Mass Extinction
... More than 99 percent of all species that have ever lived are now extinct. Usually, extinctions happen for the reasons that Darwin proposed. Species compete for resources, and environments change. Some species adapt and survive. Others gradually become extinct in ways that are often caused by natural ...
... More than 99 percent of all species that have ever lived are now extinct. Usually, extinctions happen for the reasons that Darwin proposed. Species compete for resources, and environments change. Some species adapt and survive. Others gradually become extinct in ways that are often caused by natural ...
Macroevolution 11/18/04 Macroevolution
... In the case of the Triassic, a rapid exploitation of biological opportunities after the major mass extinction of the end-Permian. This was also an adaptive radiation, but also a replacement of the pre-existing biotas. Similarly, note below the rapid diversification of mammals into many different hab ...
... In the case of the Triassic, a rapid exploitation of biological opportunities after the major mass extinction of the end-Permian. This was also an adaptive radiation, but also a replacement of the pre-existing biotas. Similarly, note below the rapid diversification of mammals into many different hab ...
Pleistocene Megafauna Extinction
... they found themselves in a fertile land full of large, inexperienced prey. This food bonus stimulated an unprecedented human population explosion, but eventually resulted in the extinction of the continent’s megafauna. The fact that there are very few kill sites in North America as compared to Europ ...
... they found themselves in a fertile land full of large, inexperienced prey. This food bonus stimulated an unprecedented human population explosion, but eventually resulted in the extinction of the continent’s megafauna. The fact that there are very few kill sites in North America as compared to Europ ...
Lecture 22: Coevolution
... • Evidence for coevolution? • Less evidence for coevol’n of running speed Why? costs of adaptation • resistance to 1 pred. may ↑ vulnerability to others e.g. Cucurbitacins:protect from mites; attract beetles ...
... • Evidence for coevolution? • Less evidence for coevol’n of running speed Why? costs of adaptation • resistance to 1 pred. may ↑ vulnerability to others e.g. Cucurbitacins:protect from mites; attract beetles ...
Chapter 6
... Evolutionary Convergence • Evolution of similar forms in two or more different biological groups • Marsupials and placental mammals – Similar form – Isolated, adaptive convergent evolution after initial divergence ...
... Evolutionary Convergence • Evolution of similar forms in two or more different biological groups • Marsupials and placental mammals – Similar form – Isolated, adaptive convergent evolution after initial divergence ...
Pleistocene Vertebrates
... Name comes from Greek meaning “most” and “new” 4 major glaciation events End of the Pleistocene corresponds to the end of the Paleolithic period in Archaeology ...
... Name comes from Greek meaning “most” and “new” 4 major glaciation events End of the Pleistocene corresponds to the end of the Paleolithic period in Archaeology ...
CHAPTER 32 Characteristics of the Class Mammalia are: have hair
... Genus Paranthropus: Huge grinding back teeth to eat plants like modern gorillas. Hominid evolution did not proceed by the simple, straight line transformation of one species to another. Rather, like the evolution of other mammalian groups, a series of complex adaptive radiations produced a large num ...
... Genus Paranthropus: Huge grinding back teeth to eat plants like modern gorillas. Hominid evolution did not proceed by the simple, straight line transformation of one species to another. Rather, like the evolution of other mammalian groups, a series of complex adaptive radiations produced a large num ...
Sixth Extinction
... • Single islands (mountain tops) always have fewer species than areas on the “mainland” of similar size • Because islands are isolated, it will be harder for species to immigrate to them, lowering the rate of immigration. • Because of limited resources on islands, carrying capacity will be lower, de ...
... • Single islands (mountain tops) always have fewer species than areas on the “mainland” of similar size • Because islands are isolated, it will be harder for species to immigrate to them, lowering the rate of immigration. • Because of limited resources on islands, carrying capacity will be lower, de ...
Presentation
... running water Most fossils are in water-laid rocks Bias toward aquatic organisms ...
... running water Most fossils are in water-laid rocks Bias toward aquatic organisms ...
Notebook #8 Extinctions
... many plants and animals are likely to become extinct in the near future as a result of the negative impact of human activities (clear-cutting, water and air pollution, etc) on the environment. Scientists have evidence to support the claims that human effects on the environment could threaten some bi ...
... many plants and animals are likely to become extinct in the near future as a result of the negative impact of human activities (clear-cutting, water and air pollution, etc) on the environment. Scientists have evidence to support the claims that human effects on the environment could threaten some bi ...
Lecture 09 - Extinction vulnerability
... transgression, occurs when flooding from the sea covers previously exposed land. Evidence of marine regressions and transgressions occurs throughout the fossil record, and these fluctuations are thought to have caused or contributed to ...
