lecture 2: intro to biology part 2 Flashcards
What is the most identified species?
Beetles (invertebrate animals)
What explain the striking unity that underlies the diversity of life?
Evolution from a common ancestor
What is taxonomy?
Branch of biology that identifies and names species and classfies them into groups
- Organized into “taxa” (groups)
- The smaller the group, the more shared characteristics
What is Aristotle’s scale of nature?
- Species are fixed types (no change)
2. Some species are “higher” on the ladder = larger, more complex than others
Who is Linnaeus and what was his thinking?
- Important figure in taxonomy: came up with binomial nomenclature (still used today)
- Did not believe in evolution
What is rank-based classification?
Domain - Kingdom - Phylum - Class - Order - Family - Genus - Species (Dumb Kings Play Chess On Fine Grain Sand)
How does binomial nomenclature work?
- Scientific name
- Italics
- Genus - species
How did we classify organisms before? (Linnaean classification)
Groupes organisms into rank-based taxa determined by physical similarities
How does phylogenetic classification (tree-thinking) work?
- Based on homologies (similarities due to common ancestor)
- Groups organisms into clades which are groups of organisms that are all descendants from a common ancestor
What is a homology, its 3 types, and at what level can it be observed?
- Shared traits due to a common ancestor
- Anatomical, physicological, behavioral
- Organism, cell and molecular level
What are analogies?
Physical similarities, but no from common ancestor
What is a node in a phylogenetic tree?
Represents an ancestor where one groups splits into 2 branches
(can be flipped)
What is a root in a phylogenetic tree?
Represents last common ancestor’s lineage
What is a branch in a phylogenetic tree?
Represents a lineage
What does a tip represents in a phylogenetic tree?
Represents a descendant taxon
