Our distant female relatives may have cruised around for mates while the guys may have been more stay-at-home types, scientists find.

Until now, much of what was known about our human ancestors' biology and lifestyle was deduced with little hard evidence.

In the new study, scientists analyzed fossils of extinct apelike hominids from the Sterkfontein and Swartkrans caves in South Africa. These 1.8 million to 2.2 million-year-old specimens included eight members of Australopithecus africanus, which may have been a direct ancestor of humans, as well as 11 members of Paranthropus robustus, which dead-ended on a side branch of the hominid family tree for reasons still unknown. These landscapes were much the same back then as they are now - hilly grasslands with rivers - although they had a bit more water and vegetation.

The investigators concentrated on traces of naturally occurring strontium isotopes in the enamel of 19 molar and canine teeth. Isotopes of an element all have the same number of protons in their atoms, but they differ from each other in how many neutrons they have; for instance, strontium-86 has 48, while strontium-87 has 49.

Johns Hopkins team discovers brain defense in mice and a possible new strategy for treating neurologic disorders.

Johns Hopkins scientists say that a newly discovered "survival protein" protects the brain against the effects of stroke in rodent brain tissue by interfering with a particular kind of cell death that's also implicated in complications from diabetes and heart attack.

Reporting in the May 22 advance online edition of Nature Medicine, the Johns Hopkins team says it exploited the fact that when brain tissue is subjected to a stressful but not lethal insult a defense response occurs that protects cells from subsequent insult. The scientists dissected this preconditioning pathway to identify the most critical molecular players, of which a newly identified protein protector - called Iduna -- is one.

Named for a mythological Norwegian goddess who guards a tree full of golden apples used to restore health to sick and injured gods, the Iduna protein increased three- to four-fold in preconditioned mouse brain tissue, according to the scientists.

"Apparently, what doesn't kill you makes you stronger," says Valina Dawson, Ph.D., professor of neurology and neuroscience in the Johns Hopkins Institute of Cell Engineering. "This protective response was broad in its defense of neurons and glia and blood vessels - the entire brain. It's not just a delay of death, but real protection that lasts for about 72 hours."

Japan's Earth-observing satellite Daichi is dead in orbit, three weeks after a mysterious anomaly crippled the spacecraft, the nation's space agency announced today (May 12).

Daichi, formally known as the Advanced Land Observing Satellite (ALOS), unexpectedly powered down on April 22 for reasons that remain murky. The Japanese Aerospace Exploration Agency (JAXA) repeatedly tried to re-establish communication with Daichi over several weeks, but finally threw in the towel today.

"We decided to complete its operations by sending a command from the ground to halt its onboard transmitter and batteries at 10:50 a.m. on May 12 (Japan Standard Time), as we found it was impossible to recover communication with the satellite," JAXA officials said in a statement.

As I sit here now, I'm looking at this Ephemeris software showing the orbital positions of the planets. This has actually been a daily activity for me over the past several weeks, kind of like checking the weather in the morning. I can see that Jupiter and Saturn have just passed opposition (the actual date was April 28th). Speaking of planetary alignments, there's been a lot of talk of these in the news as of late. SOTT carried an article earlier this month describing an unusual planetary alignment that happened on May 11th. On this day Mercury, Venus, Mars and Jupiter all lined up neatly in the sky. Interestingly, an earthquake was felt in Spain that same day. Just for clarification, this alignment in early May was actually a geocentric alignment, meaning that the Earth was lined up with these planets, or the Earth was the frame of reference as opposed to the Sun, for instance.

Astrologers typically speak of planetary positions from the geocentric perspective too. There may be some significance to these geocentric alignments (as the Spanish earthquake may indicate), but in this article I'm going to focus on heliocentric, or Sun centered, alignments. Now why are any of these planetary alignments important, you ask? Are we going to start giving astrology reports on SOTT? Well, no, but for this article it might seem like it. The thing is, these planetary alignments do cast light upon the changes taking place on the Big Blue Marble. Hopefully this article will elucidate some of how this process works; there's obviously a lot that we still don't understand.

The part of the brain used by people who can "see like a bat" has been identified by researchers in Canada.

Some blind people have learned to echolocate by making clicking noises and listening to the returning echoes.

A study of two such people, published in PLoS ONE, showed a part of the brain usually associated with sight was activated when listening to echoes.

Action for Blind People said further research could improve the way the technique is taught.

