Rough Doublings of Rate of Progress in Natural History
I was thinking about the longevity of life on Earth, and I saw this interesting pattern. All the dates are very approximate, and I'm aware that my rounding may be creating a pattern where none really exists. Anyway, roughly ...
4.000 GYA, prokaryotes.
2.000 GYA, eukaryotes.
1.000 GYA, colony creatures
0.500 GYA, complex multi-cellular life.
0.250 GYA, possible first sentient (*) life
0.125 GYA, possible first sapient (**) life
The pattern continues with the K-T extinction, which at 0.066 GYA is very close to the 0.0625 GYA halfway point. I'm not sure that this extinction accomplished anything positive, though one positive effect may have been that it cleared the way for two Classes (Mammalia and Avia) to develop sapient species. 0.033 GYA would put us around the time of the transition from the Paleogene, during which mammals got demonstrably smarter. 0.016 GYA is neatly around the time of the evolution of the Great Apes, 0.008 GYA when the chimpanzee line (including us) break off from the gorilla line, 0.004 GYA the appearance of the ardipithecenes, 0.002 GYA genus homo, 0.001 GYA sees full tool-using including fire and shelters, 0.0005 GYA the appearance of the common ancestors of Sapiens and Neanderthalensis, 0.00025 GYA the first archaic Homo sapiens, 0.000125 GYA syntactically modern language, 0.00006 GYA the expansion of Homo sapiens sapiens Out of Africa, 0.00003 GYA the extinction of most competing human species, 0.000015 GYA the first stirrings of agriculture, 0.000007 GYA (around 4000 BC) of civilization.
That's as far as it goes, and I think it's interesting, though obviously far from decisive as I am arbitrarily choosing "significant" developments, and in some cases very speculatively (we don't really know how smart early mammals or any dinosaurs were, for instance).
===
(*) Having a sense of personal identity and true emotions rather than merely collections of instincts. I'm talking about the early dinosaurs and mammals, following the P-T extinctions. Emotions are especially important in mammals because of how they raise their young.
(**) Having full consciousness: being able to think about thinking. Assuming that they used the (more efficient) avian rather than reptilian brain plans, some dinosaurs may have been as smart as elephants or apes, which demonstrably have this capability.
4.000 GYA, prokaryotes.
2.000 GYA, eukaryotes.
1.000 GYA, colony creatures
0.500 GYA, complex multi-cellular life.
0.250 GYA, possible first sentient (*) life
0.125 GYA, possible first sapient (**) life
The pattern continues with the K-T extinction, which at 0.066 GYA is very close to the 0.0625 GYA halfway point. I'm not sure that this extinction accomplished anything positive, though one positive effect may have been that it cleared the way for two Classes (Mammalia and Avia) to develop sapient species. 0.033 GYA would put us around the time of the transition from the Paleogene, during which mammals got demonstrably smarter. 0.016 GYA is neatly around the time of the evolution of the Great Apes, 0.008 GYA when the chimpanzee line (including us) break off from the gorilla line, 0.004 GYA the appearance of the ardipithecenes, 0.002 GYA genus homo, 0.001 GYA sees full tool-using including fire and shelters, 0.0005 GYA the appearance of the common ancestors of Sapiens and Neanderthalensis, 0.00025 GYA the first archaic Homo sapiens, 0.000125 GYA syntactically modern language, 0.00006 GYA the expansion of Homo sapiens sapiens Out of Africa, 0.00003 GYA the extinction of most competing human species, 0.000015 GYA the first stirrings of agriculture, 0.000007 GYA (around 4000 BC) of civilization.
That's as far as it goes, and I think it's interesting, though obviously far from decisive as I am arbitrarily choosing "significant" developments, and in some cases very speculatively (we don't really know how smart early mammals or any dinosaurs were, for instance).
===
(*) Having a sense of personal identity and true emotions rather than merely collections of instincts. I'm talking about the early dinosaurs and mammals, following the P-T extinctions. Emotions are especially important in mammals because of how they raise their young.
(**) Having full consciousness: being able to think about thinking. Assuming that they used the (more efficient) avian rather than reptilian brain plans, some dinosaurs may have been as smart as elephants or apes, which demonstrably have this capability.