Primate Classification Flashcards
Systematics
A field of evolutionary biology concerned with organizing the diversity of life
What are the three tasks of systematics?
1.) Naming and defining different kinds of organisms (alpha taxonomy)
2.) Discovering the evolutionary relationships among the groups (phylogenetics)
3.) Classifying the groups into hierarchically more inclusive groups (beta taxonomy)
- These groups should reflect the evolutionary relationships (beta)
Famous sketch from Darwin’s “Notebook B”
This is the first illustration of his new idea of descent with modification– the first depiction of what we now know as the “Tree of Life”
Who created the taxonomic system still in use today?
Linnaeus
Hierarchical nature of taxonomic classification
Multiple lower-level taxonomic divisions are grouped into one higher-level division
The hierarchical structure contains information about evolutionary relationships
~ All of the species in a single genus should be more closely related to each other than to a species in a different genus
~ All genera in a family should be more closely related to each other than to a genus in a different family
Hierarchical classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
Levels of taxonomic hierarchy that will be on your test (spelling counts!)
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Superfamily: Hominoidea
Tribe: Hominini
Genus: Homo
Species: sapiens
Taxonomy Rulebook
International Code of Zoological Nomenclature (ICZN)
Rules for writing taxonomic names
1.) Binomial nomenclature: each species has a scientific name that consists of two parts
- Scientific names are italicized
- Genus name is capitalized and the species name is not capitalized
- Genus name can be abbreviated (H. sapiens)
2.) Higher order taxonomic groupings are capitalized when they are used formally (ex. Hominoidea)
3.) In informal usage, the names can be shortened by dropping the Latin ending (-oidea, -idea, -inae, -ini) and then you do not capitalize (ex. hominoids)
PRIMATES is an ORDER within the class Mammalia
All primates are mammals
BUT primates take the mammal lifestyle to the extreme!
Characteristics of Living Mammals (CLASS: Mammalia)
1.) Reproduction
- Parents invest heavily in their offspring
2.) Brain organization
- Higher order brain structures make learning possible
3.) Temperature regulation
4.) Diet
Reproductive investment
Trade-off between number of offspring and investment in offspring
- prenatal and postnatal parental investment
Reproductive strategy
Suite of adaptations (behavior, morphology, physiology) that increase the chance of mating and fertilization, and infant survival
K-selected!
Mammals invest more in each offspring
“K-selected” (as opposed to “r-selected”) reproductive strategy
- Primates tend to have only 1 dependent offspring at a time
- Apes are an extreme version of K-selection
Brain organization
1.) Mammals share development of the limbic brain, which is not present in more primitive animals
- Emotions and feelings are biology’s mechanism to encourage offspring care
- Mammals have a greater reliance on sensory input
2.) Mammals– and especially primates– have a relatively large cerebrum
- Ability to learn
- Thoughts
3.) The neocortex is a part of the cerebrum associated with rational thought
- Conscious behavioral control
~ These last two especially are vital to living in social groups
Characteristics of Primates
1.) Grasping hands and feet
- 5 fingers and toes
- thumb and “big” toe position
2.) Nails instead of claws
- distal phalanx
3.) Pronation and supination ability
- radius and ulna
- tibia and fibula
4.) Binocular and stereoscopic vision
- Eye orbits facing anteriorly (forward)
5.) Color vision (cones)
- ability to see red
- for fruit? for sex?
6.) Reduced reliance on smell
- reduced snout