Mankind

Mankind was created in the Third Age, being the second sentient race in inhabiting Marn. The first were the Elvish. They were created by Gaia in an act to create a thriving people of Marn. They were easily moldable, quickly becoming the God's favorites. Aera was able to influence their emotions and minds; God's of War could make them fight, God's of Anger could make them mad. They could do anything to them, but they were their children.

When the Human's were created, they were placed in the Western World. They did not know of the world of the Aera but could see signs of them across the world. Biblically, every so often a human would claim to have seen and be guided by God himself. That, of course, would be an Aera itself actually speaking to the person.

As Human's crossed the great continent, they became civilized and broke off into groups. The Empire that once was the Empire of Man became dozens of countries. They began to fight, feel emotions, and be overcome by greed. The Aera began to influence them. But a confounding sense of exploration overcame them too. They traveled the oceans and found Carridan, inhabiting it. They went further and found the Darklands, a place they never wished to go to again.

Elves and Yatan
The Elves were unlike the Humans, they were free from the limiting minds given to the humans by Gaia. They were created by Achelous to be highly intelligent and capable of understanding the world. They were separate from the influence of the Gods, not impacted by their rule or influence over emotion and mind. The Aera despised the Elves and left them alone in Yatan until 14,000 years ago, where the humans had gone there.

The last act of exploration of mankind would have been the discovery of Yatan. The huge ship that went there had planned to leave to report the finding, but they encountered a weird group of people. Thriving in the mana filled land, the Elves had great abilities and culture that baffled the humans. They stayed and joined them. Over time, the crossbreeding led to a new race of Half-elves.

As time progressed, the influence of the Mana in the air was able to effect the humans. It had not been able to do so to Elves. They gained an eastern appearance as generations went on. The Elvish blood drew thinner as humans continued to breed with them, eventually killing off the Elvish blood.