Why human population control isn't the answer to the world's problems

Its weird how things in my 2 worlds (falconry and Ecology/Evolutionary Biology) seem to mirror each other. The last two weeks of one of my ecology classes have been dedicated to human pop dy issues, and I woke up yesterday morning to find a thread on IFF advocating human population control. Well after a pretty extensive literature review on why this really won't work I spent a large chunk of my day typing up responses rather than putting the finishing touches on my thesis. It's a week before my defense anyway, so no rush. After all this time I figured may as well write a blog post on the subject so here it goes.

Controlling population really isn't the magic bullet people see it to be. People look for a quick fix, and more importantly one that doesn't require them to change their lifestyle. In many respects human population control measures fit this bill. People making these suggestions tend to be educated, fairly well off (as in having some amount of disposable income and making a good living when compared to the majority of the world), and live in developed nations. Statistically speaking people with these criteria tend to have fewer kids compared to people with less education or living in developing nations. Because of this they see population control measures effecting other people, not them. Population growth is a southern hemisphere problem, a developing nation problem, a less educated section of society's problem, etc and "those" people need to be controlled, because they are having a large number of kids and causing the population to grow at a fast rate. Once control measures are adopted suddenly resource consumption drops, environmental pressures ease, and life is good. Or so we thought.

A lot of recent work (last 5 years) has discovered a much different reality. A paper by Liu et al. (2003) showed that household dynamics- basically how many people live in a household, affluence of the household, resource consumption etc- really this plays an even more important role than straight up population size does. Even more interesting in areas identified as biological hot spot by Conservation International (regardless of their location in developed or developing nations) the number of households is growing at a much faster rate than population.

So even though the number of people is staying the same or growing at a certain rate (average growth rate in hotspot countries was 1.8%) the number of households is increasing at a much faster rate (those same countries average of 3.1%). While this is happening the number of people living in a household is decreasing substantially so households are becoming less efficient. Even if we had zero population growth (or even a decrease in population growth which is occurring in some countries) as of today, consumption (and environmental impact) would continue to accelerate.

Think about it this way. You have 5 people in a population and they all live in the same house- that is going to use substantially less resources than 4 people living in 2 houses because that 5 person house is 1) going to use the same amount of energy to build, heat, and maintain regardless of the number of people in it, 2) the same amount of infrastructure (roads, gas lines etc) goes in regardless of how many people live in it. Conversely even though there is one fewer person in the 4 people 2 house scenario they over all will use more resources than 5 people living in a single house. Yes 5 people in 1 house will eat more food and use more water, but the overall impact will still be less than 4 people in 2 houses because of the efficiency differences. For instance, two-person households in the United States in 1993–94 used 17% less energy per person than one-person households (O’Neill, B. and Chen, B. 2002). When you have a great increase in the straight up number of households this is a huge deal because now you've got more strain on the environment for the same number of people.

Population control measures themselves can also result in higher environmental impacts. For example affluence- if you have 3 kids and make somewhere around the poverty level you are basically just scraping by, have a pretty small house, and not a lot of money to spend on things like cars or other "luxury items". But if you make the same amount of money and only have one kid you are going to have a lot more disposable income. This translates into larger houses (average house size in China for example has tripled since 1980 while household size in that time has decreased), more cars (again in China from about 2 million to over 20 million), and other status symbols (China data from Liu and Diamond 2005).

So while there may be fewer people those fewer people are having a much larger effect on the environment. This doesn't even address the fact that people living in cities have a much lower environmental impact that those that live in rural situations, which I’ll hit on briefly at the end.

What can be done

Resource consumption is what really needs to be targeted, but who wants to be told that they can live in a smaller house just fine (seriously why do 2 people need a 1,500square foot house), to walk instead of drive their car to the grocery story, etc. This is the answer that educated people in developed countries do not want to hear because it will involve changes in their behavior.

Interestingly enough being oriented towards the environment such as a feeling of environmental activism, participation in recycling programs, or donating to environmental causes seems to encourage people to live in more sensitive areas and more resources (Peterson et al. 2008). Think about it, people who like nature want to live in nature- house in the country, etc. A house in the country is much worse ecologically than living in an apartment in the city, or even a house in the city because infrastructure had to be created in order to live there. So ironically people who tend not to consider themselves “environmentally oriented” in general have a smaller environmental impact. Additionally, people living in natural areas tended to have much smaller households compared to people living in previously developed areas.

