Biology Notes - Module 9.3 - Blueprint of Life
James Ruse Agricultural High School
Module 9.3 Blueprint of Life
Biology Notes 2013
Helen Ying 19/03/2013
By Helen Ying © 2013 Biology Notes – HSC Course 2013 MODULE 9.3 – BLUEPRINT OF LIFE 1. Outline the impact on the evolution of plants and animals of: a. Changes in physical conditions in the environment o Rising and falling sea levels – land and ice bridges across continents have affected distribution and therefore evolution when these bridges disappeared and populations were isolated from the main population. o Fossil evidence indicates mass extinctions resulting from changes in the physical environment e.g. dinosaur extinction from meteor. o Movement of continents. As Australia moved north, it became drier and plants and animals needed to adapt to these new conditions. b. Changes in chemical conditions in the environment o Original anoxic environment. As primitive organisms metabolised, carbon dioxide was released. Over millions of years, carbon dioxide accumulated and at some stage, organisms capable of using carbon dioxide in photosynthesis evolved and became dominant. Oxygen was then released as a product of photosynthesis, and oxygen-using organisms became dominant. c. Competition for resources o During the Cretaceous period, mammals were limited to the niches in which they originally evolved because the world was dominated by dinosaurs. When the dinosaurs died, the mammals were able to populate larger areas of the world as they had few competitors. As they populated these different areas, they evolved into new species to adapt to these new conditions. o Long-term competition usually results in one of the species dying out or evolution of one of the competing species so that they can occupy a different environment. Organisms alive today have all arisen from simpler organisms that existed millions of years ago. Evolution is the change in living organisms over many generations. Changes in the environment of living organisms can lead to the
Module 9.3 Blueprint of Life
Biology Notes 2013
Helen Ying 19/03/2013
By Helen Ying © 2013 Biology Notes – HSC Course 2013 MODULE 9.3 – BLUEPRINT OF LIFE 1. Outline the impact on the evolution of plants and animals of: a. Changes in physical conditions in the environment o Rising and falling sea levels – land and ice bridges across continents have affected distribution and therefore evolution when these bridges disappeared and populations were isolated from the main population. o Fossil evidence indicates mass extinctions resulting from changes in the physical environment e.g. dinosaur extinction from meteor. o Movement of continents. As Australia moved north, it became drier and plants and animals needed to adapt to these new conditions. b. Changes in chemical conditions in the environment o Original anoxic environment. As primitive organisms metabolised, carbon dioxide was released. Over millions of years, carbon dioxide accumulated and at some stage, organisms capable of using carbon dioxide in photosynthesis evolved and became dominant. Oxygen was then released as a product of photosynthesis, and oxygen-using organisms became dominant. c. Competition for resources o During the Cretaceous period, mammals were limited to the niches in which they originally evolved because the world was dominated by dinosaurs. When the dinosaurs died, the mammals were able to populate larger areas of the world as they had few competitors. As they populated these different areas, they evolved into new species to adapt to these new conditions. o Long-term competition usually results in one of the species dying out or evolution of one of the competing species so that they can occupy a different environment. Organisms alive today have all arisen from simpler organisms that existed millions of years ago. Evolution is the change in living organisms over many generations. Changes in the environment of living organisms can lead to the