News / Science & Technology

Climate Changes Appear to Coincide with Human Evolution Milestones

U.S. National Research Council calls for more exploration

Rick Potts has led excavations at early human sites in the East African Rift Valley, and currently directs a multidisciplinary research team at the famous handaxe site of Olorgesailie, Kenya.
Rick Potts has led excavations at early human sites in the East African Rift Valley, and currently directs a multidisciplinary research team at the famous handaxe site of Olorgesailie, Kenya.

Multimedia

Audio
Rosanne Skirble

Rick Potts tackles the mysteries of human origins for a living.

For over 25 years, the paleo-anthropologist at the Smithsonian Institution in Washington has led expeditions to East Africa to explore how our early ancestors adapted to changes in landscape and climate.

"You walk up a hillside of this eroded region of southern Kenya and you see layer after layer that indicates a huge lake was here, but then the lake is gone," says Potts. "Then there's a volcanic eruption that covered over all the grass. Animals had to move away. Then there's a river that came through that area. The lake is back and then there's a big drought, on and on, layer after layer — amazing chapters in this story of climate change."

Climate and evolution

Potts says prehistoric climate changes appear to have coincided with milestones in human evolution, such as the emergence of bipedalism — walking on two feet — the development of a larger brain and tool-making skills.   

"What we were able to investigate is how those tool makers, using stone hand-axes for hundreds of thousands of years were able to adjust. But then the environmental changes got ramped up, and the hand axes disappear, and we see the technologies that are smaller," he says. "We have stone points that were attached to arrows that allowed our direct ancestors, right before the emergence of our own species, to hunt animals and do many more diverse things."

Multipurpose tools used to chop wood, butcher animals, and make other tools -- dominated early human technology for more than a million years.
Multipurpose tools used to chop wood, butcher animals, and make other tools -- dominated early human technology for more than a million years.

Search for answers

That link between climate and human evolution is the subject of a new National Research Council study.  

Andrew Hill is professor of anthropology at Yale University and part of the team of scientists that contributed to the report. He says efforts to better understand the link between climate and evolution — and to more clearly define those evolutionary adaptations — are limited by gaps in the fossil record.

"Any time you find something, it's likely that there's some before that you haven't found yet, and so you're not really dating the origin of these things precisely," says Hill. "That gets better if you find more stuff. The bigger the size, the more likely you are to have an accurate first-appearance of a new behavior. And that's where we are deficient at the moment and why we need to explore more."

Climate and fossil records suggest that some events in human evolution coincided with substantial changes in African and Eurasian climate according to a new report published by the National Research Council.
Climate and fossil records suggest that some events in human evolution coincided with substantial changes in African and Eurasian climate according to a new report published by the National Research Council.

High-tech exploration

Hill says the research team recommends a major new effort to locate additional sites. And he notes that remote-sensing devices aboard satellites and unmanned aircraft can help to more precisely target where to excavate.

"You can actually search for different types of rock because different types of rock give off different types of signal in the non-visible part of the spectrum. And so you can look for sedimentary rocks as opposed to volcanic rocks and different kinds of rocks like lake beds where there might be something plausible."    

Hill says the NRC report also recommends more extensive drilling to extract sediment cores from dry land, lake beds and ocean floors in regions where humans evolved. "In doing that you are also finding more specimens of other kinds of animals and archeology."

And, Hill adds, computer-generated climate models using data on temperature, precipitation and vegetation near human fossils can be a huge help not only in reconstructing past environments, but in understanding the science of climate change in our own era.  "A very concrete way in which it's useful is that when you are working out models for what will happen in the future, the only way in which you can really test it, is by applying the models to the past where you know what really happened from other signals."

Family tree


Over at the Museum of Natural History in Washington Rick Potts is curator of a new exhibit on human origins.

He is also a contributor to the NRC report, which he says recommends new education programs to build on already-strong public interest in the science of human origins.  

"The idea of being able to trace the emergence of our own species' resilience as the last remaining member of a diverse family tree, and how that evolutionary history interacts with the possibilities of the future, I think are extremely relevant, bringing together these two enormous areas of public curiosity, climate change and human evolution."

Potts says fossil and climate records can bring us a little closer to answering two fundamental questions: What does it mean to be human? And how will our resilient species adapt to a future of changing climate?

