today
9 a.m. International Education Week Humboldt State University
read >noon Redwood Region Audubon Society Meeting Golden Harvest Cafe
read >noon Dreamscapes The Oasis
read >4:30 p.m. HomeWork Hotline Call for details
read >5 p.m. Guitar Jazz Cafe Brio
read >5 p.m. Henderson Center Holiday Open House Henderson Center
read >6 p.m. Americans for Safe Access Bayview Courtyard Complex
read >6 p.m. Matthew Cook Cher-Ae-Heights Casino
read >6 p.m. Bill McBride and Friends Hotel Ivanhoe
read >6 p.m. Kindred Spirits Mad River Brewing Company
read >6 p.m. Watershed Restoration Week Celebration Wharfinger Building
read >6:30 p.m. Seabury Gould at Gallagher's Gallagher's
read >6:30 p.m. Share a Story: Growing Vegetable Soup Arcata Library
read >6:30 p.m. 2008 Transgender Day of Remebrance Humboldt County Courthouse
read >7 p.m. Blue Grass Jam Old Town Coffee & Chocolates
read >7 p.m. Mr. Calamari's Jazz Machine Mosgo's
read >7 p.m. All Ages Open Mic East Side Deli
read >7 p.m. Don's Neighbors Gilded Rose
read >7 p.m. KEET-TV's Annual Holiday Auction See Event Description
read >8 p.m. Karaoke WAVE @ blue lake casino
read >8 p.m. Karaoke at Bear River Casino Bear River Casino
read >8 p.m. Smuin Ballet: The Christmas Ballet Van Duzer Theater at HSU
read >8 p.m. Getting It Arcata Playhouse
read >8 p.m. She Loves Me North Coast Repertory Theater
read >8 p.m. The Medium Gist Hall Theater at HSU
read >8:30 p.m. Keak da Sneak, San Quinn Mazzotti's Arcata
read >9 p.m. Soldiers of Shangri-la Six Rivers Brewery
read >9 p.m. Dancehall/Reggae Thursday with Rude Lion Sound DJ Jimmy Jonz The Red Fox Tavern
read >9 p.m. Scotch Wiggly The Boiler Room
read >9 p.m. The Common Vice, Silent Giants, Rooster McClintock Humboldt Brews
read >9 p.m. Hillstomp, O'Death Jambalaya
read >9:30 p.m. DJ Ray Ragg's Rack Room
read >10 p.m. Music by DJ Sidelines
read >10 p.m. Lightnin' Bill Woodcock Pearl Lounge
read >previous columns
Jan. 3, 2008
Basic Birds & Bees
I had intended to write about ferns and their shady ...
read >Dec. 27, 2007
A Counting Problem
This Holiday season deserves a fun project: Count the seeds ...
read >Dec. 20, 2007
What Is Geologic Time?
Geologic time was involved in my previous articles on earthquakes, ...
read >
Photos
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Five Finger Fern, 'Adiantum pedatum', at Bull Creek. Photo by Don Garlick.
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Fern diagram by Don Garlick.
The Shady Lives of Ferns
By Don Garlick
A human female is diploid, having paired maternal and paternal chromosomes. She is born with over a million haploid eggs with unpaired chromosomes. Each egg has the potential of being fertilized by a haploid sperm.
A fern’s life cycle is more complex. It alternates generations between a large diploid “sporophyte” plant that produces haploid spores and a small haploid “gametophyte” plant, grown from a spore, that produces sperm and egg gametes. A sperm swims through water to fertilize an egg which then grows into the familiar fern. The gametophyte is inconspicuous because it is smaller than a finger nail, is photosynthetic green and has a relatively short life (measured in months).
Ferns are shade-tolerant and thus common in our forests. They are also quick to recolonize burnt forests. Asteroidal impacts and their fires that terminated the Triassic and Cretaceous Periods allowed ferns to flourish for several years, as documented by spores preserved in sediments.
Mosses alternate generations after the fashion of ferns, but their gametophytes are larger than their sporophytes, and mosses are not vascular (they lack plumbing).
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