So rather than advocating for population control measures environmentalists should be pushing for household control measures- making people live in smaller houses, having more people per household, and encouraging people to live in urban areas rather than moving to rural regions.

Below are a few papers people should check out. Keilman 2003 and Liu et al. 2003 explain household dynamics. The Liu paper especially set off a wave of research. Liu and Diamond 2005 examines China’s impact on the environment and looks at trends over the last 30 years. Peterson et al. 2007 is a more theoretical paper discussing why household control measures should be preferred over population control. Peterson et al. 2008 looks at various facts about a household and how they impact location (and environmental impact).

Keilman, N. 2003. The threat of small households. Nature. 421: 489-490

Liu, J., G. C. Daily, P. R. Ehrlich, and G. W. Luck. 2003. Effects of household dynamics on resource consumption and biodiversity. Nature 421:530–533.

Liu, J. and Diamond, J. 2005. China's environment in a globalizing world. Nature. 435: 1179-1186

Peterson, M. N., M. J. Peterson, T. R. Peterson, and J. Liu. 2007. A household perspective for biodiversity conservation. Journal of Wildlife Management 71:1243–1248

Peterson, M. N., X. D. Chen, and J. Liu. 2008. Household location choices: Implications for biodiversity conservation. Conservation Biology 22:912–921

Well thats a big bigger than a tiercel

So i randomly decided to go to Idaho to meet a falconer I've been corresponding with for a few years. While there I was treated to some awesome merlin flights plus got to hang around at Merlin Systems and see some of the new things they are coming out with. I also went to the Peregrine Fund. Since I worked for them for a few years on Aplomados (and Jim's p-fund connections helped I expect) we went on a behind the scenes tour. The culmination was having a male Harpy on the fist. It was pretty dang heavy, made my tiercel feel like my kestrel. Pictures below


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So what do systematists do for spring break?

Thanks to a post on Darren Naish’s blog Tetrapod Zoology about plastic pelicans the taxon of interest was pelicans. For people who actually care how I got the tree hear are the methods. Otherwise just skip it and go check out the tree. I only did a parsimony analysis, but if I get bored I’ll do a Bayesian analysis also. As I’m not a pelican taxonomist I’ll leave the result interpretation to someone who actually knows something about these birds.

Methodology

Sequence data

Due to my inability to get morphological data and the fact I was on spring break so didn’t want to spend the entire time tracking down original descriptions etc to code a morph matrix my analysis is only of molecular data mined off of Genbank. I narrowed the sequence data to genes that had sequences for at least 3 taxa included in the analysis (5 pelicans and 1 outgroup a shoebill, Balaeniceps rex). Genes included in my analysis were cytochrome oxidase subunit 1, ATP synthase subunit 8 and 6, 12s, Fibrinogen beta chain gene, cytochrome b, and ornithine decarboxylase gene. A total of 3893 bases were included in the analysis of which 3409 were constant. Of the remaining characters 313 were parsimony uninformative leaving 171 characters as parsimony informative. Because sequences were not from the same specimen they were combined at random in order to have one sample of each taxa with the most possible sequences for analysis.

Taxon sampling

Data were only available for 5 of the 8 species of Pelecanus. Included taxa were the brown pelican (P. occidentalis), American white pelican (P. erythrorhnchous), great white pelican (P. onocrotalus), Dalmatian pelican (P. crispus), and the Australian pelican (P. conspicillatus). Only a single gene (which was not available for any other species) was available for the spot-billed pelican (P. phillippensis). The remaining two species, the Perunvian pelican (P. thagus) and the pink-backed pelican (P. rufescens) lacked any sequence data.

