What's Inside. 1  Start. Stay on top of your day with the latest updates, recommended resources, upcoming events, and pawpular posts. 2  Guide. A comprehensive collection of university resources to help you find what you need. 3  Events. Explore the wide variety of activities happening at UMBC by browsing the event calendar. Community See what the UMBC community is talking about by browsing the most pawpular posts. Groups Browse hundreds of groups to find and follow ones that you're interested in.
But dinosaurs didnât appear until about 230 million years ago. Mammals first appeared around that same time. The first human-like animal, or hominid, dates to about 4.5 million years ago, but modern humans only date back perhaps 60,000 years.And recorded civilization has lasted only about 5,000 years.ammals first appeared around that same time. The first human-like animal, or hominid, dates to about 4.5 million years ago, but modern humans only date back perhaps 60,000 years. And recorded civilization has lasted only about 5,000 years.
Life on Earth first appeared as early as 4.28 billion years ago, soon after ocean formation 4.41 billion years ago, and not long after the formation of the Earth 4.54 billion years ago. Earth's current life may have descended from an RNA world, although RNA-based life may not have been the first. The mechanism by which life began on Earth is unknown, though many hypotheses have been formulated and are often based on the MillerâUrey experiment.