#extinction

“Conservation-induced extinction” is certainly a strange term. Isn’t the entire point of conservation to preventextinction? 

Let’s start with the venerated conservation success story of the California condor. In 1987 there were only 22 California condors left in existence, and all 22 birds were brought into human care for the purpose of starting a captive breeding program that would eventually save the species from extinction.

As part of bringing the last California condors into human care, all 22 birds underwent anti-parasitic treatment. As a direct result, in the spring of 1987, Colpocephalum californici–a unique species of louse known to only host on the California condor–was driven to extinction.

It bears mentioning that this extinction was a result of negligence, not intentional destruction; it simply did not occur to the people running the California Condor Recovery Plan to account for parasite conservation. There is no evidence that the California condor louse was harmful to its host or that driving it to extinction was in any way helpful to the captive breeding program.

Now at this point you may be thinking, “Oh, well it was only a parasite, I don’t really care if they go extinct”. However, if you subscribe to the ecological notion that every scrap of biodiversity is precious, why is the California condor louse any less valuable than the California condor?

Beyond the intrinsic value of a species, parasites make up an inextricable part of a host species’ biology. Without them, part of the host’s ecological context is lost forever. For example, scientists estimate that less than half of the cells in a human body are actual human cells; the rest are part of our microbiome. To cleanse ourselves of those other organisms would be to remove half of what makes up the human organism–we would be killing off vital co-passengers that contribute to our immune systems, digestion, and other critical functions.

For thousands of years the louse and the condor–and their evolutionary predecessors before them–impacted each others’ evolutionary trajectories like comets caught in each others’ orbit. The California condor would not be the species it is today without the influence of its now extinct louse. Its future trajectory may be more wobbly and unstable as a result of the louse’s extinction.

Some scientists estimate that nearly half of all species on Earth could be parasites in at least one stage of their lives. Failing to conserve parasites would cost us a huge amount of biodiversity. We would also lose scientific knowledge on the evolutionary history of both parasite and host, we would have less healthy ecosystems, and we would see genetic diversity and fitness atrophy in host species (which is of particular relevance to critically endangered species). 

Already, conservation-induced extinction has cost us at least four high profile species other than the California condor louse; these were host-specific parasites from the Guam rail, little spotted kiwi, scimitar horned oryx, and Iberian lynx. As more and more species require the help of captive breeding programs, this will only become a larger issue.

We may not like parasites–they may annoy us or make our skin crawl–but they are an important part of our ecosystems and a vital aspect of biodiversity. They deserve to be conserved alongside their hosts, both for their benefit and for the benefit of their hosts.

“The conservation of parasites might well be an essential part of the conservation of their hosts. Thus, if the goal of conservation is to maintain biodiversity, as well as the ecological and evolutionary processes that generate and sustain it, then parasites must also be conserved for their host’s sake.“ (Spencer, H., Zuk, M., 2016, For Host’s Sake: The Pluses of Parasite Preservation)

Sources: (1) (2) (3) (4) (5)

Image Sources: (1) (2)

On today’s episode of The Young Ones, we learn the answers to some tough questions, such as: “Which version of Mountain Dew is the best?”, “What is going on with Extinction and X-Men: Disassembled?” and, “Why is Charles Xavier the worst?”

We also answer some of your questions from Twitter.

Direct Link: https://youngonescast.pinecast.co/episode/29c830a3-8cab-4feb-8c33-c26c85ccaa5a

If you enjoyed the episode, please rate us on Apple PodcastsorStitcher!

a-dinosaur-a-day:

prehistoric-aesthetic-of-the-day:

Everything is about to change for you little guys. Also @apsaravis can I just say thanks for drawing so many pictures of basal Avemetatarsalians with protofloof? I wouldn’t have any accurate drawings for this series otherwise. Source: http://apsaravis.tumblr.com/post/74736331120/back-to-the-triassic-period-redondasaurus-with 

Time: 201.3 million years ago, in the Rhaetian age of the Late Triassic of the Mesozoic of the Phanerozoic 

Analogy: Did you ever play on a team in High School? Even like an academic one? I was on my school’s Science Olympiad team (always won a medal in fossils, thank you very much. I also was in charge of organizing bio events, no big deal). Anyway do you remember when, like, the upperclassmen graduated, and suddenly you had a lot of responsibility and you were an important member of whatever club or team you were on? Like, they disappeared, and you got to take their place and be the big guys? Yeah that’s this, but for dinosaurs. 

This thing was one of the many, many, many weird non-dinosaurs of the Triassic. Art from http://markwitton-com.blogspot.com/ 

Causes: Where did we leave off? Oh right nearly everything died. My favorite! Well life eventually did recover after the Permian Extinction - obviously, as we’re all here today. Archosauromorphs were really taking over the scene, and there we many different kinds everywhere - dinosaurs were a relative minority compared to all the other different types of reptiles, and pterosaurs were extremelyrare as well. Nothosaurs, Pachypleurosaurs, Placodonts, and the first Plesiosaurs evolved; there were Thalattosaurs, and Ichthyosaurs were verysuccessful in the Triassic. There were many amphibians, Rhynchosaurs, Phytosaurs, Aetosaurs, Rauisuchians, the first Crocodylians, Prolacertiformes, the earliest turtles, and the cynodonts all evolved and diversified, with cynodonts getting closer to being mammals. In fact, looking at the assemblage of the Triassic, one could hardly guess that it would be dinosaurs that would become the dominant megafauna of the Mesozoic period - various Pseudosuchians (crocodile-line Archosaurs) seemed to be taking that role. 

