As the size of a population grows, so too does its ability to quickly create clever new tools. Lab experiments suggest that connections between people give rise to the new creations.
SCIENCEBefore reading:1. Can you list one or more traits you inherited from your parents?2. Pick a plant or animal that lives near you. How has it adapted to life in its environment? What makes it well suited there? What might make it poorly suited to live someplace quite different?During reading:1. In what ways does a trait help an organism?2. What do kudzu, lionfish and fire ants have in common?3. List some ways people alter Earth.4. What are cichlids?5. How did the introduction of Nile perch change the cichlid population in Lake Victoria?6. Did all cichlids adapt to the introduction of the perch? How did researchers answer that question?7. What is the advantage to cichlids of having a big head? A smaller head?8. Why do male crickets chirp?9. Explain the difference between a parasite and a parasitoid.
Scientists observe some evolutionary speed demons as they adapt over the course of just a few years to new environmental conditions.
A newfound fossil appears to explain why ancestors of T. rex didn’t begin their growth in size — and dominance — any earlier than they did.
Scared of something and don’t know why? Maybe your parents or grandparents passed along their fear to you, a new mouse study suggests.
People who seek to get a grip on something — especially in wet environments — might want to take a lesson from some common shellfish. Among those who might benefit most: surgeons.
SCIENCE Before reading:1. People use glue — do other animals? Can you think of a creature that sticks to something? How do you think it does that? Where would the glue they use come from?2. Which animals do you think can hold onto their environments most strongly, and why?During reading:1. What’s a mussel? Why is its shell so important?2. Describe two ways that mussels stick to wet surfaces.3. How does being stretchy help something be strong?4. Why do scientists think a mussel-like glue might work well on and in the human body?5. Besides wet, what two other types of surfaces can mussels cling to?6. About how many byssal fibers does one mussel need to stay put?7. Describe how a mussel makes a byssal fiber. Why is flushing out the seawater from the tube an important step?8. What is MFP-1 and where is it typically found?
The body’s internal clock can be thrown off when people alter their day and night routines. That mix-up may lead to a buildup of immune cells that can cause inflammation, according to a new study on mice.
Serenading males can sing some surprisingly low notes, and scientists have just uncovered how they do it.
A new mouse study suggests the effects of steroids can last at least months. That’s long after most sporting authorities would be able to identify signs of doping in athletes.
Teen use of cigarettes has dropped a bit in recent years. But many kids have been turning to other tobacco and tobacco-like products. And which they choose can differ sharply by gender and ethnic group.
Australian researchers found leafy nano-evidence pointing to rich deposits of the precious metal deep below ground.
Get that mouse a sweater! A chilly environment suppresses the immune system in mice. This can foster cancer growth, a new study finds.
SCIENCEBefore reading:1) Describe what you know about HIV and AIDS. What causes HIV? How does it spread from person to person?During reading:1) What announcement did doctors make a few years ago about patient Timothy Ray Brown?2) When did HIV first come to the attention of doctors and scientists?3) Worldwide, how many new cases of HIV emerge every year?4) How many people have died from AIDS so far?5) Why did Duzi’s family choose to share his diagnosis with the public?6) Name three ways people can NOT become infected with HIV.7) Name two ways people CAN become infected with HIV.8) Is the number of people dying from AIDS rising or falling? What about the number of new HIV infections — is it increasing or decreasing?9) By what percentage do anti-HIV drugs reduce the risk of spreading the infection?
New research suggests the infection, while serious, can be treated — and maybe cured.
ScienceBefore reading:1. What is the difference between an atom and a molecule?2. Have you ever taken a photograph of someone or something in motion and had it come out blurry? Explain why that blurriness probably occurred.During reading:1. Express the size difference between an atom and an amoeba (give it as a ratio).2. What is a chemical reaction?3. What occurs during photosynthesis?4. Besides being very small, why are individual atoms so hard to image?5. What role does wavelength play in imaging tiny atoms?6. Describe how a fast camera flash can help “freeze” objects in motion.
Movie directors often make “short” subjects, flicks running sometimes just a few minutes or so. But scientists have begun making much quicker “shorts,” essentially nanofilms. Their goal: catching science in action.
Injecting carbon dioxide underground seems like a good way to slow down global warming. A new study shows, however, that the process could trigger earthquakes.
Many people report seeing their own hands moving in the dark, a new study finds. In these people, brain areas responsible for motion appear to fool vision centers into seeing what they would have — if there had been enough light to do so.
A new study finds that teens may act impulsively in the face of fear. This might help explain high rates of violence among such adolescents, the authors say.