
Originally Posted by
gonzales56
The South China Sea has shifted very swiftly in its PH levels in the past, and has done so on a scale of decades and centuries. The process of evolution is not always about outside forces pushing or forcing genetic change in order for a species to survive.. In fact, that type of demand usually leads to the extinction of species rather than the survival of them. It is often random and continuous mutations that are life's insurance policy against the future's unknown and multiple possibilities. Environmental, biological, chemical, etc. changes that favor some within a species over others based on existing mutations is perhaps the most important aspect to and for survival. There are always going to be a % of life, and life within a highly populated species, that will amaze you concerning how resilient, capable and genetically prepared they are to deal with change/s.
Same goes for people. If they cant move (human's have had to move from the very day they started walking) then they may very well die.
Indeed but consider that the acidity in the South China Sea is NOT representative of global average sea level acidity. In fact the very paper you pulled makes this quite clear:
"The pH variation in the mid-late Holocene is most likely linked to a change of the monsoon climate in the SCS. A unique feature of climate conditions in the SCS is the influence of the East Asia (EA) monsoon and their response to both terrestrial and marine climatic changes (Fig. 1).Upwelling induced by the summer monsoon is a common phenomenon in the SCS (Wu and Li, 2003). The modern pH value of the SCS at a depth of 500 m is 7.60 (Chenet al., 2006), significantly lower than the pH value of surface seawater which ranges from 7.96 to 8.10 (Pelejero et al.,
2005; Chen et al., 2006). Thus, the average pH value of surface seawater will increase as upwelling of subsurface waters wanes when the summer monsoon weakens. On the other hand, strengthening of winter monsoon will bring more dust (nutrients, trace elements like Fe) from the arid
areas in the north—for example, the loess plateau, into the SCS (Fig. 1), which can elevate surface nutrient levels and lead to increased photosynthetic fixation of CO2 and increased seawater pH."
There Conclusion also makes the point:
"CONCLUSIONS
The P-TIMS isotopic technique is demonstrated to be a good method to determine the d11B composition of corals
and satisfies the high analytical precision required to document the small variability of d11B related to surface
seawater pH change. Our data are the first to show that significant variations of the boron isotopic ratios recorded
in fossil corals in the Holocene may be linked with synchronous climate change. In contrast to a trend
of gradually increasing pH in the SCS since the Holocene thermal optimal, modern pH of the SCS is much lower. We believe that increasing concentration of anthropogenic carbon dioxide in the atmosphere may have reversed the natural pH trend in the SCS since the mid-Holocene. It is estimated that global seawater already has been acidified by 0.1 pH unit relative to the pre-industrial times (Caldeira and Wickett, 2003). Further
studies in this area can potentially provide important information regarding the links between changes of surface seawater chemistry and climate change."
It's a regional phenomena more related to the Monsoon strength and up-welling than a general measure of sea acidity, though they think that there's been some contribution by increased CO2 during the period of their study.
The resilience of life doesn't so much come from rapid evolution...but from displacement of species to remaining niches. For corals and its life, most likely from other places that aren't as sensitive to the up-welling, such as the mid-Pacific. The relevant question here is what happens when there are no remaining niches of greater than PH 8, for life to survive in?