Archive for April, 2019

Pleistocene Mulberries (Morus sp.)

April 28, 2019

Ordering fruit trees from a catalogue or internet site is a dodgy endeavor.  The trees are overpriced with an added cost of shipping, and in my experience I’ve learned the trees produce poor quality fruit, if they even survive long enough to bear.  I’ve had much better luck transplanting trees from local nurseries.  I have 26 year old grape vines and blueberry bushes almost as old that I purchased from local nurseries, and I’d still probably have a great fig tree, if plumbers didn’t have to dig a new drain field for my septic tank.  Peach trees I’ve grown from seed are much stronger and produce much better fruit than any I ever purchased through the mail.  A mulberry tree growing by the side of my house is an example of mail order disappointment.  The tree is thriving and flowers every spring but it produces no fruit.  This puzzled me until I finally figured out why.  The tree died back the first year I bought it, but it regrew from the stump.  Nurseries sell mulberry trees with male and female branches.  (Male flowers produce no fruit.)  Unfortunately, the part that grew back on my tree is all male.

Male flower on my mulberry tree.  Female flowers have a more round shape.  All the flowers on my mulberry are male, much to my disappointment.  Click to enlarge the photo.

Mulberries belong to an ancient family that has existed since at least the mid-Cretaceous, and dinosaurs likely dispersed the seeds of the fruit from this family in their feces.  The Moraceae family includes mulberries, figs, Osage orange, jack fruit, and bread fruit.  The species of native mulberry common and widespread in eastern North America is Morus rubra.  The range map of this species shows some affinity in its northern limit with the ghost boundary of the Laurentide Glacier.  (See https://markgelbart.wordpress.com/2017/03/30/the-ghost-boundary-of-the-last-glacial-maximum-ice-margin/ ) However, like many other species of trees M. rubra successfully recolonized some territory that became deglaciated following the last Ice Age.  It’s likely red mulberry grew in mixed forests all the way to the glacial boundary during Ice Ages but became much more common during warmer wetter interstadials and interglacials.  Mulberry trees prefer early to mid successional woodlands where they can get plenty of sunlight.  Hence, they are a pioneer species dispersed in bird droppings.  Disturbed plant communities caused by rapid climate change and megafauna foraging were common during the Pleistocene and so were mulberries, though their pollen is rarely detected in core samples.

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Range map of the red mulberry.  It has been widely transplanted outside its range.  Avian dispersal helped this species recolonize deglaciated regions following the end of the last Ice Age.

Birds love mulberries, and avian dispersal explains how mulberries recolonized deglaciated regions when so many other species did not.  A study of 1 backyard mulberry tree in Arkansas counted 32 species of birds feeding on the fruit.  Cedar waxwings and robins made up 77% of the individual birds visiting the tree.  Other birds feeding on the fruit from this tree included mockingbirds, finches, catbirds, eastern kingbirds, and warblers. The fruit appeals to bird species that normally prefer insects.

Mulberries were especially common around Indian villages during Colonial times and earlier.  William Bartram mentioned M. rubra  at least 20 times in his Travels. Mulberries ripen over a 3 week period during late May and early June and were an important earl summer fruit for the Indians.  They can be dried and dried mulberries are a staple in Afghanistan.  European settlers brought white mulberries (M. alba) to North America, hoping to start a silk industry.  For 4 thousand years the Chinese have been raising the silk worm moth (Bombyx mora), a species no longer found in the wild.  The silk worm moth larva feed upon mulberry leaves and produce silk for their cocoon.  The silk industry collapsed in North America long ago and now they grow wild, often hybridizing with native mulberries.

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Silkworm moth larva feeding on mulberry leaves.

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Red mulberry fruit.  Despite the name, they aren’t ripe until they turn black.

Mulberries are very sweet and nutritious.  They are high in Vitamin C and iron and also a good source of potassium, Vitamin K, Vitamin E, and fiber.  They are rich in cholesterol-reducing and cancer-fighting anti-oxidants.  They make good desserts as well, but they do have 1 drawback.  The stem grows well into the fruit and is difficult to remove.

