Drawing on my work in evolutionary ecology, wilderness ethics, and machine learning, I reflected on the tension between our desire to intervene and our limited ability to forecast long-term ecological outcomes. Using examples like the Chernobyl exclusion zone—where many species are thriving in the absence of people despite nuclear contamination—I argued that ecological recovery is often less about precision intervention and more about restraint. We discussed how machine learning can help us simulate alternative futures and understand potential tradeoffs, but that ultimately, the most powerful conservation tool may be humility. More wilderness, not more control, might be the best way to meet the uncertainties ahead.

Listen to the episode here or wherever you get your podcasts.

I am deep in the Alaskan Arctic,  300 miles from the nearest road system, attempting to conduct the kind of science that usually requires a specialized laboratory. We rowed 30 miles of meandering flatwater today, bringing our total to 200 river miles in 12 days since we landed at a lonely gravel bar on the headwaters of Ambler River in Gates of the Arctic National Park.

Mosquitoes spangle the tent canopy arching over me. Backlit by summer solstice sun, the silhouettes of the insects make an inverted night sky of shifting constellations. The sun never sets on the banks of the Kobuk River this time of year. It hangs high above the horizon even now at 11 p.m., transforming my tent into a solar oven as I, ironically, work to uncover the secrets of a frog that can turn into ice.

… Read the rest of the article here.

Take me to the photos!

Step 1: Come up with a hair-brained scheme.

My labmate Yara and I had been dreaming up the idea studying wood frog genomes from across the species’ range since she started her PhD. Wood frogs have the largest range of any North American amphibian. They also happen to be the only North American amphibian that can survive North of the Arctic circle.

Dr. Julie Lee-Yaw had done a similar study back in 2008. She embarked on a road trip from Quebec all the way up to Alaska to collect wood frog tissue. So, out first step was to ask Dr. Lee-Yaw if she would collaborate and share her samples.

Those samples gave us a solid backbone across the wood frog range, but we were missing population in expansive regions north and west of the road systems. We worked with the Peabody Museum to search for tissue samples that were already housed in natural history collections around the world. We filled a few gaps, but huge portions of the range were still missing.

We knew that there must be samples out there sitting in freezers and labrooms that were not catalogued in museum databases. So, our next step was to begin sleuthing. We looked up author lists from papers and cold-called leads. I even reached out to friends on Facebook (…which actually turned out to be a big success. The aunt of a friend from undergrad happens to do herpetology research in Galena, Alaska and was able to collect fresh samples for us this year!). This effort greatly expanded our sample coverage with new connections (and friends) from Inuvik and Norman Wells in the Northwest Territories, Churchill on the Hudson Bay, and the Stikine River Delta in Southeast Alaska.

But as the points accumulated on the map, we noticed some glaring holes in our coverage. Most importantly, we had no samples from Northwestern Alaska. Populations in this region are the most distant from the ancestral origin of all wood frogs in the southern Great Lakes. If we wanted a truly “range-wide” representation of wood frog samples, we needed tissue from that blank spot on the map!

Step 2: Convince your advisor and funders it’s a good idea.

This might be the hardest step. In our case, Yara and I were lucky that our advisor, Dave, was immediately supportive of the project. After we made the case for the importance of these samples, funders came around to the idea as well.

Step 3: Make a plan …then remake it …then make a new plan yet again.

Once we knew where we required samples from, we needed to figure out how to get there. Alaska in general is remote, but northwestern Alaska is REALLY remote. The road system doesn’t stretch farther than the middle of the state. All of the communities–mainly small villages–are only accessible by plane, and most of them only have runways for tiny prop planes. Travelling out from the villages into the bush is another layer of difficulty. Most people here either travel by boat on the river or by snowmachine during the winter. Traveling on land, over the soggy and brush-choked permafrost, is brutal and most locals only do it when necessary, if at all.

Prior to academia, I made a career of organizing expeditions to the most remote places in the rugged southeastern archipelago of Alaska. Despite my background, the logistic in the Arctic were even inscrutable to me. Fortunately, I had a couple of friends, Nick Jans and Seth Kantner, who know the area well. In fact, Seth grew up in a cabin out on the Kobuk. (Seth and Nick are both talented authors. I suggest checking out Ordinary Wolves by Seth and The Last Light Breaking by Nick). With their help, I was able to piece together the skeleton of a trip.

After many logistic iterations, Yara and I decided to follow in the footsteps of local hunters who, for generations, have used the rivers as conduits into the heart of the wilderness. Our plan was to travel down one of the major arterial rivers and hike inland to search for frog as we went.

Our original itinerary was to raft the 100 mile section of the Kobuk River from just north of Ambler village to the village of Kiana. But at the last minute (literally), our plans changed. As we were loading up the plane, the pilot told us that he couldn’t fly into our planned starting point. Instead, he suggested that we fly into a gravel bar 30 miles up river in Gate of the Arctic. Those “30 miles” turn out to be AIR MILES. Following the river, it ended up adding over 60 miles to our trip.

We packed two inflatable oar rafts, almost 150 pounds of food, and another 300 pounds of camping, rescue, and science gear, into the balloon-wheeled plane. For the next two weeks, we rowed down the swift Ambler River from the headwaters to the confluence of the Kobuk. Then, we rowed down the massively wide and meandering Kobuk River, eventually extending our trip by an additional 30 miles, by-passing Kiana, and continuing to Noorvik, the last village on the river.

Step 4: Recruit a crew.

Despite being the worlds first and only Saudi Arabian Arctic Ecologist with limited camping experience, I knew Yara would be a stellar field partner. But I never like traveling in brown bear country with fewer than four people. Plus, expedition research involves too many daily chores for the two of us to manage alone. So, we recruited a team.

Sam Jordan is a dry land ecologist, but he had been willing to help me with my dissertation fieldwork in wetlands before, so I knew he would be willing to defect for a good adventure. Sam is also an exceptional whitewater paddler and all-around outdoor guru. Plus, he’s just a great guy (when he leaves his banjo at home). He and I spend two weeks floating the Grand Canyon in the dead of winter and there are few people I would want along on a remote river trip.

Kaylyn Messer and I guided sea kayak expeditions in Southeast Alaska back in our youth. I am a bit particular about how I manage my camp system (read: “extremely picky and fastidious to a fault”) on big trips. Kaylyn is one of the few people as scrupulous as me, but she’s also a super amenable Midwesterner at heart. I knew she’d be a huge help out in the field.

