Sunday, September 2, 2007

More thoughts on human biogeography

Here are some thoughts and questions to accompany your reading and thinking about human biogeography, the topic of our third week. I’ve defined some vocabulary words at the end.

Chapter 1 of Lomolino et al. contains an excellent discussion of the philosophy of science generally and biogeography specifically. It’s well worth reading. Terrell’s article is nicely historical and provides both good information and provocative ideas.

First familiarize yourself with biogeography as a topic and as a science. Like other scientific fields, biogeography starts with the relationship between pattern and process. What are some examples from human ecology not covered in the readings? How might you go about investigating them? For example, how does “isolation by distance” affect human ecology? How might you “test” for human uniqueness in this respect?

Lomolino et al. note that “H. sapiens possessed an unrivaled ability to adapt to, modify, and eventually dominate a variety of environments.” What are some implications of such “niche contruction” ability, as Terrell would say? Terrell also stressed the importance of environmental factors in structuring human biogeography. How might one begin to tease such distinctions apart?

How might the development of key technologies, as with seafaring vessels, parallel hypotheses about the drivers and pace of biological evolution? (Hint: look for info on John Maynard Smith’s ideas about evolutionary innovations and transitions) , This perspective might be useful for examining modern aspects of human ecology.

Terrell notes that “Although the basic ingredients of what might be called human biogeography have long been part of academic life, these elements have not become a prominent feature of modern advances in ecology and evolution.” From what you know, do you agree?

Vocabulary

admixture – mixture of genetically different groups

biogeography – “the science that attempts to document and understand spatial patterns of biodiversity”. Biogeographers explore how biodiversity varies over the Earth and underlying reasons for this variation. Biogeography is typically a comparative and observational science rather than an experimental one.

island biogeography, equilibrium theory of (Lomolino p. 734, 2nd to last paragraph)– idea that the number of species on an island “represents a dynamic equilibrium between opposing rates of immigration and extinction.” It’s an “equilibrium” because new arrivals are offset by extinctions, and it’s “dynamic” because the precise makeup of species changes over time. Ecologists Robert MacArthur & E.O. Wilson proposed it in 1967.

mesic (p. 730, paragraph 2, Lomolino) – relatively moist, with relatively stable temperatures

taxon cycle (Lomolino p. 738 bottom) – a “cycle” of colonization, evolved specialization, and eventual replacement by new generalized colonists. E.O. Wilson proposed the idea to explain patterns in the Melanesian ant fauna, and Jared Diamond extended it to humans

vicariance (p. 730, end of paragraph 1, Lomolino) – geographic separation due to physical events, such as tectonic shifts, rather than active dispersal of organisms

xeric (p. 730, paragraph 2, Lomolino) – relatively dry

24 comments:

dodegard said...

How would biogeography account for variation in social changes that do not have a genetic basis?

Fred Whiteman said...

Colonization of Pacific islands required a sizable investment of effort and technology. What impulse drove this endeavor? Were these people seeking new resources, trying to get the advantage over neighboring groups, or simply curious?

Fred Whiteman said...

What do you think of Terrell's use of the term "Mother Nature" in his paper?

Wenyun said...

Whether should we highlight human or not? It is a species on the earth among billions of species. It is the biggest species, at least the largest impact species nowadays. Should we specially consider human biogeography as a subdiscipline of geography? Is it because of our uniqueness, a part out of nature or an important part of nature?

Justin Smith said...

What is the role of "environmental concern and activism" in a science such as biogeography?

Terrell quotes Lomolino & Hearney (2004): "the earth is dynamic... and this dynamism creates a changing geographic template to which all species must respond" (emphasis added). In Lomolino et al (2005), we read that "conserving the distributions, diversity, and natural character of Earth's imperiled species" is "one of history's greatest challenges" (p.742) (emphasis added). How do we reconcile these two views?

Dan said...

Terrell cites Odling-Smee et al 2003, with coining the term "niche construction". Does niche construction really exist or is it some unseen ecologic factor which compells an organism to use make use of an alternative niche?

Deepta said...

In the Lomolino chapter, the authors mention increasing understanding of "geography of nature; including that of current and future human populations" and how this contributes to the research in conservation. How can they predict our future behavior? Wouldn't the increases in technology make patterns in human behavior less predictable?

tlvandeest said...

Terrell points out the Western need for separating the natural from the unnatural and its futility. How is the third point of his recipe for human biogeography, where "difficulties of defining taxonomic units in human biogeography will increase" with more available genetic evidence, not also attempting to separate out unnatural groups from the natural whole of the human race?

Senorita Myra said...

Is niche construction something that is a "conscious" (purposeful) change among species because they are the ones taking action to change there environment or can it be argued that niche construction is a reaction to the climatic and environmental perturbations to a particular species, that in turn make a species adapt and create a niche?

