many stalked glands as possible. According to Charles Darwin, the contact of the legs of a small gnat with a single tentacle is enough to induce this response. In addition to tentacle movement, some species are able to bend their laminas to various degrees in order to maximize contact with the prey. 

Nepenthes truncata: Natures own Slip and Slide
Pc.4 A mouse is found!
We currently know very little about the Nepenthes Truncata. Its inner lining of its tube shaped opening and neck are lined with an extremely slippery substance where once a critter has stepped even the slightest bit to close, it will fall in and become prey. At the bottom of the plant it collects a water-like substance which seems to attract insects, as well as mice. Its the only recorded plant that has successfully devoured a mammel bigger then a grasshopper or bumble bee. 
pc.5 the mouse and his decaying body..

The Bladderwort: The underwater vacuum
pc6. This is the Bladderwort

The trapping mechanism of The Bladderwort is purely mechanical. There is no sence from the plant, irritability, that is  required in the presence of prey. 
As water is pumped out ,because it is an underwater plant,  the bladder's walls are sucked inwards by the partial vacuum created, and any dissolved material inside the bladder will become more concentrated. The sides of the bladder bend inwards, storing potential energy. Soon, no more water can be gained, and the bladder trap is good and ready. 

Extending outwards from the bottom of the trapdoor are several long bristle-stiff protuberances that are sometimes referred to as trigger hairs, but which have no similarity to the sensitive triggers found on other plants.  These bristles are simply levers, the force of the suction exerted by the primed bladder on the door is resisted by the adhesion of its flexible bottom against the soft-sealing velum. T
he bladder walls spring back to a more rounded shape; the door flies open and a column of water is sucked into the bladder. The animal which touched the lever, if small enough, is inevitably drawn in, and as soon as the trap is filled, the door resumes its closed position. The whole operation being completed in as little as one-hundredth of a second

pc7. The Shell of the Bladderwort
Once inside, the prey will be dissolved by digestive secretions. This generally occurs within a few hours, although some protozoa appear to be highly resistant and have been observed to live for several days inside the trap. All the time, the trap walls continue to pump out water, and the bladder can be ready for its next capture in as little as 15 to 30 minutes.

III. biography of investigator:
Charles Darwin, was the first to look into the idea of carnivorous plants. In 1860, soon after he encountered his first carnivorous plant, the sundew Drosera, he wrote, "I care more about Drosera than the origin of all the species in the world." He spent months running experiments on the plants. He dropped flies on their leaves and watched them slowly fold their sticky tentacles over their prey. He excited them with bits of raw meat and egg yolk. He marveled how the weight of just a human hair was enough to initiate a response. Yet sundews ignored water drops, even those falling from a great height. 

Darwin expanded his studies from sundews to other species, eventually recording his observations and experiments in 1875 in a book, Insectivorous Plants. He marveled at the power of the Venus flytrap, a plant he called "one of the most wonderful in the world." He showed that when a leaf snapped shut, it formed itself into "a temporary cup or stomach," secreting enzymes that could dissolve the prey. He noted that a leaf took more than a week to reopen after closing and reasoned that the interlocking spines along the margin of the leaf allowed undersized insects to escape, saving the plant the expense of digesting an insufficient meal. He noted that the plants were behaving much like animals, however they did not have muscles. This struck him as a true phenomenon.

IV. impact on hummanity:
The discovery of plants with a thirst for blood has given scientist a whole new  realm of diet possibilities for plants today, and ones who are today extinct. Given the fact that plants cannot move, and are stuck in one place it is unbelievable that they have the ability to catch their own prey. These plants get their nutrients from the bugs they eat, but gain energy from the sun, like the average plant.  The evolution of carnivorous plants is obscured by the past of their fossil record. A lot can be deduced from the structure of todays traps. There are over a quarter of a million species of flowering plants. Of these, only around 630 are known to be carnivorous. True carnivory has probably evolved independently at least six times, however, some of these "independent" groups probably descended from a recent common ancestor with a predisposition to carnivory. It has been suggested that all trap types are modifications of a similar basic structure—the hairy leaf. The Bacteria jumpstart decay, releasing from the corpse nutrients that the plant can absorb through its leaves.

