Examples of extinction rate in the following topics:
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- Human activities probably caused the Holocene mass extinctions; many methods have been employed to estimate these extinction rates.
- The background extinction rate is estimated to be about one per million species per year (E/MSY).
- One contemporary extinction rate estimate uses the extinctions in the written record since the year 1500.
- Taking these factors into account raises the estimated extinction rate closer to 100 E/MSY.
- This work argues that the species-area relationship leads to an overestimate of extinction rates.
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- Biodiversity has been affected by five mass extinction periods, which greatly influenced speciation and extinction rates.
- When speciation rates begin to outstrip extinction rates, the number of species will increase; likewise, the number of species will decrease when extinction rates begin to overtake speciation rates.
- There are many lesser, yet still dramatic, extinction events, but the five mass extinctions have attracted the most research.
- The Ordovician-Silurian extinction event is the first-recorded mass extinction and the second largest.
- The end-Permian extinction was the largest in the history of life.
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- Climate change, specifically, the anthropogenic (caused by humans) warming trend presently underway, is recognized as a major extinction threat, particularly when combined with other threats such as habitat loss.
- Scientists disagree about the probable magnitude of the effects, with extinction rate estimates ranging from 15 percent to 40 percent of species by 2050.
- The rate of warming appears to be accelerated in the arctic, which is recognized as a serious threat to polar bear populations that require sea ice to hunt seals during the winter months; seals are the only source of protein available to polar bears.
- The rate of decline observed in recent years is far greater than previously predicted by climate models.
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- Plant biodiversity, vital to ecosystems, food crops, and medicine production, is threatened by habitat destruction and species extinction.
- The explosion of the human population, especially in tropical countries where birth rates are highest and economic development is in full swing, is leading to human encroachment into forested areas.
- Ebony and Brazilian rosewood, both on the endangered list, are examples of tree species driven almost to extinction by indiscriminate logging .
- The number of plant species becoming extinct is increasing at an alarming rate.
- They may become extinct before we have the chance to begin to understand the possible impacts resulting from their disappearance.
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- In fact, there were several factors that played a role in the extinction of perhaps 200 cichlid species in Lake Victoria.
- Extinction, a natural process of macroevolution, occurs at the rate of about one out of 1 million species becoming extinct per year.
- The fossil record reveals that there have been five periods of mass extinction in history with much higher rates of species loss.
- The rate of species loss today is comparable to those periods of mass extinction.
- However, there is a major difference between the previous mass extinctions and the current extinction we are experiencing: human activity.
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- Overfishing leads to fishery extinctions, loss of a food source, and affects many other species in ways that may be impossible to predict.
- Resource depletion, low biological growth rates, and critically low biomass levels result from overfishing.
- Fishery extinctions rarely lead to complete extinction of the harvested species, but rather to a radical restructuring of the marine ecosystem in which an abundant species is so over-harvested that it becomes a minor player, ecologically.
- In general, the fish taken from fisheries have shifted to smaller species as larger species are fished to extinction.
- In general, the fish taken from fisheries have shifted to smaller species as larger species are fished to extinction.
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- Results of climate change, past and present, have been documented and include species extinction, rising sea levels, and effects on organisms.
- Global warming has been associated with at least one planet-wide extinction event during the geological past.
- The Permian extinction event occurred about 251 million years ago toward the end of the roughly 50-million-year-long geological time span known as the Permian period.
- On average, the sea is rising at a rate of 1.8 mm per year.
- However, between 1993 and 2010, the rate of sea-level increase ranged between 2.9 and 3.4 mm per year.
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- Ecologists use the term to describe populations that are harvested at a rate that is unsustainable, given their natural rates of mortality and capacities for reproduction.
- Overharvesting can lead to resource destruction, including extinction at the population level and even extinction of whole species.
- In these cases (for example, whales) economic forces will always drive toward fishing the population to extinction.
- In turn, the unchecked prey can then overexploit their own food resources until population numbers dwindle, possibly to the point of extinction.
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- The Pleistocene Extinction is one of the lesser extinctions and a relatively-recent one.
- The extinction appears to have happened in a relatively-restricted time period between 10,000–12,000 years ago.
- It seems probable that over-hunting was a factor in extinctions in many regions of the world.
- In general, the timing of the Pleistocene extinctions correlated with the arrival of humans and not with climate-change events, which is the main competing hypothesis for these extinctions.
- It seems clear that even if climate played a role, human hunting was an additional factor in the extinctions.
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- They are the only living synapsids as earlier forms became extinct by the Jurassic period.
- After the Cretaceous–Paleogene extinction event wiped out the non-avian dinosaurs (birds are generally regarded as the surviving dinosaurs) and several other mammalian groups, placental and marsupial mammals diversified into many new forms and ecological niches throughout the Paleogene and Neogene, by the end of which all modern orders had appeared.
- The sauropsids are today's reptiles and birds, along with all the extinct animals more closely related to them than to mammals.
- The increased metabolic rate required to internally-modify body temperature went hand-in-hand with changes to certain skeletal structures.