Tag Archives: java

First human ancestor to walk on two legs made its final stand in Java

A million years before humans made their first baby steps out of Africa, one of our ancestors was already busy fashioning tools and exploring the world walking on two legs. Homo erectus is famous for being the first hominin to walk upright. Now, a new study suggests that our ancestor was the most successful member of the genus Homo, having survived from 1.8 million years ago until as recently as 108,000 years ago.

The Ngandong site. Credit: Russel Ciochon.

The Ngandong terrace, a floodplain on the Indonesian island of Java, is the site of the largest collection of Homo erectus fossils in the world, showing that the human ancestor was able to travel a huge distance from its birthplace in Africa. Nearly a century ago, anthropologists have unearthed at least a dozen partial skulls and two shin bones at the site.

For a long time, scientists have tried to date the site, but until recently all these efforts return wildly different estimates from as early as 27,000 to half a million years old. The fact that the original bonebed first excavated by Dutch geologists in the 1930s had been lost made the investigation all the more challenging.

In their new study, researchers at the University of Iowa and the Institute of Technology in Bandung, Indonesia, used modern techniques (uranium-series dating, luminescence, and electron-spin resonance) to date the landscape and some animal fossils excavated from the Ngandong terrace. To find the original bonebed, the researchers employed maps and journals inherited by the grandchildren of one of the Dutch geologists.

Ngandong bonebed. Credit: University of Iowa.

They also dated the stalagmites in the caves of nearby mountains, showing that the mountains themselves rose at least half a million years ago, diverting the Solo river into the Kendeng hills and forming the Ngandong terrace. Entangling the thread even further, the researchers found that the terrace is between 140,000 and 92,000 years old.

Although they couldn’t find new Homo erectus fossils, the researchers gathered hundreds of animal remains — ranging from water buffalo to elephants — which were found in the same layer as the Homo erectus skulls. Using a sophisticated computer model, the researchers weighed the different dates for each fossil, coming up with an age range of the site.

They conclude that although Homo erectus went extinct in many other parts of the world by this date, the species survived on Java until 108,000 to 117,000 years ago. Modern humans arrived on the island about 35,000 years after the last known appearance of Homo erectus.

“This site is the last known appearance of Homo erectus found anywhere in the world,” says Russell Ciochon, co-corresponding author on the study. “We can’t say we dated the extinction, but we dated the last occurrence of it. We have no evidence Homo erectus lived later than that anywhere else.”

A Homo erectus skull cap found at the Ngandong site. Credit: Griffith University.

This means that around the same time, our species, Homo sapiens, shared the planet with at least seven other different hominin species, including Denisovans and Neanderthals.

Around 130,000 years ago, the environment at Ngandong changed, and perhaps this may have sealed Homo erectus’ fate.

“There was a change in climate,” Ciochon explains. “We know the fauna changed from open country, grassland, to a tropical rainforest (extending southward from today’s Malaysia). Those were not the plants and animals that Homo erectus was used to, and the species just could not adapt.”

However, considering that the researchers couldn’t find direct evidence of Homo erectus fossils, the debate isn’t settled yet. For instance, the animals at the site could have been butchered by Denisovans whose presence in the area is established. More research may provide more insight in order to clear some of the mist surrounding the Ngandong site.

The findings appeared in the journal Nature.

Mining sulphur in an active volcano

Photo by Jean-Marie Hullot.

Whenever you think you have the worst job ever, you definitely should think about the sulphur miners from Eastern Java, the men who treat poisoned lungs, burns, scars and constant danger as part of their everyday living. Each day, a few hundred men go deep in the heart of the Ijen volcano, with the sole purpose of collecting yellow lumps of sulphur that solidify beside its acidic crater lake.

Photo by Aditya Suseno.

Just in case you’re wondering, sulphur has numerous uses, both inside Indonesia and outside: it is used to vulcanise rubber, make matches and fertiliser and even bleach sugar. Each day, they go up the mountain and gather 90 kg loads from the toxic lake, which they then have to carry back to a weighing station at the base of the volcano; and they do this several times per day.

Photo by Aditya Suseno.

“There are many big mountains but only one gives us the sulphur we need,” says Sulaiman, 31, who has mined the crater for 13 years.

Photo by Matt Paish.

Photo by Matt Paish.


About protection, you really shouldn’t – gas masks or gloves would be nothing less than a luxury for these men, who get paid around 10-15$ per day. The only protection from the deadly gas is clothing. But deadly gases aren’t the only thing they have to be wary of. In the past 40 years, 74 miners have died because of fumes that can come from fissures in the rock, more specifically hydrogen sulphide and sulphur dioxide gases, which are so concentrated they can even dissolve teeth, let alone the other parts of the body.

This practice wasn’t so uncommon 200 years ago, but by now it is mechanized in pretty much every part of the world. Clive Oppenheimer, of Cambridge University explains:

“Until the late 19th Century, there were sulphur mines in volcanic countries such as Italy, New Zealand, Chile and Indonesia.”

Photo by Aditya Suseno.

The work they do takes a harsh toll on their bodies; few of them live to grow old. However, their bodies have adapted, and most of them can hold their breath for several minutes; they also tend to develop amazing shoulder muscles from carrying baskets twice their bodyweight.

 

“Our families worry when we come here. They say working here can shorten your life,” says Hartomo, 34, a sulphur miner for 12 years. “I do it to feed my wife and kid. No other job pays this well,” adds Sulaiman.