Apps that Darwin would have loved

Was Charles Darwin first? Kind of depends – Harvard Gazette

Most people know that Charles Darwin was a cerebral, deep thinking type. He traveled the world, collecting data about those finches and other stuff on field expeditions, synthesizing big ideas over decades to form his magnum opus, On the Origin of Species, where he set out his theories on natural selection and its role in evolution. However, you might not know that on a day-to-day level, Darwin was an all-around nerd’s nerd who just wanted to learn everything he could about the world, motivated by an unending sense of curiosity.

Darwin was a man who pulled plankton nets, filtering seawater just to see what cool stuff would show up when he put the resulting sample of goo under the microscope. He fiddled for earthworms and wrote a book about them over 40 years (including an experiment where he watched their progress burying a bunch of rocks over a 30 year period). He kept a heated greenhouse where he studied orchids and carnivorous plants. I consider Darwin a role model, because it’s hard to find a topic in natural history that he didn’t write about. The dude was just an unfillable sponge of knowledge.

A view of Darwin’s greenhouse. Source: The Darwin Correspondence Project

I think Darwin would have marveled the online information that we have easy access to today. If Darwin were a researcher today, I could imagine him hosting a forum or listserv where he’d moderate, muse over the natural world and keep correspondence with the other leading scientific minds, much as he was a prolific letter writer with other researchers of his time. He might not be huge on Twitter: a bit too fast paced for his liking I bet; but I think he’d love two apps that I have also fallen in love with over the last few years.

The Explore page on iNaturalist, where you can see what species other people have recently observed in your area!

The first is iNaturalist (Android, iOS), a website and social network where you can upload pictures of any lifeform, attach information about its location, time of day and other info, and the machine learning powering the site will try to identify it for you, with amazingly accurate results. If the AI can’t figure it out, experts are waiting in the wings to provide an identification or confirm yours. Think of it like a Pokedex or Pokemon Go, but for “collecting” real life creatures. And like Pokemon Go, it can be insanely addictive to find out about all the species that are all around us at all times. iNaturalist also has an app called Seek that makes the process even more gamified!

a view of my observations

I am definitely an iNaturalist addict, and have accumulated a healthy collection of observations over the past couple years. My first was a red-shouldered hawk that I saw on campus during my PhD, but then I moved onward to fungi and plants I saw walking from my car to the office, and went back through my past pictures to identify bats I saw in Belize, fish I saw diving, and of course, my beloved banana slugs. I find it’s particularly satisfying to find out how life around you changes through the year, with the seasons. When I felt like pulling my hair out during my PhD, it kept me grounded to be able to know that the first spring flowers were opening, or the fledglings of birds were leaving the nest, or the winter rains were bringing all sorts of new fungus and banana slugs to life among the undergrowth.

I think being in touch with our natural world can help us now. While we’re sheltering in place, we don’t have to be trapped within ourselves. Even in the densest cities, there are so many bugs, flowers, birds and squirrels all around us going about their lives while we are effectively on pause. It brings me relief to know that life continues, and satisfaction to be able to understand them. Knowledge really is power, and if you know the relations between all the types of life both in evolution and ecology, it makes the world make sense in a way that provides a weird zen-like peace.

To that effect, there is a #citynaturechallenge happening starting yesterday, from 4/24-4/27/20. Take pictures of living things around you and upload them to iNaturalist, Twitter and elsewhere with that hashtag! My uploads there have been of interest to researchers studying rare snails of the Negev desert, writing books about tropical bats, and researching invasive beetles. I have been following uploads of giant clams on iNaturalist for quite some time, including the newest described species, Tridacna elongatissima, which users had been observing on the Eastern coast of Africa before it was formally described in a recent paper! I bet Darwin would have been a major, influential user on iNat.