We fell into an effective rhythm on the trip.  Each morning we woke, made breakfast, broke camp, packed the boats, and launched early in the day. While one person on each boat rowed, the other person checked the maps for frog surveying spots, fished, or photographed. We stopped along the way to bushwhack back into wetlands we’d identified from satellite images. We typically arrived at camp late. Yara and I would set up one tent to process the specimens from the day while Same and Kay made camp and cooked dinner. One of the hidden disadvantages of 24-hour Arctic sunlight is that it is easy to overwork. Most nights we only managed to get sampled finished, dinner cleaned up, and camp bearproofed with enough time to crawl into tents with just eight hours till beginning again the next day.

Step 5: Do the science.

Doing science in the field is difficult. Tedious dissections seem impossible while baking in the omnipresent sun and being alternately hounded by hundreds of mosquitoes or blasted by windblown sand. Trading lab coats for rain jackets and benchtops for sleeping pads covered in trashbags compounds the trouble. Not to mention, keeping tissues safe and cool. Organization and adaptability go a long way.

On remote, self-supported trips, it is inevitable that equipment fails or is lost. On one of the first days, we discovered that our formalin jar was leaking—and formalin is not something you want sloshing around! We cleaned the boats and found a creative solution to replace the offending container: a 750ml Jack Daniel’s bottle!

Planning ahead and engineering backup plans also helps. One of our main struggles was figuring out how to preserve specimens and get them home. It is illegal to ship alcohol by mail and you can’t fly with the high-proof alcohol needed for genetic samples. You can ship formalin, but it is difficult to fly with. To make matters worse, we were flying in and out of “dry” or “damp” villages where alcohol is strictly regulated or forbidden. Also, we happened to be flying out on a Sunday, making it impossible to mail samples home. The solution we arrived at was to ship RNAlater and formaldehyde to our hotel room ahead of time. Tissue would remain stable in RNAlater for a couple of weeks and we could make formalin to fix the specimens. After fixing, we cycled the specimens through water to leach out the formalin. This made it possible for me to fly with all of the tissue tubes and damp specimens in my carry on. Other than a few concerned looks from the TSA folks, all of the samples made it back without issue!

Step 6: Enjoy the adventure.

Despite the hard work, there was a lot to appreciate about the Arctic. We witnessed major changes in ecology as we travelled from the steep headwater streams in the mountains to the gigantic Kobuk. Every day was an entirely new scene.

Here’s an illustrated thread on our collecting trip to the Alaskan Arctic for the @Yale @yalepeabody this past summer. 1/22 pic.twitter.com/Jh3VCqVEgx

— A. Z. Andis Arietta (@azandisarietta) August 24, 2021

Step 7: Forget the hardships

Looking back, it is really easy to forget the sweltering heat, swarms of mosquitoes, inescapable sun, and freak lightning storms. And, it’s probably better to forget those anyway!

Arctic CircleSam illustrates that we are, in fact, above the Arctic Circle.

GearGear (minus food and rafts) ready for weigh-in before loading the plane.

Upper Ambler RiverOur drop-off point on the braided upper reach of the Ambler River in Gate of the Arctic National Park.

Gates of the ArcticGetting dropped off on a gravel bar in Gates of the Arctic National Park.

The first dayUnloading the plane on the first day of the trip.

Camp, night 1Campsite along the Kobuk River.

Rigging the raftsPacking up the two-person rafts on the first day.

Kaylyn Messer at the helm.In the upper rivers, near the headwaters, the current was pleasantly swift.

Upper riverSam and Yara rowing down the Kobuk River.

Early morning rowingRowing the swiftwater on the headwaters of the Ambler River in Gates of the Arctic National Park.

Searching for frogs

First frogs!Yara and I after finding the first frogs of the trip!

Science in the fieldYara preparing to do the sciencing with a garbage back as a makeshift lab bench.

Dinner. night 6Dinner and a view on the banks of the Kobuk River.

Midnight sunTrying to avoid getting a sunburn while sleeping in the Arctic.

Midnight sunThe sun baking our tent at 1130pm.

Rainy rowingSam and Yara floating downstream.

Arctic frogYara proudly presents her first wood frog collection.

Kobuk viewsSmoke and clouds mute the midnight sun.

Sam JordanSam Jordan in his happy place.

Chocolate con culicidae.With hundreds of bugs circling your head at all times, it is impossible not to end up with a few in every meal.

CutbanksMassive cutbanks made much of the shore inaccessible for sampling.

StormA freak lightning storm.

SunsetBeautiful light from the midnight sun.

Field dissection Taking tissue samples for sequencing.

TadpolesTadpoles from "Seth's Pond".

Prepping collectionsYara and I taking tissue samples and prepping specimens.

Arctic Wood FrogBeautiful arctic wood frog.

Fixing specimensHere, I am fixing specimens with formalin to preserve them for the Peabody Museum.

Bushwhacking The view while bushwhacking in to search for frogs.

BugsA random sample of friendly mosquitoes.

BearGrizzly bear prints on the beach.

FishingSam with his first of many greyling.

The Kobuk River valleyThe Kobuk Valley watershed is just an endless expanse of wetlands.

The end of the tripFlying back to Kotzebue in a packed plane at the end of the trip.

Heading homeCatching a ride out to the airstrip with our truckload of gear on the last day of the trip.

The study:

One of the most consistent findings arising from 20 years of study in our lab is that wood frogs seem to adapt to life in cold, dark ponds. In general, cold-blooded animals like reptiles and amphibians are not suited for the cold and function much better in warmer conditions. So, wood frogs that live in colder ponds should have a harder time competing against their neighbors in warmer ponds.

In response, cold-pond wood frogs seem to have developed adaptations that level the playing field. In separate experiments, we’ve found that wood frog tadpoles in cold-ponds tend to seek out warmer water (like in sunflecks) and have lower tolerance to extremely warm temperatures. Most importantly, they can mature faster as eggs and larvae.

But I’ve always struggled with a lingering question: if cold pond frogs have adapted these beneficial adaptation to compete with warm-pond frogs, what is keeping those genes out of the warm-ponds? Shouldn’t cold-pond genes in a warm pond mean double the benefits? One would expect the extrinsic environmental influence and the intrinsically elevated growth rates to produce super tadpoles that metamorphose and leave the ponds long before all the others.

Kaija, who was an undergrad in the lab at the time, decide to tackle that question for her senior thesis.

We hypothesized that there might be a cost to developing too quickly. Studies in fish suggested that the trade-off could be between development and performance. The idea is that, like building Ikea furniture, if you build the tissue of a tadpole too quickly, the price is loss of performance.

