Category Archives: Musings & News

Slime Molds Solve The Maze

Last Monday I wrote about the weird world of slime molds.

They're not plants.  They're not animals.  They're not even fungi.  They're single-celled organisms as much as 10 feet long ... and they move!

It gets weirder.

Though they have no brain, slime molds remember where they've been and don't go back there.   This video shows that they can solve a maze!

If you missed last week's slime mold blog, read amazing facts about them at: Plant Or Animal?

 

(video from It's Okay To Be Smart on YouTube)

Plant Or Animal?

Internal surface of the peridium of the plasmodial slime mold, Tubifera dudkae. Magnification 2000x via electronic microscope, colored with computer graphic tools (Featured photo from Wikimedia Commons)
Internal surface of the peridium of slime mold, Tubifera dudkae, magnified 2000 times (a Featured photo from Wikimedia Commons)

This beautiful photograph from Wikimedia Commons is a living organism magnified 2000 times by an electronic microscope, then colored using computer graphics.  Can you guess what it is?

The description says:  "Internal surface of the peridium of the rare myxomycete Tubifera dudkae is covered with folds resembling sea waves. Among them oval shaped reticulate spores occur."

In other words, the blue waves and brown beads are part of the same organism, a slime mold called Tubifera dudkae.  It is a rare member of the Myxomycete class.  I don't know if it occurs in North America but I do know it lives in Crimea (thanks to the photos from Wikimedia Commons) and in Tasmania, Australia (thanks to the Myxomycetes website by Sarah Lloyd, an expert in slime molds).

In the photo, the blue waves are the inner surface of the protective layer that holds the spores until they're ready to release.  This layer is called the peridium.

The brown beads with squiggly lines on them (i.e. reticulated) are the spores.

Here's what this slime mold looks like from the outside at normal size, sitting in a matchbox.

Fruiting body of the rare myxomycete Tubifera dudkae (photo from Wikimedia Commons)
Fruiting body of the rare myxomycete Tubifera dudkae (photo from Wikimedia Commons)

And here's the amazing thing:  Are slime molds plants or animals?

Neither.  They're not even fungi.  Slime molds are such weird organisms that scientists keep changing their minds about their classification.  Here's why, with thanks to Ann Jone's article The Blob:

  • In their reproductive stage, slime molds release spores.
  • When the spores settle down they become one-celled organisms similar to amoebas that move around looking for food. They don't need to swim in water to do this.
  • At some point in their life cycle, the amoeba-like individuals are drawn to each other and meld into one big cell with millions of nuclei.  Yes, there's only one cell wall.  This cell is called a plasmodium and it's slimy.
  • The plasmodium can move! In fact it oozes across the forest looking for food: bacteria, fungi, other slime molds. Some slime molds can stretch 10 feet.
  • Though they have no brain, slime molds remember where they've been and don't go back there.

Watch a slime mold move in this Deep Look video on YouTube.

Read more about slime molds in Ann Jone's Australian radio article:  The Blob, but smaller: Tasmania's slime molds.

And learn about Sarah Lloyd, a birder, gardener, and self-taught slime mold expert who lives in the wet eucalypt forest of northern Tasmania.

 

(Featured photo from Wikimedia Commons; click on the image to see the original)
p.s. I'm using the American English spelling of mold, which is also spelled mould.

Earthquakes Ramping Up?

USGS map of 30 Nov 2017 earthquake centered at Bombay Hook, Delaware
USGS map of 30 Nov 2017 earthquake centered at Bombay Hook, Delaware

Two weeks ago I read in The Guardian that big, damaging earthquakes could increase in 2018 because Earth's rotation has slowed slightly.  Then yesterday afternoon there was an earthquake at Bombay Hook, Delaware, a place where earthquakes are rare.  Are the two related?

In a study published last summer in Geophysical Research Letters, geophysicists Rebecca Bendick and Roger Bilham examined a century of data on major earthquakes (7.0 and above) looking for patterns that might indicate what causes them.  They found that there are indeed periods of increased seismic activity when there are up to 20 major earthquakes per year instead of 8 to 10.

They then looked for Earth attributes that fluctuate on a similar time scale. Nothing fit until they found a match with the periodic slowing of Earth's rotation.

Earth's rotation slows very slightly -- only a millisecond -- about every three decades. It's so slight that you need an atomic clock to notice it, but Earth's crust appears to notice as well.  About five years after rotation enters a slow cycle, there are more frequent major earthquakes around the world.

2018 is five years after Earth entered a slow-rotation period so perhaps there will be more intense earthquakes next year.  We'll have to wait and see.

Meanwhile, what does this finding have to do with the mild 4.1 earthquake at Bombay Hook yesterday?  Maybe nothing.  But I wonder about it because earthquakes are so rare in Delaware.

