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Global Cooling (global + cooling)

Distribution by Scientific Domains
Life Sciences75%

Selected Abstracts

LIVE-BIRTH IN VIPERS (VIPERIDAE) IS A KEY INNOVATION AND ADAPTATION TO GLOBAL COOLING DURING THE CENOZOIC

EVOLUTION, Issue 9 2009
Vincent J. Lynch
The identification of adaptations and key innovations has long interested biologists because they confer on organisms the ability to exploit previously unavailable ecological resources and respond to novel selective pressures. Although it can be extremely difficult to test for the effects of a character on the rate of lineage diversification, the convergent evolution of a character in multiple lineages provides an excellent opportunity to test for the effect of that character on lineage diversification. Here, I examine the effect of parity mode on the diversification of vipers, which have independently evolved viviparity in at least 13 lineages. I find strong statistical evidence that viviparous species diversify at a greater rate than oviparous species and correlate major decreases in the diversification rate of oviparous species with periods of global cooling, such as the Oligocene. These results suggest that the evolution of viviparity buffered live-bearing species against the negative effects of global climate change during the Cenozoic, and was a key innovation in the evolution and diversification of live-bearing vipers. [source]

Limiting Global Cooling after Global Warming is Over , Differentiating Between Short- and Long-Lived Greenhouse Gases

OPEC ENERGY REVIEW, Issue 4 2003
Axel Michaelowa
Current climate policy does not take into account that, after greenhouse gas emissions have been reduced to an extent that atmospheric concentrations stabilise and then start to fall, natural decay of greenhouse gases will lead to a global cooling phase spanning several centuries. This cooling will lead to damage to humans and ecosystems that depends on the rate of temperature change. Current climate policy should thus concentrate on the reduction of short- and medium-lived greenhouse gases, while exempting long-lived gases. This reduces the cooling rate. Another policy option is to sequester carbon in geological reservoirs that allow controlled release in the future. [source]

LIVE-BIRTH IN VIPERS (VIPERIDAE) IS A KEY INNOVATION AND ADAPTATION TO GLOBAL COOLING DURING THE CENOZOIC

EVOLUTION, Issue 9 2009
Vincent J. Lynch
The identification of adaptations and key innovations has long interested biologists because they confer on organisms the ability to exploit previously unavailable ecological resources and respond to novel selective pressures. Although it can be extremely difficult to test for the effects of a character on the rate of lineage diversification, the convergent evolution of a character in multiple lineages provides an excellent opportunity to test for the effect of that character on lineage diversification. Here, I examine the effect of parity mode on the diversification of vipers, which have independently evolved viviparity in at least 13 lineages. I find strong statistical evidence that viviparous species diversify at a greater rate than oviparous species and correlate major decreases in the diversification rate of oviparous species with periods of global cooling, such as the Oligocene. These results suggest that the evolution of viviparity buffered live-bearing species against the negative effects of global climate change during the Cenozoic, and was a key innovation in the evolution and diversification of live-bearing vipers. [source]

Mitochondrial DNA variation and biogeography of eastern gorillas

MOLECULAR ECOLOGY, Issue 9 2001
M. I. Jensen-Seaman
Abstract Mitochondrial DNA variation in 109 individuals from four populations of wild living gorillas in East Africa was ascertained by sequencing the first hypervariable segment of the control region, or ,d-loop', amplified from noninvasively collected hair and faeces. d- loop haplotypes from eastern gorillas fell into two distinct clades, each with low levels of genetic diversity; most observed haplotypes within each clade differing by only one or two mutations. Both clades show evidence of population bottlenecks in the recent past, perhaps concomitant with the tropical forest reduction and fragmentation brought on by global cooling and drying associated with the last glacial maximum. [source]