So we collected eggs from 10 frog ponds that spanned the gradient from sunny and warm to dark and cold. We split clutches across two incubators that we set to bracket the warmest and coldest of the ponds.

Then we played parents to 400 tadpoles, feeding and changing water in 400 jars two to three times a week.

We reared the tadpoles to an appropriate age (Gosner stage 35ish). Those in the warm incubator developed about 68% faster than those in the cold incubator. In addition to our lab-reared tadpoles, we also captured tadpoles from the same ponds in the wild as a comparison. Development rates in the lab perfectly bounded those in the wild.

Once they reached an appropriate size, we put them to the test. We simulated a predator attack by a dragon fly naiad by poking them in the tale. Dragonfly naiads are fast, fierce, tadpole-eating machines and a tadpole’s fast-twitch flight response is a good indicator of their chance of evading their insect hunters. It’s a measure of performance that directly relates to a tadpole’s fitness.

Above the test arenas, we positioned highspeed cameras to capture the tadpoles’ burst responses. We recorded 1245 trials, to be exact—way more than we ever wanted to track by hand. Fortunately, Kaija is a wiz at coding; and with a bit of help, she was able to write a Matlab script that could identify the centroid of a tadpole and record its position 60 times per second.

We measured the tadpoles’ speed during the first half second of their burst response and looked for an association with their developmental rates. One complicating factor is that a tadpole’s fin and body shape can influence burst speeds. So, a weak tadpole with a giant fin might have a similar burst speed to a super fit tadpole with a small fin. To account for this, we took photos of each tadpole and ran a separate analysis mapping their morphometry and included body shape into our models.

As we had hypothesized, tadpoles reared at warmer temperatures show much slower burst speed than their genetic half-sibling reared in the cold incubator. We even saw a similar, but weaker effect for the tadpoles that were allowed to develop in their natal ponds. It seems that developing too fast reduces performance.

Thus, it certainly seems that the counter-gradient pattern we see of faster development in cold-pond populations, but not in warm-pond populations, is at least partially driven by the trade-off between development rate and performance.

In fact, it may even be the case that we’ve been viewing the pattern backwards all along. Perhaps instead we should consider if warm-pond populations have developed adaptively slower development rates to avoid the performance cost. This especially makes sense given the range of wood frogs. Our populations are at the warm, southern end of the range. Maybe this tradeoff is also a factor constraining wood frogs to the cold north of the continent?

If warm weather and faster development are a real liability for wood frogs, it is only going to get worse in the future. We know from another recent study that our ponds have been warming quickly, especially during the late spring and early summer months. But climate change is also causing snow to fall later in the winter forcing frogs to breed later. The net result is that wood frogs may be forced to develop fast intrinsic developmental rates in response to a contracting developmental window, while at the same time, extrinsic forces drive development even faster. That’s a double whammy in the trade-off with performance. And might lead to too many “Ikea furniture mistakes” at the cellular level.

As a separate part of this study, we also measured metabolic rates in out tadpoles in hopes of understanding the relationship between developmental rates, performance, and cellular respiration. I’m in the process of analyzing those data, so stay tuned for more!

Here’s my talk from the conference, “Evolution of Intrinsic Rates: Can adaptation counteract environmental change?“:

Rats have traveled around the globe alongside humans. Where we make our homes, they are happy to make their own, too. Unfortunately, they can make terrible neighbors, especially when they become vectors for diseases.

The rats that live in the slums of Salvador, are to blame for the widespread of emergence of leptospirosis infections that poses a serious health risk. In response, the municipality planned a multi-year rat-eradication project.

The bad news is that it is nearly impossible to fully eradicate rats from large territories. After just a short time, the populations tend to rebound, either because some rats were missed and then repopulate from within or because new rats migrate from outside and colonize the area. Understanding how rats repopulate after eradication efforts is important for deciding how best to proceed with future management strategies.

To test which of these scenarios was at play in Salvador, my collaborators trapped rats before, during, and after the eradication campaign in three contiguous geographic regions within the slums. We looked at the genetic relatedness of the populations across the three time-points. If the rebound populations were more similar to each other post-eradication, it would suggest that the populations were recolonized from source populations outside. However, if the regions became more genetically distinct post-eradication, it would suggest that the rebound populations were seeded from the few local genetic lineages that persisted.

We found that the populations showed distinct genetic differences immediately after the eradication effort, suggesting that remnant rats from the original populations had repopulated from within. Those difference persisted after 7 months.

In addition, we looked at the genetic signatures of population expansion and contraction. We found that post-eradication populations had pronounced reductions in genetic diversity. As animals were removed from the population during eradication efforts, it created a bottleneck. Since the new populations arose from the few remaining rats, only those few genetic variants left over persisted.

If enough genetic diversity is lost, and is not replaced by migrant mice from outside the original population, it might eventually lead to inbreeding and reduced fitness. If that is the case, it means that creating serial bottlenecks in the population through eradication efforts could be an effective way to weaken the rat populations to manageable levels, even if the overall population number rebounds in the short term.

I think my collaborator Dr. Jonathan Richardson (@JRichardson_44) did a nice job of succinctly outlining our findings in this Twitter thread:

I'm very excited about our new paper out today on the significant genetic impacts that accompany an urban eradication campaign of rats in 3 areas of Salvador, Brazil, w/ @georgisil_ & many Twitterless colleagues. The TL,DR version is in short thread below:https://t.co/WLqmQ1UJkD

— Jonathan Richardson (@JRichardson_44) June 6, 2019

Speciation starts small. The path of divergence starts with minute change in just a handful of basepairs among the billions of bases in a genome. Overtime, these small differences create feedbacks that propagate further divergence.

That’s the idea of sympatric speciation, the emergence of two species out of one. I’m most interested in the very first steps of this process, but catching this kind of small-scale divergence is hard, because the difference are small and easy to overlook. We call noticeable differences within a species polymorphisms. In most cases, we notice polymorphisms that we can see. For instance, it is hard to miss difference in color morphs of chimpmunks. Many of the classic examples of polymorphisms are visually detectable: industrial melanism in moths, beak size in Galapagos finches, stripe and color pattern in Timema stick insects, etc.

