hormins Flashcards
Taxonomy
science of classifying, naming, describing organisms
Linnaean classification based on
natural features of organisms
Binomial nomenclature
Consistent and hierarchical system
Homologous traits
present in two organisms because they inherited the trait from a common ancestor
Analogous traits
present in two organisms because they evolved it independently
Ancestral traits
a trait in an organism that is the same as the trait in the ancestor
Derived traits
a trait in an organism that is different (evolved) from the trait in the ancestor
features for classification
Homologous traits
Ancestral traits
Analogous traits
Derived traits
Grouping organisms
Clade
Grade
Clade
a group that includes an ancestor and all its descendants (e.g., Primates)
Grade
a group that doesn’t include an ancestor and all its descendants, but may still be useful (e.g., fish)
Vertebrate evolution
Dinosaur extinction: 65 million years ago (“K-Pg Extinction”)
Mammals diversify after K-Pg extinction
Earliest true primates: appear ~55 million years ago
Mammals diversify after
K-Pg extinction
Dinosaur extinction
65 million years ago (“K-Pg Extinction”)
Primate traits:
Postorbital structure
Larger and more complex brain
Nails instead of claws
Grasping hands and feet
Relatively short snout
Forward facing eyes
Earliest true primates
appear ~55 million years ago
The living Order Primates is divided into two Suborders
the Strepsirrhini and the Haplorhini.
The strepsirrhines are
lemurs, lorises, and galagos,
tarsiers, New World monkeys, Old World monkeys, apes, and humans
are haplorhines.
