Human Evolution: An Algorithmic Process Shaped by Climate Change
The ultimate test for the common origin of all living beings is the universality of the genetic code. The genetic code translates the letters a, g, c, and t into the language of proteins (amino acid sequences).
In February 2005, the Department of Education allowed Florida State to include in its educational programs explanations of evolutionary theory, referring to it as “the organizing principle of the natural sciences.”
Natural Selection as an Algorithmic Process
The theoretical power of Darwin’s proposal lies in its algorithmic character. An algorithm is a formal process that can produce—logically—a decisive result, provided it is working properly. Three important features of algorithms are:
Substrate Neutrality
Algorithmic procedures work regardless of the material used. Their power derives from their formal or logical structure, not the causal power of the materials used.
Underlying Stupidity
Each step of the procedure is absolutely simple. “How simple? Simple enough for an idiot to follow, or a mechanical device to carry out” (Dennett 71).
Guarantee of Results
An algorithm, if run correctly, always reaches a solution.
An algorithm accepts competitors as input and ensures that eventually, a winner emerges. Interpreting evolution as an algorithmic process helps us understand that, like any algorithm, it doesn’t follow a plan, purpose, or objective. We cannot understand evolution by natural selection as a process designed to produce human beings.
The Process of Human Evolution
Climate Change and Evolution
Climate change has been essential in the evolution of hominids. Although the global temperature has increased in the last ten thousand years, this is a brief period within a larger cold period, and the warming has been uneven. For 4 or 5 million years, there has been a general trend of global cooling, with less rainfall. Factors influencing climate change include:
- Catastrophic events
- Geodynamic evolution of the planet
- Behavior of the hydrosphere-atmosphere system
- Natural fluctuations of Earth’s orbit around the Sun
- Effect of the biosphere
Milutin Milanković developed a theoretical model relating Earth’s orbital motions to climate. Several factors related to Earth’s movements influence climatic cycles:
- Earth’s orbit around the sun is not perfectly circular.
- The sun is not at the geometric center of the orbit.
- The inclination of Earth’s axis (currently 23.5 degrees) changes every 100,000 to 400,000 years. For shorter periods (around 41,000 years), the Earth’s axis fluctuates between 21º and 24.5º.
These factors cause very slow changes in the amount of solar radiation received by Earth. This results in torrid summers alternating with cool summers every 11,000 years.
Climate Change and Development in Africa
Africa can be divided based on climatic differences. West and Central Africa have abundant subtropical rainfall, unlike East Africa, which has much lower rainfall. During winters, cold, dry winds from the northwest affect the eastern region. Consequently, West Africa retains subtropical wet forests, while the east is dominated by savannas with more herbaceous vegetation than trees.
Around 5 million years ago, rainforests covered the entire African subtropical region. About 2.8 million years ago, large-scale climate oscillations began, with permanent ice in many northern lands during cold seasons. This significantly impacted equatorial African ecosystems. The cooling of North Atlantic waters resulted in cooler, less humid African monsoon summers, affecting the tropical forests of East Africa. This led to a decline in forests and an increase in wooded savannas.
These climate changes caused the disappearance of many hominid species, while simultaneously (in the late Miocene and Pliocene) creating open ecosystems across much of Africa, with new plant and animal species, including new hominids.