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Key energy-producing proteins missing in this plant
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To produce cellular energy, nearly all multicellular organisms use a series of highly specialized proteins embedded in the inner member of the mitochondria to transport and pump electrons, collectively known as the electron transport chain. A new study has revealed that this is not the case in European mistletoes, the traditional Christmas ornament hung to give someone a kiss underneath it. After sequencing the organism's genome, researchers couldn't find any mitochondrial genes for coding the protein subunits that make up the electron transport chain’s first station, called complex I. To find out which parts of the assembly line machinery had disappeared, researchers extracted proteins from mitochondria in the mistletoe's leaves and compar [ ... ]
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940 |
bio_man |
A month ago |
Poison dart frog
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The poison dart frog is the common name given to the most poisonous animals on Earth. Native to Central and South America, these species of frogs (family: Dendrobatidae) produce several lethal toxins that are capable of killing a human or other large animal with just 2 micrograms (μg). In other words, one drop of their venom could be powerful enough to kill 8000 people. The most toxic of poison dart frog species is Phyllobates terribilis. Unlike snakes, dart frogs do not synthesize their poisons, but sequester the chemicals they consume from arthropod prey, such as ants, centipedes and mites. This is why in captivity, they produce far less poison than wild frogs due to their change in diet. What makes these frogs immune to their own poison i [ ... ]
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1180 |
bio_man |
9 months ago |
What causes the rattle in a rattlesnake's tail?
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Rattlesnakes are a group of venomous snakes native to the Americas known for their loud rattling tail. The tip of their tail, known as the rattle (middle), vibrates to deter predators or serves as a warning to passers-by. The rattle is composed of a series of hollow, interlocked segments made of keratin, which are created by modifying the scales that cover the tip of the tail. The contraction of special "shaker" muscles in the tail causes these segments to vibrate against one another, making the rattling noise (which is amplified because the segments are hollow) in a behavior known as tail vibration. The muscles that cause the rattle to shake are some of the fastest known, firing 50 times per second on average, sustained for up to three hour [ ... ]
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5643 |
bio_man |
A year ago |
An essential bone lost
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Despite slang terms that imply otherwise, the human penis contains no bones. The same cannot be said for many of our closest evolutionary relatives: Chimpanzees and bonobos both have penis bones (a macaque one is pictured, left), also known as bacula. To find out why some primates have the feature whereas others don’t, researchers traced the bone’s evolutionary history through time. The baculum first evolved between 145 million and 95 million years ago, as reported in the Proceedings of the Royal Society B. That means it was present in the most recent common ancestor of all primates and carnivores. Why some descendants, like humans, lost their bacula appears to be due to differences in mating practices: In primates, the presence of a penis [ ... ]
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16322 |
duddy |
2 years ago |
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3793 |
duddy |
2 years ago |
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4417 |
duddy |
2 years ago |
This synthetic organism survives with less than 500 genes
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This week in Science, researchers led by genome sequencing pioneer Craig Venter report engineering a bacterium to have the smallest genome - and the fewest genes - of any freely living organism. Known as Syn 3.0, the new organism has a genome whittled down to the bare essentials needed to survive and reproduce, just 473 genes. However, the function of 149 of Syn 3.0's 473 genes remain unknown. As Syn 3.0's name suggests, it’s not the first synthetic life made by Venter. In 2010, Venter's team reported that they had synthesized the sole chromosome of Mycoplasma mycoides - a bacterium with a relatively small genome - and transplanted it into a separate mycoplasma called M. capricolum, from which they had previously extracted the DNA. After s [ ... ]
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10470 |
duddy |
2 years ago |
Being afraid of the dark is totally normal
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Even though being afraid of the dark sounds childish, our fear of the dark is an evolutionary trait that we picked up to survive real-life predators stalking the night. Researchers have hypothesised that this innate fear stems from a point of human history when we were nowhere near the top predators we are today. Humans only really became super predators with the advent of technology, which wasn’t that long ago. Before technology, our ancestors were constantly on the look-out for predators that wanted nothing more than to chow down on human sandwiches. To make that even scarier, most of these predators hunted at night - a time of day when we are especially vulnerable to attack because of our relatively poor eyesight. This means that it was [ ... ]
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12882 |
duddy |
3 years ago |
Why do humans have chins?
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What sets Homo sapiens apart from other animals? Among other things, our chins do. That piece of bone sticking out from your jaw is somewhat of a mystery - one that's inspired a diversity of wild theories to explain its purpose, according to a paper published this month in Evolutionary Anthropology. The author of the paper dismisses a number of these explanations, such as the possibility that the chin serves as a sexual signal (such traits usually only appear in one sex - like the mane of a male lion). Another proposal is that the chin acts to protect your throat - an idea the paper's author also shoots down, because for this to be a substantial advantage, humans would have to be constantly punching each other in the face. So the mystery rem [ ... ]
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13753 |
duddy |
3 years ago |
Turns out that fish oil only benefits those who have the right genes
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Most foods today are fortified with essential oils like omega-3 fatty acids. Naturally, these oils are found in fish, and are known to benefit many parts of the body, including the eyes, brain, heart, and joints. So, are these so-called beneficial oils important for people who lack the DNA profile needed to metabolise them? It turns out that the extra omega-3 might not do much good at all. According to a study published in Science, Inuit people living in Greenland whose traditional diet of fish and marine mammals have the right enzymes in their bodies needed to metabolise these foods that are very high fat content. The researchers reported that their DNA that was most different was on chromosome 11, specifically among genes that control the [ ... ]
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15189 |
duddy |
3 years ago |
Pre-crastination
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Some of us may be guilty of procrastination, but we all are pre-crastinators at some level. Procrastination is a serious problem to many of us that like to put off work and cram the night before. Not only is procrastination a behavioral problem, but also one with a psychological implication. Procrastination is the "thief of time". On the other hand, precrastination, discovered to be the complete opposite, is the tendency to do things ahead of time - and really ahead of time- just for the sake of completion. Precrastination was found to be exhibited in pigeons as well. And the fact that we and pigeons have separated in phylogeny 300 million years ago suggests that precrastination is a behavior also found earlier in phylogeny. How has this be [ ... ]
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8871 |
ehd123 |
3 years ago |
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4328 |
duddy |
3 years ago |
Bees up-close
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Barry from Bee Movie has taught us that without bees, we won't survive. These pollinators may terrify us when they are swarming around out at the park, but they are more terrifying if they were not around. What is happening to our bees with domestication? What have we lost? What are we trying to restore? The answers to these questions are in this video. Check it out
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2328 |
ehd123 |
3 years ago |
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5690 |
duddy |
3 years ago |
What mechanism allowed early terrestrial animals to transition from water to land?
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A new study finds that Mudskipper fish carry water in their mouths in order to eat prey outside of water. As seen in the video below, the hidden water is expelled at the moment of eating and it serves as a suction to move the water and their meal back toward the esophagus. The water suction, or “hydrostatic” tongue, may serve as the evolutionary bridge that allowed our aquatic ancestors to begin feeding on land.
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35616 |
duddy |
3 years ago |
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