Seahorse evolution

By Jennifer Viegas, Discovery News:

Seahorses ‘Stood Up’ 25 Million Years Ago

May 6, 2009 — Seahorses first stood up sometime after 25 to 20 million years ago, when bodies of open water between Australia and Indonesia changed, leaving these horse-resembling bony fishes with shallow sea grass habitat, according to a new study.

The study, published in the latest Royal Society Biology Letters, explains that an upright stature, shared by humans but which is extremely rare throughout the entire animal kingdom, allowed seahorses to reside in what was essentially a lawn under water.

To this day, seahorses prefer to live in sheltered areas, such as sea grass beds, coral reefs and mangroves.

“Not only can an upright fish maneuver much better in such an environment than a horizontally-swimming one, but the upright sea grass blades would have improved their camouflage,” explained Peter Teske, who co-authored the paper with Luciano Beheregaray.

“Camouflage is of great importance to seahorses, which are poor swimmers,” added Teske, a postdoctoral researcher in Macquarie University’s Molecular Ecology Lab. “It affords them both protection from predators and allows them to sneak up on their prey — including small crustaceans and tiny fish — without being noticed.”

Teske and Beheregaray first took note of pygmy pipehorses, which look like “non-upright proto-seahorses.” They wondered when these two bony fishes diverged, and how this fit into the bigger picture for the Syngnathidae, a family of fish that includes seahorses, pipefishes and both weedy [see also here and here and here] and leafy sea dragons.

To answer these questions, they constructed a family tree using genetic information gathered from the genus Hippocampus, which includes all seahorses, and the genus Idiotropiscis, which contains the very seahorse-resembling southern little pipehorse.

Molecular dating indicates seahorses split from their pygmy pipehorse sister taxon during the Late Oligocene, right when tectonic events in the Indo-West Pacific resulted in the formation of new shallow water sea grass habitats. It appears that seahorses remained mostly isolated in these new regions, allowing them to evolve a number of distinctive features.

Male seahorses like big mates: here.

UK Seahorse tagging project at Studland Bay in Dorset: here.

October 2010: Marine scientist Paul Kay took this picture of pipefish off the Welsh coast. Thought to be a shore or black-striped pipefish, the photograph is so unusual because of where it was taken – such pipefish are normally found only as far north as the Southern Biscay, with the odd one making its way slightly further up the French coast: here.


Condoleezza Rice defends Bush torture policy

Rice defends Bush torture policy

This cartoon about the US Bush administration torture policies is from Internet Weekly in the USA.

Inspiration: Condoleezza Rice Defends Bush Torture Policy Again, To Grade School Student.

A Justice Department draft report produced under Bush opposing criminal prosecution of government lawyers who justified torture has been embraced by the Obama administration: here.

A memo released Wednesday lists 40 secret briefings for members of Congress on the use of “Enhanced Interrogation Techniques”—in plain words, torture. Republicans have used the memo to indict Democrats for complicity in these criminal practices: here.

Rutgers historian Rudy Bell leads protest against Condoleezza Rice speaking at commencement: here.

Campus Activists Shut Down Condoleezza Rice Speech At Rutgers: here.

Last Saturday, former US Secretary of State Condoleezza Rice announced that she would not deliver the May 18 commencement speech to the Rutgers University graduating class of 2014. For months, students and faculty at Rutgers, the state university of New Jersey, had mounted a protest campaign against Rice’s invitation to be commencement speaker: here.

Queen Nefertiti bust only 100 years old?

From Egyptology News:

The bust of Queen Nefertiti housed in a Berlin museum and believed to be 3,400 years old in fact is a copy dating from 1912 that was made to test pigments used by the ancient Egyptians, according to Swiss art historian Henri Stierlin.

Stierlin, author of a dozen works on Egypt, the Middle East and ancient Islam, says in a just-released book that the bust currently in Berlin’s Altes Museum was made on the orders of Germany archaeologist Ludwig Borchardt on site at the digs by an artist named Gerardt Marks.

