Many chapters are cross-referenced. Modern evolutionary theory has expanded significantly within only the past two to three decades. In recent times the definition of a gene has evolved, the definition of organic evolution itself is in need of some modification, the number of known mechanisms of evolutionary change has increased dramatically, and the emphasis placed on opportunity and contingency has increased.
This book synthesizes these changes and presents many of the novel topics in evolutionary theory in an accessible and thorough format. This book is an ideal, up-to-date resource for biologists, geneticists, evolutionary biologists, developmental biologists, and researchers in, as well as students and academics in these areas and professional scientists in many subfields of biology.
Discusses many of the mechanisms responsible for evolutionary change Includes an appendix that provides a brief synopsis of these mechanisms with most discussed in greater detail in respective chapters Aids readers in their organization and understanding of the material by addressing the basic concepts and topics surrounding organic evolution Covers some topics not typically addressed, such as opportunity, contingency, symbiosis, and progress Coevolution Of Life On Hosts Author : Dale H.
But for a certain breed of biologist, lice make for fascinating scientific fodder, especially enlightening in the study of coevolution. In this book, three leading experts on host-parasite relationships demonstrate how the stunning coevolution that occurs between such species in microevolutionary, or ecological, time generates clear footprints in macroevolutionary, or historical, time.
By integrating these scales, Coevolution of Life on Hosts offers a comprehensive understanding of the influence of coevolution on the diversity of all life. Following an introduction to coevolutionary concepts, the authors combine experimental and comparative host-parasite approaches for testing coevolutionary hypotheses to explore the influence of ecological interactions and coadaptation on patterns of diversification and codiversification among interacting species.
Ectoparasites—a diverse assemblage of organisms that ranges from herbivorous insects on plants, to monogenean flatworms on fish, and feather lice on birds—are powerful models for the study of coevolution because they are easy to observe, mark, and count. As lice on birds and mammals are permanent parasites that spend their entire lifecycles on the bodies of their hosts, they are ideally suited to generating a synthetic overview of coevolution—and, thereby, offer an exciting framework for integrating the concepts of coadaptation and codiversification.
The structure dence that the impact played a major role in the mass extinctions at the end of the is about kilometers across and Cretaceous.
In the 1 million years leading to the impact, temperatures rapidly rose and fell several times, possibly due to major volcanic eruptions that occurred at the time. Sea levels also changed drastically. Renne and his colleagues propose that these perturbations put stress on the global ecosystem, and the impact delivered the fatal blow.
There is no single mechanism that explains all mass extinctions. By they had assessed 71, species, most of which live on land or in fresh water. They found that were either extinct or surviving only in zoos. Many of the remaining species were at risk of extinction in the future. The scientists have estimated that 21, are threatened and are critically endangered Pimm et al. Deforestation, overfishing, and other distur- bances are pushing these species toward extinction Figure Are these recent extinctions any different from the background extinctions that have occurred for billions of years?
Or have the Big Five become the Big Six? To answer such questions, scientists have to compare extinction rates today to extinction rates in the past. Anthony Barnosky and his colleagues have been studying what hap- pened to mammalian biodiversity in North America when humans arrived roughly 15, years ago Carrasco et al.
These scientists compiled databases of fossils from 15 different biogeographical provinces across the continent, such as the Gulf Figure This map shows the past and projected loss of rain forests on Borneo, an island the size of Texas.
The forests are being cut for timber and palm oil plantations. Adapted from BlueGreen Alliance B: The rapid loss of forest habitat in Borneo is endangering many species, including the orangutan, which lives only on Borneo and Sumatra, where severe deforestation is also taking place.
In each province, they estimated the diversity of mam- mals for the past 30 million years and calculated the mean extinction rate. The background extinction rate was 1. Barnosky and his colleagues found that immediately after the arrival of humans, the diversity of mammals dropped between 15 and 42 percent. While the changing climate at the end of the Ice Age may have driven some extinctions, humans likely caused extinctions of a number of mammal species by hunting them for food San- dom et al.
Barnosky and some of his fellow Berkeley biologists have also compared past mass extinctions to the changes to biodiversity over the past five centuries Barnosky et al.
When they considered how many species have been documented as going extinct over the past five centuries, they found that the current rate of extinction is higher than that of the end-Pleistocene event. But if endangered and threatened species also become extinct in the near future, the rate will rise dramatically. At the moment, they conclude, we are not in the midst of the sixth mass extinction event.
But unless we stem the tide of extinctions, they will rise in a matter of centuries to the ranks of the Big Five Figure As sobering as these results may be, they may actually underestimate the threat of extinction. Barnosky and his colleagues took into account only the extinctions that have already occurred due to factors such as exploitation, habitat loss, and the spread of diseases.
