Looking at the vast range of living creatures today makes us gasp at their diversity. From giant whales to tiny insects, and every imaginable variation in between. We know, from studies like genetics, embryology and fossils that all came from a single form. And that form had sufficient potential, enough plasticity in its DNA to slowly morph into every animal that has ever lived. What that earliest animal looked like, we can only conjecture, at the current state of knowledge. But there must have been quite an early diversification into creatures that at least represented the first members of the great phylae of animals. The first arthropod, the first vertebrate, the first mollusc ,nematode, and so on.
Two recent discoveries give us an exciting picture of what two of those may have been like: the first arthropod (ancestor of insects, spiders, shrimps, scorpions etc) And the first mollusc (ancestor to the amazing world of slugs, snails, clams and cephalopods). Researchers at Durham University have used advanced microscopical techniques to look at a tiny fossil [1] named Youti yuanshi which lived in what is now Yunnan about 520 million years ago. Details of its internal organs suggest it is close to the ancestors of all those jointy, segmented arthropods, probably the most successful and diverse group of animals on the planet. And not to be outdone, the molluscs have come up with their own Ur-ancestor, called Shishania aculeata, a kind of spiny slug which lived at around the same time. [2]
We will leave you to explore the details in the links which we have provided. We hope you will jump off from these to find out more. We will marvel at the skills and techniques of scientists who wring so much fresh learning from intricate new techniques. And above all at the window provided to the lives simple creatures in a warm sea half a billion years ago, who stood at the start of so much life.
[1]https://phys.org/news/2024-07-million-year-worm-fossil-mystery.html
#genetics #embryology #evolution #arthropod #mollusc #yunnan
Learning, Science and Society 