Chapter 10 Synthesis: Ecological Implications
The chapter discussed how general the patterns and processes discussed in the book are within all realms of ecology. Does a macroecological approach work just as well for birds and small mammals as it does for reptiles, trees, bacteria and insects? At the time of the books publication not much work had been done with existing data sets to evaluate the ubiquitous nature of these patterns and many conclusions are based from a qualitative approach. One such observation is the latitudinal diversity gradient that exist in marine corals. At the heart of the chapter was a defense for the traditional naturalists approach through observation and limited impact on the inputs into a system and exposing inherent errors in a strict controlled ecological experiment.
The Limitations of Ecological Experiments
The Limitations of Ecological Experiments
1) Creation of artifacts through controlled and manipulated systems
2) Type II statistical error
3) Difficulty assessing the generality of results
The synthesis of both the naturalists approach and modern science is suggested to come through the energetics. Combining the two major models of dE/dt and dN/dt, individual and population survival, essentially individual organisms must acquire rare resources to sustain themselves in order to convert that energy into offspring. Allowing the finite picture of the individual to help construct the picture of the population and vice versa. This can also be expressed with abiotic factors such as described in Roughgarden's experiments within Monterey Bay, where larger ocean currents were responsible for the local species diversity of the experimental plots. Overall the chapter made a good argument for when approaching an ecological question there is no one approach which will give you an answer. The finite experimental approach can help to define very local interaction but will be incomplete without the larger picture.
Article:
Fishes on coral reefs: changing roles over the past 240 million years
Christopher H.R. Goatley et. al.
Paleobiology, 36(3), 2010
The paper looked at fossil records of coral fish over the past 240 million years as well as recent populations comparing jaw length and eye orbital size to determine the ecological niche they served. These key morphological traits are used to determine the ecology of the fish assemblages. The paper found that overall there has been an increase in the number of large eye large gape (jaw) species over the past 240 m.y. The advantage of larger eye orbitals, or larger eyes, are nocturnal feeding and sharper acuity, for both feeding and predator avoidance.
I really enjoyed both the paper and the chapter, and there will be plenty to discuss regarding the merits of both experimental ecology and LTER and their impacts and contributions towards paleoecology as shown in the paper.
Sorry this posting is so late guys!
Can you predict macroevolutionary processes based on microevolutionary processes?
ReplyDeleteI wonder if there are other correlations with enlarged orbits other than nocturnal feeding, such as living in crevices more or living in deeper water. I do like that they address that larger eyes could also be due to more photosensitivity. Are there any fossils of fish eyes (like there are of some trilobites)?
I also liked in this study how they incorporated what the community must have looked like (e.g., topography of reefs) compared to niche-space the fish inhabit.
Overall, it’s a nice picture that they depict.
Pg 182 in Jim's book: "...historical events play a major role in ecology. Seemingly insignificant changes in abiotic conditions or species compositions that happened long ago or far away can have large, irreversible effects on the structure and dynamics of local ecological systems." This highlights something that I have always been interested in but never really pursued: how long does it take for ecosystems to recover from disturbances? I know work has been done with recovery after fires, with succession of biotas. But what about large scale changes like rapid climate change? At what time scale do we need to look before we see "equilibrium"? I've read some papers that would have me believe some small mammals are STILL in the process of adjusting their geographic range since the end of the last ice age. That's thousands of years! Abiotic conditions are also constantly changing, so do we ever see equilibrium? At the scale that most ecologists are interested, does it matter?
ReplyDeleteIs the paper for this week suggesting some kind of evolutionary arms race in teleost fish? Or some kind of co-evolution between fish morphology and reef morphology? I would have liked to see more details about how reefs changed along side changes in fish.
ReplyDeleteAs always this weeks reading was super intriguing! In reply to some of the comments posted thus far: I think that there are some unifying generalizations between micro- and macroecological processes but we must be careful. Also, I don't think equilibrium can ever be reached. There is always change and organisms are always having to respond to these changes. My main take home message or thought about this chapter is the calling to start more large scale experiments. We have always been doing small "closed" system studies and now we must pull the data together and make more macroecological assumptions/conclusions. Gotta run but will comment more when I get back from class!!
ReplyDeleteI found the article and chapter interesting as usual. I also think that it would have been nice if they showed how the reefs changed alongside the changes that occur in the fish. Why is it that the K/T extinction had such a small impact on marine life?
ReplyDeleteI don't know if I will be able to make it to class today. My grandmother is having open heart surgery, but I will try to be there.
ReplyDeleteI think this article presented a neat little story with a neat conclusion. I would love to see more context about what else was going on in coral reefs at that time. The study of ancient reef ecosystems is a fascinating discipline all its own. I'm fascinated by the turnover of reef-building organisms through time -- reefs haven't always been built by corals, and when corals came into the picture, a lot of them looked very different from dominant corals today. I'd love to talk more about this in class.
ReplyDeleteGood article! I found their approach interesting, but as usual, I am somewhat skeptical. How conserved is the relationship between orbit size and lens size? I'm not aware of any fossil fish eye that is preserved in sufficient detail to measure the specific parts of the eye (or for that matter, the ratio of cones to rods etc.)
ReplyDeleteI am very interested in how changes in predatory animals may have effected the evolution of the various fish taxa. Prior to the K-Pg event, Mososaurs and other marine reptiles were a huge part of marine habitats; how might have their extinction effected the niche partitioning in fish groups?
I was also a little disappointed in the authors' lack of explainantion in changes in reef formation, and how the changes would effect feeding strategies. Up until the end of the Jurassic, most reefs were predominated by Rudist bivalves as opposed to scleractinian corals, which would assumably present very different feeding opportunities than reefs do today. Perhaps is this the reason fish developed the ability to pick out tiny organisms on a reef? Or is this just an example of increasing specialization over time?
Kat and Fred you brought up a very good point about the dominant reef structure which I had taken for granted, I just assumed reefs have been for the most part the same for the past few hundred million years. I want to look at the plots again and see when there was a greater diversification, based on your comments. The article did a very good job at creating a story, which I feel is an important trait in taking a macroecological approach. Class is about to start, see you all there.
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