 

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It’s been way too long since I celebrated #TaxidermyTuesday All of these specimens are the same species of Eastern chipmunk (Tamias striatus), but two of them have genetic quirks that make their coats either all black (melanistic) or all white (leucistic). #biology #naturalhistorymuseum #naturalhistory #specimen #taxidermy #chipmunk #zoology

A post shared by Andis A. (@azandis) on Mar 6, 2018 at 3:54am PST

But many polymorphisms cannot be detected visually. For instance, polymorphism in dart frogs is often detected by the chemical composition of their skin toxins. Divergence in birds is often diagnosed by the sound of their calls. I’m in the middle of a collaboration to detect possible divergence in clover populations within and outside of cities via cyanogenesis.
The reliance on our human sight to detect polymorphisms is a problem because human sight, while impressive, is very narrowly limited. There is no reason for us to expect that the most relevant variation (from an ecological or evolutionary perspective) in a population would fall within the range of our senses. For instance, there is a whole vision of the world in the ultra-violet frequency that we cannot see. Flowers that all appear a uniform color to you and me can exhibit huge variation in ultra-violet light. Since birds and bees see ultraviolet, it stands to reason that the strongest selection for divergence would occur in this frequency, completely unknown to us.

All of this led me to think about how we, as eco-evo scientists, can start to shift our paradigm to think about the world through the senses of the organisms we study, which would give us a much better ecological picture of the selection pressures maintaining polymorphisms. The first step, is to take one small step outside of our anthropocentric sense and see the world through the eyes of animals. Thanks to the Yale Center for Teaching and Learning, I was able to design an interactive digital project that helps take those first few steps along a Proustian walk.

But it turns out, when you take the time to look closely, evolution is taking place all around us, fast enough for us to see and measure. What’s more, evolution may even happen faster around us since we humans tend to create novel and often extreme selection environments that encroach into natural habitats (or entirely new habitats for those species that hitchhike into citeis with us). Johnson and Munshi-South (2017) reviewed the growing list of studies uncovering rapid evolution of wildlife in response to urbanization.

I showed the article to my partner (Baylaart.com) who used it as a theme for her most recent piece which is comprised of organisms subject to contemporary urban adaptations. Both the article and the painting are exceptional work that I’ll walk through below.

When faced with new environmental challenges, populations of organisms are faced with two options: move or adapt. (The third, extreme alternative is extinction). Urban wildlife populations are either residual populations that existed prior to urban development or new populations that colonized after a city emerged.

A classic example of urban adaptation is industrial melanism in the peppered moth (Biston bitularia) (Kettlewell 1955, 1958). As soot poured out of cities during the industrial revolution, the light colored polymorphism of the peppered moth offered poorer camouflage than the black, soot-colored morph. As a consequence, the dark morph came to dominate urban populations. As industry cleaned up its act, the trend reversed.

We can see the effects of urbanization in modern cities, today. White-footed mice (Peromycus leucopus), a North American native, in urban settings are marked by much less genetic variation, and therefore, lower evolutionary potential (Munshi-South et al. 2016). On the flip-side, this reduced variation could be the result of selection sweeping all unadapted alleles from the population, leaving a more genetically homogenous population as a result of the evolutionary process. Even animals that look unchanged may have evolved subtle adaptations. For instance, blackbirds (Turdus merula) in cities exhibit a molecular level difference in a gene associated with harm avoidance behavior compared to their natural brethren (Mueller et al. 2013).

Some species have adapted so well to urbanization, that they are almost synonymous with cities world-wide. For instance, the German cockroach (Blatella germanica), Rock dove (Columba livia), and Norway rat are veritable mascots of cities. Urban roaches and rats have evolved resistance to pesticides (Booth et al. 2011; Rost et al. 2009), and roaches in cities have even evolved an aversion to glucose in response to selection by sugar-baited traps (Wada-Katsumata et al. 2013). Rock doves in the cities have evolved defenses, not to human extermination attempts, but to predation by city-dwelling falcons (Palleroni et al. 2005).

Some populations precede city creation. Red-backed salamanders (Plethodon cinerus) in Montreal, Canada managed to persist as the city was constructed around them, but their populations have been isolated genetically, resulting in low variation (Noel & Lapointe, 2010). Across the Atlantic fire salamanders (Salamandra salamandra) also had a city (Oviedo, Spain) built atop their population starting over a millennia ago and managed to persist despite severe restriction in gene flow (Lourenco et al. 2017). Animals don’t need hundreds of years to adapt to new development, though. Water dragons (Intellagama lesueurii) inhabiting newly established city parks built as recently as 2001 in Brisbane, Australia have developed genetic difference in body shape and total size (Littleford-Colquhoun et al. 2017). Similarly, a small population of dark-eyed juncos (Junco hyemalis) established in the 1980s have been thoroughly studied (due largely to their location on the UC San Diego campus) and found to have evolved shorter wings, shorter tails, and alternate plumage pattern in just the past few decades (Rasner et al. 2004; Yeh 2007).

Other species, like the common wall lizard (Podarcus muralis) and striped mouse (Apodemus agrarius), seem to have been able to adapt to the development of Trier city in Germany (for lizards (Beninde et al. 2016)) and Warsaw, Polans (for mice (Gortat et al. 2014)) and now disperse through the city architecture in a similar way to their natural environment. Cityscapes can offer very similar (although much more angular) habitat to an organism’s natural habitat. For instance, Anoles (Anolis cristatellus) perch on the vertical trunks of trees in the forest. The flat walls of building in Puerto Rico offer a similar niche; however, artificial walls tend to provide less grips for lizards. In response, urban Anoles have evolved longer limbs and stickier toepads to cling to homes and businesses (Winchell et al. 2016).

Small animals are not the only wildlife subject to urban impacts. The movement of many large mammals, such as bobcats (Lynx rufus) (Serieys et al. 2014), are restricted by roadways, despite our best efforts to promote connectivity. In some cases, large and mobile animals are able to break into the new habitats afforded by cities. Red foxes (Vulpes vulpes) colonized the city of Zurich, Switzerland less than two decades ago and in that time their urban populations have exploded (Wandeler et al. 2003). While the original urban populations were likely established by just a few intrepid foxes, now that the urbanite populations are large enough, they have established genetic connectivity with their rural counterparts, essentially extending the larger population’s range to include the city.

In addition to landscape alterations that reduce gene flow and incur selection, urban settings can actually increase genetic mutation rates (which is ultimately the raw substrate for evolutionary adaptation). As an example, the rate of mutation in herring gulls (Larus argentatus) that nest in a heavily industrialized site in Ontario is double their less urban counterparts likely due to exposure to toxic chemicals in the environment (Yauk & Quinn 1996).

