The biological arrow of time

Life is a process that seems to defy the laws of thermodynamics, in that reproduction appears to prevent the dissipation of a particular species. Although individual organisms age and eventually die in a temporal direction aligned with the expansion of the universe, the paradox is the appearance of younger versions of the species. The resolution of this paradox is resolved by the same principles that allow refrigerators to cool down objects: the laws of thermodynamics do not apply to components of a system but to complete systems. For example, when an object of temperature T1 is placed in thermal contact with another object of temperature T2 < T1, the combined system tends to an equilibrium temperature T3 such that T2 < T3 < T1. If we looked only at the second object, it would appear to have increased its temperature.

The evolutionary arrow of time

Recent fossil analysis has supported the hypothesis that human psychology evolved more recently than human physiology [Brown et al., 2012]. It is believed that Stone Age man fashioned shards of stone, known as microliths, into arrow heads. The new evidence suggests that the earliest microliths were fashioned 71,000 years ago, whereas our species, Homo sapiens, is between 150,000 and 200,000 years old. This suggests that the human mind evolved into its near modern form relatively late, crossing the threshold beyond which humanity could develop in the form we have today. Moreover, arrowheads suggest an advanced conception of weaponry unique to humans.

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