Human Evolution and Climate Change
Broad Topic: Climate Change and Evolution
Earth's climatic history during the period of evolution of ancient species leading up to the present day human include fluctuations in cooling, drying, and wider climate changes. This research assesses how the changing environment affects the evolution of early hominin species leading to our own species in terms of biology and evolution (Climate Effects on Human Evolution).
How do we determine the environmental fluctuations in temperature?
Deep sea cores can be analyzed for the ratio of two oxygen isotopes which then indicates changing temperature or glacial ice over time. The two trends observed from these cores are an overall decrease in temperature and development of a larger degree of climate fluctuation (Climate Effects on Human Evolution).
Carbon isotope excursion measures carbon dioxide and methane gases release into the atmosphere. Therefore, the higher the carbon release, the higher the temperature will be (Cachel).
Types of environmental change
Unpredictable shifts in temperature or precipitation can cause dramatic changes in vegetation, such as from grasslands to forests and from extremely cold to extremely warm climates (Climate Effects on Human Evolution). Some species were driven to extinction by the advancing and retreating ice ages, while some species were forced to develop larger brains. (O'Neil).
In northern China the uplift of the Tibetan Plateau changed rainfall patterns (Climate Effects on Human Evolution).
Tectonic activity can change the location and size of lakes and rivers and therefore changing the availability of certain resources (Climate Effects on Human Evolution).
The Indian Plate slamming into the Asian plate created the Himalayas that changed the pattern of rainfall, bringing in never before seen amounts of rainfall into the Indian and African subcontinents (Walking with Cavemen).
D. Hypotheses of evolution...