Life on Earth is Old

Life on Earth began somewhere. Scientists think that there was one single ancestor, which they call LUCA (Last Universal Common Ancestor). This would have been a unicellular organism that eventually diverged to create every living thing we have today. And I mean everything, from tiny bacteria to blue whales. And LUCA began a long, long time ago.

About 530 million years ago, the Cambrian Explosion saw the major expansion of complex life. It’s been estimated that LUCA appeared 4 billion years ago, about 600 million years after Earth’s formation.

But one study pushes that arrival back to about 4.2 billion years ago. It also indicated fascinating details of what life for LUCA might have been like.

To find exactly when life appeared on Earth, scientists had to work backward. They first compared genes in species living today and counted the number of mutations that have occurred since the common ancestor. Using a genetic equation, they worked out that LUCA must have existed as early as 400 million years after the planet’s creation. That would put his organism in the middle of the Hadean Eon, which was a hellish geologic nightmare. During this time, Earth experienced frequent collisions, including the one that created the moon. The surface was unstable, with lava bubbling to the surface.

The evolutionary history of genes is complicated. Scientists had to use complex evolutionary models to reconcile the history of genes with the genealogy of species.

The team also retraced the physiological characteristics of living species to discover what LUCA must have been like. Surprisingly, even though it was a unicellular organism, it appears to have had an immune system. This would indicate LUCA was already fighting off primordial viruses, which makes one wonder if viruses are truly alive.

While LUCA was exploiting and changing its environment, it’s likely it didn’t live alone. Its waste would have been eaten by other microbes such as methanogens, which produce methane as a by-product of their metabolism. Such arrangements might have created a recycling ecosystem.

Although this is the oldest common ancestor known, scientists don’t understand how life evolved from its very origins to the early communities that LUCA was part of.

 

https://www.msn.com/en-us/news/technology/all-life-on-earth-comes-from-one-single-ancestor-and-it-s-so-much-older-than-we-thought/ar-AA1So3MH?ocid=hpmsn&cvid=694052ebf2b54b488c496cce3ccd1493&ei=107

Ancient Tools Contradict Civilization Timeline

A long-standing question has stumped researchers: How did humanity come to inhabit the Islands of Southeast Asia (ISEA) such a long time ago?

The thought is that doing so would have required seafaring advancements beyond that considered likely during the Paleolithic era (Old Stone Age). But research shows that the ancient people of the Philippines and ISEA may have mastered seafaring before anyone else.

The evidence is stone tools excavated in the Philippines, Indonesia, and Timor-Leste. As far back as 40,000 years ago, there existed a technological sophistication in these ancient seafarers that rivals that of much later civilizations. The researchers say this challenges the believe that Paleolithic technical progress was centered in Africa and Europe.

Proving seafaring history is a trick endeavor. Organic wood and fiber—likely used in constructing seacraft—rarely survive in the archaeological record. But stone tools do. The most recent discovery shows traces of plant processing for the extraction of fibers. The fibers would have been used to make ropes, nets, and bindings, which are essential for building boats and open-sea fishing.

When you add in the discovery of fishing hooks, gorges (a fish book alternative), net weights, and the remains of tuna and sharks, it seems obvious a robust seafaring culture existed.

The presence of large open-sea fish at these sites indicate advanced seafaring techniques and knowledge of the time and routes of the migration of those species. There was a need for strong, well-crafted ropes and fishing lines.

The archaeologists believe these ancient seafarers made boats held together with ropes. The same rope technology would have been adapted for fishing.

Fossils and artifacts across the island proves that early humans moved across the open sea. But these scientists do not accept the theory that the prehistoric migrations were passive, that people drifted on bamboo rafts. Instead, they think the movement came from skilled navigators. They feel that direct or indirect evidence of boat-building is vital to understand human movement across island environments.

Such advanced maritime technology in prehistoric ISEA shows ingenuity. Their boat-building knowledge probably made the region a center for technological innovations tens of thousands of years ago. It would have laid the foundation for the maritime traditions that still thrive there today.

 

https://www.msn.com/en-us/news/world/archaeologists-found-ancient-tools-that-contradict-the-timeline-of-civilization/ar-AA1QBNgO?ocid=hpmsn&cvid=693f6c4211d9422bb32ac5d9db0e778e&ei=29