Tuesday, March 6, 2012

Human origins traced to a worm

The origins of humans and other vertebrates have been traced to a worm that swam in the oceans half a billion years ago.

A new analysis of fossils unearthed in the Canadian Rockies determined that the extinct Pikaia gracilens is the most primitive known member of the chordate family, which today includes fish, amphibians, birds, reptiles and mammals.

The research, published in the British scientific journal Biological Reviews this week, identified a notochord (or rod) that would become part of the backbone in vertebrates, and skeletal muscle tissue called myomeres in 114 fossil specimens of the creature. They also found a vascular system.

"The discovery of myomeres is the smoking gun that we have long been seeking," said the study's lead author, Simon Conway Morris of the Cambridge University in England. "Now with myomeres, a nerve chord, a notochord and a vascular system all identified, this study clearly places Pikaia as the planet's most primitive chordate. So, next time we put the family photograph on the mantle-piece, there in the background will be Pikaia."

Humans' humbling origin
The first specimens of Pikaia were collected by early explorers of the Burgess Shale in 1911. But the animals were overlooked as an ancestor of earthworms or eels.

It was not until the 1970s that Morris suggested the 5-cm-long, sideways-flattened, somewhat eel-like animal that likely swam by moving its body in a series of side-to-side curves could be the earliest known member of the chordate family.

"In particular, it was our use of an electron microscope that allowed us to see very fine details of its anatomy," said co-author Jean-Bernard Caron, an assistant professor of ecology and evolutionary biology at the University of Toronto in Canada. "It's very humbling to know that swans, snakes, bears, zebras and, incredibly, humans all share a deep history with this tiny creature no longer than my thumb."


UN moved for faster Sagar-Runi probe

Journalists and Bangladeshi expatriates in Bonn, Germany, on Tuesday sought the United Nations' intervention for a faster investigation into the killing of journalist couple Sagar Sarowar and Meherun Runi.

In a memorandum submitted to UN secretary-general Ban Ki-moon, they requested UN assistance towards transparency in the enquiry and arrest of the killers without further delay.

Earlier in the morning, dozens of expatriate Bangladeshis along with citizens from other countries joined hands to form a human chain on the UN campus here in the former West Germany capital that currently hosts 17 United Nations institutions.

Journalists from Germany's international broadcaster Deutsche Welle (DW) Radio also participated in the human chain. Sagar had worked with the Bangla service from June 2008 to May 2011 as a radio host and reporter.

Sagar stayed there with his wife Runi, senior reporter of Bangla TV channel ATN Bangla, and their only son Mahir Sarowar Megh. On his return, Sagar joined Masranga Television as a news editor in Dhaka and has been working there until he and his wife were murdered on Feb 11 in their West Razabazar residence in Dhaka.

About a month into the killing police have failed to find out the motive behind killing, let alone identify and arrest the killers.

The memorandum submitted to the UN chief mentioned that different statements given by police relating to the killing have already caused frustration and confusion among people in Bangladesh.

Organisers of the human chain told that they had to turn to UN secretary-seneral since they had not heard any heartening remark from the Bangladesh government high-ups except hollow promises.

"We want to know who the killer is. We demand justice," said Marina Jwarder, Sagar's former colleague from the DW Radio.

She was critical of the recent High Court order on the media to not publish any news regarding the murders unless authenticity of the information was confirmed beyond doubt. "Freedom of press and right to information has been infringed by the direction of the Bangladesh High Court," she said.

Another Deutsche Welle journalist, Supriyo Banerjee, urged Bangladeshi journalists to rally behind their demand of justice.

"I wonder if they (the government) are trying to hide anything regarding the killing," said DW journalist Nikhil Ranjan.

One of Sagar's former German colleagues, Christianne Rabbe, attending the programme t hoped that justice will be served.

Deutsche Welle's Asia Department editor Sarah Berning urged the Bangladesh government to ensure security of journalists.

Bonn university researcher Dr Majharul Islam said, "Our appeal is that the United Nations helps Bangladesh government find out the killers through fair investigation. Through the United Nations we want the world to learn about the brutal killing." 

Pentagon's robot cheetah 'sets speed record'

A headless robot dubbed "Cheetah" has set a new world speed record, according to its owners.

The US Defense Advanced Research Projects Agency said the four-legged machine achieved 18mph (29km/h) on a laboratory treadmill.

The agency said the previous land speed record by a legged robot was 13.1mph.

Darpa said that the project was part of efforts to develop robots designed to "more effectively assist war fighters across a greater range of missions".

Darpa - which is run by the Pentagon - funded the Massachusetts robotics company Boston Dynamics to build the machine.

"We plan to get off the treadmill and into the field as soon as possible," said the firm's chief robotics scientist, Alfred Rizzi, in a statement.

"We really want to understand what is possible for fast-moving robots."

Animal designs
The robot's movements have been modelled on those of fast-running animals in the wild. The machine is designed to flex and un-flex its back to increase the length of its stride. 

The current version is dependent on an off-board hydraulic pump, requiring one of the researchers to hold the tubing out of its way. However, the researchers said a free-running prototype was planned for later this year.

The four-year project, which was commissioned in February 2011, ultimately aims to deliver a robot which can "zigzag to chase and evade", and be able to come to an abrupt halt.

It builds on other models based on animals created by Boston Dynamics including its BigDog rough-terrain robot, designed to recycle energy from one step to the next, and its lizard-like Rise, which can climb walls, trees and fences by using micro-claws on its six feet and a tail for balance.

Noel Sharkey, professor of artificial intelligence and robotics at the University of Sheffield said the latest achievement was very impressive.

"With faster than human speed, this is a step in the development of a high speed killer that could negotiate a battlefield quickly to hunt and kill," he said.

"The biggest concern about this is that no artificial intelligence system can distinguish between civilians and enemy combatants, and so if this was operating on its own it would fall foul of the laws of war."