Ricki Lewis

DNA is the calling card of life. 

In and on our bodies, traces of DNA sequences other than our own announce the presence of many microbes, our microbiome.

DNA in Natural and Artificial Ecosystems

In the environment, snippets of environmental, or "e" DNA, are also abundant, yet more dynamic, constantly changing, compared to the more staid microbial communities inhabiting our skin folds, intestines, armpits, and elsewhere. Airborne eDNA sequences in natural ecosystems are particularly in flux, as species come and go. 

Human-made (artificial) ecosystems also have transient microbial residents that leave in their wake genetic material. One early study probed the short sequences of DNA mired in sticky goo scraped from banisters and stairways of a New York City subway stop, where millions of commuters regularly deposit the microoganisms on their skin.

To continue reading, go to DNA Science, where this post first appeared.

The reconstruction of a once-living landscape in northern Greenland from 2 million years ago, deduced from bits of DNA bound to minerals, reveals an Ice Age ecosystem in the throes of climate change that may suggest ways to mitigate rising global temperatures today. The collection, analysis, and interpretation of environmental DNA from this distant time and place provides a "genetic roadmap" for how organisms can adapt to a warming climate. The work is the cover story in Nature this week. Six of the 40-member multinational team discussed the findings at a news conference.

eDNA

Environmental DNA – eDNA – is used to describe habitats both ancient and contemporary. Until now, the oldest eDNA was from a mammoth that lived in Siberia one million years ago.

To continue reading, go to DNA Science, where this post first appeared. Image credit Beth Zaiken.

Many years ago, a dear friend took me to the Detroit zoo to see the Hippoquarium. Much to my delight, the resident hippo positioned her rear to the glass of the enclosure and let loose, her whirring tail distributing the intestinal contents like blowing on an open milkweed pod.

A few years later I saw the same demonstration at the Tampa zoo, a hippo's whirligig-of-a-tail in action.

Hippo Microbiomes

Recently, researchers from the US and Kenya described in Scientific Reports their investigation of the ejection of hippo feces into the pools of the Serengeti's Mara River. A more natural environs than a zoo, the river is home to more than 4,000 hippos wallowing in some 170 hippo pools in the Kenyan part of the territory.

To continue reading go to my blog DNA Science at Public Library of Science.