Let’s not forget that animals are not alone in their evolutionary response to urbanization—plants have also demonstrated adaptations to cities. Clover (Trifolium repens) in urban populations have evolved a reduction in cyanogenesis, a process that makes the plant less palatable to herbivores but in trade-off leaves the plant less tolerant of freezing temperatures (Thompson et al. 2016), which makes sense since there aren’t many large grazers wandering city streets and urban settings tend to act as heat islands.

In order to reduce seeds falling on infertile concrete streets and sidewalks, Holy hawksbeard (Crepis sancta) a weed in Montpellier, France have evolved to produce less dispersing seeds (Cheptou et al. 2008). In addition, the urban plants evolved an increase in photosynthesis and larger flowers (Lambrecht et al. 2016). Virginia pepperweed (Lepidium virginicum), is a common weed in many U.S. cities. A study of genetic divergence between urban and rural settings found that urban plants were more closely related than the more geographically proximal rural populations (Yakub & Tiffin 2016). In addition, the city pepperweed had developed a different shape and growing season to rural plants.

It’s clear that almost anywhere you look in cities, wildlife is evolving in response to our presence. This bestows us with a massive responsibility and indebts us to an ethic of conservation, not of species themselves, but to preserve as much unencumbered wild habitat as possible (for instance, as designated Wilderness). Where saving wild space is impossible, we must work on mitigating the effects of our urban infrastructure (for instance).

Literature cited:

Beninde, J., Feldmeier, S., Werner, M., Peroverde, D., Schulte, U., Hochkirch, A., et al. (2016). Cityscape genetics: structural vs. functional connectivity of an urban lizard population. Mol. Ecol. 25, 4984–5000.

Booth, W., Santangelo, R. G., Vargo, E. L., Mukha, D. V., and Schal, C. (2011). Population genetic structure in german cockroaches (blattella germanica): differentiated islands in an agricultural landscape. J. Hered. 102, 175–183.

Cheptou, P.-O., Carrue, O., Rouifed, S., and Cantarel, A. (2008). Rapid evolution of seed dispersal in an urban environment in the weed Crepis sancta. Proc. Natl. Acad. Sci. U. S. A. 105, 3796–3799.

Gortat, T., Rutkowski, R., Gryczyńska, A., Pieniążek, A., Kozakiewicz, A., and Kozakiewicz, M. (2015). Anthropopressure gradients and the population genetic structure of Apodemus agrarius. Conserv. Genet. 16, 649–659.

Johnson, M. T. J., and Munshi-South, J. (2017). Evolution of life in urban environments. Science 358.

Kettlewell, H. B. D. (1955). Selection experiments on industrial melanism in the Lepidoptera. Heredity 9, 323.

Kettlewell, H. B. D. (1958). A survey of the frequencies of Biston betularia (L.) (Lep.) and its melanic forms in Great Britain. Heredity 12, 51.

Lambrecht, S. C., Mahieu, S., and Cheptou, P.-O. (2016). Natural selection on plant physiological traits in an urban environment. Acta Oecol. 77, 67–74.

Littleford-Colquhoun, B. L., Clemente, C., Whiting, M. J., Ortiz-Barrientos, D., and Frère, C. H. (2017). Archipelagos of the Anthropocene: rapid and extensive differentiation of native terrestrial vertebrates in a single metropolis. Mol. Ecol. 26, 2466–2481.

Lourenço, A., Álvarez, D., Wang, I. J., and Velo-Antón, G. (2017). Trapped within the city: integrating demography, time since isolation and population-specific traits to assess the genetic effects of urbanization. Mol. Ecol. 26, 1498–1514.

Mueller, J. C., Partecke, J., Hatchwell, B. J., Gaston, K. J., and Evans, K. L. (2013). Candidate gene polymorphisms for behavioural adaptations during urbanization in blackbirds. Mol. Ecol. 22, 3629–3637.

Munshi-South, J., Zolnik, C. P., and Harris, S. E. (2016). Population genomics of the Anthropocene: urbanization is negatively associated with genome-wide variation in white-footed mouse populations. Evol. Appl. 9, 546–564.

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Overview:

Isle Royale is an island in Lake Superior that is designated as a Wilderness Area and managed by the National Park Service. In the 20th century, wolves and moose migrated to the island and their dynamic spurred one of the longest predator-prey studies in history. Now, the wolf population has dropped to 2 and the Park Service is planning a major intervention that will install an entirely new, synthetic population of wolves on the island. This plan is the result of myopic research perspective and disregard for eco-evolutionary dynamics. It is bad policy and even worse science. Here’s why:

Background:

Isle Royal is a smallish-island (just over 200 square miles) that sits about 8 miles from the north shore of Lake Superior. (Although it is small, it is large enough to host its own internal lake with an island, making it, as upper-midwesterners are fond of point out, the largest island on the largest lake on the largest island on the largest lake in the world.) The Isle and its many tiny satellite islands became a National Park in 1940 and were designated as a federal Wilderness Area in 1976.

Because the island is small and a long swim from the mainland, large fauna populations have been inconsistent denizens, historically. Moose first arrived on the island in the early 1900s. Wolves followed the moose in the 1940s, adding two major trophic levels to the island ecosystem. The complex predator-prey interactions became one of the classic test cases of ecological theory (see Peterson et al. 1984; McLaren & Peterson 1994).

Over the decades, the wolf and moose populations have demonstrated a standard predator-prey oscillation, with the wolves generally bouncing around about 20 individuals, but reaching a population maximum of 50 individuals in the 1980.

However, Isle Royale is a small place. Small islands are more susceptible to tipping points on the roller-coaster of demographic stochasticity. It’s kind of like drunkenly walking along the centerline of a bridge versus drunkenly walking a tightrope. If you stumble off course too far on the bridge, you have the latitude to recover and get back on course. Too big a waiver on a tightrope and you’re done for. The small size and isolation of Isle Royale makes it a tight rope for large predators. Like all oscillatory ecological patterns, what goes up eventually comes down, and in the last decade or so, the wolf population has declined in a mirror-like inversion of the population boom in the 1980s. As of this year, there are only two wolves left. As per the dynamics of island-biogeography, the natural course looks like the rein of the wolf will eclipse on the island, probably followed by a boom and eventually extirpation of moose, and the island will continue along as it did for the many decades prior to the most recent immigration events. That is, until the next colonists arrive, as has happened multiple times in the past. Coyotes immigrated and blinked out in 50 years in the early to mid-1900s. At times, lynx and caribou both made the pilgrimage to the island and subsequently slipped off the tightrope.