... transgression, occurs when flooding from the sea covers previously exposed land. Evidence of marine regressions and transgressions occurs throughout the fossil record, and these fluctuations are thought to have caused or contributed to ...
2013年1月12日托福写作真题回忆
... may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food resources may be affected by environmental changes, which will then cause problems for a species requiring these resources. Other species may become better adapted to an ...
... may render an environment hostile to a species. For example, temperatures may change and a species may not be able to adapt. Food resources may be affected by environmental changes, which will then cause problems for a species requiring these resources. Other species may become better adapted to an ...
Biodiversity and risk patterns of freshwater megafauna Global
... Biodiversity and risk patterns of freshwater megafauna Fengzhi He Your picture Significance: Coupled with the susceptibility of megafauna to anthropogenic threats and the fact that freshwaters habitats have experienced extensive degradation because of human activities, it can be hypothesised that fr ...
... Biodiversity and risk patterns of freshwater megafauna Fengzhi He Your picture Significance: Coupled with the susceptibility of megafauna to anthropogenic threats and the fact that freshwaters habitats have experienced extensive degradation because of human activities, it can be hypothesised that fr ...
Extinctions: Past and Present
... John James Audobon wrote of the passenger pigeon in 1844 in The Birds of America: "In the autumn of 1813, I left my house at Henderson (Kentucky), on the banks of the Ohio, on my way to Louisville. In passing over the barrens a few miles beyond Hardensburgh, I observed the pigeons flying from northe ...
... John James Audobon wrote of the passenger pigeon in 1844 in The Birds of America: "In the autumn of 1813, I left my house at Henderson (Kentucky), on the banks of the Ohio, on my way to Louisville. In passing over the barrens a few miles beyond Hardensburgh, I observed the pigeons flying from northe ...
Man-Made factors of Extinction
... o Volcanic eruptions (and their side effects) o Global warming and global cooling (ice ages) o Changes in oxygen levels in seawater o Massive impact from an asteroid or comet o Competition for Resources: too many organisms fighting over the same food/water/etc. o Inability to Adapt: cannot change wi ...
... o Volcanic eruptions (and their side effects) o Global warming and global cooling (ice ages) o Changes in oxygen levels in seawater o Massive impact from an asteroid or comet o Competition for Resources: too many organisms fighting over the same food/water/etc. o Inability to Adapt: cannot change wi ...
The postCambrian era was characterized by animal
... aerial specialists. The appearance and dominance of flowering plants in the Cenozoic Era created new niches for insects, as well as for birds and mammals. Changes in animal species diversity during the late Cretaceous and early Cenozoic were also promoted by a dramatic shift in earth's geography, as ...
... aerial specialists. The appearance and dominance of flowering plants in the Cenozoic Era created new niches for insects, as well as for birds and mammals. Changes in animal species diversity during the late Cretaceous and early Cenozoic were also promoted by a dramatic shift in earth's geography, as ...
PPT
... Removal of keystone herbivores causes extinction cascade for midsize herbivores and their predators (Domino Effect) ...
... Removal of keystone herbivores causes extinction cascade for midsize herbivores and their predators (Domino Effect) ...
Megafauna
In terrestrial zoology, megafauna (Ancient Greek megas ""large"" + New Latin fauna ""animal"") are large or giant animals. The most common thresholds used are 45 kilograms (100 lb) or 100 kilograms (220 lb). This thus includes many species not popularly thought of as overly large, such as white-tailed deer, red kangaroo, and humans.In practice, the most common usage encountered in academic and popular writing describes land animals roughly larger than a human that are not (solely) domesticated. The term is especially associated with the Pleistocene megafauna – the land animals often larger than modern counterparts considered archetypical of the last ice age, such as mammoths, the majority of which in northern Eurasia, the Americas and Australia became extinct as recently as 10,000–40,000 years ago. It is also commonly used for the largest extant wild land animals, especially elephants, giraffes, hippopotamuses, rhinoceroses, and large bovines. Megafauna may be subcategorized by their trophic position into megaherbivores (e.g., elk), megacarnivores (e.g., lions), and, more rarely, megaomnivores (e.g., bears).Other common uses are for giant aquatic species, especially whales, any larger wild or domesticated land animals such as larger antelope and cattle, as well as numerous dinosaurs and other extinct giant reptilians.The term is also sometimes applied to animals (usually extinct) of great size relative to a more common or surviving type of the animal, for example the 1 m (3 ft) dragonflies of the Carboniferous period.