(the instant video wouldnt work. but this is the best video by far)

V. Journal Entry 
Carnivorous Plants
By: Alexander Volkov 

Today's biologists are using 21st-century tools to study cells and DNA. they are beginning to understand how these plants hunt, eat, and digest. as well as how these bizarre adaptations arose in the first place. After years of study, Alexander Vol­kov, a plant physiologist at Oakwood University in Alabama, believes that he has figured out the Venus flytrap's secret. "This," Volkov declares, "is an electrical plant."
Volkov's experiments reveal that the charge travels down fluid-filled tunnels in a leaf, which opens up pores in cell membranes. Water surges from the cells on the inside of the leaf to those on the outside, causing the leaf to rapidly flip in shape from convex to concave, like a soft contact lens. As the leaves flip, they snap together, trapping an insect inside.
The bladderwort has an equally sophisticated way of setting its underwater trap. It pumps water out of tiny bladders, lowering the pressure inside. When a water flea or some other small creature swims past, it bends trigger hairs on the bladder, causing a flap to open. The low pressure sucks water in, carrying the animal along with it. In one five-hundredth of a second, the door swings shut again. The cells in the bladder then begin to pump water out again, creating a new vacuum.
 a pitcher plant that grows in jungles on Borneo, produces nectar that both lures insects and forms a slick surface on which they can't get a grip. Insects that land on the rim of the pitcher hydroplane on the liquid and tumble in. The digestive fluid in which they fall has very different properties. Rather than being slippery, it's gooey. If a fly tries to lift its leg up into the air to escape.


Thursday, February 17, 2011

Revealing the Colors of a Dinosaurs Feathers

Dinosaur's True Color Revealed
By Alea DelleCave
I. Introduction:
From the pages of "How do Dinosaurs say Goodnight" to the screens of "Jurassic Park", our minds have been planted with the image of what people think dinosaurs look like. Never have researches been able to find the true colors of them; all we know for certain is the basic structure. The skeletons give us those clues. Guessing and playing around with the color wheel may be a way of the past. Scientists believe that they may have cracked the color-code. They got to work on their first trial, a "bird-like" dinosaur about the size of a chicken. Its color patterns were decoded after researchers used a scanning electron microscope to study pigment samples taken from the fossils feathers from the specimen and then matched it to todays birds.

II. Discovery:
For years we have tried to solve the mystery of Dinosaurs may have looked like, but for the first time in history scientists have discovered how to decode the full body color of certain dinosaurs. Within the research, scientists found color pigments isolated to a few parts of the bodies, using less rigorous methods for assighning colors to the fossilized, filament-like "protofeathers" discovered on the specimens. By learning the colors of the extinct creatures we hope to find an improved sense of knowledge that could lead to a hot insight on how some of the prehistoric predators behaved and why feathers, scales,and furs evolved in the first place.

Our fist case was the Anchiornis Huxlyi, this 155 million year old species, turned out to look like a woodpecker the size of an extremely large chicken chicken! The colorful patterns of "chicken-not-so-little" are "quite similar to the silver-spangled Hamburg chicken, a domestic breed of ornamental chicken," said ornithologist Richard Prum, of Yale University. The Anchiornis is a recent discovery as well, its color patterns were decoded after the researchers had used a scanning electron microscope to study pigment samples taken from fossil feathers all over a specimen and then was compared to samples to pigments from modern birds. Similar to its brother-bird, the woodpecker, Anchiornis also consists of reddish brown, black, grey. and white feathers. This lead to the speculation that perhaps this coloration was used for attracting mates as well, or a form of visual communication, like as todays birds. They feathers found that were elongated first appeared within the fossil record, they were distinctively spotted and striped. Now we obtain patterns within the individual feathers in dinosaurs. "This could have been in lots of contexts, including sexual display, territoriality, et cetera," Prum said. "It could also have been like modern redstarts, which use their bright wing and tail patches to scare up insects, which [the birds] then seize in flight." The scientists found the colors, and determined the shapes by analyzing the shape and density of the melanosomes within the fossil feathers. Melanosomes are nonoscale, pigment-carrying organelles within the little feathers. The microscopic particles were first found preserced in a fossil, similar to the plot line of Jurassic Park only instead this time we only found colors, in our birds today the different melanosomes are known to produce different colors in the feathers.

