Exam 1 Flashcards
Mammalian features
- Mammary glands
- Hair
- Placenta
- Highly developed cerebral cortex
- Skeletal developmentrestricted to early life
- Heterodonty
- Single jaw bone & 3 inner ear ossicles
- Efficient respiratory & circulatory system
Size range of mammals
Shrews (2 g) - blue whale (90,000,000 g)
When did mammals first appear?
200 million years ago (Triassic period)
How long have mammals been the dominant terrestrial vertebrate?
60 million years
Plesiomorphy
Ancestral character state
Apomorphy
Derived character state
Homologous features
“Identical by descendent” or inherited from a common ancestor
Analogous features
Similar in form and function but not the same
Mammalian features related to homeothermy
- Hair
- Heterodonty
- Efficient respiratory andcirculatory system
Viviparity
Live birth
Paraphyletic unit
Not a real clade because it does not include all descendants
Homology
Two species bearing the same phenotype caused by common ancestry
Parallelism
Two species with the same phenotype descended from a common ancestor with a different phenotype and genotype
Convergence
Two species with the same phenotype whose common ancestor is very far in the past
Carnivores (define and example)
Eats meat (includes scavengers); ex. Lion, tiger, coyote etc.
