Phylogeny Programs

Phylogeny Programs available online.

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Turtle fossil

Grabbed this from BBC Knowledge Evolution Special

The fossil has only a shell on the underside, supporting the theory that the shell is formed from the backbones and ribs.

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Last Ant Standing – Science Daily

Excellent example on Altruism.

Last Ant Standing

By Charles Choi
ScienceNOW Daily News
23 September 2008

Every night, the Brazilian ant Forelius pusillus takes self-sacrifice to a whole new level. At sunset, the colony protects its nest by sealing off the entrances with sand, and a few ants remain outside to complete the job. Unable to reenter, they die by the next morning–making them the first known example of a suicidal defense that is preemptive rather than a response to immediate danger.
Social insects are well-known for their willingness to die for their colonies; a number of bees, wasps, and ants succumb after their stings lodge in targets and break off. But until now, these insects were thought to engage in such suicide missions only when enemies were present.

Behavioral ecologist Adam Tofilski of the Agricultural University of Krakow, Poland, and his colleagues were studying how F. pusillus dispersed sand in a sugar cane field near São Simão in Brazil when they saw that as many as eight ants remained outside the sealed nests. These ants weren’t stragglers: They deliberately helped hide the entrances, spending up to 50 minutes carrying and kicking sand into the hole until it was indistinguishable from its surroundings.

Come morning, when the nest reopened, these ants were nowhere to be seen. The researchers found out why when they plucked ants left behind into a plastic bowl: Only six of 23 survived the night. These findings, which will appear in the November issue of the journal American Naturalist, show that staying outside was suicidal. “In a colony with many thousands of workers, losing a few workers each evening to improve nest defense would be favored by natural selection,” said co-author Francis Ratnieks, an insect biologist at the University of Sussex, U.K.
The ants stuck outside might be old or sick, Tofilski conjectured. Thus, they may have essentially sacrificed themselves for the greater good, being more expendable members of the colony. Still, community ecologist Michael Kaspari of the University of Oklahoma, Norman, who did not participate in this study, noted that F. pusillus is “very, very flimsy” and that even young, healthy ants could easily die if left behind. “They might have burned through all their sugar or dehydrated outside the buffered environments of their nests,” he explained.

It remains a puzzle what the ants are guarding their colonies against. Kaspari speculated that F. pusillus might be hiding from large, roaming colonies of army ants. Uncovering the pressures that drive this self-sacrifice could shed light on the evolution of altruism, Kaspari added.

Antibiotic resistance mechanism in bacteria found

Scientists have found that nitric oxide produced by the bacteria eliminates some key effects of a wide range of antibiotics.

The latest research, done by a team at New York University, showed that in bacteria the production of nitric oxide – a small molecule made up of one nitrogen and one oxygen atom – increased their resistance to antibiotics.

This could very likely advance the science in dealing with antibiotic resistance bacteria.

Full report here by BBC News.

Antibiotic resistance clue found

US scientists have uncovered a defence mechanism in bacteria that allows them to fend off the threat of antibiotics.

It is hoped the findings could help researchers boost the effectiveness of existing treatments.

The study published in Science found that nitric oxide produced by the bacteria eliminates some key effects of a wide range of antibiotics.

One UK expert said inhibiting nitric oxide synthesis could be an important advance for tackling tricky infections.

Antibiotic resistance, for example with MRSA, is a growing problem and experts have long warned of the need to develop new treatments.

“ Here, we have a short cut, where we don’t have to invent new antibiotics ”
Dr Evgeny Nudler, study leader

The latest research, done by a team at New York University, showed that in bacteria the production of nitric oxide – a small molecule made up of one nitrogen and one oxygen atom – increased their resistance to antibiotics.

They found the enzymes responsible for producing nitric oxide were activated specifically in response to the presence of the antibiotics.

They also showed that nitric oxide alleviates damage caused by the drugs as well as helping to neutralise many of the toxic compounds within the antibiotic.

The researchers then showed that eliminating nitric oxide production in the bacteria allowed the antibiotics to work at lower, less toxic doses.

More effective

Study leader, Dr Evgeny Nudler, said developing new medicines to fight antibiotic resistance, such as that seen with MRSA is a “huge hurdle”.

“Here, we have a short cut, where we don’t have to invent new antibiotics.

“Instead we can enhance the activity of well-established ones, making them more effective at lower doses.