But humans are also altering the atmosphere, and the effects of that change are just now starting to be felt. Every year, humans release more than 7 billion metric tons of carbon dioxide into the atmosphere. Over the past two centuries, humans have raised the concentration of carbon dioxide in the air from parts per million ppm in to ppm in Depending on how much coal, gas, and oil we burn in the future, levels of car- bon dioxide could reach parts per million in a few decades Figure As this carbon dioxide enters the oceans, it is making the water more acidic, with potentially huge impacts on marine life.
As the pH of seawater drops, the additional hydrogen ions interfere with the growth of coral reefs and shell-bearing mollusks, such as snails and , Distant past Recent past Future fossil record known extinctions modeled 10, Extinctions per thousand species per millennium Projected future extinction rate is more than 10 times as high as current rate Current extinction rate is up to times higher than 10 rate in fossil record 1 Figure If it increases, as many scientists now predict, we are enter- ing a new pulse of mass extinctions.
B: As a result, the average temperature of the planet has shown a warming trend for the past century. C: Computer projections consistently show that the planet will warm much more in the next century if the concentration of atmospheric carbon dioxide continues to increase. This rapid climate change may raise the extinction rate even higher by reducing the habi- tat where species can find suitable temperatures and rainfall.
These animals may simply die, and the reefs may disinte- grate. The collapse of coral reefs could lead to more extinctions because they serve as shelters for a quarter of all marine animal species Figure Ocean acidification has been hypothesized to have caused the disappearance of coral reefs after all five of the mass extinctions. The reefs did not return to their former extent for at least 4 million years after each event Veron Carbon dioxide, as we saw earlier, is also a heat-trapping gas.
The average global temperature has already risen 0. Over the next century, computer models project, the planet will warm several more degrees unless we can slow down the rise of greenhouse gases in the atmosphere. Animals and plants have already responded to climate change Parmesan Thousands of species have shifted their ranges. Other species that live on mountainsides have shifted to higher elevations.
This movement is a common evolutionary event, but today it may be occurring at a faster than normal rate. The effects of climate change on biodiversity in the future are far from clear, but many scientists warn that they could be devastating.
Among the first victims of climate change may be mountain-dwelling species. Polar bears and other animals adapted to life near the poles may also see their habitats melt away. In other cases, the climate envelope will shift far away from its current location. Some species may be able to shift as well, but many slow-dispersing species will not Hannah ; Urban After all, extinction is a fact of life, and life on Earth has endured through big pulses of extinctions in the past, only to rebound to even higher levels of diversity.
Mass extinctions are a serious matter, even on purely selfish grounds. Mangroves protect coastal populations from storms and soil erosion, but they are now being rapidly destroyed. People who depend on fish for food or income will be harmed by the collapse of coral reefs, which provide shelter for fish larvae.
Bees and other insects pollinate billions of dollars of crops, and now, as introduced diseases are driving down their populations, farmers will suffer as well. Biodiversity also sustains the ecosystems that support human life, whether they are wetlands that purify water or soil in which plants grow.
In some cases, a single species can disappear without much harm to an ecosystem. The studies by Barnosky and his colleagues show us that if we maintain our current course, we will enter the sixth great mass extinction event. In other words, we still have time to change our impact on the natural the global temperature, atmospheric world. And we can use the insights from macroevolution to guide our actions.
To sum up. Macroevolution describes evolution at a much larger scale; it is evolu- tion applied above the species level, including the origination, diversification, and extinction of species and clades over long periods of time. Disper- sal describes the movement of organisms from their place of origin, for example, a seed being transported to an island by wind. Vicariance is the process of bar- rier formation, such as the barriers that develop through plate tectonics e.
Lineages can also experi- ence stasis and bursts of change. The difference between a and V determines the fate of a particular clade. These key innovations can allow the organism to exploit new and undercontested habitats or novel ways of life. The struggle between predators and prey acceler- ated the diversification of animal lineages. At least five mass extinctions have occurred, but no clear ecological or taxonomic signal or cause unites all five.
Multiple Choice Questions Answers can be found on page How are extinctions related to biodiversity? What is the turnover rate in stage B in Figure Which of the following is NOT a hypothesis about the biodiversity. The typical tempo of extinctions within a particular taxon 3. Which of these statements about vicariance is TRUE? Plate tectonics are a primary mechanism of vicariance. Background extinction. Mass extinction.
Vicariance prevents dispersal. Total extinction. Both a and b are true. Episodic extinction. All of the above are true. Can the Big Five extinctions all be attributed to a single cause? If so, what caused them? The Big Five extinctions were caused by asteroids that had major impacts on habitats when they hit the Earth. The Big Five extinctions were caused by various abiotic and biotic factors that affected different taxa differently. The Big Five extinctions resulted from low origina- tion rates that resulted from a variety of biotic factors.