Data analysis

Data were extracted from genbank, aligned in clustal w (using bioedit) then manually checked by eye. Data were then analyzed using parsimony in PAUP*. A heuristic search was done using 1000 random adition sequences. Next duplicates of taxa were removed and an exhaustive search performed (tree shown below)

Results

A single most parsimonious tree was recovered with a length of 547. CI and RI were 0.956 and 0.870 respectively. The ingroup was monophyletic with a bootstrap value of 95. The Australian pelican was the most basal of the ingroup sampled. I haven't done bremer supports or looked at the Ti/Tv ratios etc if people are curious though it could be arranged.

What were they thinking?

The alleged Brazilian wandering spider in Tulsa is a great example as to why we need collections (and taxonomists to work in them). A brief summary of the story: spider found in banana section of whole foods in Tulsa, OK. Manager is concerned its dangerous and commits mistake number 1- taking it to University of Tulsa. Now I'm sure U. of Tulsa is well known for something, but trust met arachnid identification is not it. Once there the spider is shown to the animal facilities manager- mistake number 2. I'm not exactly sure what animal facilities managers do but I expect their knowledge of exotic spider taxonomy is rather limited. Rather than sending the manager off to an actual expert he gave an ID. I'm not sure what his id was based on but whatever the case he made an identification as a Brazilian wandering spider. To be fair if you don't know what something is (and you've made the decision somehow to still answer the question) I guess its safer for all involved to go with it being the more dangerous option rather than saying its not dangerous and finding out the hard way it was (like the assumption an unidentified snake is venomous until it is identified as otherwise). After the determination was made mistake number 3 occurred. According to the new articles after identification the specimen was destroyed at urging of an administrator at the school making it impossible to figure out what species the spider actually was. Based on photos and videos of the spider in question various scientists are questioning the identification.

Although the first two mistakes caused the problem in the first place (taking the specimen to a diagnostic lab at major university or the USDA would have allowed identification by either a trained personal or if that was not possible sent to a specialist for determination) they are not the biggest problem. That distinction goes to mistake number 3. The first two mistakes could have been easily fixed if the specimen was available for study. Destroying the specimen compounded the previous errors by preventing a formal identification by experts. Instead they are stuck watching videos trying to look for distinguishing characters, a process which would take seconds with the specimen in hand.

Incidents like these highlight the need for taxonomists and collections. One of the cardinal rules of taxonomy is always keep the specimens. If the spider had been shown to a taxonomist of any flavor be it spiders or sea-slugs the importance of keeping the specimen in good condition would have been known. Related to the retention of specimens is the need for well maintained collections. If the manager of Whole Foods had taken the spider to Oklahoma State it could have been compared to known specimens held in the collection, making identification (even by someone with limited spider knowledge) more possible.

another month have passed

Well another month has passed and my life can pretty much be summarized with a few brief statements.
1. I defend my first thesis next month, i sank about have the members of the genus, and described a new species. Additionally I'm working on the description of 2 species in a related genus. No names posted so as not to cause confusion.
2. I got a 3 year fellowship to University of Illinois Urbana-Champaign to get my PhD in Ecology, Evolution, and Conservation. Start up there in August doing leafhopper systematics, hopefully some biogeography, and of course still playing in avian ecology
3. My peregrine is molting like its going out of style, if this continues he should be ready to go in September. I flew him in the Texas Sky Trials and learned an important lesson about greedy pitches. My kestrel is still weak from WNV but she is finally flying pretty strongly
4. I go back to africa in May. Will get my plane tickets next week, but it looks like I'll be there for 2.5 months, plenty of time to get the black spar hunting.
5. My pointer is going to be awesome, hes 9 months and already holding point like a pro.

Thats all for now, maybe I'll really start updating this thing now that its spring break and i have time to find cool stories to talk about...

Two months later...

Lets see been to Africa and back yet again, this time South Africa and Swaziland. Was collecting insects in the sugarcane fields among other things as part of some wildlife research projects being done by students at TAMU. My data looked pretty promising so the plan is go to back for a couple months this northern hemisphere summer (southern hemisphere winter). Should be a good time especially since its falconry season- if all goes to plan have a black spar in my future! Plus some hawk trapping for good times.

In other news the peregrine is doing well, hit his first duck a few days ago, been two years in the making. I have to say falcon stoops are always cool, but when its your own bird there is nothing like it in the world. Kes's season starts in 2 weeks starlings beware.