Ferns took to the trees and thrived

Jul 02, 2009 By Karl Leif Bates
Hymenophyllum jamesonii, an epiphytic fern of neotropical rain forests, has berry-like clusters of sporangia where reproductive spores are produced. | Courtesy of Eric Schuettpelz

(PhysOrg.com) -- As flowering plants like giant trees quickly rose to dominate plant communities during the Cretaceous period, the ferns that had preceded them hardly saw it as a disappointment.

In fact, they flourished. While modern tropical rain forests were becoming established, ferns climbed aboard, and experienced a flowering of their own species diversity.

"The canopy is there and -- boom -- diversification," said Duke University researcher Eric Schuettpelz, who is completing a post-doctoral fellowship in biology with associate professor Kathleen Pryer.

By integrating genomic data from 400 living fern species with information from the fossil record, Schuettpelz and Pryer constructed a new time-calibrated family tree for ferns. Their study appears on the cover of the July 7 .

Though ancient, it appears that ferns really came into their own during a very hot, very wet period that peaked about 10 million years after the Cretaceous/Tertiary boundary 65 million years ago.

Two key innovations may have led to the ferns' success in the face of the new competition from , Schuettpelz said. Some ferns developed the ability to make a living on light that was more toward the red end of spectrum -- shade, in other words. And, around this time, some ferns also developed the ability to live on trees, sometimes without soil, as epiphytes.

By storing water, developing thicker skin, or being more tolerant to drying out, the epiphytic ferns could now perch on a trunk, limb, or twig and live quite happily more than 100 feet off the forest floor, where moisture, temperature, and sunlight are very different indeed.

Whereas the fossil record seemed to suggest that ferns experienced three distinct pulses of species diversification, the Duke team's analysis shows that there was a fourth, roughly corresponding with the development of epiphytism.

So, as rain forests developed and tropical trees and vines clawed past each other to reach heavenward, they took the ferns up along with them. Thousands of new fern species evolved to take advantage of all the new niches being created in the canopy.

"In some ways I guess, the epiphytes escaped the battle on the ground," Schuettpelz said.

Today, epiphytes comprise about 30 percent of the more than 9,000 living fern species. But this isn't the only plant group that includes epiphytes. This fall, as a post-doctoral fellow at the National Evolutionary Synthesis Center (NESCent), Schuettpelz will begin to look for parallel patterns of diversification in epiphytic flowering plants like bromeliads and orchids.

Source: Duke University (news : web)

Explore further: Dutch barnacle geese have more active immune system than same species in the North

add to favorites email to friend print save as pdf

Related Stories

Rapid burst of flowering plants set stage for other species

Feb 09, 2009

A new University of Florida study based on DNA analysis from living flowering plants shows that the ancestors of most modern trees diversified extremely rapidly 90 million years ago, ultimately leading to the formation of ...

Two studies on bee evolution reveal surprises

Dec 09, 2006

The discovery of a 100-million-year old bee embedded in amber -- perhaps the oldest bee ever found -- "pushes the bee fossil record back about 35 million years," according to Bryan Danforth, Cornell associate professor of ...

Invading trees put rainforests at risk

Mar 03, 2008

To the list of threats to tropical rainforests you can add a new one — trees. It might seem that for a rainforest the more trees the merrier, but a new study by scientists at the Carnegie Institution warns ...

Tropical plants go with the flow ... of nitrogen

May 07, 2007

Tropical plants are able to adapt to environmental change by extracting nitrogen from a variety of sources, according to a new study that appears in the May 7 early online edition of The Proceedings of the National Academy of ...

Recommended for you

Study shows starving mantis females attract more males

7 hours ago

A study done by Katherine Barry an evolutionary biologist with Macquarie University in Australia has led to the discovery that a certain species of female mantis attracts more males when starving, then do ...

African swine fever threatens Europe

9 hours ago

African swine fever, or ASF, is a viral disease that kills almost every pig it infects and is likened to Ebola. It gained a foothold in Georgia in 2007, when contaminated pig meat landed from a ship from ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.