Category Archives: Life Science

One Reason Bacteria Gain Tolerance So Quickly

I recently read Good Gems, Bad Germs as part of my effort to learn more about bacteria, viruses, how are bodies work, cells, microbiology etc.. It is a great book, I highly recommend it. Page 111:

In 1951 the husband-wife team of Joshua and Esther Lederberg, microbiologists at the University of Wisconsin, demonstrated that their elegantly simple proof that preexisting mutations, not gradual tolerance, accounted for the many instances of new drug resistance… This meant that every new antibiotic became a powerful new force for bacterial evolution, winnowing away every bacterium but the otherwise unremarkable one that could survive its effects. With its competition gone, that lucky mutant could populate, giving rise to a newly resistant colony overnight.

Since bacteria can grow remarkably quickly, eliminating all but a small number just means that the new population boom will come from those few, resistant, ancestors. But that is not the only reason bacteria are so challenging to fight. They have been around billions or years and have survived because they can adapt well. Bacteria, in fact, can get their genes from distantly related bacteria. So if one bacteria gains immunity another bacteria can get that immunity by getting genes from that other bacteria (seems like science fiction but it is actually science fact).

Really Old Coral – Over 2,000 Years Old

photo of sea coral (leiopathes_glaberrima)

Worlds oldest animal aged to 4000 years

deep-sea gold corals (Geradia sp.) and black corals (Leiopathes glaberrima, pictured left) indicate these animals live between two and four millennia
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The new findings break all records previously claimed for marine invertebrates like the cold seep tubeworms (estimated 200 years old), quahog clams (estimated 400 years old), as well as the deep-sea wannabees Primnoa spp. and bamboo corals (45 – 300 years old). Given the new results, deep-sea animals can finally measure up to the longevity of the “Methuselah tree”, the Bristlecone Pine, estimated to be near 5000 years old.
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perhaps the most important thing to mention is that gold and black corals are colonial zoantharians. No single polyp is thought to be this old, just the skeletal axis.

How is Coral an animal?

Coral is an animal that belongs to the phylum cnidaria…
During the mating season coral polyp release eggs and sperm into the water (picture below) and when an egg and a sperm meet they form a larva known as a planula…
The baby coral looks like a little tiny jellyfish and it floats around in the water until it finds a hard place to attach to, usually a coral reef. Then it lands and starts to build itself a shell. It builds it by combining carbon dioxide (CO2) and calcium (Ca) in the water to make calcium carbonate (CaCO3) also known as limestone. This shell is shaped like a round vase and the coral polyp lives inside…

Parasitic Worms Reduce Hay Fever Symptoms

Parasitic worms reduce hay fever symptoms

Researchers are seeking to use the ability of the hookworm, Necator americanus, to suppress immune system responses that occur in conditions including Crohn’s disease, multiple sclerosis, asthma and other allergies. Recently-completed studies suggest giving worms to people with hay fever is safe, and potentially beneficial.
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Scientists have suggested a lack of such intestinal parasites has left those in the developed world more vulnerable to diseases caused an overactive immune system.

Parasite Rex is an excellent book exploring similar ideas and more on the interaction of parasites with hosts. And from Good Germs Bad Germs, page 100:

in 1999 the Dutch biologist Maria Yazdanbakhsh found that eliminating intestinal worms from infected children in African villages immediately predisposed them to allergies.”

Dead Zones in the Ocean

Oceanic Dead Zones Off West Coast are the ‘New Normal’

Ever since it was first noticed by crab fishermen who hauled up hundreds of dead and dying crabs in 2002, the “dead zone” that popped up in the waters along the northwestern coastal shelf just off the coast of Oregon has claimed unknown millions of lives. This oxygen-depleted region has transformed formerly rich seafloor communities teeming with life into vast graveyards filled with the bodies of crabs, echinoderms, molluscs, sea worms and other creatures.
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a low-oxygen zone appears each spring off the coast of Louisiana due to fertilizers in farm runoff and sewage present in the Mississippi River. When the Mississippi flows into the sea, it creates a nutrient-rich area that triggers huge but short-lived algal blooms that soon die, sink to the seafloor and are decomposed by bacteria that produce toxic sulfide gases.
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the dead zone off the West Coast of North America has another cause: global warming. Here’s how it works: Winds cause the oceanic rivers of nutrients, such as the California Current in this case, to flow upwards from the deep, carrying nutrients and phyoplankton into the sunlight, which triggers the phytoplankton to reproduce, to “bloom”. This is the normal state of things, but since global warming has been causing land temperatures to increase, these winds have become stronger and more persistent. This is not normal because it prolongs the oceanic upwelling, producing a surplus of phytoplankton that isn’t consumed and subsequently dies, and sinks to the seafloor to decay. As the bacterial-mediated breakdown occurs, dissolved oxygen in the surrounding water is depleted to dangerously low levels

As I was Saying… More Dinosaur Discoveries

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As I was Saying… Tiny flying reptile with 10 inch wingspan found:

Palaeontologists have found a tiny flying reptile that, with a wingspan of less than 10 inches, is the smallest relative of the largest flying creature ever. Pterosaurs, the first creatures with backbones to take to the air, ruled the skies during the days of the dinosaurs and died out with them some 65 million years ago.

