Sunday, May 16, 2021
Home Lead Story Study: Modern Brains Developed More Rapidly Than Initially Assumed

Study: Modern Brains Developed More Rapidly Than Initially Assumed

The youngest African fossils, dating back 1.5 million years, showed characteristics of modern human brains

Modern brains are younger than originally thought, possibly developing as recently as 1.5 million years ago, according to a study published Thursday. By that time, the earliest humans had already begun walking on two feet and had started fanning out from Africa.

Our first ancestors from the genus Homo emerged on the continent about 2.5 million years ago with primitive, apelike brains about half the size of those seen in today’s humans.

Scientists have been trying to solve a mystery for as long as our origin story has been known: Exactly when and where did the brain evolve into something that made us human?

Follow NewsGram on Quora Space to get answers to all your questions.

“People had thought that these humanlike brains evolved actually at the very beginning of the genus Homo, so about 2.5 million years ago,” paleoanthropologist Christoph Zollikofer, a co-author of the study published in the journal Science, told AFP.

Modern Brains
The best-preserved specimens turned out to be primitive brains. Pixabay

Zollikofer and lead study author Marcia Ponce de Leon examined skull fossils from Africa, Georgia, and the Indonesian island of Java and discovered the evolution took place much later, between 1.7 million and 1.5 million years ago.

Since brains themselves do not fossilize, the only way to observe their evolution is to study the marks they leave inside the skull.

The scientists created virtual images, known as endocasts, of what had filled the skulls long ago.

In humans, the Broca area, part of the frontal lobe linked to speech production, is much bigger than the corresponding zone in other great apes, said Zollikofer of the University of Zurich.

The expansion of an area results in the shifting of everything behind it.

“This backward shift can be seen on the fossil endocasts when we track imprints of the brain fissures,” Zollikofer said.

‘Surprise’ 

By studying skulls from Africa, the researchers were able to determine that the oldest ones, dating back more than 1.7 million years, had a frontal lobe characteristic of great apes.

Modern Brains
Brains do not fossilize, so the best way to track their evolution is to look at the scars they left behind within the skull. Wikimedia Commons

“This first result was a big surprise,” Zollikofer said.

It signified that the genus Homo “started with bipedalism,” or walking on two legs and that the evolution of the brain had nothing to do with being bipedal.

“Now we know that in our long evolutionary history … the first representatives of our genus Homo were just terrestrial bipeds, with ape-like brains,” the paleoanthropologist said.

However, the youngest African fossils, dating back 1.5 million years, showed characteristics of modern human brains.

This signified that the evolution of the brain took place between the two dates, in Africa, according to the study.

The conclusion is backed up by the appearance of more complex tools during this same period, called Acheulean tools, which have two symmetrical faces.

“This is not a random coincidence,” Zollikofer said, “because we know those brain areas that get expanded in this time period are those that are used for complex manipulative tasks like tool-making.”

Two migrations from Africa 

Modern Brains
The earliest members of the Homo genus were simply terrestrial bipeds with ape-like brains. Wikimedia Commons

The second surprising result of the study comes from observations of five skull fossils found in present-day Georgia, dating between 1.8 and 1.7 million years ago.

The particularly well-preserved specimens proved to be primitive brains.

“People thought you need a big modern brain to disperse out of Africa,” Zollikofer said. “We can show these brains are not big, and they are not modern, and still people have been able to leave Africa.”

ALSO READ: Study: Increased Sunlight Exposure Can Reduce COVID Deaths

Meanwhile, fossils from Java, the youngest specimens in the study, showed modern brain characteristics. The researchers, therefore, believe that there was a second migration out of Africa.

“So, you have a spray first of primitive-brained people, then things evolve to a modern brain in Africa, and these people sprayed again,” Zollikofer said.

“It’s not a new hypothesis … but there was no clear evidence. And now for the first time, we have real fossil evidence.” (VOA/KB)

STAY CONNECTED

19,509FansLike
362FollowersFollow
1,773FollowersFollow

Most Popular

Consults For Liver Diseases Increased Amid Pandemic

Inpatient consults for alcohol-related gastrointestinal (GI) and liver diseases have surged since the beginning of the Covid-19 pandemic and remained elevated, a new study...

International Day Of Families: Experts Weigh In On The Importance Of Health

Every year, May 15 is observed as International Day of Families. It celebrates the importance of families and aims to raise awareness of issues...

Yoga, Breathing Exercises For Kids With ADHD

Yoga and breathing exercises positively affect children with attention deficit hyperactivity disorder (ADHD), a new study suggests. The researchers, including Sergey Kiselev from the Ural...

US Facing Challenge Of Restoring Public Trust: Survey

A new survey has revealed that health agencies in the US were facing the challenge of restoring public trust over a year into the...

Leveraging New Technologies Can Help Protect Families During Covid-19

Families across the world have been under tremendous pressure in the face of the ongoing crisis. Deep-seated gender inequalities and discrimination have ensured that...

Popularization Of Clear Teeth Aligners In India

Traditionally, the orthodontic procedure that seeks to "correct" crooked, overlapping, crowded, and gapped teeth has relied on metal braces. The image of a wired-teethed...

How To Achieve The Feathered Eyebrow Look In 5 Simple steps

The 2021 photo-ready brow look of the year is 'Feathered eyebrows'. Light and fluffy brows that enhance the natural face structure and at the...

Knowing About Mental Health Awareness Week

Mental Health Awareness Week runs from May 10-16 this year. During this pandemic, millions of us have experienced a mental health problem or seen...

Recent Comments