Scientists from England and China studied many different fossils but only artistically created one. Using the fossil feather melanosomes they found reddish-brown and white stripes on the tail of a small little critter known as a Sinosauroptreyx. Derek Briggs, a co-author of the new study, said, "The other team's (team England&China) report is based on isolated samples from several different taxa, so they can't paint an entire animal." Even so, the earlier study did include a picture of an entire Sinosauropteryx, but any coloration beyond the tail and the crest running along its head and back was artistic guesswork.By contrast, Briggs said, "We have 29 samples from the same specimen, covering the whole plumage." Still, a striped tailed dinosaur only makes us more curious about how other animalia may have looked during this time period. More researchers behind the new study also say that were more meticulous in how they interpreted the pigment samples. Orange is a hard color to study because very few of todays birds seem to be the similar tint. (My guess is because our Anchiornis can be traced to a woodpecker, where the poor little Sinosauropteryx may not have a living relative in todays life.) The Melanosomes found in his tail are all phaeomeloanosomes, this is harder to pinpoint an exact color because of the wide range. Phaeomelanosomes are round and produce colors that range from reddish brown to a yellow. Eumelanosomes are rodlike and are mostly found to be black and grey. A lack of melannosomes makes a white. Not many modern birds have 100% phaeomelonosomes or eumelanosomes in their feathers, so distinguishing color from the phaeomelanosomes can become complicated. Research is still being continued on our friend the Sinosauropteryx.

III. Biography of Investigators:
Richard Prum is an evolutionary ornithologist, meaning he studies the evolution of birds. He also studies phylogenetics, meaning he studies the similarities between different evolving species, behavior, feathers, the structural color, evolution, sexual selection, and the historical bio-geography. Most of his research has included the development and evolution of feathers, finding new tools dedicated to the study of physics an the evolution of structural coloration. He continues to work on the efforts in phylogenetic ethology of polygynous birds. He is the Curator of Ornithology at the Yale Peabody Museum of Natural History, and the Head Curator of Vertebrate Zoology.

Jakob Vinther is a Yale University Grad student. He studies molecular paleobiology, a science that utilizes the evolutionary history found within rocks, and molecules to develop the most supported hypothoses of organismal evolution.

Derek Briggs is the director of the Peabody Museum of Natural History. He studies the taphonomy and evolutionary significance of preserved fossils, decays and minerilazations, molecular preservation, and the Cambrian radiation.

IV: Impact on Humanity
Scientists never thought they would be able to recreate images of dinosaurs that lived over 

64 million years ago. "The reality of what we achieved didn't really sink in until I saw the color reconstruction," stated Briggs. "At that point I felt very emotional, like we had ... brought something back from the dead—or at least gone back in time and taken its picture." Todays research promises brighter more advanced technology for the future. Finding the prehistoric colorations in dinosaurs will provide the role of color within their behavior.Some features, like the crest, might have allowed the dinosaur to attract mates. But white and black limb feathers might have helped Anchiornis escape predators. A number of living animals like zebras use similar color patterns to dazzle predators, so that they can run away.  Thus solving just another piece of the evolution puzzle. Not just birdlike dinos have feathers; many of the reptiles have been discovered to have hairlike fragments, similar to human hair,often
 called dino fuzz,which is linked to bird feathers.  Researchers can intend on a lot more scientific discoveries and progressions as they study more and more into the fossil life of dinosaurs. 
The transformation of mankind's view of dinosaurs from dull to flamboyant was made possible by a discovery by Yale graduate student Jakob Vinther in the Department of Geology and Geophysics. Vinther was studying the ink sac of an ancient squid and realized that microscopic granular-like features within the fossil were actually melanosomes -- a cellular organelle that contains melanin, a light-absorbing pigment in animals, including birds. By knowing the historic background of these animals not only will it give us information on the dinosaurs themselves but  also insight on the type of animal that they may have similarities like. By viewing one of todays birds we can maybe learn some of the certain traits that the dinosaur-ancestors had. 

