COMMON DESCENT

Listen to Episode 8 on PodBean, Spotify, YouTube, or wherever you get podcasts!

This episode’s topic comes from a fan request! Thanks to Josh on Facebook for inspiring us to dive into the fascinating and fairly young field of Conservation Paleontology.

In the News:
Sea Scorpions Had Tail-Swords!
The “sea scorpions” of the early Paleozoic didn’t have stingers, but a lovely new specimen reveals some of them had very sharp tails, possibly useful for slicing at prey! [Report]
Ancient DNA Without Bones!
Scientists sampled sediment from caves across Europe and found that the minerals held traces of ancient DNA of all sorts of creatures, including prehistoric humans! [Report]
Extinction in a Wet Time
Fossils across the Quaternary Megafaunal Extinction reveal that environments were undergoing increases in moisture – a likely climate-related contributor to the extinction. [Report]
The Oldest North American Humans?
A new study claims to show evidence of humans in North America 130,000 years ago, WAY earlier than previous finds, but as they say, extraordinary claims require extraordinary evidence, and this evidence is hotly debated. [Report]

What is Conservation Paleontology?

Conservation paleontology (or conservation paleobiology) is a relatively fresh field of science where we use information from the fossil record to guide us in preserving living wildlife.

There are several detailed and excellent overviews of this subject.
-Here’s a not-too-technical description on Letters From Gondwana.
-For much more detailed overviews, with plenty of examples of case studies, look to technical papers by Barnosky et al. 2017 and Dieti & Flessa 2011. Much of the information for this episode came from those papers.

Way back in Episode 1, we talked a bit about how the fossil record offers us insights into how ecosystems change over time, how species respond to those changes, and what factors affect extinction. Conservation paleontology draws on these sources of information in several ways.

“Natural” vs. “Unnatural”

Which of our modern-day ecosystems are stable, the result of long-term ecological health, and thus worth protecting for the future? Which are newly-disturbed and yet recovered? Which phenomena in our modern-day world are part of long-term natural Earth processes, and which are human-caused disruptions? These are essential questions for conservation.

Some great examples:
-Yellowstone National Park is a major conservation interest. For many years researchers have turned to the fossil record to tell us what a long-lasting healthy Yellowstone ecosystem actually looks like.

-The Chesapeake Bay oysters we mentioned in Episode 4 inspired a fossil study that led to an incredible revelation: “A manager of the Chesapeake Bay has never seen a healthy oyster reef.”

-A fascinating study by Baumgartner et al. 1992 looked into the fossil record of commercial fish species, and found that recent population crashes were (at least partially) NOT our fault! Imagine that!

A Long History of Change

The fossil record provides hundreds of millions of years of natural experimentation, revealing the answers to questions like: What factors put a species at risk of extinction? How do ecosystems respond to major disturbances? How do struggling ecosystems recover naturally? And so on.

The two overview papers listed above provide plenty examples – different species’ reactions to climate changes of the past, species struggling to survive after major extinctions, and more.

Here’s one particularly interesting example: Boyer 2010 Looked at patterns of extinctions in island birds in response to human arrivals. The incredible fossil record of the Pacific allowed her to get at answers to the all-important question: Which species suffer when humans enter the picture, and why?

What Is A Healthy Ecosystem, Anyway?

A healthy ecosystem is stable in the long term, able to weather disturbance and the gradual pressures of time. The fossil record is full of examples of ecosystems that persist for thousands of years, providing vital information about what an ecosystem actually requires to survive even as individual species come and go.

Rewilding (restoring normal, healthy wilderness) is a process now being pursued around the world, from North America to Europe to Australia. These programs focus on restoring habitats to a sustainable state: high diversity of plants and animals, vast interconnected patches of wild, and natural patterns of fire, water flow, and nutrient cycling.

But some scientists have suggested that our benchmark for restoring healthy ecosystems should specifically be the end of the last Ice Age, before humans starting mucking up ecosystems. This is the idea of Pleistocene Rewilding – engineering replacements for extinct ecosystems.

There’s a lot of talk – and controversy – around this idea. Here are the fairly technical Donlan posts we mentioned in this episode – from 2005 and 2006, plus a less technical introduction to the idea.
Here are technical and non-technical introductions to the concept.

It sounds great in theory, but it’s hard not to feel a bit uncomfortable at the suggestion of releasing elephants and lions into North America. But the basic principle is in motion in efforts like the replacement of extinct tortoises in the Indian Ocean, and the recreation of ancestral cattle.

And then there’s Sergey Zimov’s wild idea: Pleistocene Park. He and his son are on a mission to recreate the extinct mammoth steppe biome in Siberia by gradually assembling an Ice Age community of plants and animals.
Learn more (seriously, check it out) here and here and here.

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If you enjoyed this topic and want more like it, check out these related episodes:

• Episode 35 – De-extinction
• Episode 55 – The “Sixth Extinction” (Modern Biodiversity Crisis)
• Episode 25 – The Pleistocene Megafaunal Extinction

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