The issue:

Now, the National Park Service has released an Environmental Impact Statement (EIS) for a plan to install a new populations of wolves on the island (available here). If you are unfamiliar with the NEPA process, here’s how it works: When a land management agency like the National Park Service wants to embark on a project that might run counter to its mandate and/or result in large impacts, they are required to vet all potential options, usually as an EIS, and ask for the public’s comments on the plan. After the revision process, they make a final decision to enact one of those potential options, the “preferred alternative.”

Since 99% of  Isle Royale Park is a designated Wilderness, “where the earth and its community of life are untrammeled by man” and “generally appears to have been affected primarily by the forces of nature, with the imprint of man’s work substantially unnoticeable” (Wilderness Act, 1964), shipping in a boatload of wolves to manipulate the ecosystem required an EIS.

As a scientist and especially as an ecologist, I tend to view Wilderness Areas as our most critical ‘controls’ or ‘baselines’ for science to contrast other areas where human impact alters systems. Though every system is touched by human impact to some extent, there is huge value in preserving the least impacted places in an unmanipulated state. As an analogy, a blemished diamond might be worth a little less than a perfect diamond, but that doesn’t reduce it to equal value with a lump of coal.

But, not all scientists think that way.

To introduce or not to introduce:

The push to introduce wolves to Isle Royale has been championed primarily by two researchers at Michigan Tech, John Vucetich and Rolf Peterson, whose careers are rooted in the Isle’s wolf-moose study.

I first heard about this proposal when Vucetich gave a presentation at the Sigurd Olsen Environmental Institute. At the time, it wasn’t the science that bothered me about the presentation–it was the patent misrepresentation and obvious straw-man Vucetich employed to characterize the intention of the Wilderness Act. Since then, these researchers have made major pushes in film (and this one) and popular press to portray wolves as an ever-present and integral part of the Isle Royale ecosystem, and pit the “health” of the ecosystem against what they believe is an outdated philosophy of conservation.

Essentially, their argument is that since climate change impacts the whole globe, no wilderness is really free of human manipulation, so we should be free to further manipulate it to our own design. They explicitly argue for “new visions for the meaning of wilderness,” with their preferred vision being “a place where concern for ecosystem health is paramount, even if human action is required to maintain it” (from here).

Intentionally or not, their use of relativistic “ecosystem health” rhetoric and attempts to stretch the ‘wilderness myth’ concept into their own application has thoroughly muddied the debate.

And it’s resulted in a lot of public confusion on the topic. For instance, here’s one comment I pulled from the public response in the EIS:

I have visited Isle Royale twice and it remains one of my favorite places in the world. The wolves and the moose have become a part of the island and that is a good thing. Wolves and moose aren’t faring well on the mainland due to politics ignorance and climate change. Isle Royale remains a unique microcosm where we can still observe and study this ancient predator-prey relationship. In a world where species are becoming extinct on a daily basis, this rare relationship has endured and that should be given a lot of weight when making the decision of what to do about the wolf-moose problem on Isle Royale. Please use common sense and act sooner rather than when it is too late.

First off, it’s not an ancient relationship (it’s only been going on for 60 years on the island), and it’s not a rare relationship (wolves eat moose all over the continent all the time). What makes it “rare” is the fact that it happens without human intervention (at least until NPS takes control of the population) on an isolated island with researchers tracking every move.

This person’s comment shows that opinions on the wolf issue are completely colored by human perception: i.e. anything that happened before your lifetime is “ancient,” anything that looks the way it is when you first saw it is “natural,” if you’ve only heard about something in one place, it must be “rare,” etc. The most pernicious perception is that the only species that are worth concerning ourselves with are the big ones with faces that you can relate to (after all, amphibian populations fluctuate on and off in ponds all over the upper midwest following the exact biogeographic pattern as the wolves of Isle Royle, but I’ve yet to see an outrage).

Even the main proponents of wolf introduction, Vucetich et al. and the National Parks Conservation Association invoke the myth that a “sustainable” wolf population is critical to the island’s “health.” Considering that wolves only appeared on the island within a human lifetime and probably blinked on and off the island historically, wolves are only an ephemeral component of this dynamic ecosystem. They never have been “sustainable,” and if ecosystem “health” hinges on the presence of wolves, the island has always been naturally unhealthy.

The rhetoric of “healthy” ecosystems is useless in science, because its meaning is entirely relative. Rolf Peterson, the researcher who initiated the moose-wolf study in the 70s, states that, “There’s a mythical belief that Isle Royale has been working well because we kept our hands off it; my opinion is, it worked well because there were wolves there” (from here). You can only consider a wolf-inhabited Isle Royale as “healthy” if you define a “healthy” ecosystem as one that looks the same way it did when you started your research plan. The real myth is conflating wolf presence with Isle Royale’s natural state, and in this case, it seems a personal mythology crafted to shore the legacy of Peterson’s research project.

The Park’s plan:

The preferred action of NPS is to install 20-30 wolves on the island over the next 3 years, and if those don’t take, to continue introducing for 2 more years.

Originally, the proponents of airdropping new wolves onto the Isle proposed it as genetic “rescue.” But with only two post-breeding age, inbred stock left, there is little chance that new wolves will breed with the two relics. Thus, in reality, this is not a genetic rescue project, it is a genetic replacement project.

So, where do the replacement wolves come from? The EIS suggests that wolves should be sourced from the mainland near the Park, but that many different populations around Lake Superior should be mixed on the island. They also suggest sourcing wolves with experience hunting moose (which are rare in mid-western populations).

Will a new population fair better? The reason wolves lost the plot in the first place was due to the ubiquitous force of natural selection. When faced with strong selection pressure, organisms are faced with three choices: move (not possible on an island), adapt, or disappear. The current wolves were not able to adapt to the ecological scenario they found on the island, so they are disappearing. The NPS knows that new wolves will be even more likely to succumb to selection pressure because they will not be locally adapted. This is why they are planning recurring introductions for a total of up to 5 years. The new population, with lots of diverse genetic material to work with, might be more prone to local adaptation, or it might be more prone to crash because the animals are too locally adapted to their naive system to cope in the new setting.

