Biodiversity question?

Question

How do scientists determine the rate of loss of species and Why are scientists so concerned with the rapid rate of biodiversity loss?????????

Answer 1

Copying and pasting what is in Wikipedia is not what is meant by offering your own answer unless you wrote the original article, but that person was considerate enough to post her or his sources.

Biodiversity is a general measure of the health of an individual environment. By measuring the number of individuals of each species present, trends toward domination by a few species can be suspected and then a search for the missing species can be initiated.

Even if the present species are all healthy individuals, the loss of less vigorous species suggests that the overall environment is less healthful and stessors have reduced or eliminated these less vigorous species from the environment (or drove them into undetectable locales, like burrowing, becoming inactive or developing camouflage)

Answer 2

The generality of the latitudinal diversity gradient

Recently, Hillebrand (2004) performed an extensive meta-analysis of nearly 600 latitudinal gradients from published literature to determine the generality of the latitudinal diversity gradient across different organismal, habitat and regional characteristics. Hillebrand found the latitudinal gradient occurs in marine, terrestrial, and freshwater ecosystems, in both hemispheres. The gradient is steeper and more pronounced in richer taxa (i.e. taxa with more species), larger organisms, in marine and terrestrial versus freshwater ecosystems, and at regional versus local scales. The gradient steepness (the amount of change in species richness with latitude) is not influenced by dispersal, animal physiology (homeothermic or ectothermic) trophic level, hemisphere, or the latitudinal range of study. The study could not directly falsify or support any of the above hypotheses, however results do suggest a combination of energy/climate and area processes likely contribute to the latitudinal species gradient. Notable exceptions to the trend include the ichneumonidae, shorebirds, penguins, and freshwater zooplankton.

[edit] Conclusion

The fundamental macroecological question that the latitudinal diversity gradient depends on is ‘What causes patterns in species richness’? Species richness ultimately depends on whatever proximate factors are found to affect processes of speciation, extinction, immigration, and emigration. While some ecologists continue to search for the ultimate primary mechanism that causes the latitudinal richness gradient, many ecologists suggest instead this ecological pattern is likely to be generated by several contributory mechanisms (Gaston and Blackburn 2000,Willig et al. 2003, Rahbek et. al 2007). For now the debate over the cause of the latitudinal diversity gradient will continue until a groundbreaking study provides conclusive evidence or there is general consensus that multiple factors contribute to the pattern.