Bats and dolphins bounce sound waves off their surroundings and by listening to the echoes can "see" the world around them.

A rare and impossibly cute all-white chick has hatched at New Zealand's Pukaha Mount Bruce National Wildlife Centre. "This is a first for us," said Bruce's chairman, Bob Francis, "and as far as we know, the first hatched in captivity."

He's not an albino, he's just the rare offspring of North Island brown kiwis who were brought over from Little Barrier Island in May 2010. The centre has seen the most successful kiwi breeding season in Pukaha's history, with 14 hatched chicks, and staff were delighted to see it punctuated by this surprise hatching.

To mark the occasion, the chick has been named Manukura, which means "of chiefly status" in the New Zealand Maori language.

When it comes to visiting asteroids, NASA doesn't pick run-of-the-mill space rocks. The target of NASA's latest asteroid mission is not only thought to be rich in the building blocks of life, it also has a chance - although a remote one - of threatening Earth in the year 2182.

The asteroid 1999 RQ36 is the target of a new unmanned spacecraft, which NASA plans to launch in 2016 to collect a sample from the space rock and return it to Earth by 2023.

The mission's leaders spent a long time surveying possible destinations for the mission, and finally settled on 1999 RQ36. NASA calls the mission OSIRIS-Rex, which is short for Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer.

"We went through a whole series of selection criteria," OSIRIS-Rex's deputy principal investigator Dante Lauretta, a planetary scientist at the University of Arizona, told SPACE.com. "There are over 500,000 asteroids known. [1999 RQ36] looks really optimum."

Hi Dr. West,

I've been following the latest news. And I thought you could use a bit of moral support.

It probably sounds crazy for a certified welding inspector and ironworker to retire and pursue impact research full-time. Especially since I'm pretty much a nobody. But like many others, I'm looking to identify the planetary scarring and blast-affected materials of the impact storms of the Early Holocene. A little military training in battle damage assessment from aerial photography and a copy of Google Earth goes a long way here.

And being a nobody makes me especially sensitive to ad hominem attacks. I am prepared to debate the science I propose with the big kids. But as an autodidact, an outsider and a complete nobody, I have no defense if the attacks are personally about me, and not the science. So whenever I'm reading along and one side or another, in any given debate, sinks to ad hominem, I have a policy of looking past it at the science that's being ignored or smoke-screened. I tend to mentally disqualify any debater who sinks to such small-minded tactics, and ignore further comments from them in the future. And from what I see of it, the science of yours I see smoke-screened by all the ad hominem crap in the popular press lately is, nevertheless, as good as it gets.

Like you and the others of Firestone et al, what I've been able to find pretty much flies in the face of the kind of Uniformitarian/Gradualist assumptive reasoning that's been the foundation postulate of the Earth Sciences since Sir Charles Lyell published Principles of Geology back in 1830. And regarding the events of the Pleistocene-Holocene transition, I'm ready to make the case that the foundation geologic principle in the Earth sciences, expressed in the slogan, "The present is the key to the past", is almost as naïve as flat-world theory.

One of the more heated scientific debates of recent years has been stirred up again with the publication of new criticisms of the reported finding of "arsenic life."

The prestigious journal Science published the criticisms today (May 27) along with a defense of the study, which Science had posted online this past December.

A team of researchers led by Felisa Wolfe-Simon of NASA's Astrobiology Institute had studied bacteria collected from California's Mono Lake and reported finding evidence that these microorganisms were substituting the poisonous molecule arsenic for the phosphorous usually used to build DNA.

The discovery stood to overthrow scientists' understanding of the basic requirements for life.

Igniting a firestorm

The December report in Science was immediately met with skepticism from other scientists, as the journal noted today.

"Science received a wide range of correspondence that raised specific concerns about the Research Article's methods and interpretations," editor-in-chief Bruce Alberts wrote.

Others put it more bluntly: "The paper was harshly criticized for its lack of controls and unjustified conclusions," zoologist Rosemary Redfield of Canada's University of British Columbia wrote on her blog today.

Arctic reindeer can see beyond the "visible" light spectrum into the ultra-violet region, according to new research by an international team.

They say tests on reindeer showed that the animal does respond to UV stimuli, unlike humans.

The ability might enable them to pick out food and predators in the "UV-rich" Arctic atmosphere, and to retain visibility in low light.

Details are published in the The Journal of Experimental Biology.