ARCL-1006EL Lecture Notes - Lecture 9: Adaptive Radiation, Quadrupedalism, Bipedalism
16 Jun 2018
School
Department
Course
Professor
ARCL 1006
Feb 12, 2018
Primate Evolution
ā¢
ā¢(photo) Relationships between primates
ā¢adaptive radiation: from the photo we can see which points are getting adaptive radiation
ā¢speciļ¬cally w lemurs, w new world monkeys, old world monkeys, and between ancestors
of strepp and ancestors of haplo
ā¢Adaptive radiation
ā¢where you have a diversiļ¬cation between species//organisms move to new niches
ā¢Generalized trait
ā¢trait that allows for variety of uses//is ļ¬exible
ā¢primates limbs- can swing from branches, can be quadrupedal and bipedal
ā¢primate dentition- molars and premolars have rounded cusps and is associated with
omnivore
ā¢advantages: when circumstances change you can easily adapt to those new
circumstances
ā¢Example) if you can move around on and and trees, and the world dries up, you can
still move around on the ground
ā¢Specialized Trait
ā¢Adapted to speciļ¬c circumstances
ā¢some primates (gorillas) have a specialized diet- leaves
ā¢no leaves= sticky situation
ā¢Tarsiers- long tarsal bones that allow a particular type of locomotion (vertical clinging
and leaping)
ā¢Disadvantage: if no trees, they might have a hard time getting around
ā¢Difļ¬culties faced by palaeoanthropologists
ā¢Discontinuities in fossil record
ā¢space
ā¢fossils are sometimes very well preserved and some not
ā¢time
ā¢different fragmentations of bones
ā¢sexual dimorphism
ā¢might classify different genders as different species
ā¢age related variation
ā¢bones may not be fully formed in juveniles
ā¢pathologies
ā¢Individual variation
ā¢distinguishing homologous from analogous traits
ā¢Homology: human hand VS bat wing //ļ¬nger bones (evolved from common ancestors)
ā¢Analogy: bat wing VS butterļ¬y wing // adapt to ļ¬ight// very distantly related organisms
have evolved the same structure on the surface in order to adapt to certain conditions
(not from the same ancestor)
ā¢Are humans more closely related to tarsiers than gorillas because tarsiers have long
legs like we do?
ā¢probably not