Darwin was also a big nerd regarding rocks and fossils. Evolution is the story of life, and we can only understand that story by turning to the fossil record for information. Environmental changes provide a major motivating factor pushing life to constantly change. Geology in Darwin’s day was a developing field, with the first geological maps appearing only due to the work of William Smith and others, mere decades before Darwin’s work came to be. But his work would not have happened without the growing understanding of the massive passages of time needed to deposit the rocks all around us today. Evolution typically needs time, and fossils provide proof of how life has changed during those almost incomprehensibly long intervals.
One of William Smith’s geologic maps

To find a fossil of an age we are interested in, we must know the rocks present in the area. And the second app I’ll mention today is RockD (Android, iOS), which we can use to figure out the type of rocks right under our feet, how they were made, how old they are and even what kind of fossils have previously been found within. The data in RockD is pulled from two sources that scientists have lovingly curated. Macrostrat is a database of stratigraphic (rock layer) data that scientists have aggregated into one of the most detailed and comprehensive geologic maps ever made. And the Paleobiology Database collects observations that scientists have made over the decades of almost every fossil that has ever been found and recorded.

Of local geology when you first open RockD (my detailed coordinates obscured ;))

Rather than relying on only printed maps for his work, Darwin would have loved the ability to pull out his phone in the field and instantly know the combined work of dozens of previous researchers to understand the rock he was looking at. You can even “check in” and upload your own pictures of rocks to help researchers improve their databases, and go back in time to look at where the continent you live on was during the time of the dinosaurs!

Geologic map of my area. Darwin would have seriously nerded out checking out the locations of faults, formations and other features

These are only two of many apps and websites that I think would have blown Darwin’s mind. We are living in a golden age of digital science, with so many new discoveries being precipitated by the availability of easily accessible, free information in the palms of our hands. But more than that, it is fun to go outside and be able to decode the mysteries of the world around you without even being an expert in natural history. In the process, you might find yourself becoming an expert!

Why do worms surface after a rain?

Source: Eva the Weaver on Flickr

Biologists have long wondered at the capabilities of earthworms. When he wasn’t crafting foundational theories of modern biology, Charles Darwin discovered that earthworms assist plant growth by aerating and turning over soil. Previously derided as pests, his work helped to shed light on the dark, dirty, essential role of these silent tillers of the earth. Earthworms spend most of their lives converting organic matter into compost. They play an important role in nutrient cycling, as the castings that they leave behind are rich in important nutrients like phosphorus and calcium.

Our sunny, dry surface world is not safe for these subterranean beasts. Earthworms are not at home in daylight and are usually only there by necessity. One of the most common times to observe them is during and after a rainstorm, particularly at night. As a child, I often wondered why earthworms seemed so determined to drown themselves in puddles. Researchers have still not reached consensus on the causes for this behavior. Darwin supposed that the sicker worms were driven to the surface by flooded soil. Some propose that they are driven from the saturated soil by low oxygen content, where many drown in puddles as they attempt to find non-waterlogged soil. Other researchers are skeptical of this angle, as worms require moisture to breathe through their skin, and many species can survive immersion in water for extended periods. They suggest that the worms are using the wet conditions brought by rains to aid migration to new patches of soil, or even to mate. The reality, as often is the case, is likely something of a combination of all of the above.

One team found that different earthworm species have different tolerance levels for low oxygen conditions. The worms that can survive extended periods of immersion in water are the same species that often remains under the ground following a rainstorm. These worms have lower oxygen consumption. The worms with higher rates of oxygen consumption leave the ground when dissolved oxygen levels are too low to sustain respiration. They do so preferentially at night, partially because this is a period when they are more active, and thus respiring more oxygen, and also because at night they are less exposed to predation by birds. The early bird (at least before sunrise) really does tend to get the worm.

Some have suggested that the rhythm of raindrops stimulates the emergence of earthworms, and that the same mechanism allows fishermen (and animals) to use “worm fiddling” or charming to gather thousands of worms at a time for bait. Worm fiddling can take many forms, but one of the most common techniques observed involves rubbing a long piece of metal against a post driven into the ground. The vibrations induce thousands of worms to rise up out of their burrows.

Ken Catania, a biologist at Vanderbilt University, rejected the rain rhythm idea and proposed that worm fiddling actually works by imitating the noise of a burrowing mole, one of the most ravenous predators of worms. Rather than fleeing from the simulated rain, the worms are fleeing the jaws of their greatest enemy, only to be trapped at the surface by a different adversary. Like a whale driven to beach itself by noise pollution or the threat of a predator, surfaced earthworms deserve our sympathy, particularly if they’re destined to become our fishing bait.