The Big Five extinctions resulted from plate tec- e. The Big Five extinctions are statistical anomalies tonics that changed the quantity and quality of avail- caused by examining families as taxonomic units able habitats.
Short Answer Questions Answers can be found on page What are the differences between microevolution and 3. What is the difference between an abiotic and a biotic macroevolution? What are the similarities? Provide examples. Should humans be concerned about the pace of extinc- 2. What lines of evidence have macroevolutionary biolo- tions of organisms that are not directly related to our gists used to determine the origin of marsupials?
How are survival? Additional Reading Barnosky, A. Berkeley: University of California Press. Chicago: University of Chicago Benton, M. Introduction to Paleobiology Press. Hoboken, NJ: Wiley. Sepkoski, D. Ruse, eds. The Paleobiological Revolution: Erwin, D.
The Cambrian Explosion. Essays on the Growth of Modern Paleontology. Chicago Press. Hunt, G. Macroevolution, Pattern and Process. Baltimore, Origin of Species. American Naturalist S1 — Kocher, T.
Eldredge, eds. Nature Reviews Genetics — Lawrence, KS: Paleontological Society. Schluter, D. The Ecology of Adaptive Radiation. Oxford: Oxford University Press. Age and Rate of Diversifi- Fossil Record.
Proceed- Suppl 1 — Alvarez, L. Alvarez, F. Asaro, and H. Knoll, and J. Anatomical terrestrial Cause for the Cretaceous-Tertiary Extinction. Marine Realm. Princeton, 10 — NJ: Princeton University Press. Bambach, R. Knoll, and S. Origination, Alvarez, W. Kauffman, F. Surlyk, L. Asaro, et al. Extinction, and Mass Depletions of Marine Diversity. Paleobiology 30 Science — Barnosky, A. Matzke, S. Tomiya, G. Wogan, B. Swartz, et al. Nature — Ridgwell, D.
Schmidt, E. Thomas, S. Gibbs, et al. The Geological Record of Ocean Acidification. Science Paleobiology 32 4 — Beck, R. Godthelp, V. Weisbecker, M. Archer, and S. International Institute for Species Exploration. State of Tempe: Arizona State University. Bertelsmeier, P. Leadley, W. Thuiller, and F. Impacts of Climate Change on the Future of Biodiversity. Ecol- Jablonski, D.
Macroevolutionary Trends in Space and Time. Grant and B. Grant pp. Princeton, tion of All Time. BlueGreen Alliance. Phylogeny Reconstruction mental, Economic and Social Costs. Keller, G. Brusatte, S. Butler, P. Barrett, M. Carrano, D. The Extinction of the Dinosaurs. Biological Reviews.
Sutton, G. Edgecombe, and J. Pro- Burgess, S. Bowring, and S. Proceedings of the National Lerner, H. Meyer, H. James, M. Hofreiter, and R. Academy of Sciences USA 9 — Barnosky, and R. Pre-Anthropogenic Baseline. Losos, J. American Naturalist 6 — In Models in Paleobiology, ed. Adaptation and Diversification Schopf pp. Erwin, D. Upchurch, R.
Benson, and A. The Years Ago. Latitudinal Biodiversity Gradient through Deep Time. Trends in Ecol- Erwin, D. Mayhew, P. Perspec- Grimaldi, D.
Evolution of the Insects. Cambridge: tives from Fossils and Phylogenies. Biological Reviews 82 3 — Cambridge University Press. Bell, T. Benton, and A. Bio- Hannah, L. Saving a Million Species. Proceedings of the National Island Press. Academy of Sciences USA 38 — Harvey, P.
Holmes, A. Mooers, and S. Infer- Millennium Ecosystem Assessment. In Models in Well-Being: Synthesis. Washington, DC: Island Press. Phylogeny Reconstruction, eds. Scotland, D. Siebert, and D. Williams pp. Tittensor, S. Adl, A. Simpson, and B. PLoS Biol- ogy 9 8 :e Newell, N. Fossil Populations. Sylvester-Bradley pp. London: Sahoo, S. Planavsky, B. Kendall, X. Wang, X. Shi, et al.
Ocean Oxygenation in the Wake of the Marinoan Glaciation. Salzburger, W. Mack, E. Verheyen, and A. BMC Evolutionary Biology 5 1 Nicholson, D.
Ross, and P. Proceedings Sandom, C. Faurby, B. Sandel, and J. Churakov, M. Sommer, N. Tran, A. Zemann, et al. PLoS Biology 8 7 :e Schopf, J. Proceedings of the National Parmesan, C. Climate Change. Annual Review of Ecology, Evolution, and Systemat- ics 37 1 — Sepkoski Jr. Paleobiology 7 1 — Harmon, and J. Post a Comment Note: Only a member of this blog may post a comment. Newer Post Older Post Home.
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