BIO354H5 Lecture Notes - Lecture 1: Exaptation, Ontogeny, Zygote
Document Summary
Phylogeny: describes pattern of relationship that has changed over time. Family tree of genetically related animals showing their ancestral relationships in proper chronological order. Clade: a phylogenetic (unique entity) unit having a single common ancestor. Homology refers to structures not entire organism"s. Homologous structures were derived from a single structure in the common ancestor - may or may not have same function. Preadaptation - concept used to suggest that a feature evolved before it was needed. Incorrect bc not how evolution works - not how natural selection works. Term is not very useful but can help describe that the reason a feature was formed may not have been for what it is used now. Morphological series: a gradation of structures from simple to complex irrespective of chronology; may also apply to entire organism"s. Grade: a structural adaptive level acquired by lineages evolving in parallel.
