Life Traced Back to a Single Ancestor

The origins of life on Earth have long fascinated scientists, particularly the nature of the last universal common ancestor (LUCA). LUCA, the root of the evolutionary tree from which Bacteria and Archaea diverged, represents a key node in life’s history. 

This ancient organism’s characteristics, age, and ecological role offer critical insights into the early evolution of life on Earth.


LUCA is estimated to have existed approximately 4.2 billion years ago. Researchers from the University of Bristol and international collaborators employed innovative methods to trace its timeline. 

They used divergence time analysis of pre-LUCA gene duplicates, combined with microbial fossils and isotope records, to establish LUCA’s position in evolutionary history.


These findings challenge prior assumptions that life could not survive the Late Heavy Bombardment, a period of intense asteroid impacts occurring between 3.7 and 3.9 billion years ago.      READ MORE...

Pharaohs Stopped Building Pyramids

The iconic pyramids of Egypt dot the landscape and were built by pharaohs to be their tombs for 

over a millennia. But why did the ancient Egyptians stop building them? (Image credit: Islam 

Moawad via Getty Images)


For more than a millennia, Egyptian pharaohs had pyramids constructed and often were buried beneath or within the massive monuments.

Egyptian pharaohs constructed pyramids between the time of King Djoser (reign 2630 to 2611 B.C.), who built a step pyramid at Saqqara, to the time of King Ahmose I (reign 1550 to 1525 B.C.), who built the last known royal pyramid in Egypt at Abydos.

These iconic pyramids displayed the pharaohs' power, wealth and promoted their religious beliefs. So why did the ancient Egyptians stop building pyramids shortly after the New Kingdom began?

In ancient Egypt, pyramid construction appeared to wane after the reign of Ahmose, with pharaohs instead being buried in the Valley of the Kings near the ancient Egyptian capital of Thebes, which is now modern-day Luxor. The Theban Mapping Project notes on their website that the earliest confirmed royal tomb in the valley was built by Thutmose I (reign 1504 to 1492 B.C.). His predecessor Amenhotep I (reign 1525 to 1504 B.C.) may also have had his tomb built in the Valley of the Kings, although this is a matter of debate among Egyptologists.

Why stop?
It's not entirely clear why pharaohs stopped building royal pyramids, but security concerns could have been a factor.

"There are plenty of theories, but since pyramids were inevitably plundered, hiding the royal burials away in a distant valley, carved into the rock and presumably with plenty of necropolis guards, surely played a role," Peter Der Manuelian, an Egyptology professor at Harvard University, told Live Science in an email.

"Even before they gave up on pyramids for kings, they had stopped placing the burial chamber under the pyramid. The last king's pyramid — that of Ahmose I, at Abydos — had its burial chamber over 0.5 km [1,640 feet] away, behind it, deeper in the desert," Aidan Dodson, an Egyptology professor at the University of Bristol, told Live Science in an email.  READ MORE...

Hidden World - Earth's Inner Core

Earth's "solid" inner core might actually be a bit mushy, researchers now find.  For over half a century, the scientific community thought that Earth's inner core was a solid ball of compressed iron alloy surrounded by a liquid outer core. But new research, published Sept. 20 in the journal Physics of the Earth and Planetary Interiors, suggests that the firmness of the planetary ball ranges from hard to semisoft to liquid metal.

"The more that we look at it, the more we realize it's not one boring blob of iron," Jessica Irving, a seismologist at the University of Bristol in England, who was not involved in the study, told Live Science. "We're finding a whole new hidden world."

In some ways, Earth's inner core remains as mysterious as it was when Jules Verne published his fanciful "Journey to the Center of the Earth" in 1864. Though scientists have known since the 1950s that our planet isn't hollow as Verne predicted, the planet's interior is still unexplored; the immense heat and pressure are simply too great for any human or human-made probe to travel there. "Unless something awful happens to our planet, we will never have a direct observation of Earth's core," Irving said.

Instead, geophysicists rely on seismic waves generated by earthquakes. By measuring these massive vibrations, scientists can reconstruct a picture of the planet's inner workings in a way that's "akin to a CT scan of a person," Irving said. These waves come in two main flavors: straight-line compressional waves and undulating shear waves. Each wave can speed up, slow down or bounce off of different mediums as it travels through the ground.  READ MORE...

From The Graves of Children

Unearthed from the graves of children, ceramic baby bottles from thousands of years ago would look perfectly at home in nurseries today. Some have little feet, and one bottle’s spout juts from a ceramic critter’s bottom like a tail. These itty-bitty Bronze and Iron Age vessels smack of whimsy. But they, like many other everyday items used for feeding and food preparation, are providing scientists an unprecedented taste of how people ate long ago.

An examination of fatty molecules called lipids, for example, tucked into the pores of three ceramic bottles from Bavaria suggests that mothers living between 1200 BCE and 450 BCE were weaning or supplementing their kids’ diets with animal milk, Julie Dunne and her colleagues reported in 2019.

Dunne, a biomolecular archaeologist at the University of Bristol in England, speculates that the bottles’ creators may have been inspired to amuse their children. “They make us laugh today,” she says. More importantly, studying them “gives you such a close connection to the past.”

There aren’t many ways to study the feeding of infants in ancient times, Dunne says. Ancient bones have yielded insights about when infants were weaned, but “we know very little about how mothers brought up their babies.” The same is true of the eating lives of the ancients in general — much of the evidence has been indirect.  READ MORE