Outcome 1: “On completion of this unit the student should be able to (1) analyse evidence for evolutionary change, (2) explain how relatedness between species is determined, and (3) elaborate on the consequences of biological change in human evolution.”
Evidence for evolutionary change is abundant in the fossil record, biogeography (distribution of species across the earth), developmental biology and structural morphology. This area of study will allow us to investigate these four types of evidence.
Paleontologists have unearthed a wide range of evidence that provides a record of the change in the number of different species and the particular characteristics of those species over time. The fossil record demonstrates that living organisms first evolved in aquatic environments and gradually moved onto land. After plants had successfully colonized terrestrial habitats and converted a percentage of carbon dioxide into oxygen, animals were able to survive out of the oceans and freshwater environments. Evidence for these changes lies in the relative ages and absolute dating of fossils in different parts of the world.
Other evidence is provided by the similarities between living species – homologous structures in vertebrates, for example – and the similarities in developmental biology among different species. These similarities suggest that living organisms descended from a common ancestor and that species that are more closely related in the family tree have a more recent common ancestor. This evidence is supported by genetic research which confirms evolutionary relationships between species.
- NECSI Evolution – Ancient organism remains, fossil layers, similarities among living organisms and similarities of embryos.
- “What is the evidence for evolution?” (YouTube video, 11.21min)
- Lines of evidence – the science of evolution – Berkeley
- What is the evidence for evolution? – Biologos