Ferns in the news: weird sex

Photo by Harry Roskam

It's always a good day when ferns make the news, so the last few weeks have been pretty great! Carl Rothfels and colleagues have determined that two ferns alive today, but whose ancestors diverged from one another around 60 million years ago, have hybridized to form a new (although sterile) species. The new species is a hybrid between two different genera, Cystopteris and Gymnocarpium, and its name is Cystocarpium roskamianum. Intergeneric hybrids are very rare, because it becomes more and more difficult to be interfertile the more diverged two organisms are from one another. We often consider species to be units that are distinct from one another reproductively (although this is frequently untrue, particularly in plants), and genera are implicitly assumed to be even more so. There are four other known intergeneric hybrids in ferns, including Dryostichum singulare, a hybrid between Dryopteris goldiana and Polystichum lonchitis, but none involve parental genera as anciently diverged as Cystocarpium's. The authors use the analogy that this would be like a human and a lemur mating and producing offspring – the genetic distances involved are similar!

The story has been covered by a number of news outlets. Links are below, and I'm pleased to add that I was contacted for a comment for the NPR piece, which I very happily gave. 

• NPR: 'Weird' fern shows the power of interspecies sex
• Nature News: Fern hybrid does not mind the gap
• ScienceDaily: Distant species produce 'love child' fern after 60-million-year breakup
• IFLScience: Distinct species produce hybrid 60 million years after their split

180 million year old fern fossil discovered

Photo from the Science paper, credit: Benjamin Bomfleur

Several Swedish biologists (from Lund University and the Swedish Museum of Natural History) have published a paper in Science documenting an exquisitely preserved, 180 million year old fern fossil! The Jurassic-era fossil is a member of the family Osmundaceae, which includes modern taxa like cinnamon fern (Osmundastrm cinnamomea), royal fern (Osmunda regalis), and interrupted fern (Osmunda claytoniana), all of which are widespread in the temperate northern hemisphere (and are pictured below). The fossil's exquisite preservation is attributed to rapid burial during volcanic activity.

It has long been known that modern members of Osmundales don't vary much morphologically compared to ancient forms – fossilized members of the order dating to the early Mesozoic (ca. 220 million years ago) are remarkably similar in several aspects of their morphology to modern species. The new fossil goes a step further: it contains intact cells, and even individual chromosomes, that the researchers were able to visualize with various types of microscopy. The fossil species had the same number of chromosomes and roughly the same predicted DNA content in the nucleus as modern cinnamon fern. This suggests that the lineage has not experienced significant upheaval in DNA content, through whole-genome duplication (polyploidy) or extensive gene loss, in the last 180 million years. The authors note that to date, most of what we know about ancient fern genome size is due to extrapolation from living taxa; this new fossil has permitted the first direct observations of paleo-DNA content in a fern.

Coverage of the new fossil online:
- From Lund University
- From Phys.org

The paper (requires a subscription): Bomfleur, B., S. McLoughlin, and V. Vajda. 2014. Fossilized nuclei and chromosomes reveal 180 million years of genomic stasis in royal ferns. Science 343: 1376–1377.


If you want to read more about relationships of Osmundales (also requires a subscription): Metzgar, J.S., J.E. Skog, E.A. Zimmer, and K.M. Pryer. 2008. The paraphyly of Osmunda is confirmed by phylogenetic analyses of seven plastid loci. Systematic Botany 33: 31-36.

Osmundastrum cinnamomea 

Osmunda regalis

Osmunda claytoniana

New Fern Genus Named for Lady Gaga!

Kevin Winter/Getty Images; Duke University

Nevermind the impending presidential election. The most important breaking news today: a new genus of ferns, segregated from Cheilanthes, has been named in honor of Lady Gaga! The new genus comprises 19 species, two of which (Gaga germanotta and Gaga monstraparva) are new to science. The rest were formerly in Cheilanthes, but all 19 share features that indicate they should belong to their own genus, including a DNA signature unique to the group, which consists of GAGA spelled out in base pairs. The new genus has been described by the fern group in the department of Ecology and Evolutionary Biology at Duke University, led by Dr. Kathleen Pryer and graduate student Fay-Wei Li.

It may seem odd or farcical to name a plant species after Gaga, but there are great reasons to do so, which are elegantly described by Dr. Pryer: "We wanted to name this genus for Lady Gaga because of her fervent defense of equality and individual expression," and the fact that "...her second album, 'Born this Way,' is enormously empowering, especially for disenfranchised people and communities like LGBT, ethnic groups, women -- and scientists who study odd ferns!" Those sound like excellent reasons to me!

The article officially introducing the genus will appear in the forthcoming Oct-Dec issue of Systematic Botany (available by subscription only), but you can read more about the discovery in today's news:

• Nineteen species of ferns named for Lady Gaga (DukeToday.com)
• Germinated this way: New fern species named after Lady Gaga (NYTimes.com)

Ferns on the radio

Ferns will have their day on the radio next Thursday, November 19. If you live in Madison, tune in to WORT 89.9FM for Perpetual Notion Machine from 7-7:30pm, or you can listen live online at WORT's site, or you can download the show as a podcast afterwards. Yours truly will be the guest, talking about ferns, science-blogging, and my favorite passage in the Origin of Species (whose 150th birthday is coming up soon...).

Googly Eyes Gardner

One of my students (thanks Em!) sent me this video of an SNL skit starting Christopher Walken. It's fantastic! Never underestimate those ferns. My favorite lines:

GEG: Ferns don't have pricklers like cactuses, but what if they all ganged up, tried to choke you, in your sleep? If enough of these ferns lodged themselves in your throat, you'd choke. It's probably not gonna happen, but what if it did? What if it did? What do you think your last thought would be? Mine would be: I always knew. It's gonna be the ferns...

Enjoy!