Dr Matthew Dryden, consultant in microbiology and communicable disease at Royal Hampshire County Hospital and general secretary of the British Society for Antimicrobial Chemotherapy, said if the enzyme which creates nitric oxide could be inhibited, it could suppress the ability of the bacteria to counteract antibiotics.

“This would be a useful therapeutic advance, especially as we are running out of new classes of antibiotics and there is less antibiotic development in general.”

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/2/hi/health/8248020.stm

On the origins of eukaryotes

A few good articles worth mentioning:

One on the current state of the science of taxonomy. Some call it an art, but taxonomy is able to make predictions, so I think its a science, an important one too. See the article by Carol Kaesuk Yoon:
Reviving the lost art of naming the world.

Carl Zimmer has an excellent series on the evolution of Eukaryotes and warming of the earth. On the origin of Eukaryotes

On global warming and evolution

We are all just microbes within microbes? No, we are microbes within microbes within microbes according to Carl Zimmer in Science.

The forgotten evolutionist

A very good biography on the co-founder of the theory of evolution. Alfred Russel Wallace.

12 Elegant examples of Evolution – WIRED Science

Wired Science reports 12 Elegant examples of Evolution. Very fitting to start the 150th anniversary of the publication of the Origin of Species by Charles Darwin.

12 Elegant Examples of Evolution
By Brandon Keim

Related articles by the same author:
A Theory of Evolution for Evolution

The Complexity of Evolution

Biologists Take Evolution Beyond Darwin — Way Beyond

The neck is a shallow water adaptation

We always assumed that the neck is very advantageous for terrestrial life. Being able to swivel and look around for predators and also searching for food is clearly more advantageous than having to swing the whole body around.

Well it turns out that the neck could have been an adaptation for emerging out of shallow water to breath air.

For more read this article by Discover:

World’s First “Walking Fish” Also Had the World’s First Neck

A new study of a the fossilized remains of the Tiktaalik, the “walking fish” that illuminates how swimming fish evolved into land-dwelling amphibians, shows that there was more to the transition than the switch from fins to limbs. The study shows that the head and braincase were changing, a mobile neck was emerging and a bone associated with underwater feeding and gill respiration was diminishing in size, a beginning of the bone’s adaptation for an eventual role in hearing for land animals [The New York Times].
The creature, dubbed Tiktaalik roseae — or, to be less formal, Fishapod — lived 375 million years ago 600 miles north of the Arctic Circle in a subtropical floodplain that eventually became Ellesmere Island, where it was discovered in 2004 [Wired News]. The fishapod has already earned its reputation as a “missing link” in evolutionary history due to its sturdy, jointed fins and its dual breathing system, with both gills and lungs. But the new study suggests that changes to the animal’s head and the development of the first neck also played a critical role in its evolution.
In the study, published in Nature [subscription required], researchers showed that the Tiktaalik’s head bones weren’t fused to its shoulder bones, giving it a flexible neck. This could have allowed the fishapod to easily poke its head out of the shallow water to gulp down air or to go after prey. Meanwhile, the diminishing of the head bone that helps fish control their gills may indicate that the Tiktaalik was already less dependent on gill respiration.
Study coauthor Jason Downs says the new findings show that many of the traits that would come in handy on land evolved much earlier. “So what it’s really demonstrating is that many of these changes that are occurring and things that we once associated with terrestrial life are turning out, in fact, to be adaptations for life in shallow water settings that Tiktaalik might had found himself in,” Downs added. It likely inhabited the mudflats of freshwater flood plains of a subtropical environment. It was a large aquatic predator, measuring up to 9 feet long, with sharp teeth and a flattened head like a crocodile and unlike primitive fish [Reuters].

Related Content:
The Loom: The Shoulder Bone’s Connected to the Ear Bone…
80beats: Researchers Find Primitive Finger Bones in Ancient Fish
80beats: Prehistoric Creature Moved from Sea to Land, but Went Extinct Anyway

July 1 1958

The date when Darwin and Wallace announced the theory of evolution

Good article from Wired.

Darwin’s first draft goes online

Darwin’s first draft of his theory of evolution now goes online, now joining the 20,000 archive items in the online archive run by Cambridge University ‘The Complete Work of Charles Darwin Online‘.

This will definitely be a valuable resource for educators and scientists alike.

For more read:
Darwin’s first draft goes online