V. Journal Article:
The National Geographic
True-Colored Dinosaur Revealed
Noted By Andrew Berger   

A team of Chinese and British scientists reported that the first clear evidence of dinosaur colors from studies of 125-million-year-old fossils of a dinosaur called Sinosauropteryx. Many pictures have been painted multiple times, but the colors were products of a painter’s imagination, not a scientist’s laboratory. Dinosaur fossils are mostly drab collections of mineralized bones. A few preserve traces of skin, and fewer still preserve structures that many scientists have argued are feathers.

“We might be able to start painting a picture in color of what these things looked like,” said Lawrence M. Witmer, a paleontologist at Ohio University, who was not involved in the study.

In the new study, Michael Benton, a paleontologist at the University of Bristol, has analyzed the structures of what seems to be prehistoric-feathers and say they match the feathers of living birds down to the microscopic level. They have been using microscopic technology to determine the ancient feathers’ color. Benton used the same mechanism as Mr. Vinther in 2006 had discovered what looked like an ink sac preserved in a squid fossil. Putting the fossil under a microscope, he discovered the sac was filled with tiny spheres. The spheres were identical to pigment-loaded structures in squid ink, known as melanosomes. 

They determined, for example, that a 47-million-year-old feather had the dark iridescent sheen found on starlings today. Starting in the 1970s, a growing number of paleontologists argued that birds had evolved from a two-legged group of dinosaurs called theropods. The paleontologists pointed to traits in their skeletons found elsewhere only in birds. In 1996, Chinese paleontologists discovered an exquisitely preserved fossil of a miniature theropod, called Sinosauropteryx, that had whiskerlike structures on its head and back. Some paleontologists argued that these whiskers were simple feathers. Since then, however, scientists have found a number of well-preserved theropod fossils with many more featherlike structures, corresponding to downy feathers and feathers with vanes. Scientists have even found bumps on the arm bones of dinosaurs, where the quills had attached. If all of these structures really were feathers, Dr. Benton reasoned, then they might have melanosomes. The scientists also looked at a piece of the tail of Sinosauropteryx, one of  the first feathered dinosaur ever found. 


"Yale Department of Ecology & Evolutionary Biology." Yale University. Web. 17 Feb. 2011. <>.

Yale), Michael DiGiorgio/Courtesy. "Dinosaur Had Vibrant Colors, Microscopic Fossil Clues Reveal." Science Daily: News & Articles in Science, Health, Environment & Technology. Web. 17 Feb. 2011. <>.
Cohpek, Mitch. "Dinosaurs and Their Colors." Science Invesigation: Colors. Web. 17 Feb. 2011. <>.

Sunday, December 12, 2010

Toxic Algae Destroys Shark Brains

Biology Block D
Alea DelleCave

Toxic Algae Destroys Shark Brains
I. Introduction
Being Floridians most of us know the factors of Red Tide, we see lots of dead fish on the shorelines, the strong scent fills our lungs with its sickening toxins, and every year thousands of dollars are used to help fix the problem. Is there a possibility that humans can be put to blame as a contributing factor? Agricultural run-off effects the formation and bloom of the algae by increasing the amount of it. The increasing amount of deadly blooms have the ability to alter sharks brains, making them hyper-excited, which eventually leads to the shark killing itself. With the advancing amounts of Red Tide blooms could  the threat of losing high numbers of sharks come along with it?

II. Discovery
The toxins produced in Red Tide effect the brains of sharks, so far studies show that the lemon shark is the most sensitive to its toxins. The sharks are exposed through consumption of brevetoxin-contaminated water and food. The toxins are easily crossed through the sharks blood-brain barrier that protects the sharks brain. Brevetoxins are brain changing conpounds synthesided by the harmful algae blooms. Once entered into the brain, the brevetoxins bind very strongly to a protein that controls the sodium flow. If the sodium flow is interrupted the nerve cells in the brain will over-fire and cause hyperexcitability.

