madbadgalaxyman
20-12-2021, 08:51 AM
Here is a wonderful series of several lectures which comprehensively describe that signal event in the evolution of life and mind on our planet; the very early evolution of the animals/plants (technically, the eukaryotic metazoans), in the context of the ecological and geo-climatic changes that occurred during & before this event.
For, as we know, the first 3 billion years of the evolution of life on our planet were "the boring billions", in that life on Earth was exclusively microbial during this vast length of time, and the onset of the true metazoa (colloquially but imprecisely known as "multicellular animals") then occurred relatively abruptly over a period of only 100 million years (though not, I might add, as abruptly as the "Cambrian Explosion" of multiple animal Body Forms (Phyla) might suggest)
(( well actually, the Boring Billions were not really so boring, as there was one (only one!) Very Major transition that occurred (and probably on just a single occasion) towards greater biological complexity, in what is probably a single very-low-probability series of events......the transition from simple prokaryotic cells through to complex eukaryotic cells. ))
Anyhow, it is remarkable how human knowledge has grown in the last 40 years of how the first true multicellular animals (metazoans)(= with multiple cells, and with tissues and organs) evolved from their
single-celled ancestors;
in 1980 there was just a grab bag of untested ideas about lots of weird & wonderful early animals, but now the evolutionary pathways and the ancient ecologies and even the concomitant environmental/geo-climatic changes are becoming fairly well characterized.....
though exactly how and why animals came into being from simpler antecedents remains one of the greatest scientific mysteries that is still in need of a solution.
( I would even advance the truly heretical(!) notion that this is an even more interesting problem than explaining the evolution of the galaxies; but probably I will be roundly attacked for saying this in an astro forum!)
Anyhow, if you really want to know what is now known about all of this, look no further than these lectures.......
https://www.youtube.com/watch?v=blN-F8n2IAc
https://www.youtube.com/watch?v=ehkEltjGmpM
https://www.youtube.com/watch?v=cNeHTOpf1T4
https://www.youtube.com/watch?v=Z841KEUkfnU
https://www.youtube.com/watch?v=Qq1eyftRK2A
You will find several more lectures on this topic if you go to the "Oxford University Museum of Natural History" Youtube channel and you select the option of ordering the videos in terms of their popularity.
There is no textbook on much of this; a lot of this knowledge is so new that the textbooks haven't been written. (I can think of one, from 2007, that is still useful; though it is very out of date)
There are a few sketchy popularizations but I wouldn't bother with them, except to get your brain prepared for the mind-boggling task of conceptualizing a far-off time when the geology and climate and ecology and lifeforms of our planet were radically different from what they now are.
For, as we know, the first 3 billion years of the evolution of life on our planet were "the boring billions", in that life on Earth was exclusively microbial during this vast length of time, and the onset of the true metazoa (colloquially but imprecisely known as "multicellular animals") then occurred relatively abruptly over a period of only 100 million years (though not, I might add, as abruptly as the "Cambrian Explosion" of multiple animal Body Forms (Phyla) might suggest)
(( well actually, the Boring Billions were not really so boring, as there was one (only one!) Very Major transition that occurred (and probably on just a single occasion) towards greater biological complexity, in what is probably a single very-low-probability series of events......the transition from simple prokaryotic cells through to complex eukaryotic cells. ))
Anyhow, it is remarkable how human knowledge has grown in the last 40 years of how the first true multicellular animals (metazoans)(= with multiple cells, and with tissues and organs) evolved from their
single-celled ancestors;
in 1980 there was just a grab bag of untested ideas about lots of weird & wonderful early animals, but now the evolutionary pathways and the ancient ecologies and even the concomitant environmental/geo-climatic changes are becoming fairly well characterized.....
though exactly how and why animals came into being from simpler antecedents remains one of the greatest scientific mysteries that is still in need of a solution.
( I would even advance the truly heretical(!) notion that this is an even more interesting problem than explaining the evolution of the galaxies; but probably I will be roundly attacked for saying this in an astro forum!)
Anyhow, if you really want to know what is now known about all of this, look no further than these lectures.......
https://www.youtube.com/watch?v=blN-F8n2IAc
https://www.youtube.com/watch?v=ehkEltjGmpM
https://www.youtube.com/watch?v=cNeHTOpf1T4
https://www.youtube.com/watch?v=Z841KEUkfnU
https://www.youtube.com/watch?v=Qq1eyftRK2A
You will find several more lectures on this topic if you go to the "Oxford University Museum of Natural History" Youtube channel and you select the option of ordering the videos in terms of their popularity.
There is no textbook on much of this; a lot of this knowledge is so new that the textbooks haven't been written. (I can think of one, from 2007, that is still useful; though it is very out of date)
There are a few sketchy popularizations but I wouldn't bother with them, except to get your brain prepared for the mind-boggling task of conceptualizing a far-off time when the geology and climate and ecology and lifeforms of our planet were radically different from what they now are.