
By Edythe McNamee and Jacque Wilson, CNN
Neuroscientists love Aplysia. They are a type of sea slug that grows to be about a foot long. With only 20,000 nerve cells - compared with about 100 billion found in the human brain - Aplysia are the perfect lab animals for brain researchers hoping to isolate a crucial connection.
Plus, "they're just attractive to look at," says Dr. Eric Kandel, a biochemistry and biophysics professor at Columbia University.
Kandel won the 2000 Nobel Prize in Physiology or Medicine for his work with Aplysia - or more specifically, for his work on the biological mechanisms of memory storage.
For decades, Kandel has studied how we create short-term and long-term memories at the molecular level. His work has shown what genes are changed during the learning process, how these genes are altered and how the changes contribute to the growth of new connections in the brain.
CNN spoke with Kandel about his research and why he's fascinated by the human brain. The following interview has been edited for brevity and clarity:

By Elizabeth Landau, CNN
You wouldn't want to shower in it, but researchers have discovered pockets of water in a deep reservoir in Canada that may be up to 2.64 billion years old.
Researchers extracted the fluid from ancient rocks in a mine 1.5 miles underground in the area of Timmins, Ontario. In other mines, water has been found to support life, but scientists are still working to determine if there is life in this particular location. They say this is the oldest water found in such an environment.
We spoke with Chris Ballentine, professor of geochemistry at the University of Manchester in the United Kingdom, and senior author on this study, which published in the journal Nature. Here is an edited version of our email Q&A:
Whether we like it or not, just about everything changes – from our bodies acquiring new wrinkles to fashion trends that differ by the week.
But what about the world itself? Just like us, Earth doesn't stay the same. Some of the changes have been beneficial, while others are quite troubling.
Now a partnership between Google, NASA and Time is revealing how our planet has radically changed over the decades.
The new TIME Timelapse website allows users to view how the Earth has altered through millions of time-lapsed satellite images.
With a few clicks, you can learn how climate change, urban expansion and population growth have modified the planet.
Click on the above video to learn about Timelapse and get a taste of what you will find on the website.
By Elizabeth Landau, CNN
In some ways, it's just a number, but it's a big number with enormous implications.
For the first time, scientists measured an average concentration of atmospheric carbon dioxide of 400 parts per million in Mauna Loa, Hawaii, where the National Oceanic and Atmospheric Administration observatory is located, on Thursday.
"Most experts that really study CO2 amounts estimate that we haven't seen that amount of CO2 in our atmosphere in about 3 million years," said J. Marshall Shepherd, climate change expert and professor at the University of Georgia. In other words, modern humans have never seen carbon dioxide in these proportions before.
By Jacque Wilson, CNN
They emerge from the ground after 17 years, their worm-like bodies creating hundreds of peanut-sized holes near the base of your tree. As they begin to climb, their dark brown skin starts to shed. Two beady red eyes appear.
By the time they reach a steady branch their transparent wings have stretched, opened and closed. Within an hour their white bodies will turn black.
Soon the males will start to sing.

By Kelly Murray, CNN
From the darkest brown to the pastiest white and every shade in between, humans display a tremendous variety of skin colors. Human skin color is directly linked to our survival as a species as we lost our fur and developed a need for protection from the sun, and then migrated into cloudier regions of the globe. Over the course of evolution, scientists argue, skin color was influenced, among other factors, by our need for healthy bones.
To begin to explain this, we turn to Nina Jablonski, professor of anthropology at Pennsylvania State University. She is a well-recognized researcher in primate evolution, and specifically the evolution of human skin, and she was the subject of a Science Seat on CNN Light Years.
The story of human skin color begins with our furry ancestors about 6 to 7 million years ago in Africa, the last time that humans and chimpanzees shared an ancestor. Jablonski says that these ancestors, called Australopithecus, still had ape-like body proportions: fairly long arms and relatively short legs.
By Eoghan Macguire and Matthew Knight, CNN
Ever since it was discovered in 2004, graphene has been hailed as a natural wonder of the materials world destined to transform our lives in the 21st century.
Graphene's amazing properties excite and confound in equal measure. How can something one million times thinner than a human hair be 300 times stronger than steel and 1,000 times more conductive than silicon?
CNN Labs asked the head of MIT's graphene research department, Tomas Palacios, to explain why graphene is such a special material and what we can expect it to do for us in the future.
Editor's note: The Science Seat is a feature in which CNN Light Years sits down with movers and shakers from different areas of scientific exploration. This is the 10th installment.
By Matthew Rehbein, CNN
For more than 30 years, Susan Haig’s mission has been to ensure that endangered bird species don’t become extinct.
Haig’s professional achievements are beyond impressive: She is a supervisory research wildlife ecologist for the U.S. Geological Survey, a full-time professor at Oregon State University and president of the American Ornithologists’ Union, the largest professional society of ornithologists in the world.
Her current work seeks to find the best methods to preserve specific bird populations — often, populations that are endangered — with a combination of lab-based genetic research and field-based behavioral study. She also examines the effects of climate change and other environmental stressors on water birds and the places they live.
Haig’s efforts to reintroduce the California condor in the Pacific Northwest are detailed in her upcoming book “The California Condor in the Pacific Northwest,” which she cowrote with Jesse D’Elia, one of her Ph.D. students. The book comes out next month.
CNN Light Years caught up with Haig last week to talk about how we protect endangered species — especially in the face of climate change — and even how we might one day bring some back from extinction. Here is an edited transcript of our interview.
By Steve Kastenbaum, CNN
Follow on Twitter: @SKastenbaumCNN
(CNN) – The Northern Snakedhead fish is not going to win any beauty contests.
With a mouth full of sharp teeth beneath bulging eyes, the invasive predator – native to waters in China and Russia – may be threatening the balance of the ecosystem of the Harlem Meer, a man-made lake in New York’s Central Park.
By Ben Brumfield, CNN
Nuclear scientists in Switzerland recently dropped some antimatter. The world didn't blow up, but there were some tiny explosions.
Scientists are hoping the experiment will teach them more about how the universe developed after the Big Bang.
Physicists with ALPHA Collaboration research group are trying to figure out how antimatter interacts with gravity, and if it produces "antigravity," says the group's founder, Jeffrey Hangst.
Their experiment mirrors the way Sir Isaac Newton came up with the law of gravity in the late 17th century.
Legend has it that an apple fell off a tree and hit the English nobleman on the head.
Newton got to thinking how gravity made the apple speed up as it fell.