It might be tempting to think that evolution won’t be a factor considering the short tenure of wolves on the island, but wolf generation times are under 5 years (Mech et al. 2016) which means that they’ve had about 20 generations on the island. We know from the deluge of rapid evolution studies in the past few years that 20 generations is well within the timespan for marked evolution. Similarly, one can expect that moose have been evolving in that time too (Hoy et al. 2018), as have the plants that are browsed by moose, and the small mammals, and the microorganisms that exists in concert… In other words, the entire trophic system has been subject to dynamic eco-evolutionary change that has refined its assemblage and genetic composition. Replacing local wolves with wolves from elsewhere will short-circuit that dynamic process and set a new eco-evolutionary trajectory. Any study that occurs post-introduction will be studying a different eco-evolutionary system, altogether.

Proponents have made the case that occasional genetic influx from the mainland population (when a wolf might cross the ice to the island in cold winters) is part of the natural dynamic, but that climate change has disrupted this process. Leaving aside the fact that much of Isle Royales history was wolf-less long before climate change, reintroducing wolves does not simulate this natural process. In natural migration events, wolves are not randomly selected from a larger pool. The process of migration is a selective sieve that winnows out some potential migrants and selects for others. By high-grading the genetic stock from the mainland based on their own criteria, the Park Service will not be replicating nature, they will be conducting a large-scale, manipulative selection experiment.

The value of non-intervention:

As I mentioned, one of the most critical values of Wildernesses are their role as baselines. This is a point  repeatedly highlighted in the “Strategic Plan for Scientific Research in Isle Royal National Park” (Schlesinger et al. 2009).  The Plan lists as “Unique Attributes of Isle Royale National Park” that it is “An Isolated Location for Baseline Studies”, and “an Ideal Place to Study Fundamental Ecological Concepts” like island-biogeography and predator-prey dynamics.

Isle Royale attracts biogeographers, whose focus is the distribution of life forms as determined by the balance of regional dispersal and local extinction processes (MacArthur and Wilson 1967). Determination of the relative importance of both dispersal and extinction is of central interest to ecologists wishing to explain variability in the species diversity of a given environment and the potential changes brought about by environmental change. As the Strategic Plan states, “the pristine nature of Isle Royale offers an opportunity to examine the potential influence of regime shifts due to natural causes or indirect anthropogenic causes such as climate change.” If we choose a policy of artificially imposing stasis on a naturally dynamic ecosystem we lose that value almost entirely.

On the other hand, if we practice humility and allow natural systems to be dynamic, we can ask a list of interesting questions: What happens if we remove those top trophic levels of moose and wolf? How will that impact the nutrient cycle? How will it impact community dynamics? In what ways will the change in selection pressures drive evolution? Will the eco-evo dynamic play out in predicatable ways based on theory and inference from other archipelagos? What will the post-wolf community composition look like and will it be the same as the pre-wolf community? Etc. etc…

There are endless scientific questions that a wolf-less IR can answer. On the other hand, a replacement wolf population cannot even answer the original question that it is intended to address because such a manipulation cannot be considered a continuation of that community; at best, we can only consider this a manipulative experiment at the price of sacrificing an entire natural ecosystem and ruining an exemplary opportunity to study eco-evo dynamics.

References:

Hoy, S.R., Peterson, R.O., and Vuctich, J.A. 2018. Climate warming is associated with smaller body size and shorter lifespans in moose near their southern range limit. Global Change Biology. DOI: 10.1111/gcb.14015

Losos, J. 2017. Improbable Destinies: Fate, Chance, and the Future of Evolution. Riverhead Books; New York.

Right up front, I have to admit that I was very excited for this book. As someone with an academic interest in both herpetology and rapid evolution, I’ve been an admirer of Dr. Losos’s research for a long time.

I ordered my copy as soon as it came out. Unfortunately, it arrived just a little while before my comprehensive exams. Rather than let it sit lonely on my bookshelf while I studied for the next few weeks, I stayed up a couple of consecutive nights and read until my eyes fell shut just before my morning alarm sounded. My intent was to give it a more thorough read again before writing a review, but then Ethan Linck wrote the words right out of my mouth in his review over at The Molecular Ecologist blog, so I’ll just add a few of my non-overlapping thoughts quickly here.

The read:

Improbable Destinies is written by an author with a truly unique perspective at the far forward fringe of eco-evolutionary research. The book is written less as an academic exposition than as a casual conversation between Losos and a new undergraduate researcher. Sometimes, the tone broached into the realm of chummy-awkward conversation, though.

As Linck points out in his review, Losos has a noticeable penchant for dad jokes and puns. At times I also got the feeling that, like a dad misusing slang around his kids in attempt to inflate his hip-factor, Losos tried a too hard to reach for modern references. The references to Chris Pratt in Jurassic Park, Futurama, and Seinfeld were well-placed, but in other cases, like comparing Anole skin patterns to QR-codes, the analogy was dated years before the book was published (I’m a millennial and I’ve never used a QR-code; I can just imagine Gen Z-ers falling back to Wikipedia to understand that reference).

Despite the occasional “dad-vibe” the delivery is inviting and it is written to be accessible for anyone interested in ecology. Although it is an easy read, the book manages to introduce the absolute freshest research while also rooting contemporary studies in the field’s deep history. In some ways, I think of Improbable Destinies as an update and continuation of Weiner’s 2006 book, The Beak of the Finch, which shares the same tone and many of the same characters.

The story:

Without too many spoilers, here’s a quick introduction to the book:

The primary question laid out in the first chapter is borrowed from Stephen J. Gould (who, in turn borrowed it from the movie It’s a Wonderful Life), and boils down to: Is evolution deterministic or contingent? In other words, if we could repeat the Plinko game of evolution, would the puck always end up in the same slot no matter the path (deterministic) or would the puck land in a new slot every round (contingent)?

Just as Gould couched the thesis of his eponymous book (Wonderful Life: The Burgess Shale and the Nature of History) in the movie, Losos uses the same tactic with a different move: Pixar’s The Good Dinosaur. More specifically, Losos wonders, if events had transpired differently many years in the past and the asteroid had not struck the Earth (the plot of The Good Dinosaur)–and thus, if mammals had not inherited the Earth–would some other species have evolved to occupy the same niche as humans? Would a highly intelligent, environment-engineering, abstract-concept-wielding, apex predator have played the part in our absence? And if so, how different would it look alongside a human comparison?

But Losos formulates his question slightly differently in order to answer it with real-world examples. Rather than asking ‘how contingent is evolution?’ he asks ‘how convergent is evolution?’
It’s an interesting question to tee off a long list of empirical examples, including his own research (accompanied by behind-the-scenes anecdotes of the research), that Losos uses to make his case.

