Altered climatic conditions and global warming are causing noticeable changes in the size of animals, leading to evolution of miniature versions, new research indicates.

A study published in the latest issue of the journal Nature Climate Change finds that apart from the other effects of global warming like melting glaciers and altered bird migration timings, there has been a decrease in the size of animals as over pre-warming days.

The research was conducted by Jennifer Sheridan, a conservation biologist at the University of Alabama, and David Bickford, an evolutionary ecologist at the University of Singapore.

Since this diminution in size is not uniform among species, it could play havoc in the food chain. This, in turn, may predispose certain animal species to the risk of extinction.

Included in the study are examples of species which have already shown marked decrease in their size such as the Soay sheep found in the Scottish highlands.

Besides this, there have also been fossilized examples in the past where marked changes were observed in the size of certain species.

According to LiveScience, some modern shrinkage is expected to come about indirectly. For instance, increasing acidity in the ocean - caused by increased carbon dioxide in the atmosphere - interferes with some organisms' ability to build their calcium carbonate shells or skeletons like corals.

However, the research doesn't imply that there will be any drastic changes in animal's size or sudden shrinkage in the size of humans.

I don't think that organisms will shrink to the degree that you'll walk outside and see that trees are suddenly half the size that they used to be, The New York Times quoted Sheridan stating.

At the same time, the researchers grant that it is still too early to make detailed predictions.