Nope, not a dinosaur. Art from http://www.arcadiastreet.com/cgvistas/earth/03_mesozoic/earth_03_mesozoic_0900.htm 

So what happened then? After all, this is pretty quick after the last death machine - only about fifty million years. Well, the causes of this extinction are actually… not very clear. Once again people have tried to pin it on an asteroid - which would make somesense, since it was the large non-dinosaurian archosaurs that were hit the hardest - but no such crater has been found, and all possible candidates have been ruled out. There was some climate change and sea level fluctuations, but they weren’t sudden enough to explain the extinctions in the ocean - this was a very sudden pulse of death, more so than what you would expect from just gradual environmental fluctuations. 

Theremayhave been some massive volcanic eruptions again - yay! more lava! - which seems to be the best bet.  The flood basalts of the Central Atlantic Magmatic Province would have released carbon dioxide, sulfur dioxide, and aerosols, causing - once again - pretty terrible global warming and cooling. There seems to be evidence for a major CO2 greenhouse crisis in ocean extinction deposits, and evidence that both the marine and terrestrial extinctions happened at once, which may indicate that a sudden influx of carbon dioxide and accompanying warming caused the extinction. However, there’s a chance that the eruption of the CAMP was too old to have caused the extinction. 

More… lava? http://palaeo.gly.bris.ac.uk/palaeofiles/triassic/triextict.htm 

If it was the volcanic activity, perhaps exacerbated by already occurring climate change, then the increase in global temperatures would have had another terrible effect on life on the planet - which had just recovered, and thus would be fairly vulnerable. 

Extinction Rate: This was not as bad of an extinction pulse as the last one, so if it was volcanic activity, it was the kind notin the worst possible place ever. Hooray! 23% of all families, 48% of all genera, and 70 to 75% of all species went extinct.

Effects: This was actually more acutely felt in the terrestrial environments than in the marine ones, though they were also affected. A large portion of the non-dinosaurian Archosauromorph groups went extinct, which emptied ecological niches on the land extensively. In the ocean, there seemed to just be less diversification - a decrease in speciation events rather than an extinction of already existing taxa. Phytosaurs and Aetosaurs were completely wiped out, as well as others. 

Which means yougot to evolve, buddy. Art from http://www.smithsonianmag.com/ist/?next=/science-nature/dilophosaurus-an-early-jurassic-icon-57431583/ 

If we can call any time periods much of anything, then, the Triassic was truly the age of reptiles, with a wide variety of forms and diversity across different major clades. One could argue, then that this age ended after the Triassic extinction - though many reptiles remained very common, it was really more specifically the Age of Dinosaurs after this point. Dinosaurs evolved to fill the vacant niches and finally started growing to the sizes to which we are accustomed with them - sauropods started evolving (at last, from stinking prosauropods), large theropods began to grow more and more common, and Ornithischians also finally had a chance to diverge. 

In fact, the rapid pulse of diversification of dinosaurs after the end-Triassic extinction lead to a large morphological diversity of dinosaurs, and at some point between the middle and late Jurassic epochs, the earliest members of Avialae evolved - the group that would eventually lead to birds. 

Birds. Birds everywhere. Empty niches everywhere means more dinosaur diversity which means trying out new and weird things which means birds. Art from http://emilywilloughby.com/gallery/paleoart/anchiornis 

Mammals also evolved in the Early Jurassic, probably due to pressures following this extinction event. They remained small predators, living in regions where there was still many places to hide, though they did diversify somewhat, and more so than previous paleontologists believed. 

So, though a relatively minor extinction, it once again directly lead to the world we know and love today - mammals became a thing, dinosaurs grew into what we really know and love about them (widely diverse and weird, because birds are weird you guys,) and other reptiles began to dominate the sea and air (hellooooo pterosaurs, pterosaurs everywhere). In fact, dinosaurs were so versatile and widely morphologically diverse following the Triassic extinction, thanks to all those sweet, sweet available niches, that they were very well adapted to their world. 

What could go wrong? 

Of course, now we have to deal with sauropods, but whatever. http://haghani.deviantart.com/art/Some-of-the-Jurassic-period-dinosaurs-and-plants-385694737

We often forget about this one, I think, but yay! More death! Dinosaurs are survivors, people.

great-and-small:

I travelled to the year 2036 and brought back this depressing meme

CFP (ASLE 2019) – Prehistoric Creatures and Anthropocene Fears: The Past Comes Back to Bite Us

Conference: ASLE (the Association for the Study of Literature and Environment) – Paradise on Fire Dates of Conference: June 26-30, 2019 Location: University of California, Davis Deadline for Submissions: December 15, 2018 at 11:59 pm (EST) via Submittable

Horror and science fiction have long featured the return of the prehistoric, the monstrous past coming back to intrude upon the present and…

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