Reference:

Jackson, J; and R. Kanin

“Avian Frugivory in a Fruiting Mulberry Tree (Morus rubra) in Arkansas”

Journal of Arkansas Academy of Science 2016

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Paper Clowns

April 20, 2019

When I was in my mid-20s I was not an ambitious person.  I happened to be looking through the want ads 1 day and I thought I  found an ideal job.  A company would send me the material to construct paper clowns, and I would send them back, and they would pay me $5 for each clown I constructed.  I thought I could also save money by not having to drive to work everyday.  Better yet, it sounded like a job I could manage while high on pot.  I eagerly told my mother about this opportunity, but she was not enthused.  Instead, she gently insisted I get a real job with insurance benefits and paid vacations.  I did go out and get a real job and went on to meet my wife indirectly through work.  My mom was rewarded with a granddaughter, and I avoided the ignominy of being the kind of adult who lives in their parents’ basement and never really grows up.  There are many ways my mom influenced my life, but this incident always comes to mind when I think about them.

This is my mom with my father, my younger sisters, and me in 1967.

My mother, Audrey Gelbart, was born on  August 5th, 1939, in Cleveland, Ohio.  She was the product of a mixed marriage–her mother was a Yankee from New York and her father was a southerner from Georgia.  She grew up in Willoughby, Ohio with 2 brothers and a sister.  After graduating from high school she worked as a secretary in an hospital where she met my father who was a resident doctor there.  They married in 1961 and by 1966 they had 3 children.  She raised us while my father was busy working, and she always kept her house ultra clean.  She was a patient, sweet-tempered mother and grandmother, and a devoted wife.  She took good care of my father, especially during his many health crises, until his death in 2014.  My mom passed away on April 19th 2019.  We will miss her.

Flemish Carbonnade and Parsnip Pie

April 15, 2019

A good beef stew generally beats any fancy decorated plate constructed by 4 star chefs.  I like a beef stew recipe from Belgium known as a Flemish carbonnade because it gives me an excuse to buy beer.  It is a simple dish to make.  Cut about 1.5 pounds of a bottom round beef roast into 1-2 inch squares, season with salt, and brown in butter.  Put them in a crock pot and brown 2 diced onions in the pan the beef was browned in.  Sprinkle a little salt on this and when the onions are translucent, add them to the beef in the crockpot.  Cover the beef and onions with 1 bottle of good dark beer–I prefer Guinness with this recipe but any dark stout beer is good.  Add a good tablespoon of mustard and stir.  Then set the crockpot on low for 4-5 hours.  You can serve it on mashed potatoes, but I usually add the potatoes directly into the stew to thicken after the stew is finished.  Chopped parsley is nice on this, if you happen to have it.  Beef, mustard, beer, and onions really go together.

Carbonnade

I was looking for a parsnip in Kroger 1 day, but all they had were 2 1 pound bags wrapped together and cheaply priced.  They were probably trying to get rid of them because parsnips are not particularly popular, especially in the south.  They were formerly a common vegetable grown in northern Europe, but following the introduction of the potato from the Americas, they’ve declined in importance.  The parsnip is related to the carrot, and they have a sweet aromatic flavor. I suppose people prefer the bland starchy taste of potatoes that can absorb flavors of what they are served with.  Parsnips are the 2nd most important ingredient in a good Jewish chicken soup–they contribute a nice sweet flavor to the broth.

I bought the whole bag and I didn’t want to waste the rest of the parsnips, so I invented a recipe for parsnips.  I decided to try making it like a sweet potato pie.  Other recipes for parsnip pie that I found on the internet were savory, but mine is a dessert.  First, I boiled 1.5 cups of diced parsnips until they were soft.  I mashed them in a bowl and added 2 beaten eggs, 1 can of sweetened condensed milk, 1/3rd cup of brown sugar, along with nutmeg, cinnamon, and ground ginger.  I mixed this well and put it in a pie shell.  Then I baked it in a 350 degree oven for about 45 minutes.  I served the pieces with whipped cream.  Everybody liked it.

Parsnip pie

Pleistocene Microfauna Inherited the Earth

April 8, 2019

The biblical passage “Blessed are the meek: for they shall inherit the earth” always makes me think of the late Pleistocene megafauna extinctions.  The passage is part of Jesus’s sermon on the mount and is found in Matthew 5:5, though for some reason Luke omits it.  Most biblical scholars believe the word meek in this passage means powerless, and it represents the slaves and the small powerless Christian sect within the Roman Empire.  A large segment of the Roman Empire’s population consisted of slaves, and the Christian religion appealed to them because of the concept that their miserable lives might be rewarded in the afterlife, if they believed in Jesus.  Ironically, after the Roman Emperor Constantine made Christianity the official religion of the empire centuries later, Christians no longer acted meek–they oppressed all other religions. The late Pleistocene extinctions make me think of this passage because so many powerful animals such as giant lions, saber-tooths, short-faced bears, dire wolves, mastodons, mammoths, ground sloths, and giant bison all disappeared from the face of the earth; but small animals continued to live and were just as common as they’d always been.  Among them are 2 of the smallest mammals on earth–the southern short-tailed shrew (Blarina carolinensis) and the eastern pipistrelle (Pipistrellus subflavus).