Hawass reaction to this: here.

Egypt’s antiquities chief has declared that he will formally demand the return of the 3,300-year-old bust of Queen Nefertiti from a Berlin museum after confirming it was sneaked out of Cairo through fraudulent documents: here.

Another article about the Nefertiti bust dispute: here.

Germany to celebrate centennial of Nefertiti bust discovery: here.

Women in ancient Egypt: here.

Dutch caiman eggs

This is a broad-snouted caiman video.

According to Dutch daily De Stentor, there are now caiman eggs in the Ecodrome zoo in Zwolle, the Netherlands.

They are eggs of the broad-snouted caiman. This species has never before laid any eggs in a Dutch zoo. At the moment, the only other Dutch zoo with these caimans is Burgers’ in Arnhem; but there, they are still too young to reproduce. Only five European zoos have broad-snouted caimans.

Effects of climatic conditions on sex ratios in nests of broad-snouted caiman: here.

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850 million year old animal discovered

By Randy Boswell, Canwest News Service in Canada:

Sponge-like body believed to be oldest evidence of animals

May 5, 2009

Canadian scientists probing a mountaintop in the Northwest Territories have discovered what they believe is the oldest evidence of animals on Earth — about 850-million-year-old traces of a primitive, sponge-like organism that could push back direct proof of the origin of humanity’s own kingdom of life by an astonishing 200 million years.

The microscopic but distinctively patterned remains — unearthed from a dramatic pinnacle in the Mackenzie Mountains about 800 kilometres northwest of Yellowknife — are interpreted by the research team as rock-encased residues from the decomposed tissues of a primordial sea creature that was the earliest common ancestor of all animals, including humans.

The organism, believed to have lived in the nooks of a reef from a long-lost ocean, represents a stage of life “before sponges and other animals we know today evolved,” University of Laval geologist Fritz Neuweiler, told Canwest News Service.

Experts in evolution, including the famed Origin of Species author Charles Darwin, have long postulated that animals must have been developing eons before the existence of known creatures that left easy-to-see skeletal fossils during the Cambrian and Ediacaran geological eras, reaching back about 635 million years ago.

“If you want to go back to the very origins of animals, you can’t be looking for that,” says Laurentian University paleontologist Elizabeth Turner, one of the three co-authors of a paper detailing the Canadian discovery in the latest issue of the journal Geology.

“Earlier life won’t be that complex,” she said in an interview on Tuesday. “What we’re dealing with is a texture you can see under a microscope in a rock that’s been cut until it’s 30 microns thick. This is a wholly different type of evidence of life.”

The site is part of the Little Dal formation near the N.W.T.-Yukon border, renowned among geologists for what Turner calls its “exquisitely well preserved” record of Earth’s evolution.

“These rocks are exactly the right age for us to be exploring for this type of evidence,” she said. “We know that the earliest form of animals would have been from about 850 million years ago.”

Turner added, though, that because the fossil record is “so subtle and enigmatic at this stage” of evolution, she and Neuweiler — along with U.S. geologist David Burdige — used a “novel” series of experiments to verify their theory.

These techniques included comparisons of residue patterns found at the N.W.T. site to trace remains of younger (though still prehistoric) sponge colonies in Spain and Quebec, as well as modern sponge samples from the Bahamas.

The challenge, the researchers note in their published study, was to confirm the presence of a living organism from the dawn of animal life without the aid of “conspicuous body fossils.”

See also here.

Primitive sponge fossils upturn conventional scientific thought and date animal life on earth at 650m years: here.

Packed inside the humble sea sponge is a surprisingly intricate genome: it contains the basic tool kit for all animal life, including complex vertebrates – and it’s not even an animal, really: here.

Eight new kinds of the earliest animals from the Cambrian Explosion have been found in a newly explored section of ancient rock in Canada: here.