BISC208 Lecture Notes - Lecture 2: Plasmolysis, Water Potential, Divergent Evolution

• School: University of Delaware
• Department: Biological Sciences
• Course: BISC208
• Professor: Safran Catherine

Document Summary

Revolutionary theory: all existing species evolved from preexisting species/common ancestors by natural selection. What is needed for natural selection to occur: genetic variation, heritable traits. Gene variant igf1 was the first variant discovered (insulin-like growth factor) Geographic isolation: islands: endemic species (unique to a particular location, results in divergent evolution. Convergent evolution: two species issued from different lineages end up with similar characteristics but do not have a common ancestor. Analogous structures: unrelated organisms with convergent traits. 3 types of anatomy structures: analogous (convergence), homologous (divergence), vestigial structure, no apparent function (resemble ancestral structures) Developmental homologies are observable only prior to birth. Plasma membrane, cytoplasm, and nucleic acid as genetic material (every living cell contains) Genes that encode enzymes involved in glycolysis are found in bacterial, animal, and plant cells. Ortholog genes: found in different species today but issued from one ancestral gene sequence. Point mutation: most common but often silent and rarely maintained from one generation to the next.