Man, it totally happens.
Evolution happens everywhere at every moment. It happens in your refrigerator. It happens in your stomach. It is happening right now under your couch and in your eaves. Evolution gave us the marvels of the Galapagos Islands and also, of course, the terror of antibiotic-resistant bacteria. Evolution happens independent of belief. It happens; but it happens some places more rapidly than others.
A number of things can speed up the rate of evolution. These include the availability of resources, how sharp and non-random death’s sickle is, and the fragmentation of populations. Make food ample, life hard and isolation likely and expect some new traits and species to turn up.
Where do we expect evolution to be rapid? Oceanic islands seem to work, so might our domestic environments, our homes. These environments have an excess of resources (our physical houses, our food waste, our bodies). They are fragmented by the distances between front doors and back windows. In addition, the selective pressures—the sickles—are potentially strong. We kill species non-randomly with respect to their genetic variants, whether we do so in terms of our use of pesticides, our use of antibiotics, or our use of a well-placed shoe.
All of this is to say if you want to see rapid evolution, forget the beak of the finch; consider the mouthparts of the bedbug, the legs of a housefly or the bodies of mice. Consider especially the microbes, those rapidly evolving beasts that coat every surface of every home like a fur and can evolve rapidly. Consider them.
We should consider these life forms because they are interesting. Also because, well, some eat us. Some make us sick. Others seem to help make us healthy. Their evolution is all tied up with our fate. For as much as the Galapagos is an ecosystem that is lovely because of its abstracted elegance, the evolution in and around our homes is something different, fascinating because of its messy relevance.
Yet, the study of the evolution in our homes is in its infancy. Tens of thousands of species likely inhabit the average home (not to mention those in backyards or on the outsides of homes). Yes, I said tens of thousands of species, more species than there are kinds of birds on Earth. Michelle Trautwein‘s group at the Museum of Natural Sciences in North Carolina has found more than one hundred families of arthropods in many homes in North Carolina, not to mention the other invertebrates, not to mention the protists, not to mention the bacteria and archaea, not to mention the viruses. Yet, the evolutionary stories of all but a handful of these species remain unexplored. Even when the evolution of the species around us has been studied, the view we get is partial. Jason Munshi-South has shown that white-footed mice in different parts of New York City have diverged from one and other. Another study finds urban swallows have smaller wings than do their more rural kin. Several beetles that live in grain have, in moving in with humans, lost their wings. These are glimpses of broader truths, tantalizing and yet partial. We scarcely know who lives with us in our homes, much less the general rules that govern their evolution.
Does the design of your house influence the evolution of the species within it? Are unique lineages evolving in some refrigerators but not others? Does outdoor climate shape the lineages that persist or go extinct in one home versus another? No one knows and so we are convening the minds in June at the National Evolutionary Synthesis Center to try to develop a concepts and a suite of preliminary hypotheses to frame our understanding of the evolution of the species we spend the most time alongside. We are dreaming big; we’d like to jump start a new field, a field that travels among houses the way that Darwin once moved from one shore to the next in the H.M.S. Beagle.
Image 1. As an interesting aside, artists have arguably been the ones to most seriously consider the evolution in and around houses. Alexis Rockman for one has imagined the forms of vertebrates in the urban, domestic future. He imagines the diversification that will occur in cities, a radiation of wild (and in his work, apocalyptic) forms.
Once we have predictions, we could simply wait and see–across months, years and centuries–whether the lineages that evolve in the future meet our expectations but there is also another approach. We can consider the evolution that has already occurred in our homes. The first human homes were built more than 100,000 years ago (For more on the history of homes, see the book by Jerry Moore, The Prehistory of Home; Jerry, like Jason Munshi-South and Michelle Trautwein, is also involved in our group). That is plenty of time for us to see evolution in many of the species that live with us, evolution in addition to that due to factors we already know to have had an effect, such as pesticides and antibiotics. How different are the species living in our modern homes from those of our first homes, or the nests of hominids? No one appears to have ever studied the species living in the closest analogues to the antecedents of our homes, the nests of chimps and gorillas. No one has ever sampled the species living with hunter-gatherers either. No one has compared the species found in houses of different parts of the world. It is high time to build a ship of sorts to sail along these shores and into the unknown, but before we do, we need a framework, we need ideas of what we most need to understand, we need hypotheses.
The Sloan Foundation has generously provided the support for our upcoming meeting of the minds, a gathering that will include artists, cultural anthropologists, archaeologists, evolutionary biologists, microbiologists, a psychologist, ecologists, experts in urban and household design, epidemiologists and even those strange bug-sucking beasts, the entomologists. It is a super team of people from fields that would almost never normally interact, people who might fight or disagree (though we hope not, and even if it happens it seems likely to be passive aggressive, not aggressive–we are academics after all), but will almost certainly bring to bear new insights on the questions at hand.