Read more about The real science behind the unreal predictions of major earthquakes in 2018 and news of the Delaware earthquake in the Washington Post.

 

(USGS map of 30 Nov 2017 earthquake centered at Bombay Hook, Delaware; click on the image to see the original)

Don’t Press The Snooze Button

Sleep while you work (photo from Wikimedia Commons)
Sleep while you work (photo from Wikimedia Commons)

Feeling sleepy today?  Did you hit the snooze button on your alarm clock?

I recently learned from a New Yorker article by Maria Konnikova that Snoozers Are In Fact Losers.  When you hit the snooze button that 10-minute interval is just long enough to begin a new sleep cycle but it jolts you awake again at the worst moment -- the beginning of the cycle.

The interruptions make your brain think you had a lousy night's sleep even though the bad part was actually that last 10 minutes -- or more if you hit the button several times.  The more you snooze the more you lose.

So what's the answer?  Don't use the snooze button.  Get up right away when the alarm goes off.   (Oh no!)

But it's more complicated than that. Read Konnikova's December 2013 New Yorker article Snoozers Are In Fact Losers for more information on why ...

  • The best way to sleep-&-wake is by using our own internal clock (circadian rhythm) and external light cues (sunrise/sunset).
  • The majority of us suffer from social jetlag.  Our bodies' preferred wake up time is an hour+ different than our social lives dictate (work, school, etc).
  • It's bad to wake up in the dark.
  • The brain doesn't really hit its stride until 2-4 hours after you wake up. Yikes!

We're the only animals on earth that jolt ourselves awake like this.

Egads, I want a nap!

 

(photo from Wikimedia Commons; click on the image to see the original)

Could We Bring Them Back?

Passenger pigeon specimens at Carnegie Museum of Natural History, 2016 (photo by Kate St. John)
Passenger pigeon specimens at Carnegie Museum of Natural History, 2016 (photo by Kate St. John)

A new DNA study of the passenger pigeon brings up an interesting question:  Could we bring the species back from extinction?

Genetic engineering now makes it possible to transfer genes across species boundaries.  Using these techniques a group named Revive and Restore is working to modify the genes of the passenger pigeon's closest living relative, the band-tailed pigeon (Patagioenas fasciata), to make a new bird that resembles a passenger pigeon.

Band-tailed pigeon, Sonoma County, CA (photo by Ingrid Taylar on Wikimedia Commons)
Band-tailed pigeon, Sonoma County, CA (photo by Ingrid Taylar on Wikimedia Commons)

If successful, they'll release the new bird in the wild to repopulate eastern North America.

But a new study published this month in Science may throw a wrench in their plan.

Researchers gathered DNA from the toepads of passenger pigeon museum specimens and sequenced the full genomes of four birds.  In doing so they discovered that passenger pigeons were extremely diverse at the ends of their chromosomes but had low diversity in the middle.  Most animals, including the band-tailed pigeon, aren't like that.  Most animals are diverse all the way through.

This trait may indicate that the passenger pigeon in its final form had evolved to live in enormous flocks.

Ed Yong at The Atlantic interviewed the study's author, Beth Shapiro, and writes:

So, why did this superspecies die out? Shapiro thinks it’s because the bird specifically evolved to live in mega-flocks, and developed adaptations that became costly when their numbers suddenly shrank at human hands. “Maybe they were simply not adapted to being in a small population, and didn’t have time to recover,” she says. Maybe they hit a tipping point when there were just too few of them to survive, regardless of whether they were being hunted.

Would a small population of passenger pigeons be possible in the wild?  And could the birds survive in this century's altered and deforested landscape?  Revive and Restore believes the answer is yes.

Can humans bring back the passenger pigeon?  Should we try?

 

Read more in The Atlantic at:  What DNA Says About the Extinction of America’s Most Common Bird ... and its possible resurrection.

(photo credits: Passenger pigeon specimens at Carnegie Museum of Natural History by Kate St. John. Band-tailed pigeon from Wikimedia Commons; click on the image to see the original)

For Best Results Copy Birds

Thirty years ago Japanese trains had a problem. They could travel fast but they caused sonic booms.

The answer was the bullet train.  How did Japanese engineers develop it?  They learned from birds.

Watch this 6+ minute video from Vox + 99% Invisible to learn how birds showed the way and follow one woman's quest to teach engineers that Nature has the answers.  Our world can benefit from biomimicry.

For best results, copy birds.

 

Thank you to Holly Hickling for sharing this.  For more cool videos, follow Vox (news site) or 99% Invisible (city design updates) on Facebook.

(video from Vox on YouTube)

Birds With Masks

Masked boobies, Howland Island (photo from Wikimedia Commons)
Masked boobies, Howland Island (photo from Wikimedia Commons)

On Halloween, birds with masks are here to celebrate.

