Agriculture
Watching out for vultures
Watering the Air
Flush-Free Fertilizer
Amphibians
Newts
Frogs and Toads
Salamanders
Animals
Fishy Cleaners
Polly Shouldn't Get a Cracker
Saving Africa's Wild Dogs
Behavior
Giving Sharks Safe Homes
Slumber by the numbers
Storing Memories before Bedtime
Birds
Pigeons
Rheas
Kiwis
Chemistry and Materials
A Light Delay
The Taste of Bubbles
Bang, Sparkle, Burst, and Boom
Computers
Fingerprint Evidence
Play for Science
A Light Delay
Dinosaurs and Fossils
From Mammoth to Modern Elephant
Dino Takeout for Mammals
Meet the new dinos
E Learning Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
Earth
Hints of Life in Ancient Lava
Arctic Algae Show Climate Change
Surf Watch
Environment
Sea Otters, Kelp, and Killer Whales
Shrimpy Invaders
Ready, unplug, drive
Finding the Past
Meet your mysterious relative
Words of the Distant Past
A Long Haul
Fish
Swordfish
Goldfish
Puffer Fish
Food and Nutrition
Chew for Health
Building a Food Pyramid
Healing Honey
GSAT English Rules
Finding Subjects and Verbs
Order of Adjectives
Pronouns
GSAT Exam Preparation Jamaica
E Learning in Jamaica WIN PRIZES and try our Fun Animated Games
GSAT stars reap scholarship glory
GSAT Scholarship
GSAT Exams Jamaica Scholarships
GSAT Scholarship
2014 GSAT Results for Jamaican Kids
Results of GSAT are in schools this week
GSAT Mathematics
A Sweet Advance in Candy Packing
Setting a Prime Number Record
Detecting True Art
Human Body
Don't Eat That Sandwich!
Cell Phone Tattlers
Gut Microbes and Weight
Invertebrates
Insects
Leeches
Tapeworms
Mammals
Elk
Poodles
Platypus
Parents
What Not to Say to Emerging Readers
Children and Media
Choosing a Preschool: What to Consider
Physics
One ring around them all
Black Hole Journey
Einstein's Skateboard
Plants
Stalking Plants by Scent
Fastest Plant on Earth
The algae invasion
Reptiles
Garter Snakes
Snapping Turtles
Geckos
Space and Astronomy
Cousin Earth
Planning for Mars
A Puffy Planetary Puzzle
Technology and Engineering
Reach for the Sky
Drawing Energy out of Wastewater
Crime Lab
The Parts of Speech
What is a Noun
Problems with Prepositions
What is a Verb?
Transportation
How to Fly Like a Bat
Reach for the Sky
Troubles with Hubble
Weather
Catching Some Rays
A Dire Shortage of Water
A Change in Climate
Add your Article

Stone Age Sole Survivors

The people who walked on a muddy lakeshore in southeastern Australia surely never suspected that their footprints would stick around for 20,000 years. Yet, at least 124 of their prints still exist, say a group of scientists who uncovered the barefoot impressions. It's the largest collection of Stone Age footprints ever discovered, and analyses are giving insight into the lives and bodies of the people who left them behind. The footprints were found in August 2003 during a general survey of the area's archaeology. Eighty-nine footprints were already exposed. A little digging in the soil turned up another 35. To figure out when feet last touched ground, the scientists aimed laser light on grains of sand taken from sediment just above and just below the impressions. These sediments, they figured, had to be at the surface when the people walked across the lakeshore. Light that bounced back from the sand grains provided information that allowed the scientists to estimate the age of the sand. (In particular, they looked at how much radioactivity had built up in the sediment.) They dated the footprints to between 23,000 and 19,000 years ago. The shapes and sizes of the prints and the distances between them allowed the scientists to figure out about how many people were there, how tall they were, and roughly how old they might have been at the time. Seventy-six of the impressions, they found, belonged to eight people. Six were fairly large adults. (Two measured more than 6 feet tall.) Two were younger. The adults ran across the muddy plain in one direction. A teenager and a child moved in the same general direction, but they walked. Comparisons of the prehistoric strides with the strides of similarly sized, modern distance runners showed that the largest of the adults was running at a speed of up to 12 miles per hour. That's about the speed of a fit runner today. Near the footprints, the scientists found many round indentations, measuring about 2 inches across. These could be the marks of weapons or walking sticks. Long, shallow grooves suggest that the people were also dragging poles. The group may have been moving from one lake or camp to another, the scientists speculate. Or perhaps they were out hunting or fishing—or even picnicking.—E. Sohn

Stone Age Sole Survivors
Stone Age Sole Survivors








Designed and Powered by HBJamaica.com™