Humans on EARTH Magazine

Geologic Column: The gift of intelligence

Thu, 26 Jan 2017 09:45:04 -0500

Illustration of Earth's land mammals by total weight, shown for humans, pets and livestock, and wild animals. Credit: Illxkcd.com/1338/.

In 1960, astronomer and astrophysicist Frank Drake pointed a telescope of the National Radio Astronomy Observatory toward two nearby stars. He was looking for signals that were artificially generated. His was the first modern search for extraterrestrial intelligence (SETI). Drake reasoned that the stars could anchor orbiting planets where life might have taken hold. Over eons, life on the planets might have proliferated, diversified and grown in complexity. Natural selection would have picked winners from among the blossoming variety, and intelligent life — with the ability to sense an environment and analyze information received, as well as to project future scenarios and choose among them — would seem the likely eventual winner. This intelligence could have been used to create wondrous technologies, potentially allowing for communication over interstellar distances.

Of temperature and tone: Has climate shaped human languages?

Fri, 03 Apr 2015 13:16:43 -0400

The global distribution of tonal (blue dots) versus nontonal (orange dots) modern languages as identified in a new study. Credit: K. Cantner, AGI, after Everett et al., PNAS, 2015.

Humans today speak more than 6,500 languages, and thousands more dialects once spoken have gone extinct. Understanding how and why so many languages have evolved over human history has long been the work of linguists. Recently, however, the emerging field of geo-phonetics has begun looking into how geography — and perhaps climate — affects language. In a new study, researchers suggest that humidity and temperature, which can impact our ability to craft certain sounds, appear to have influenced the evolution of tonality in languages in different parts of the world.

From boom to bust in Neolithic Europe

Thu, 20 Feb 2014 10:11:20 -0500

Even after the introduction of agriculture to Europe about 8,500 years ago, growing Neolithic communities still experienced large population swings. Copyright Mary Harrsch, Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Generic

As agricultural practices spread from the Fertile Crescent across Europe, gradually expanding west and north starting about 8,500 years ago, they brought increased and localized food production to a continent where nomadic hunter-gatherers had long made their living subject to the whims of climate and the environment. With agriculture, long-term settlements developed, fertility rates rose and, thus, populations grew steadily. Or at least that’s been the conventional wisdom.

Hominin skull discovery fuels debate about early human evolution

Thu, 17 Oct 2013 14:32:28 -0400

The face of Dmanisi Skull 5. Courtesy of Guram Bumbiashvili, Georgian National Museum

The Dmanisi Skull 5 early _Homo _cranium and herbivore fossil remains in situ at the discovery site. Courtesy of Georgian National Museum

Artist's reconstruction of the original _Homo erectus _owner of Dmanisi Skull' 5. Courtesy of J.H. Matternes

The Dmanisi site (in the upper right of the photograph), lies beneath a small medieval town about 85 kilometers from Georgia's capital Tbilisi. The site sits on top of a lava flow and covers some 50,000 square meters. Courtesy of Fernando Javier Urquijo

Five different hominid skulls have been found at Dmanisi so far, all exhibiting slightly different traits. The newest one, Skull 5 on the far right, is believed to be _Homo erectus_. The question is whether all five are _Homo erectus_ or are different species. Courtesy of M. Ponce de León and Ch. Zollikofer, University of Zurich, Switzerland

Hailed as a find for the ages, a rare skull of a 1.8-million-year-old human relative could provide answers to longstanding questions about the lineage of our species. It also fuels debate over what differentiates one hominin species from another, and could mean that Homo habilis, Homo rudolfensis and other early bipedal hominins may all be members of Homo erectus, rather than distinct species.

Oceanic records paint a more complex picture of human evolution

Tue, 28 May 2013 17:17:06 -0400

It has long been hypothesized that human ancestors evolved the ability to walk upright — a feature that appeared about 6 million years ago — in response to African landscapes changing from forests to grasslands. Now, a group of scientists has assembled the most continuous timeline of landscape evolution and grassland development over the last 12 million years near the African Rift Valley in northeastern Africa — and the timeline contradicts conventional hypotheses.

New dates place Spanish cave art as oldest in Europe

Thu, 14 Jun 2012 12:31:02 -0400

Scientists have redated art in El Castillo Cave in Spain. The new dates place a hand stencil at earlier than 37,300 years ago and a red disk at earlier than 40,600 years ago — the oldest cave paintings in Europe. Image courtesy of Pedro Saura

The Panel of Hands in El Castillo Cave. Scientists have found a new date for a hand stencil: It is at least 37,300 years old. Image courtesy of Pedro Saura

Researchers removing calcite samples for dating from Tito Bustillo Cave, Spain. New dates put the art at between 29,000 and 36,000 years old. Image courtesy of Rodrigo De Balbín Behrmann

But were the artists modern humans or Neanderthals?

Scientists have studied Paleolithic cave art for more than a century, but new research suggests paintings and carvings in some Spanish caves are thousands of years older than previously thought, which would make them the oldest cave art in Europe. The new evidence has left researchers wondering if the artists were modern humans or Neanderthals.

Voices: Redefining humanity through energy use

Fri, 20 Jan 2012 03:51:09 -0500

What is it, exactly, that distinguishes us from other species? The definition of humankind has perplexed scientists, philosophers and theorists for centuries. DNA composition differentiates species in a technical sense, but that definition is hardly satisfying. Certainly there must be something more ethereal that separates us from “lower” forms of creatures. Over the centuries, several definitions have emerged — from using tools to speaking — but have then been proven insufficient in some heuristic way. So I propose another option: manipulating energy.

Before Lucy: Older hominid Ardi challenges thinking about human evolution