Masked boobies (Sula dactylatra) breed on tropical islands around the world except in the eastern Atlantic (near Africa).  In September Hurricane Jose blew an exhausted masked booby all the way to Cape Cod.  It was rescued but died.

Masked ducks (Nomonyx dominicus) are found at ponds and small lakes from Mexico to South America and in the Caribbean.  These elusive birds are sometimes in south Texas where I missed my chance to see one.

Masked duck, Nomonyx dominicus (phot from Wikimedia Commons)
Masked duck (photo from Wikimedia Commons)

Laughing falcons (Herpetotheres cachinnans) wear a broken mask.  I heard them laugh in Costa Rica.

Laughing Falcon, Costa Rica (photo by Bert Dudley)
Laughing Falcon, Costa Rica (photo by Bert Dudley)

 

Male common yellowthroats (Geothlypis trichas) are easy to identify by their masks but the females and juveniles don't wear one.  The unmasked birds are so confusing.

Common yellowthroat (photo by Steve Gosser)
Common yellowthroat (photo by Steve Gosser)

In late October cedar waxwings (Bombycilla cedrorum) are still here in Pittsburgh though in smaller numbers.  Their faces are ready for the masquerade ball.

Cedar waxwing (photo by Cris Hamilton)
Cedar waxwing (photo by Cris Hamilton)

Can you think of other masked birds?

Happy Halloween!

 

(photo credits: Masked boobies and masked duck from Wikimedia Commons; click on the images to see the originals. Laughing falcon by Bert Dudley. Common yellowthroat by Steve Gosser. Cedar waxwing by Cris Hamilton.)

Walked On Land, Then Became A Fish

Humpback whale breaching (photo from Wikimedia Commons)
Humpback whale breaching (photo from Wikimedia Commons)

Here's a surprising thing:  The ancestors of whales were land-based walking animals that fell in love with water.  In the ensuing 50 million years successive species spent more and more time at sea, eventually lost their legs, and now resemble fish.  (No, they aren't fish. They just resemble them.)

How did they change from land to sea?  To solve the mystery, paleontologists closely examined the fossil record looking for the one trait that only whales have:  the unique bony structure of the whale's inner ear.  A fossil found in 1981 provided the missing link.

Shown below are two of the whale's ancestral relatives. Not direct ancestors, the diagram shows where those two fit on the family tree.  Whales are labelled #1.  Animal #2 looks like a dog. #3 looks like a whale.

Whales' family tree (diagram from Wikimedia Commons enhanced by Kate St. John)
Whales' family tree (diagram from Wikimedia Commons enhanced by Kate St. John)

The change from species to species was incredibly slow.

If we could go back in time 50 million years to the Early Eocene we'd meet Pakicetus inachus (#2), below.  First discovered in Pakistan in 1981, he looks like a long-headed dog but he has the whale's special inner ear.  Scientists hypothesize that he lived on land but spent time up to his eyes in water hiding from predators.

Pakicetus inachus, a whale ancestor from the Early Eocene of Pakistan, after Nummelai et al., (2006), pencil drawing, digital coloring
Pakicetus inachus, ancestral whale from the Early Eocene

 

Fast forward 10 million years to the Late Eocene to see Dorudon atrax (#3), an ancestral whale that spent his entire life in water.  His body was fish-shaped, his tail had flukes, and since he never walked his hind legs were small, almost an afterthought.

Dorudon atrox, an ancestral whale from the Late Eocene of Egypt
Dorudon atrox, an ancestral whale from the Late Eocene

 

From "the fish walked" to the walker that became fish-like, whales turn our misconceptions about evolution on their head.  Evolution doesn't "make progress" from simple water-based organisms to us land-based humans at the pinnacle of development.   It's just any change over time.

For more information about whales, see their family tree at U.C. Berkeley's The evolution of whales and an article in Smithsonian Magazine: How Did Whales Evolve?

 

(all images from Wikimedia Commons; click on the images to see the originals)

A Guide to the New Layout

Puzzled by the new blog design? Here's a guide to finding familiar tools.

Search is a magnifying glass that's always at top right beneath the banner photo.
The sidebar has Archives, Resources (useful links!) and Categories.

On desktop screens, the sidebar is on the right.  On cellphones the sidebar is at the bottom.

The Menu navigates to major sections, including Peregrine FAQs.  Just below the banner photo, it looks like this on a big screen.

On a cellphone you have to click on "Menu" to open it (open/closed shown below).

 

If you've read this far you get a Quiz! Find "Peregrines" under Categories and see how many times I've written about them.

 

(screenshots of Outside My Window layout as of 28 Oct 2017)