Photo of a short-tailed shrew my cats killed last week.

The southern short-tailed shrew weighs between .5-1 ounce.  They hunt in burrows near the surface but also scurry though more permanent burrows located up to 2 feet underground.  They eat half their own weight in food everyday.  Their diet consists of worms, spiders, centipedes, insects, snails, amphibians, and mice.  During winter they can subsist on fruit, acorns, and fungi.   They are smaller than mice but can subdue them with a venomous bite.  Southern short-tailed shrew specimens have been recorded from at least 23 Pleistocene-aged fossil sites, including the Isle of Hope in southeast Georgia.

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Eastern pipistrelle.

The eastern pipistrelle weighs between .1-.3 ounce and is about the size of a large moth.  Their wingspan reaches a width of only about 2 inches.  They feed upon flying insects.  Both eastern pipistrelles and short-tailed shrews navigate in the dark by using echolocation.  Fossil specimens of this species have been found from at least 19 Pleistocene-aged fossil sites including Ladds in north Georgia.

Of course, not all species that inherited the earth are meek.  Man is a notable exception.

 

New Species of Mastodon (Mammut pacificus) Recognized

April 1, 2019

I didn’t have to search for this science news.  A link to the complete scientific paper appeared on my facebook page last week, and I knew right away this important new study was blog worthy.  Some pundits complain about the way social media intrudes on privacy, but I love how information relevant to my interests is directed to me.  If people are worried about their privacy, they should not go on the internet.

For almost 100 years paleontologists thought just 1 species of mastodon occurred in North America during the Pleistocene.  They believed the American mastodon (Mammut americanum) ranged from coast-to-coast and from the Rio Grande to Alaska.  However, 10 years ago some scientists noticed mastodon skeletal material from the Rancho Labrea Tar Pits in California differed from mastodon bones found elsewhere in North America.  Mastodon bones are relatively uncommon from Rancho Labrea where they are greatly outnumbered by mammoth (Mammuthus colombi) specimens.  Open dry environments prevailed around this site during the Pleistocene–an habitat favored by grass-eating mammoths.  Mastodons were semi-aquatic browsers, preferring to feed upon leaves, twigs, fruit, and wetland vegetation.  Within the last 10 years scientists discovered 700 mastodon bones during construction of the Diamond Lake Reservoir in Riverside County California.  This was enough material for scientists to anatomically compare California mastodons with American mastodons, and they concluded they were indeed 2 different species.

Map showing distribution of 2 mastodon species is from the below referenced paper.  Click to enlarge.  The red dots represent M. pacificus; the blue dots represent M. americanus.  Scientists aren’t sure which species ranged into Oregon.  It’s not a comprehensive distribution map for M. americanus.  I’m aware of 5 additional locations where mastodons were found in Georgia but not represented on this map.  American mastodons were more abundant in eastern North America than western.

Paleontologists named this new species M. pacificus because all specimens of this species have been found within 620 miles of the Pacific Ocean.  Apparently, this species occurred in California, southern Idaho, and possibly Oregon.  Mastodon material found in Oregon is not diagnostic, meaning there is not enough to make a species identification.  All mastodon material north of Oregon (from Washington, the Yukon, and Alaska) belongs to M. americanum, the species found throughout most of North America north of the Rio Grande.

The Pacific mastodon differs from the American mastodon in several ways.  Their molars are smaller and more narrow.  They also tend to have more sacral fused vertebrae. Pacific mastodons had 6, whereas American mastodons usually had 4 or 5 (but sometimes 6).  Pacific mastodons had thicker femurs in proportion to the length of their legs, but their tusks were smaller in diameter.

Geographical barriers likely caused the divergence of these 2 species.  Habitat favorable for mastodons was more scarce in western North America.  High mountain ranges frequently covered by glaciers during Ice Ages, and large deserts separated these 2 species.  Over time the isolated California population evolved into a different species of mastodon.

Reference:

Dooley, A.; et. al.

“Mammut pacificus sp. nov., a Newly Recognized Species of Mastodon from the Pleistocene of Western North America”

Peer J March 2019