Tuesday, February 21, 2012

Flower Offers New Hope for Pleistocene Park

Arctic Ground Squirrel in
Denali National Park
Scientists with the Russian Academy of Science in Moscow have reported that they have successfully germinated a flower from a 32,000 year old seed-bearing fruit.  The fruit was collected and deposited in a midden by an ancient Arctic Ground Squirrel.  The ground squirrels create the middens, stuffed with seeds, fruits, and other food sources to help them during periods when food is scarce.

The midden, and its fruit, were discovered in the arctic tundra of Siberia.  The middens that researchers, Svetlana Yashina and the late David Gilichinsky, were searching for were sealed by wind-blown sediment and buried 125 feet below the surface where they were less likely to be contaminated by extant rodents depositing extant arctic plant seeds.  Some of the excavated ancient burrows contained more than 600,000 fruits and seeds.

Flower grown from 32,000 year old seeds. 
Photo by Svetlana Yashina/AP
Additionally, the depth of the middens in the tundra soil means that they were permanently frozen at -7 deg. C.  This cool temperature may have acted as a storage freezer to help preserve the seeds, however in some experiments freezing temperatures have also been shown to damage seeds and severely reduce the likelihood of successful germination.

The germinated ancient flowers share similiarities with modern Narrow-leafed Campion (Silene stenophylla), but exhibit some small differences like narrower petals that are more splayed apart and slower average root growth.

The age of the seeds was verified through radiocarbon dating of the placenta in the fruit from which the seeds originated.  Additionally, a chemical analysis of the placenta exhibited high levels of sucrose and phenols, both of which help provide freeze tolerance for some organisms.

If the age of the flowers can be independently verified, and seeds can be successfully germinated again in other labs, then this discovery may bode well for resurrecting other plant species, including those that may have gone extinct.  This would be good news for researchers trying to recreate Pleistocene ecological conditions in the tundra of Siberia.

Caribou male in Denali
National Park
Researchers with Pleistocene Park have been working to (re)introduce large grazing herbivorous species back into parts of Siberia in an effort to recreate ecological conditions similar to those that would have been present during the Pleistocene Epoch, which included grassland steppe habitat.

The ability to re-introduce extinct plants from the Pleistocene may increase our understanding of the ecological interactions between steppe plants and grazers, which included mammoths, moose, bison, musk ox, horses, and caribou. 

Monday, February 13, 2012

Darwin Day 2012

Yesterday, February 12th, 2012, would have been the 203rd birthday of Charles Darwin. The unofficial holiday, commemorated as International Darwin Day, made me think about ways in which we could and should celebrate Darwin's accomplishments and the importance of his work on our everyday lives.

I should clarify that when I say that we should celebrate this occasion I mean that it provides us with an opportunity to appreciate the natural world and how Darwin's theory has allowed us to better understand that world and our place in it.  I definitely do not mean conducting various ritual or rites based on tradition in the manner that people celebrate religious holidays.

Below are some of my suggestions for "celebrating" Darwin's birthday and the Theory of Evolution.

1.) Re-familiarize (or familiarize) yourself with Darwin's writings via the Complete Works of Charles Darwin On-Line.  This resource allows you to not only explore Darwin's writings, but also different editions of his books.

2.) Watch Creation the movie.  This movie explores Darwin's family life, how the death of his daughter influenced his view of god and religion, and how, in spite of her mis-givings about his work, his wife's support allowed him to continue on and publish his book.

3.) Visit your local Natural History Museum.  Explore the many collections illustrating the diversity and history of life on Earth.  Look for shared characteristics between different organisms over time.

4.) Visit your local Zoo.  Zoo's provide people with a unique opportunity to compare and contrast many related organisms in one location.

A series of adult male American Robin specimens, from the
Cincinnati Museum of Natural History, illustrating a
range of phenotypic diversity within the species. 
5.) Visit your local park or nature center to observe a specific group of organisms (e.g. male Northern Cardinals) to learn more about natural variation within populations and species.

6.) Watch Inherit the Wind; a re-creation of the Scopes Monkey Trial of 1925 in which a high school teacher was taken to trial for teaching evolution in the classroom.

While Darwin's birthday comes but once a year, these are things that can be done throughout the year to reconnect ourselves with the natural world and better understand how the Theory of Evolution unifies everything in it.