8 ms·
Evolutionary Timeline, to scale
- iamwil 17y agoIt seems like there's a whole lot of nothing going on for the first 2 billion years. But what I think we miss is during that time, a lot of the complex biochemical and organic pathways were being developed--without which none of the other classifications of lifeforms would have appeared--and none of these bio pathways manifest themselves in the fossile record. If we were somehow able to classify organisms biochemically instead of by their physical features, I wonder how different the picture would look?
- fh 17y agoThat's true, many of those pathways are shared between all current species, so they must have evolved in that early period. I wonder how (for lack of a better word) inefficient organisms must have been before they evolved the modern citric acid cycle, for example.
- rman666 17y agoYeah, he said "Domestic Asses." Huh, huhhuhuh.
- njharman 17y agoThis has always been the best explanation of why we don't see evidence of aliens. Any detectable species is less than a pixel on that timescale. Combined with likelyhood of getting wiped out by natural (comet/asteroid) or technological(nuke, pollution/climate, custom disease, etc).
- AngryParsley 17y agoI think this timeline tells a different story: Intelligent life is very rare. Typically, life doesn't evolve beyond single-celled or primitive multi-celled organisms before the star goes red giant. The chances of general intelligence evolving are so small that we're probably the first.
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- AngryParsley 17y agoUmm... no? Life on Earth started about 4 billion years ago. The universe is about 13 billion years old. Also, earlier stars had lower metallicity, which made it less likely for rocky planets to form. Population I stars (like the sun) are probably the first generation of stars with high enough metallicity to make rocky planets and life likely.
- JoeAltmaier 17y agoHow are Homo Sapiens NOT the pinnacle of evolution? What are we then, the hind-end? Brick wall? Full Stop?
- tom_rath 17y agoWe're the species currently dominating a niche. Calling anything the 'pinnacle' of evolution implies some sort of progress towards perfection. Evolution does not work that way.
- JoeAltmaier 17y agoSays a member of the only race in 2 billion years that CAN argue about it...
- tom_rath 17y agoYou misunderstand how evolution works. It is not a progression towards perfection. You're conflating biological evolution with creationism / 'intelligent design'.
- JoeAltmaier 17y agoNo, I'm being funny. Somebody else is using words like "conflating".
- JoeAltmaier 17y agoAny anyway, how do you explain going from single-celled creatures to working organisms with a trillion cells? Darwin claims species are driven by their environment to better compete - is that not something like perfecting them?
- AndrewDucker 17y agoNo. Perfection implies a scale with a top end. We compete for spaces in a niche, we don't compete to be all round "better".