How Did Cactuses Evolve

May 15, 2006
Cactus

In a groundbreaking new study in the June issue of American Naturalist, Erika J. Edwards (Yale University and University of California, Santa Barbara) and Michael J. Donoghue (Yale University) explore how leafy, "normal" plants evolved into the leafless succulent cactus.

"The cactus form is often heralded as a striking example of the tight relationship between form and function in plants," write the authors. "A succulent, long-lived photosynthetic system allows cacti to survive periods of extreme drought while maintaining well-hydrated tissues."

Recent molecular phylogenetic work has confirmed that Pereskia, a genus that consists of 17 species of leafy shrubs and trees, is where the earliest cactus lineages began. Using field studies and environmental modeling, Edwards and Donoghue found that the Pereskia species already showed water use patterns that are similar to the leafless, stem-succulent cacti.

"[Our] analyses suggest that several key elements of cactus ecological function were established prior to the evolution of the cactus life form," explain the authors. "Such a sequence may be common in evolution, but it has rarely been documented as few studies have incorporated physiological, ecological, anatomical, and phylogenetic data."

Copyright 2006 by Space Daily, Distributed United Press International

Explore further: Cuban, US scientists bond over big sharks

Related Stories

Sacred lotus genome sequence enlightens scientists

May 10, 2013

The sacred lotus (Nelumbo nucifera) is a symbol of spiritual purity and longevity. Its seeds can survive up to 1,300 years, its petals and leaves repel grime and water, and its flowers generate heat to att ...

Chile's ALMA probes for origins of universe

Oct 26, 2012

(AP)—Earth's largest radio telescope is growing more powerful by the day on this remote plateau high above Chile's Atacama desert, where visitors often feel like they're planting the first human footprints ...

Restoration as science: case of the collared lizard

Aug 22, 2011

In a time when a five-year grant is considered a long-term grant, Alan R. Templeton, PhD, a professor of biology in Arts & Sciences at Washington University in St. Louis, has managed to follow some of the ...

Recommended for you

Researchers discover new mechanism of DNA repair

9 hours ago

The DNA molecule is chemically unstable giving rise to DNA lesions of different nature. That is why DNA damage detection, signaling and repair, collectively known as the DNA damage response, are needed.

The math of shark skin

17 hours ago

"Sharks are almost perfectly evolved animals. We can learn a lot from studying them," says Emory mathematician Alessandro Veneziani.

Cuban, US scientists bond over big sharks

21 hours ago

Somewhere in the North Atlantic right now, a longfin mako shark—a cousin of the storied great white—is cruising around, oblivious to the yellow satellite tag on its dorsal fin.

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.