They came in a huge range of sizes: there were gull-sized creatures, such as Anurognathus, giants such as Anhanguera (“Old Devil”) and Tupuxuara with wing spans of about four metres, and massive flyers like Quetzalcoatlus, with wingspans of more than 10 metres. Now a miniature version is described by Xiaolin Wang
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The remains were found in the Early Cretaceous Jiufotang Formation (120 million years ago), western Liaoning, China, and suggest it probably weighed between 30 and 50 grams. “This small pterosaur looked like a sparrow or swallow in size,” adds Dr Wang.” The creature is the smallest toothless pterosaur and the smallest to live during the Cretaceous period.”

Bollworm Evolves Resistance to Genetically Engineered Cotton

Bollworm Evolves Resistance to Bt Cotton

The genetically modified cotton that was designed to make the Bt (that’s short for Bacillus thuringiensis, a bacterium) toxins that kill boll weevils has been thwarted by the bugs, according to new research to be published in Nature Biotechnology. The bollworm is the first pest to evolve resistance in the field to so-called Bt crops, according to University of Arizona entomologists.

Bt-resistant populations of bollworm (Helicoverpa zea) were found in more than a dozen crop fields in Mississippi and Arkansas between 2003 and 2006. The first resistant worms showed up just seven years after the genetically modified crops were introduced, in 1996, according to the analysis of monitoring studies.

“What we’re seeing is evolution in action,” said lead researcher Bruce Tabashnik.

Giant Duck-Billed Dinosaur Discovered in Mexico

“‘We only know about 29 percent of all dinosaurs out there to be found,’ said study co-author Peter Dodson, a paleobiologist and anatomy professor at the University of Pennsylvania in Philadelphia.” I found this quote to be surprising when I first wrote about it in 2006: Most Dinosaurs Remain Undiscovered. Yet we keep getting new discoveries announced (New Triceratops Ancestor – Nigersaurus the Mesozoic Cow!) showing, while I was surprised, the scientists knew what they were talking about.

Giant Duck-Billed Dino Discovered in Mexico

The discovery of the 72-million-year-old fossil adds to the rich gallery of dinosaurs that scientists now know lived in western North America during the latter part of the dinosaur era. The new species was dubbed Velafrons coahuilensis in honor of the state of Coahuila in north-central Mexico where the fossil was found.

Reaching lengths up to 35 feet (10.5 meters) long, the newfound dino was a plant-eater belonging to a group of duck-billed dinosaurs, or hadrosaurs, that roamed the region together with carnivores like tyrannosaurs and velociraptors.

Electrical Brain Stimulation Boosts Memory

Deep stimulation ‘boosts memory’

The technique involves implanting electrodes into the brain: in this case into an area in the limbic system called the hypothalamus, which is thought to control the appetite. When the electrodes were stimulated by electrical impulses the patient began to experience feelings of deja vu.

He then had a sudden perception of being in a park with friends. He felt younger, thought he was around 20-years-old, and his girlfriend of the time was there. He was an observer, and saw the scene in colour. As the intensity of the stimulation increased, details in the scene became more vivid.
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The results suggest it might be possible to use deep brain stimulation directly to boost memory. “We hopefully have found a circuit in the brain which can be modulated by stimulation, and which might provide benefit to patients with memory disorders,” said Professor Lozano. He is now leading a pilot study into whether deep brain stimulation can help people with early Alzheimer’s disease. They are initially testing six patients.

Darwin Day

Find a Darwin Day Celebration near you. Events from hundreds of sites including:

Darwin Day in Italy
University of Oslo, Norway
University of Valencia, Spain
Shrewsbury Darwin Festival, UK (Darwin’s home town)
2008 Darwin Festival, Salem State College, Massachusetts, USA
Darwin Day Lecture, Central Washington University, USA
Darwin Day, Case Western Reserve University, USA

The Science of Kissing

The Differences in Gender — Sealed With a Kiss

In people, kissing to express affection is almost universal. About 90 percent of human cultures do it. One traditional view is that kissing, known scientifically as osculation, evolved from women chewing food for their children and giving it to them mouth-to-mouth, Fisher said.

But, she said, “I’ve never believed that,” adding that similar behavior is found in many species. Birds tap beaks. Elephants shove their trunks in each other’s mouths. Primates called bonobos practice their own version of French kissing. Fisher believes kissing is all about choosing the right mate.

“There’s so much information exchanged when you kiss someone that I just thought it must play a vital role in mate choice, and this paper is elegantly showing that,” Fisher said. A disproportionate amount of the brain, she noted, is geared toward interpreting signals from the mouth.

The research paper – Sex Differences in Romantic Kissing Among College Students: An Evolutionary Perspective