Final answer:
The trends in Adelie and Gentoo penguin populations are indicative of broader ecological shifts caused by global climate change, specifically reflecting the impact of diminishing sea ice on species distribution and the availability of their food sources.
Step-by-step explanation:
The data on the populations of Adelie and Gentoo penguins can either support or refute the theory of global climate change, depending on the trends observed. Adelie penguins, which are ice-dependent, are likely to decline in populations where the sea ice is receding due to rising global temperatures. Conversely, Gentoo penguins, which are ice-intolerant, may expand their habitat range or increase in number due to reduced ice coverage. This reflects broader species distribution shifts and habitat alterations that have been documented in other polar and mountainous regions, where wildlife must adapt to the changing availability of critical resources. The loss of sea ice, habitat shifts up mountains, and direct effects on species like the polar bear, which relies on sea ice to hunt seals, are all signs of shifting climatic conditions likely due to global climate change as recorded over the latter half of the twentieth century and into the 21st century.