BIOA01H3 Chapter Notes -Species Problem, Drosophila Pseudoobscura, Mangrove Rivulus

• School: Ryerson University
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Mark Fitzpatrick

Document Summary

According to stanford encyclopedia of philosophy, the biological species. Concept defines a species as a group of organisms that can successfully interbreed and produce fertile offspring. The phylogenetic species concept (which itself has multiple versions) defines a species as a group of organisms bound by a unique ancestry. The ecological species concept defines a species as a group of organisms that share a distinct ecological niche . Several problems w/ biological definition; one major problem is that many species reproduce asexually; patterns of reproduction can blur definition of species. Androdioecy (andro = male; dioecioy = male and female) and gynogenetic (gyno = female) species are two variations in patterns in reproduction. Androdioecous organisms exist as natural populations of functional males and hermaphrodites but include no true females i. e. mangrove rivulus and clam shrimps. Gynogenetic species have only females i. e. amazon molly.