Once we have reframed the study of indoor evolution, where will our own H.M.S. Beagle sail? Into your bedroom, we hope. That is the good news. We do not need to build or buy a boat to explore the evolution in our homes, we just need you to walk around your house and do experiments, sample or in other ways help us to see the wild diversity that has already emerged where we live. Where Darwin had the Beagle, we have you. For that we are grateful. The actual Beagle was a stinking (the dead finches were the least of the problem), leaking mess of a boat anyway.
But we don’t want to just wait until the fun stuff–coming up with the wild ideas–is done. We’d like your help now. We want to know what you would like to understand about the evolution of the homes (and/or cities) you are living in. We invite you to post your wild questions and ideas and, in doing so, think about how to study the species around us.
For our part, as we meet, we will make each part of our meeting as public as possible so that we might have a think tank of twenty one people in Durham, North Carolina, augmented with the ideas from thousands of other people around the world. But be prepared, if you get involved we may test your new idea and, in doing so, recruit you to go into your home and help us to see the evolution all around us, the evolution that we wake up to every day–as predictable as bird song or the sun’s rise–but mostly ignore, because whether or not we study the evolution in your bathroom or on your face, it is happening. Some versions of genes are being favored, others are becoming more rare, all because of the ways we live, the ways we live and the ways the species alongside us live, breed or die.
Note: As we get closer to our meeting, we will tell you more about the members of our group, both through stories of their work and interviews about what they have done. This meeting is being organized by Craig McClain, Kerry Kinney, Jonathan Eisen and me, Rob Dunn. You can find a brief bio of everyone else below (note, I’m editing this right now, so if you don’t see 20 people that is why).
Who is the Group of 20? Rachel Adams has studied the dispersal of fungal spores into homes. Holly Bik is an innovator in techniques to use genetic approaches to see what is otherwise invisible, particularly when those small beasts are multicellular. Ashley Bateman is a microbial ecologist who recently discovered that the bumps that occur during roller derby can transfer bacteria from one person to another. Noah Fierer is a microbial ecologist who has studied everything from armpits to Central Park, but all from the perspective of bacteria. John Hawks is a paleoanthropologist with an eye toward the big story of human evolution, or maybe both eyes. He is that good. Sarah Hird is an evolutionary biologist who has worked on everything from the love lives of chipmunks to the ancient divergences of carnivorous plants. David Hughes studies the ways in which parasites take over the minds and lives of their hosts, though he can’t rule out that that is just what his parasites are telling him to study. Stephen Kembel studies diversity and diversification, whether in hospital rooms or grasslands. Kembel has recently shown that hospital rooms with their windows open are less dominated by pathogens than those with their windows closed. Sergios Kolokotronis uses molecular tools to reveal stories about our everyday life that we had, in our busy days, missed, whether that be the identity of the fish at the supermarket or, most recently, the evolution of bedbugs. Gabriel Levy is a religious scholar working on a new book on Judaic Technologies of the World (When I said it was a broad group, I meant it). Laura Martin studies how people perceive, study and manage the environment (be it wilderness or basement). Her field work has focused on vertebrates in wetlands which sneak around and influence the life in and around our homes more than one might think. Raul Medina studies the process by which new lineages of insects evolve by switching from one host to another, whether that host is a plant or the body of another insect. Could parasites be diverging within our homes as they switch to new hosts? Maybe. Corrie Moreau studies the evolution and life history of societies (typically ants) and the species that live with them. Corrie is the only member of our group ever (to my knowledge) featured in a cartoon. Jason Munshi-South studies the evolution and ecology of vertebrates in New York Cities. Recently, he has spent some time in the sewers of New York. Rumor has it, he was looking for mutant, super rats. Rumors though can be wrong. Samuel Crane studies the evolution of species in response to human alteration of the environment. He has revealed secrets about the evolution of important agricultural weevils that even the weevils didn’t know. Will Wilson has written the book on the climates humans have constructed in cities, literally. Juan Ugalde studies the evolution and function of particular skillsets of microbes. We hope he can help us figure out not just the evolutionary stories of microbes in homes, but also what they do once there. Michelle Trautwein studies the evolution of flies (which are very, very diverse in homes) and the diversity of arthropods in homes more generally. Michelle found more than a hundred species of arthropods in my home. I am too nice a guy to say how many were found in Michelle’s (but it was more, just for the record). Martin Taeubel has worked on many aspects of indoor microbiology, specifically focused how elements of house construction influence microbe composition and how microbe composition influences health and well-being. He has also named a new species of Staphylococcus from a Himalayan goat. Jeffrey Siegel is a civil engineer, interested in indoor contaminants but also the links between outside and inside environments more generally. He has worked actively to understand how to build houses so as to make them more healthy. Laura Popova is an anthropologist interested in the ecology, culture, history and socio-politics of pastoral societies. A key element of understanding the species in our homes is understanding how those species relate to the ways we live, have lived and could live. Laura considers these ways. Clare Palmer studies the ethics of our relationship to other species. Her most recent book is Animal Ethics in Context. Sergey Nuzhidin is an evolutionary geneticist. His work has focused on model organisms (fruitflies and the like) but increasingly he has become interested in the species living alongside him in the lab and just outside. Gwynne Mhuireach is interested in the influence of home design on microbial communities and human health.