You May Like

Multimedia Obama, Modi Announce Breakthrough on Nuclear Deal

Deal resolves differences over liability of suppliers to India in event of a nuclear accident, U.S. demands on tracking whereabouts of material supplied to country More

WHO's Late Efforts in Tackling Ebola Highlight Need for Reform

Health experts debate measures to reform agency’s response to global public health emergencies in special one-day session on deadly outbreak More

One Tumultuous Year in Power for CAR's President

As sectarian violence raged across Central African Republic, interim President Catherine Samba-Panza has Herculean task: to end civil war and put country back on right track More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Worldwide Photo Workshops Empower Youthi
X
Julie Taboh
January 23, 2015 11:08 PM
Last September, 20 young adults from South Sudan took part in a National Geographic Photo Camp. They are among hundreds of students from around the world who have learned how to use a camera to tell the stories of the people in their communities through the powerful medium of photography. Three camp participants talked about their experiences recently on a visit to Washington. VOA’s Julie Taboh reports.
Video

Video Worldwide Photo Workshops Empower Youth

Last September, 20 young adults from South Sudan took part in a National Geographic Photo Camp. They are among hundreds of students from around the world who have learned how to use a camera to tell the stories of the people in their communities through the powerful medium of photography. Three camp participants talked about their experiences recently on a visit to Washington. VOA’s Julie Taboh reports.
Video

Video US, Japan Offer Lessons as Eurozone Launches Huge Stimulus

The Euro currency has fallen sharply after the European Central Bank announced a bigger-than-expected $67 billion-a-month quantitative easing program Thursday - commonly seen as a form of printing new money. Henry Ridgwell reports for VOA from London on whether the move might rescue the eurozone economy -- and what lessons have been learned from similar programs around the world.
Video

Video Nigerian Elections Pose Concern of Potential Conflict in 'Middle Belt'

Nigeria’s north-central state of Kaduna has long been the site of fighting between Muslims and Christians as well as between people of different ethnic groups. As the February elections approach, community and religious leaders are making plans they hope will keep the streets calm after results are announced. Chris Stein reports from the state capital, Kaduna.
Video

Video As Viewership Drops, Obama Puts His Message on YouTube

Ratings reports show President Obama’s State of the Union address this week drew the lowest number of viewers for this annual speech in 15 years. White House officials anticipated this, and the president has decided to take a non-traditional approach to getting his message out. VOA White House correspondent Luis Ramirez reports.
Video

Video S. Korean Businesses Want to End Trade Restrictions With North

Business leaders in South Korea are calling for President Park Geun-hye to ease trade restrictions with North Korea that were put in place in 2010 after the sinking of a South Korean warship.Pro-business groups argue that expanding trade and investment is not only good for business, it is also good for long-term regional peace and security. VOA’s Brian Padden reports.
Video

Video US Marching Bands Grow Into a Show of Their Own

The 2014 Super Bowl halftime show was the most-watched in history - attracting an estimated 115 million viewers. That event featured pop star Bruno Mars. But the halftime show tradition started with marching bands, which still dominate the entertainment at U.S. high school and college American football games. But as Enming Liu reports in this story narrated by Adrianna Zhang, marching bands have grown into a show of their own.
Video

Video Secular, Religious Kurds Face Off in Southeast Turkey

Turkey’s predominantly Kurdish southeast has been rocked by violence between religious and secular Kurds. Dorian Jones reports on the reasons behind the stand-off from the region's main city of Diyarbakir, which suffered the bloodiest fighting.
Video

Video Kenya: Misuse of Antibiotics Leading to Resistance by Immune System

In Kenya, the rise of drug resistant bacteria could reverse the gains made by medical science over diseases that were once treatable. Kenyans could be at risk of fatalities as a result if the power in antibiotics is not preserved. Lenny Ruvaga has more on the story from Nairobi.
Video

Video Solar-Powered Plane Getting Ready to Circumnavigate Globe

Pilots of the solar plane that already set records flying without a drop of fuel are close to making their first attempt to fly the craft around the globe. They plan to do it in 25 flying days over a five month period. VOA’s George Putic reports.
Video

Video How Experts Decide Ethiopia Has the Best Coffee

Ethiopia’s coffee has been ranked as the best in the world by an international group of coffee connoisseurs. Not surprisingly, coffee is a top export for the country. But at home it is a source of pride. Marthe van der Wolf in Addis Ababa decided to find out what makes the bean and brew so special and how experts make their determinations.
Video

Video Yazidi Refugees at Center of Political Fight Between Turkey, Kurds

The treatment of thousands of Yazidis refugees who fled to Turkey to escape attacks by Islamic State militants has become the center of a dispute between the Turkish government and the country's pro-Kurdish movement. VOA's Dorian Jones reports.
Video

Video World’s Richest 1% Forecast to Own More Than Half of Global Wealth

The combined wealth of the world's richest 1 percent will overtake that of the remaining 99 percent at some point in 2016, according to the anti-poverty charity Oxfam. Campaigners are demanding that policymakers take action to address the widening gap between the ‘haves’ and the ‘have nots’, as Henry Ridgwell reports for VOA from London.

Circumventing Censorship

An Internet Primer for Healthy Web Habits

As surveillance and censoring technologies advance, so, too, do new tools for your computer or mobile device that help protect your privacy and break through Internet censorship.
More

All About America

AppleAndroid