A Formica ant suspends a drop of aphid honeydew between her mandibles (which bristle with 7 or more teeth), as she drinks it. 
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Question for readers to answer:

Macaque monkey,  Crab-eating macaque (Macaca fascicularis) in Lopburi, Thailand.  Photo courtesy of 'Chris huh' and Wikipedia.

If a human yawns in front of a monkey, will the monkey yawn?

Deadline:  June 4.  We will publish the best answers on June 9.

You get the credit.

Click here to give me your answer: Answer the question.


Interacting with nature by K:

How to Offer Wild Birds Shelter in the Winter

Not all birds migrate south for the winter.  Winter is a hard season for birds, and many risk freezing to death at night. It doesn't take much effort or money to provide shelter for them, and it can make a huge difference to the little feathered guys!

More Articles >>

 

 

Feely fish, staircase angles, ‘Useless’ body parts

A Fangtooth’s toothy mouth traps fish within sucking distance. [© 2004 David Wrobel, Monterey Bay Aquarium Foundation]Q: How do fish see and feed at depths beyond the reach of light? (Ron, Sun City, CA)

A Fangtooth’s toothy mouth traps fish within sucking distance. [© 2004 David Wrobel, Monterey Bay Aquarium Foundation]

A: Primarily by smell and vibration, says Laurence P. Madin, biologist at the Woods Hole Oceanographic Institution. Some also make their own light.

Smell. Fish smell with two nostrils, one on each side of the head. Their sense of smell can be acute. Sharks, for example, can detect smells 10,000 times fainter than a human can.

The deep-sea anglerfish (found in the inky black at 2200 yards, 2000 m) have extremely large nostrils and a powerful sense of smell. Males can detect and follow the distinctive scent released by females of their kind. A tiny male (about a half inch, 1.3 cm) finds a female (which may be 10 times longer than he), bites her, fuses his skin to hers, and lives off of her. They grow together, even sharing the same bloodstream.

Vibration: hearing and feeling. Fish hear sound vibrations with internal ears.

They feel water vibrations with hair nerves. The nerves are either freely distributed on their skin and touching water or laterally along internal lines the length of their bodies.

The free-vibration sensors tell the fish in which direction it’s swimming. The lateral ones sense particulars of nearby fish motions since the sensors receive a sequence of vibrations as the disturbance moves across the fish. This enables the fish to detect prey over a short range and also to school with like fish.

When a deep-sea Fangtooth feels a fish swimming nearby, it opens its huge mouth and sucks the animal in.

Light. Other fish make their own light to find food or escape being someone else’s food. Some, like fireflies, produce light in special organs called photophores. Others rely on bacteria to make the light.

The shiny black tubeshoulder, found in the deep night 1100 yards (1000 m) down, squirts a glowing slime, distracts a predator, and slips away into darkness.

Further Reading:

Monterey Bay Aquarium: Survival in the deep

Mountain “stairs,” southeast Alaska [John Bortniak, NOAA]Q: At what angle do you climb, when you climb a flight of stairs? (Sopuruchi, Port Harcourt, Nigeria)

Stairs rise at an angle between 30 and 35 degrees.

That’s steep enough to cause an avalanche on a snowy slope. Mountain trails typically have gradients of 15, 20, and 25 degrees. For example, a 2000-foot (610 m) vertical gain over a mile (1.6 km) of horizontal distance is a 20-degree slope.

Further Reading:

Aubuchon Hardware: how to build outdoor stairs

Backpacker Magazine: Mountain miles

Himalaya, Inc: Pumori

Q: Are there any body parts of a human body that we don't use? (Ashton, Pineville, Louisiana)

A: Probably not. Some parts matter more than others but even the "useless" ones have value that we’re just learning about. We used to think 180 parts (for example, the thyroid, tonsils, appendix) were without function. Now it’s down to maybe one — an internal tail — the tail bone. Even that supports some abdominal muscles.

Indeed, until May of 2004, we believed 97% of the DNA that makes up our complete chromosome set is junk. The "junk" DNA does not provide code to produce proteins. Consequently, we deduced the DNA had no purpose at all.

Then David Haussler of the University of California, Santa Cruz noticed something downright peculiar. He found a huge number (480) DNA regions of this so called "junk" DNA that is 100% identical for man, mouse, and rat. Normally gene sequences for mouse and man average only 85% similar.

What, he wondered, was so critical to survival that creatures for 400 million years of evolution maintained the exact, identical regions of code?

He doesn’t know yet but that DNA is not junk!

To answer your question, let’s run through some likely candidates for useless parts:

  • wisdom teeth — they often grow in crooked or the opposing tooth doesn’t emerge so they end up useless for chewing.
  • male nipples — useless, perhaps, but may exist because natural selection can’t easily edit out their production without messing things up for females.
  • the plantaris muscle — a calf muscle that causes all toes to flex all at once for monkeys and thus helps their feet swing from a branch through trees. In humans, the muscle does not flex toes simultaneously and is largely useless. Indeed, it is atrophied, may be totally absent and, when present, does not even reach the toes.
  • Useless? Maybe. But...

    "Just because you can survive quite well without something doesn’t indicate that it’s useless," says Gail Sullivan, assistant research professor of medicine at the University of Virginia Health Science Center. "You may be better off without a badly infected appendix or an impacted wisdom tooth but, as is becoming apparent, this doesn’t mean that healthy counterparts are ‘useless’."

    Further Surfing:

    WonderQuest: ‘Useless’ appendices

    Wikipedia: Junk DNA

    BioEd Online: ‘Junk’ DNA reveals vital role by Helen Pearson

    (Answered Nov. 12, 2004)

     

     

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