Re: Thoughts on "Aliens: The World's Leading Scientists on the Search for Extraterrestrial Life", by physicist Jim Al-Khalili

On 4/25/26 11:48, Jim Wilkins wrote:
> "a425couple"  wrote in message news:[email protected]...
> 
> https://eartharchives.org/articles/the-alien-world-of-the-burgess-shale/ 
> index.html
> 
"These little creatures are still alive, and are about as unnoticeable 
as their extinct relative. They are, however, relatives of the 
progenitor of all vertebrates. Pikaia and its Cambrian cousins prove 
just how ancient this family is. The alien beasts of the Burgess Shale, 
while weird, were not always as unearthly as we think. They were merely 
setting the stage for other animals to come, and these future creatures 
would rise to dominate the seas and finally the land, in a very big way 
indeed."

Indeed!

IMHO, amazing how 'recently' it has been.

The Cambrian Period (approx. 541–485 million years ago) is a 
foundational era in Earth's history marking the first appearance of most 
major animal phyla and the first complex ecosystems. It is defined by 
the "Cambrian Explosion," a rapid evolutionary burst of diverse, 
hard-shelled life forms—especially arthropods like trilobites—following 
a period of increased oxygenation.
University of California Museum of Paleontology

Significance of the Cambrian Period
The Cambrian Explosion: A dramatic, relatively rapid increase in 
biodiversity where most major animal body plans appeared, shifting from 
simple to complex organisms within a few million years.
Establishment of Modern Life: It marks the start of the Phanerozoic Eon 
and Paleozoic Era, laying the foundation for all subsequent evolutionary 
history.
Geological Transformation: Supercontinent Pannotia broke up, creating 
expansive shallow seas that provided massive, new marine habitats.
University of California Museum of Paleontology
University of California Museum of Paleontology
  +4
Animals of the Cambrian Period