Will Mitchell
The Evolution of Life on Earth
Summary
This video shows a very simple yet highly accurate explanation for how life began and became more complex over billions of years through evolution. This video begins with the simplest of life forms that lived on Earth, marking the beginning of life on Earth and the beginning of evolution of life. Starting with a simple chemical reaction on the early, developing Earth, and eventually leading to the development of the humans we are today. As new forms of life in the ocean evolved over hundreds of millions of years, some sea life evolved ways to breathe and survive out of water for short periods of time. This led to the first amphibians and reptiles evolving, and plants and insects took hold on the terrestrial parts of Earth. Then came the dinosaurs, which either developed wings for flight through the air, or into reptiles that walked on land and varied greatly in size. A mass extinction wiped out the dinosaurs, but the forerunners of the dinosaurs had taken a different path, and evolved into small, mammal-like creatures by the end of the age of the dinosaurs. These small creatures slowly developed into many of the mammals we know of today, including us humans as well.
Relevance
This video is very relevant to the unit we are currently in for it discusses and includes many themes and topics from our current unit. These topics/themes include evolution, mass extinction, adaptation, descent with modification, speciation, biological diversity, and adaptive radiation. Evolution is clearly evident as the reason for life having transformed so greatly over an immense period of time. Descent with modification is seen throughout Earth's life history. Descendants of the first ancestral organisms spread into different habitats and accumulate adaptations to diverse ways of life. Mass extinctions and extinctions have occurred in the past, as they will inevitably occur in the future. The dinosaurs were wiped out due to some catastrophic event, which is labeled as a mass extinction. Each massive loss of species has been followed in the past by adaptive radiation of some survivors. In the case of the extinction of the dinosaurs, as stated in the video, smaller creatures that survived the mass extinction were able to adapt to many different types of environments that were originally dominated with dinosaurs. With adaptive radiation comes speciation(the origin of new species), and with speciation comes biological diversity.
Information
URL: http://www.youtube.com/watch?v=8SgnnV8nV9g&list=PLD0A39ADD948FECE4&index=6
Date Published: March 16, 2012.
Posted by: BestOfScience
Do you know why dinosaurs were extincted? (Any theories as to how they were extincted?)
ReplyDeleteThough we don't know all of the facts, the dinosaurs were said to have become extinct largely in part due to a massive meteor colliding into Earth.
DeleteIs all life on earth today descended from marine animals?
ReplyDeleteHello Brian. To answer your question, all life on earth today is not descended from marine animals, but more specifically, the first ancient prokaryotes. They mark the starting point of life on earth, and all animals living today are descended from those first prokaryotes.
Delete