Characteristics and Evolution of Primates

Lactation

A characteristic of mammals involving the production of milk to feed offspring.

Fur/Hair

A characteristic of mammals that provides insulation and protection.

Jaw is one bone

A characteristic of mammals where the jaw structure consists of a single bone.

Diaphragm

A characteristic of mammals that aids in respiration by separating the thoracic cavity from the abdominal cavity.

3 bones in inner Ear

A characteristic of mammals that includes three small bones (ossicles) which aid in hearing.

Heart artery blends

A characteristic of mammals where the heart's arteries are interconnected.

Postorbital bar

A characteristic of primates that provides structural support around the eye socket.

Nails instead of claws

A characteristic of primates that allows for better manipulation of objects.

Petrosal auditory bulla

A characteristic of primates that relates to the structure of the ear.

Forward facing eyes

A characteristic of primates that enhances depth perception.

Opposable hallux

A characteristic of primates that allows for grasping with the big toe.

r-selection

A reproductive strategy focusing on producing a large number of offspring with minimal parental investment, often seen in unpredictable environments.

K-selection

A reproductive strategy focusing on producing fewer offspring with significant parental investment, common in stable environments.

Cladistics

Classification based on evolutionary ancestry and branching patterns, grouping organisms by their most recent common ancestor.

Gradistics

Classification based on physical or behavioral similarity, regardless of evolutionary lineage.

Homologous Structures

Traits shared by different species due to common ancestry.

Homoplasy

Traits that look similar but are not derived from a common ancestor, often arising from convergent or parallel evolution.

Convergent Evolution

When species from different ancestral lineages independently evolve similar traits due to similar environmental pressures.

Parallel Evolution

When two species with a common ancestor evolve similar traits independently, often due to occupying similar ecological niches.

Allopatric Speciation

Occurs when populations of a species are geographically separated, preventing gene flow and leading to divergence.

Sympatric Speciation

Occurs without geographic isolation, usually through ecological or behavioral differences within a single habitat.

Parapatric Speciation

Happens when populations are adjacent and can interact but mainly breed within their respective populations.

Relative Dating Techniques

Provides an estimate of a fossil's age relative to other finds by assessing layers of sediment or rock.

Absolute Dating Techniques

Provides a more precise age in years, often by analyzing radioactive decay in minerals or isotopes.

Arboreal Hypothesis

Suggests that primates evolved traits suited to life in trees, aiding in maneuvering through the arboreal environment.

Visual Predation Hypothesis

Proposes that primates evolved forward-facing eyes and grasping hands for hunting small insects in branches.

Angiosperm Radiation Hypothesis

Primates evolved to exploit flowering plants for resources.

Human-Chimp Divergence

Humans and chimpanzees diverged 8-10 million years ago.

Plesiadapiforms

Close relatives of primates lacking full orbital closure.

Adapids

Lemur-like early primates, ancestors to strepsirrhines.

Omomyids

Tarsier-like early primates, closer to haplorhines.

Parapithecids

Ancestors to New World Monkeys with early traits.

Propliopithecids

Early catarrhine ancestors, including Aegyptopithecus.

Proconsul

First ape-like primate, lacking a tail.

Oreopithecus

European ape, considered an evolutionary dead end.

Dryopithecus

European ape possibly related to modern African apes.

Sivapithecus

Ancestor to modern orangutans based on skull similarities.

Gigantopithecus

Giant ape known from mandible and teeth fossils.

Strepsirrhines

Primates with moist noses and reliance on smell.

Haplorhines

Primates with dry noses and reliance on vision.

Tarsier Traits

Grooming claw and nocturnal behavior, unique traits.

New World Monkeys

Found in Americas, with broad, outward-facing nostrils.

Old World Monkeys

Found in Africa and Asia, with narrow nostrils.

Apes Characteristics

Lack tails, larger brains, and flexible shoulders.

Extended Parental Care

Longer gestation and care for young in apes.

Geographic Isolation

Lemurs evolved in Madagascar, leading to diversity.

Varied Habitats

Madagascar's ecological zones enabled lemur adaptation.

Adaptive Radiation

Rapid diversification of lemurs to fill ecological roles.

Low Predation Pressure

Isolation from predators allowed lemurs to diversify.