"I conclude that, while it is true that science cannot decide questions of value, that is because they cannot be intellectually decided at all, and lie outside the realm of truth and falsehood. Whatever knowledge is attainable, must be attained by scientific methods, and what science cannot discover, mankind cannot know." — Bertraind Russell

We are all born scientists. We enter this world asking questions and testing the truth of the answers we receive. Does it taste good? Is it too hot? Too cold? Too sharp? Too high? That, in its simplest form is the scientific method. Start with a question, develop a hypothesis based on what we see with our own eyes, or previous experiences, and then test that hypothesis with data (taste it, touch it, climb that ladder).

Once we accumulate data, we develop meaningful theories: ice cream always tastes good, stoves can be very hot, honeybees sting but not all bees sting, some snakes are poisonous but not all snakes are, and so on. Later, for many, we are told to accept what others tell us without question, without testing the breadth of the truth of the answers we are given. We get lazy and stop asking questions and testing whether what others tell us is correct, and whether it is correct in all situations.  We stop being scientists, and when we stop being scientists, we stop being critical thinkers. For some of those, science then becomes the antagonist, the enemy of their belief system.

Those who continue to ask questions and test hypotheses are employing the scientific method and so they are, by definition, scientists, whether or not they received formal training. Charles Darwin’s formal training as a scientist was substantially less than most middle school students get today, yet he is viewed as one of the most influential scientists of his day. Those with formal training sometimes ask increasingly narrow questions, trying to reduce the scale to the smallest units that can yield meaningful answers, molecules, atoms, and subatomic particles. For others, the questions focus on large scales: populations, landscapes, or planet-wide shifts in climate. If the questions focus on where a plant or animal lives, what are its interactions with other species, or whether a change in their habitat will impact that plant or animal, then those scientists are also naturalists. Asking where a plant or animal lives can be as simple as saying it lives here or over there, but the real answer is more complex. It lives were the geology, soils, soil moisture, aridity (or lack thereof), temperature ranges, predators, pathogens, prey or food, vegetation, pollinators, hiding places, basking places, and nesting places are all suitable for it to live, procreate, and thrive. Sometimes all the right ingredients are present, but the animal or plant simply lacks the mobility to get there. Rivers, mountains, deserts, oceans, cities, and roads can be barriers or conduits determining whether a species lives there or not.

Asking these kinds of questions necessarily gets messy. Each variable plays a part, but the strength of its influence can vary from place to place. Scientists uncomfortable with this kind of messiness, with nature’s multiple and varying shades of gray, then retreat to laboratories and greenhouses where they can limit the variables and have full control over whichever variables are left. The answers that flow from those laboratory or greenhouse experiments are clean and simple, but because they limit the influences of the multitude of variables that species face in nature, to the extent that those answers are used to infer patterns in nature, those answers should be viewed as provisional.

One of those large-scale questions being asked today is how a given species is likely to respond to modern climate change. There are powerful computer models that can project what that future climate will likely be and can project that new climate across existing landscapes. Then, by calculating the climate envelope of a species, (its range of physiological preferences), by analyzing the climate conditions of where it occurs today, the computer can then predict whether or not that species will continue to find suitable habitat there as the climate changes, or where across a landscape that species might need to move to stay within its climate envelope. Such computer models represent hypotheses, and within the framework of the scientific method, such hypotheses need to be tested. Given the multitude of variables that determine whether a species will find habitat at any given location, it would be daunting to then predict future scenarios with accuracy, even with very powerful computers. Daunting, maybe, but not necessarily impossible. Where a computer model identifies places where a species exists today and where it will or will not be able to find a suitable climate envelope in the future, that dichotomy of good today and good in the future versus good today and unsuitable in the future can be used to direct field studies. Because climate change is not a future problem, and is an ongoing process today, if the good today and good in the future locations are predicted correctly, then populations on those sites should be showing successful recruitment and sustainability. Conversely, where the computer model identified places where a species exists today but where it will not be able to find a suitable climate envelope in the future, there should be much reduced recruitment and so more fragile sustainability. That dichotomy is exactly what we have found for Joshua trees within Joshua Tree National Park. Question asked, hypothesis created (by a computer), and then tested (by people).

That simple question — is successful recruitment occurring? — is important to consider as naturalists observe nature. A forest of standing mature Joshua trees may look healthy, but if few if any young plants are present, it is akin to a town or city with only senior centers but with no elementary schools. Noting successful recruitment, whether it be with trees or lizards or whatever your species of interest, is thus an exceedingly valuable data set for understanding the impacts of a changing world. Another important variable to keep ones’ eyes on is whether a population of a species, or populations of multiple species, are changing their distributions. This addresses the question of whether species can shift where they live today as climate change shifts their preferred climate envelopes to new areas now and into the future. To be clear, a lizard or a plant does not perceive that conditions are getting better elsewhere and then moves to that “greener pasture." Rather the portions of that species’ current range that overlap with, or are closest to, a current/future better habitat should have better recruitment than areas where their climate envelope has already deteriorated. Better recruitment will then result in a larger population, and that population “bulge” should move in the direction of where there is increasingly better habitat.

We are seeing this occur with lizards along the slopes of the sky island mountains abutting the lower elevation deserts. Our cadre of community scientists/naturalists, are out individually and in groups, recording the species, their abundance, and patterns of recruitment for a community of desert and montane lizards. If we collected these data at just one or a few locations, the messiness and complexity of nature would call into question any conclusions we develop. However, we survey lizards on nearly 40 trails, with overlapping elevations ranging from 0 to over 2500 meters (0 to over 8,000 feet). From those data it is increasingly clear that the population “bulges” for each species are moving to higher elevations. The repeating patterns reduce the messiness that would be apparent on any individual trail. Question asked (can lizards shift and sustain populations as conditions become hotter and drier?), hypothesis created (population bulges should occur at the higher, cooler elevations, or within climate refugia), and then tested (by people).

Nullius in verba

Go outside, tip your hat to a chuckwalla (and a cactus), think like a mountain, and be safe