Exam 1 Flashcards
Phylogeny
-The evolutionary history of a species or group of species
Phylogenetic Tree
-The evolutionary history of a group of organisms represented in a branching diagram
Homology
- Similarly in characteristics resulting from a shared ancestry
- Ex: vertebrates all have bony skeletons
Homoplasy
- A similar characteristic that has evolved independently of two species
- Ex: Fish and whales similar becuz adapted to eater
Convergence
- Also known as convergent evolution
- The evolution of similar features in independent evolutionary lineages
Monophyletic
- Pertaining to a group of taxa that consists of a common ancestor and all of its descendants
- Monophyletic taxon= clade
Polyphyletic
-Pertaining to a group of taxa that includes distantly related organisms but doesn’t include their most recent common ancestor
Synapomorphy
- Recently evolved homology that applies to s subset of phylogeny
- Most recent common ancestor identified by this
Paraphyletic
-An ancestral species, and some, but not all, descendants
Clade
- All descendants of a common ancestor
- Nonmonophyletic= subset, excludes certain descendants
- Monophyletic= all descendants
- Doesn’t reflect evolutionary relationships
Parsimony
- The fewest character transitions are best in phylogeny
- Used to determine best relationships btwn groups
Bacteria
- Most currently known prokaryotes
- Domain of life
Archaea
- Diverse group of prokaryotes
- Inhabit wide variety of environments
- Domain of life
Eukarya
- Organisms w/ true nuclei
- Domain of life that consists of kingdoms plantae, animalia, and fungi
Major challenges multicellular organisms must overcome
- Structure
- Coordination
1. Development
2. Internal Message - Reproduction
- Getting cells what they need
1. Transport
2. Gas exchange
Structure
- Not much of a problem for cell (cell wall, movement)
- Woody tissue of tree
- Human= skeleton
Coordination
- Cell- make sure cells do job, signal transduction
- Plants and animals
1. Development: tree (seedling to big plant), egg–> adult
2. Internal message: communication btwn cells
Getting cells what they need (food, water, air)
- Single cell- slurping up stuff
- Plants and animals: roots in plants, internal messaging, internal transport and gas exchange
Reproduction
- Single cell- mitosis
- Plants and animals- 1 cell to many
Why be Multicellular?
-Division of labor/ specialization
Why to NOT be multicellular
- Some cells must forgo reproduction
- Natural selection should favor those that “cheat”, reproduce anyways and do not cooperate
Cell
-The fundamental unit of life, structure, and function
Organ
-A specialized center of body function composed of several different types of tissue
Tissue
-An integrated group of cells with a common function, structure, or both