11 - primate taxonomy and diversity Flashcards
why study primates
- diverse, social intelligent
- important ecological functions
- culturally important
- conservation
-care
humans are primates
- comparative data for the evolution of human behaviour
- important for human health
Types of primate traits
- Ancestral
Inherited from an ancestor
e.g., body hair in primates - Derived
Evolved after split from a common ancestor e.g., bipedalism in human
3.Generalised
Useful for a wide variety of things e.g., opposable thumbs
- Specialised
adapted for a specific purpose
e.g. aye ayes middle finger
visual specialisation
forward facing eyes = orbital convergence for stereoscopic vision
postorbital bar (most strepsirrhines) or postorbital closure (haplorrhines) =
- protects eye?
- stiffens orbit, so not deformed by muscle contraction?
reduced reliance on olfaction
grasping and moving
Adaptations for arboreality
5 digits with opposable thumb/big toe
Nails instead of claws
Tactile pads and fingerprints
Clavicle and arm mobility
primate teeth
Heterodont
36 teeth in platyrrhines and strepsirrhines
32 teeth in catarrhines (including humans)
extended life history
most primates have one offspring at a time
- except callitrichids, some lemurs
long inter birth intervals
- 6 months - 9 years
long lifespans
- long juvenile period
- large apes live up to 58 years in wild
= heavy investment in offspring
large brains
Enlarged neocortex relative to body size
Why the expensive tissue?
- Challenges of finding food
- Challenges of living in social groups
behavioural traits
highly social, maintaining long term social relationships
flexible behaviour:
- learnt behaviours
- tool use
- culture
ecological traits
- distributed across tropics
- species distributions vary
- mostly tropical moist forests
- different niches within habitat
taxonomy
use of derived traits and genetic similarities to reconstruct evolutionary relationships (phylogeny)
Reflects clades (which taxa shared a common ancestor based on genetic evidence) not grades ( similarity in appearance)
contracting the primate phylogeny
Types of data
- Comparative morphology
- Comparative physiology
- Genetics
Relationships between higher order taxonomic groups well-established
Relationships among some families not yet clear (mainly in Lemuriformes &
Platyrrhini)
taxonomy - things to note
- taxonomy is a science
- phylogenies are hypotheses ‘falsifiable’
- numbers of species, species names, and the relationships among them change (new evidence and species concepts)
primate species
One of the most species-rich adaptive radiations of mammals
Latest update (May 2023) from the International Union for Conservation of Nature (IUCN) recognised
* 533 species
* 82 genera
* Total of 723 species and subspecies
123 species and subspecies described since 1990
* 54 from Madagascar
* 15 from Africa
* 25 from Asia
* 34 from South & Central America
Eight new genera since 1990
species concepts
biological species concept
- different species cannot produce offspring
phylogenetic species concept
- the smallest set of organisms that share an ancestor can be distinguished from other such sets
- use ‘diagnostic characteristics’
remember - phylogeny of extant primates (genes level)
- strepsirrhini and Haplorrhini (NOT prosimians and anthropoids)
- we are just another primate
- these are just the extant species
Three examples of studies of primates
- lorises (slow loris venom)
- american monkeys (Javan lutung natal coat)
- afro-eurasian monkeys (capuchin colour vision and foraging)
slow loris venom
observations: slow lorises have venomous bite, many lorises wounded (leads to death)
question: what is the function of the weapon
hypothesis: males defending females
prediction 1.1- males fight
prediction 1.2 - males wounded
Javan lutung natal coat
observation: infants bright orange when born and change to black as they age
question: what is the function of the natal coat colouration?
hypothesis 1: natal coat colour change elicit interest in other group memebers
prediction 1.1: number of neighbours decreases as colour changes
prediction 1.2: interactions with infants decreases with colour change
capuchin colour vision and foraging
observation: mix of dichromatic and trichromatic vision and trichromat advantage for fruit foraging
questions:
- why are there dichromate
- do dichromate have another advantage in foraging?
hypothesis and predictions:
primate conservation status
