past

Is de-extinction possible?

January 28, 2025 By EarthWise Leave a Comment

Advances in genomics have created the possibility of bringing back extinct species from the past by making use of recovered DNA from preserved specimens. Companies attempting to “de-extinct” iconic species have received hundreds of millions of dollars from venture capitalists.

These companies are trying to bring back iconic species that include ivory-billed woodpeckers, Tasmanian tigers, dodos, passenger pigeons, and woolly mammoths.

Efforts to recreate extinct species are controversial. The arguments in favor include the positive effects on ecosystems when keystone species are restored, and the excitement generated about conservation in general. The opposing view is that concentrating all this effort on these restorations diverts attention and funding from more urgent conservation work.

A more nuanced viewpoint that has emerged is that actually de-extincting species is not possible. The genome of these vanished species cannot be reconstructed perfectly. Specimens are not cryopreserved from when the animal died. What can be retrieved is at best significant fragments of the genome. These are combined with DNA from related contemporary animals to produce the new species.

As a result, what emerges are proxies. They are animals that are similar to extinct animals – in some cases convincingly so – but they are not the same species that existed in the past. They may be able to fill the same ecological niches and they may have similar behavior. But they are not de-extincted specimens of the past species. Is it worth doing? Quite possibly but it’s not actually bringing back what is gone.

**********

Web Links

Despite Biotech Efforts to Revive Species, Extinction Is Still Forever

Photo courtesy of Grazelands Rewilding.

Earth Wise is a production of WAMC Northeast Public Radio

When is a heat wave just a heat wave?

December 18, 2024 By EarthWise Leave a Comment

There are lots of extreme weather events of all kinds these days. But there have always been extreme weather events. Climate change results in more extreme weather but not all extreme weather should be attributed to climate change. So, how do we know if an extreme weather event is a result of the changing climate? Communities that are affected by extreme weather events need to know whether they are likely to see more such events in the future, or if they are anomalies like a “500-year storm” or such.

Researchers at North Carolina State University, the National Oceanic and Atmospheric Administration, the University of Colorado, Boulder, and Princeton University developed a routine process for evaluating extreme weather events.

The test case was an extreme heat wave that affected Texas and Louisiana in 2023. This notable heat wave lasted almost the entire summer. The scientists used a two-step process to determine whether the heat wave was an anomaly or part of a new pattern. They took historical data from the past 100 years to see how unusual 2023 was. Then they compared that data with both past and present predictive computer models. Comparing the predictive models can indicate whether climate change was a factor in the event.

In this case, a similar drought would not have been as hot 50 years earlier, which indicates that the heat wave is related to climate change and that even more intense heat waves are likely to occur in the future.

This sort of information is important for communities to prepare for future events.

**********

Web Links

When is a Heat Wave Just a Heat Wave, and When is it Climate Change?

Photo, posted July 22, 2006, courtesy of Saturnism via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Dangerous Diseases From The Past

June 9, 2017 By EarthWise

Climate change is poised to transform life on Earth as we know it. The higher temperatures, the rising seas, the more frequent floods and droughts, among the countless other consequences associated with climate change, threaten to do irreversible damage to the world in the coming decades.