Off the cost of central Florida scientists collected 30 lemon sharks and had kept tabs on them for three years. The sharks were collected during red tide seasons, as well as non-red tide seasons.  One of the sharks collected had died as a result of too much exposure to the toxic algal bloom. Dong-ha Nam, lead investigator, annalyzed the levels of brevetoxins within the sharks tissues, the neurochemical enzyme activity, and the neurochemical receptor binding. They found high levels of the brevetoxins in he liver, gills, and brain of the sharks who had been exposed to the red tide. Once infected within its brain, the shark cannot heal itself and will die. 

lII. Biography of an Investigator

Niladri Basu is an aquatic toxicologist interested in the risk assessment of aquatic pollutants,development of neurchemical biomarkers, and the use of fish and wildlife as sentinels of human and enviormental health hazards. He is currently working at the University of Michigan. 
"Sharks are exposed via consumption of brevetoxin-contaminated water and food, such as shellfood", explained Niladri Basu to Discovery News.

4.Impact on Humanity
The blooming of toxic algae in the oceans and lakes are familiar health risks and cause problems every summer, which leads to the increased costs for water cleaning, water consumption and the tourist industry. Scientists still are not sure why algal blooms arise, or what it is that causes certain species of micro algae to multiply and form dense blooms. Scientists within the research platform MARICE (Marine Chemical Ecology) at the Faculty of Science, and the University of Gothenburg present a new possible explanation of why algal blooms arise in a study published in the international journal proceedings of the National Academys of Sciences. Currently the theory is that the algae produces toxin not only in order to inhibit the growth of the other competing species, but also to protect themselves from its predators. The research gathered shows that the only side-effect of the more aggressive behavioral of algae is that it will go to any means necessary in order to gain access to the nutrients within others cells. "The behavior of the algae can v e compared to that of a blood sucking insect", said Per Jonsson of the Department of Marine Ecology. The "warrior" tactics used on its fellow opponents makes sense for its aggressive behavior towards the sharks as well. It infects the sharks in order to sustain its own lifestyle. Could algae now be considered a parasite? Ofcoarce these are only ideas and hypothesis. 

"The area we studied represents a recetnly disovered nursery habitat for lemon sharks., and it may serve as one of the most valuble lemon shark nurseries in the U.S. waters.", sais Douglas Adams of the Flordia Fish and Wildlife Conervation COmmission told Discovery News. The Well known "Florida Red Tide" found int the waters of the Gulf of Mexico is a harmful aglae bloom (HAB) caused by the karenia brevis, a dinoflagellate which are both producers of brevetoxin. The sharks who are survivors of the massive outbreaks, the long term impact of the aquatic populations remains unkowns. Since the precence of brevetoxins in shark embryos raises questions about the effects these toxinsmay have on the reproductive success of sharks. In the near future there may be provabilities of lemon shark defects as well as other marine life. 

5. Journal Article Review 
Legacy of Poison 
By Chris Perham
The toxins are biological substances, non synthetic or natural materials. Red tide is made up of tiny little organisms that manage to wipe out things ten times their size. The massive growth and expansion of the red tide is growing in increasing amounts. It was been around for centuries though; according to some the "Red Sea" was actually red tide. Red tide completly switches up the idea of a food chain by infecting the worlds waters and killing massive amounts of fish, and even people if a contaminated seafood is consumed. A strong leading reason why this toxic algae is blooming is because of the human race. As we keep polluting our oceans not only are our sea life in danger but it can also put our own personal health in jeopardy. 

Penham, Chris. "HeinOnline." Redirecting... Web. 12 Dec. 2010. <>.

"Google Image Result for Http://" Google. Web. 12 Dec. 2010. <,786&um=1&itbs=1&iact=hc&vpx=142&vpy=239&dur=78&hovh=183&hovw=275&tx=222&ty=84&ei=vHsFTcyxGMH38AaJ8dTmAg&oei=NHsFTe2UF4T7lweBv7m3Dw&esq=2&page=2&ndsp=16&ved=1t:429,r:11,s:17&biw=1280&bih=666>.
Viegas, By Jennifer. "Toxic Algae Destroys Shark Brains : Discovery News." Discovery News: Earth, Space, Tech, Animals, Dinosaurs, History. Web. 12 Dec. 2010. <>.