Chapter 3 Primates

nocturnal

active at night and at rest during the day

ecological niche

a species way of life considered in the full context of its environment including favors such as diet, activity, terrain, vegetation, predators, prey, and climate

adaptive radiation

the rapid diversification of an evolving population as it adapts to a variety of available niches

preadapted

possessing characteristics that by chance are advantageous in future environmental fluctuations 

Homeotherm

an animal that maintains a relatively constant body temperature despite environmental fluctuations

isotherm

an animal whose body temperature rises or falls according to the temperature of the surrounding environment

K-selected

reproduction involving the production of relatively few offspring with high parental investment in each

R-selected

reproduction involving the production of large numbers of offspring with relatively low parental investment in each 

arboreal

living in the trees

diurnal

active during the day and at the rest at night

derived

characteristics that define a group of organisms and that did not exist in ancestral populations

ancestral

characteristics that define a group of organisms that are due to shared ancestry

convergent evolution

a process by which unrelated populations develop similarities to one another due to similar function rather than shared ancestry

prosimian

the suborder of primates that includes lemur, lorises, and tarsiers

anthropoid

the suborder of primates that includes new world monkeys, old world monkeys, and Including humans)

hominoid

the taxonomic diversion superfamily within the old world primates that includes gibbons, siamangs, orangutans, gorillas, chimpanzees, bonobos, and humans

hominid 

African hominoid family that includes humans and their ancestors. Some scientist, recognizing the close relationship of humans, chimps, bonobos, and gorillas, use the term hominid to refer to all African hominoids. They then divide the hominid family into two sub families: The Paninae and the Hominae

Hominin

The taxonomic subfamily or tribe within the primates that includes humans and our ancestors

Dental Formula

the number of each tooth type on one half of each jaw. primates possess equal numbers on their upper and lower jaws so the dental formula for the species is a single series of numbers

sexual dimorphism

within a single species, differences between males and females in the shape or size of a feature not directly related to reproduction, such as body size or canine tooth shape and size

binocular vision

vision with increased depth perception from two eyes set next to each other, allowing their visual fields to overlap

stereoscopic vision

complete three dimensional vision or depth perception from binocular vision and nerve connections that run from each eye to both sides of the brain, allowing nerve cells to integrate the images derived from each eye

vertebrate

animals with a backbone, including fish, amphibians, reptiles, birds, and mammals

cranium

the brain case of the skull

foramen magnum

a large opening in the skull through which the spinal cord passes and connects to the brain

clavicle

the collarbone connecting the sternum with the scapula

suspensory hanging apparatus

the board powerful shoulder joints and muscles found in all hominoids, allowing these large bodied primates to hang suspensed below the tree branches

scapula

the shoulder blade

brachiation

moving from branch to branch using the arms with the body hanging suspended below 

prehensile

having the ability to grasp

opposable

having the ability to bring the thumb or big toe in contact with the tips of the other digits on the same hand or foot in order to grasp objects

Essay Question: We humans share a number of traits with our fellow primates that go back to our arboreal origins. What are these primate traits? How are they expressed in the human body and how did they enhance our evolution as the brainiest species?

Early primates evolved in tree filled environments, and developed adaptations that helped them survive and move.

The development of grasping hands with opposite thumbs - originally helping primates to cling to branches and. pick fruit - in humans its crucial fine motor skills, tool use. Forward facing eyes gave primates stereoscopic vision, - in humans there is enhanced hand eye coordination, allowing us to hunt and craft

Primates evened ;are brains to body size - supported learning and problem solving, and the trend continued with humans, allowing for abstract language and thought. Being able to have k selected ancestors, allowed to continue into humans to develop culture, parental care and social behavior. living in social groups set the foundation for human societies and emotional intelligence. Reduced south and greater reliance on vision shifted toward facial expressions and visual cues. Flexible shoulders inherited by tree dwelling ancestors, allowed for us to be bipedal and freed our hands.