He is a great person to answer this question since he’s spent a good portion of his life studying evolutionary convergence in radiations of lizard species (e.g. Losos 1990). He also brings a whole new perspective to the question that Gould never had. In the past few decades, there has been a proliferation of research in rapid and experimental evolution (e.g. Losos, Warheitt & Schoener, 1997). While Gould was stuck playing out his scenarios as thought experiments, Losos draws on new research in rapid evolution that plays out evolutionary scenarios with real populations in contemporary timescales to consider just how deterministic/contingent evolution may be.

I really enjoyed reading the stories behind some of the foundational papers in this relatively new field, like the story John Endler’s first experiments making tinfoil hats for lizard to block light (of that experiment Losos writes “…alas, foiled by equipment malfunction.” [emphasis added for maximum dad-joke power]). Or, David Reznick’s near-death experience in Trinidad. Or, Rowan Barrett’s travails in rattlesnake wrangling. My reading was especially timely since I followed it up with a few solid weeks immersed in evolution literature for my comps. It was fun to read the publications of folks like Dolph Schluter and be able to connect the dots of academic pedigree (Grant and Grant beget Schluter who beget Barrett) and Losos’s stories about them.

The backstory:

One thematic story that the book spends quite a bit of time addressing is that of Simon Conway Morris. The first chapters of the book deal with the origination of the determinist school of evolutionary theory, of which Morris is a major proponent. Although Losos hints at the teleological assumptions adhered to by Morris, Losos avoids pointing out the religious underpinnings that color much of the determinist theory.

Morris believes in a supernatural god. He is also a serious biologist who understands the mechanism of evolution. As such, it seems that his insistence on the inevitable evolutionary outcome of “a creature with intelligence and self-awareness on a level with our own” (cited from this essay) is driven by the realization that there must be a deity-worshiping species if there is to be a deity. Jerry Coyne provides a much more in depth look into Morris’ teleology in his post.

I think Gould charges Morris on this point most clearly in their exchange, published by the Natural History Magazine in 1998 (The article is worth reading in entirety, but if you haven’t the time, I’ve included a few TL;DR excerpts below). Gould writes that Morris’s conclusions, “can arise only from a ‘personal credo’—and I would value his explicit attention to the sources of his own unexamined beliefs.”

I won’t give away Losos’s final conclusion nor where he falls on the Gould vs. Morris debate. However, I will again point out that the strength of his argument lies in the inferential power of the predictive evolution experiments he cites. Both Gould and Morris were limited to retrospective inference (i.e. telling stories about the path of a Plinko puck from nothing but its final resting slot), but predictive experiments are rigorously falsifiable (i.e. testing out stories about the path of a Plinko puck by dropping it down the board in real-time).

One last thing:

I couldn’t help but notice the striking similarity in jacket covers between Improbable Destinies and Dale Peterson’s The Moral Lives of Animals.

I’m sure it wasn’t intentional, but it is hard to miss the lion in the foreground along with the guinea fowl and peacock, the elephant in the background, and the horned ungulate in the middle.

FWIW: Peterson’s cover is a reprint of a Brueghel painting. Losos’s cover is a digital composite of original Mutzel lithographs.

Postface:

Here are my favorite excerpts from the exchange between Stephen Jay Gould and Simon Conway Morris, “Showdown on the Burgess Shale,” Natural History magazine, 107 (10): 48-55.

Morris’s argument:

“Gould sees contingency evolutionary history based on the luck of the draw—as the major lesson of the Burgess Shale. If you rerun the tape of evolution, he says, the results would surely come out differently. Some creature similar to Pikaia, a small eel-like animal with a rudimentary head, may have survived in Cambrian seas to become the ancestor of all vertebrates. If it hadn’t, Gould says, perhaps other—entirely different—major animal groups would have evolved instead from one of the Burgess Shale’s other “weird” body plans. Such a view, with its emphasis on chance and accident, obscures the reality of evolutionary convergence. Given certain environmental forces, life will shape itself to adapt. History is constrained, and not all things are possible.
…
Contingency or no, I believe that a creature with intelligence and self-awareness on a level with our own would surely have evolved—although perhaps not from a tailless, upright ape. Almost any planet with life, in my view, will produce living creatures we would recognize as parallel in form and function to our own biota. But first, life must arise, and we have no idea how rare an event that might be. If we are honest, despite our exciting fancies about extraterrestrials, we must admit the real possibility that life arose but once, and that we are alone and unique in the cosmos—with an awesome and, to many, unanticipated role as stewards of all other living things. But were we to let evolution take another route than it did, why not grant (as, Gould will not) that another kind of being would have evolved to fill our special place in nature?”

Gould’s argument:

“Conway Morris charges that my arguments for contingency arise “not from the evidence of paleontology but from Gould’s personal credo about the nature of the evolutionary process.” This claim, however ungenerously stated, is—and must be—true, for any general view of life must read evidence in the light of a favored theory. I would, however, label my view as a valid reading of paleontological evidence in the context of a theory about life’s evolution and history that I have worked out by considerable thought, practice, and intellectual struggle, and that I always explicitly identify as tentative, undoubtedly wrong in places (but not, I hope, in general approach), and embedded (as all ideas must be) in my own personal and social context.
I am puzzled that Conway Morris apparently, doesn’t grasp the equally strong (and inevitable) personal preferences embedded in his own view of life—especially when he ends his commentary with the highly idiosyncratic argument that life might be unique to Earth in the cosmos, but that intelligence at a human level will predictably follow if life has arisen anywhere else. Most people, including me, would make the opposite argument based on usual interpretations of probability: The origin life seems reasonably predictable on planets of earthlike composition, while any particular pathway, including consciousness at our level, seems highly contingent and chancy.
I don’t know how else to interpret the cardinal fact that life did originate on earth almost as soon as environmental conditions permitted such an event—an indication, although surely not a proof, of reasonable expectation and predictability; whereas consciousness has evolved only once, and in a marginal lineage among so many million that have graced our planet’s history—an indication, although again not a proof, that such a phenomenon is not inevitably meant to be.”

 

References:

Losos, J. B. (1990). The evolution of form and function: morphology and locomotor performance n West Indian Anolis lizards. Evolution 44, 1189–1203. doi:10.1111/j.1558-5646.1990.tb05225.x.

Losos, J. B., Warheitt, K. I., and Schoener, T. W. (1997). Adaptive differentiation following experimental island colonization in Anolis lizards. Nature 387, 70–73. doi:10.1038/387070a0.

Losos, J. (2017). Improbable Destinies: Fate, Chance, and the Future of Evolution. Riverhead Books; New York.

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