I think that the history of potable water supply should be researched and a Cancer statistics search should be done. I am convinced that our system of adding chlorine to our water supply to keep microorganisms from growing while in transit to our homes is killing us slowly. Most people who have house plants know to never water their plants with tap water. Since water is our major bodily consumable, this seems like an important place to start.
There are probably bigger questions out there, but if it hasn’t yet been done, it would be interesting to examine the effects of certain spices on microbial symbiont diversity and community composition. Since many spices may originally have been used for their antimicrobial properties, and some spices (including garlic) pervade the body (some people sweat garlic after they eat it), these spices may affect the composition and evolution of microbes in cultures that use more or less of those spices in their foods. This effect might be easier to tease apart nowadays, since people are really mobile, and some people in a given environments may eat spicy foods, while others do not. I’ll probably think of other ideas later… is it ok to submit more than one?
I’m quite interested in the evolutionary ecology of dust mites. At what scale do they show local adaptation? Cities, houses, rooms, beds? What is the population genetic structure with and among houses? Does house mite genotype effect humans’ allergic responses? Do their predators (whatever they are) drive evolution within populations? Have they adapted to be resistant to vacuum cleaners?
Knowing that ticks have been an issue with my dog and myself. I always wonder if they can evolve to resist certain repellants we put us and our dog. Are there certain environments on the skin that they thrive. Is it true certain foods can kill them if they bite due to toxins in sweat and oils produced by furs and skins?
So – I am over here in suburban Japan for the time being – for a couple of months longer. I will say I have been unsettled by the lack of wildlife over here in my part of town. I have seen maybe….4 species of birds on a regular basis, some moths, some other small flying insects, some ants…but overall it is bizarre to me how few animals I encounter on a regular basis. In addition, wild plants are kept largely at bay as well -I’ve got rice fields, meticulously manicured gardens, and “happy little trees”. If you want to send some sampling kits my way or ask me to collect information, I am willing! – cheers!
[…] very excited to be going to this meeting in June that focuses on the microbiome (i.e., all the living microbes) of our built environment – […]
So many questions, so little time to comment… Here are a few thoughts:
For critters that view our homes as islands, there are tons of questions related to degree of isolation vs. connectivity of populations in our residences, and mechanisms of connectivity and dispersion. What species disperse via the grocery store, via stores that sell things other than food, via shipping packages or mail order sources, via farmers markets or CSA shares, or via animal feed dealers? What species just go cross country on their own, and settle into our homes when convenient? Do people with lots of interaction with the outdoor environment (including gardeners & diversified farmers, who tend to bring lots of stuff inside from outdoors) have more critters in their homes from the local ecosystem? Do species such as meal moths, weevils, fruit flies, and other pests of food often develop a permanent residency in dwellings, or are they dependent on recolonizing on a regular basis, and from where?
I’m particularly interested in the microbial diversity/ecosystem composition of kitchens &/or food preparation surfaces that routinely get slammed with sanitizers vs. those that don’t vs. those cleaned with pro-biotic cleaners. Who gets killed, who persists, who gets out-competed, and what happens to diversity on short & longer time scales? And, in particular, what happens to pathogens as well as potentially beneficial bacteria? What are the implications for human health? Also, to what extent does the type of cooking that goes on in a kitchen affect the diversity of the kitchen microbial communities? For example, to what extent do active fermentation crocks, sourdough starters, and cheese making influence kitchen microbial ecosystems?
The introduction of a pesticide into the human food system in the form of Bt corn seems like it is begging for attention in terms of insect evolutionary adaptation. A quick Google search suggests that meal moths can evolve resistance to Bt proteins in GMO corn. From grain elevators to our kitchens, how are insects that feed on corn responding? Are there genetic differences between meal moths in the separate systems of organic and conventional grain handling? How much or how little Bt corn as a component of processed foods can exert evolutionary pressure on meal moths? (Do meal moths even go for processed food? Ours tend to gravitate to whole grains.)
Plenty of questions revolve around seasonality, too. Does the climate control of buildings lead to a loss of seasonality in the life cycles of some species? Etc…
Looking forward to learning more…