Senorita Myra said...

Dido Dan, dido.....

Senorita Myra said...

I think if biogeographers were a little lest probablistic and more determnistic in looking at human behavior, they would come up with much more interesting and radical theories as to the reasons human communities have reached the present state. I am sure I have a very narrow scope of reading in biogeography, but it seems they are simply tying together other peoples work, instead of generating theories to then be confirmed by other people's work.

KEN said...

Social scientists often stop at attributing variation to "cultural differences," and leave it at that. This begs the question, what causes these cultural differences?
I've attempted to develop ideas that incorporate cultural history and ecological and geographic variation, which necessarily introduces more complexity. However I've been discouraged by others in the field who believe all variation should be accounted for by variation in ecolohical characteristics alone -- forget cultural history!
I think it's time biogeography met studies of cultural history. This is analogous to Gould's insistence that we consider phylogenetic history in his attempts to knock down the adaptationist program. But though his argument there was a straw man, it's a sensible approach and I think it hasn't been applied in a thorough and sensible way to the study of cultural history.

paul said...

Lomolino: Biogeography deals with spatial patterns of biological diversity. Why say diversity? Why not biological phenomena? Maybe saying diversity isn’t actually being much more specific than this. There are differerences, there is variance, and we want to explain them/it. So that’s what most of us do anyway. Explain why one society is like this, while another society is like that; explain why humans are like this and chimps and gorillas are like that. Ok. So diversity.

Justin Smith said...

How does biogeography separate meaningful patterns from historical contingency?

dtinucci said...

In a habitat where the organic matrix of life is replaced by artificial intelligence and a built environment, will the tenents of biogeography, structured on spatial and natural parameters as they are, apply to the study of urban ecology, where density and social complexity define the order of life?

paul said...

Terrell: B/c biography is probabilistic rather than deterministic, it can further studies of the events and circumstances that contributed to similarities and differences among people and their ways of life. I don’t get his logic.

But maybe a probabilism allows you to answer Justin's question better than determinism? A probabilistic viewpoint can allow you to talk about which outcomes are the result of pretty arbitrary dice rolls, where alot of different things are possible and probable, and which outcomes are more deeply canalized, robust to purtubation, and more or less inevitable.

Wenyun said...

What is the difference between language-area relation and species-area relation? The language-area relation is linear. However, the species-area curve is nonlinear which generally written as S=c*A^z (was proposed by Arrhenius in 1920 and modified by Gleason in 1922). The exponent z is generally small, in the range of 0.2 or 0.3.

Dan said...

My idea behind the dichotmization of artifical and natural is that it is arbitrary because the forces of nature govern either equally.

Deepta said...

Are there any patterns to changes made through niche construction, or does it vary species to species? Specifically, are certain species more prone to making changes as opposed to leaving for a more hospitable environment?

tlvandeest said...

Terrell points out that his "sleeping giant hypothesis" and "transgenerational management of resources" ideas are still under field investigation or not sufficiently documented for New Guinea. Do these ideas stem from evidence in other islands or are they just still as yet unsupported hypotheses?

dodegard said...

What drives humans to explore and expand? It seems that a lack of land was not an issue, so are we driven to disperse no matter the amount of space?

Kenneth Letendre said...

Not sure I follow the section in Lomolino et al., regarding Diamond's application of Wilson's "taxon cycle" to cycles of colonization and extinction of human populations on islands.
How would a human population adapted for efficient exploitation of local resources be out-competed by a newly immigrating generalist culture?

dtinucci said...

If we are going to employ a biogeographical perspective to the dynamics of urban society using the parameters established for studying islands would be appropriate. In other words, necessarily treating major cities as unique identities based on cultural,spatial, demographic and economic dynamics.

Human macroecology admin said...

Senorita Myra said...

Question for Dr. Terrell,
Your paper on Human Biogeography and evidence of humans place in nature is intriguing. However, we had trouble understanding how the lack of a clear definition of population boundaries links to your other arguments. In the essay you mention that genetic differences are roughly proportional to the geographic distance between them, yet, you agree that the concept of population is still very vague. You also go on to claim that although race is non-existent genetically, "it still captures some real difference to humans". Isn’t this a contradiction? You seem very skeptical of groups yet claim that race can be used to group humans. Moreover, what can biogeography provide for us in order to make a clearer distinction between human communities? Is it possible that biogeography can identify a community, its tendencies, and the direction it will go in the future by categorizing groups of people according to a particular environmental or cultural niche they belong to? If so, what characteristics, biological, environmental, and/or cultural will determine a community’s specific niche? If not, how does biogeography confront the issue of vague population definitions in other species?

 
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