Post by Avatar on May 12, 2024 21:24:23 GMT
Normally, my interests tend toward the physical sciences.
I have a trilobite fossil from the Indiana shale layer.
Summary: the Ediacran period shows two prototype candidates for trilobites. Shows, does not mean actual. These are impressions in rock left behind by something that looks like it could / might / maybe have been an animal that ancestored the trilobite. Going back even further and with even more uncertainty, are proto mollusks, coral, worms and maybe sponges. The corresponding plants could be algae and seaweed The usual single cell bacteria suspects, parameciums, rotifers, tardigrades, etc.; might have been back there 3/4 of a billion years ago. I emphasize "might". Squiggle l
As a comparator, those conclusions are about as certain as WIMPS in physics.
Here's come the PHYSICS part of the video. Come on, you knew it was going to happen...
About ~700~630 million years ago, when the only multicellular life was hypothesized to be sponges, our Earth became a snowball. Whether the oceans were ice sheeted or icebergs and slush ice dotted the oceans is unknown. What is known, is that there is not much solid evidence of multicellular life aside from the traces of Ediacran fossils before, during the snowball and after. Post snowball earth, the geology is suddenly lousy with fossils.
One explanation for why is that happened is that when water turns cold and is mixed with minerals, it becomes syrupy. Viscosity, or resistance to flow, thickens. The animals, if any, before the snowball, had to develop efficient pumping systems to move water around inside themselves to extract nutrients. This led to cell specialization; muscles, channels (blood vessels in us.), the arise of specialized digestion (a gut), nerves and so forth. Push that for a couple of hundred million years, and you get the pre-Cambrian fauna (trilobites).
Avatar
I have a trilobite fossil from the Indiana shale layer.
Summary: the Ediacran period shows two prototype candidates for trilobites. Shows, does not mean actual. These are impressions in rock left behind by something that looks like it could / might / maybe have been an animal that ancestored the trilobite. Going back even further and with even more uncertainty, are proto mollusks, coral, worms and maybe sponges. The corresponding plants could be algae and seaweed The usual single cell bacteria suspects, parameciums, rotifers, tardigrades, etc.; might have been back there 3/4 of a billion years ago. I emphasize "might". Squiggle l
As a comparator, those conclusions are about as certain as WIMPS in physics.
Here's come the PHYSICS part of the video. Come on, you knew it was going to happen...
About ~700~630 million years ago, when the only multicellular life was hypothesized to be sponges, our Earth became a snowball. Whether the oceans were ice sheeted or icebergs and slush ice dotted the oceans is unknown. What is known, is that there is not much solid evidence of multicellular life aside from the traces of Ediacran fossils before, during the snowball and after. Post snowball earth, the geology is suddenly lousy with fossils.
One explanation for why is that happened is that when water turns cold and is mixed with minerals, it becomes syrupy. Viscosity, or resistance to flow, thickens. The animals, if any, before the snowball, had to develop efficient pumping systems to move water around inside themselves to extract nutrients. This led to cell specialization; muscles, channels (blood vessels in us.), the arise of specialized digestion (a gut), nerves and so forth. Push that for a couple of hundred million years, and you get the pre-Cambrian fauna (trilobites).
Avatar