anthro exam 2 set 45

Be prepared to recognize distinctive primates from photos, drawings, teeth, and skulls and, of course, the shapes of their noses.

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How do the characteristics of smell, vision, hands, fingernails, encephalization level(brain size and complexity), locomotion mechanism relate to primates?

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How many apes are there and how do we classify the great apes?

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What are the characteristics of Haplorhini?

Haplorhines share a number of derived features that distinguish them from the strepsirrhine "wet-nosed" primates (whose Greek name means "curved nose"), the other suborder of primates from which they parted in evolution some 63 million years ago. The haplorhines, including tarsiers, have all lost the function of the terminal enzyme which manufactures vitamin C, while the strepsirrhine prosimians, like most other orders of mammals, have retained this enzyme and the ability to manufacture vitamin C.[2] The haplorhine upper lip, which has replaced the ancestral rhinarium found in strepsirrhines, is not directly connected to their nose or gum, allowing a large range of facial expressions. Their brain to body ratio is significantly greater than the strepsirrhines, and their primary sense is vision. Haplorhines have a postorbital plate, unlike the postorbital bar found in strepsirhines. Most species are diurnal (the exceptions being the tarsiers and the night monkeys).

What are the dental formulae generally for ancestral mammals, primates, strepsirrhines, New World monkeys, Old World monkeys, and apes?

Homodontic- all teeth similar inform, sharp, and replaced continuously throughout life Heterodontic - different types of teeth present • Some specialized for chewing • One set of deciduous - baby or milk teeth are replaced by adult teeth as other mammal 1.Incisors - cuVng teeth in the front of the jaw 2. Canines - long sharp "dog-‐like" teeth 3.Premolars- more fla_ened teeth also called bicuspids 4.Molars - flat chewing teeth •Functional differences between teeth enable food to be processed before injection •Numbers and patterns of teeth are distinc>ve for different mammals. Primates are quite ancestral/primative compared to many other mammals.

What types of traits are used to construct phylogenetic trees?

Homology is a trait shared by a group of organisms from a common ancestor. Analogy is a trait similar in a group of organisms that was not inherited from a common ancestor Ancestral traits Features shared by all of the species in a group/tree Evolved long ago in a common ancestor to all the related creatures that possess the trait Example: Endothermy is an ancestral traits in mammals These traits are uninformative in building trees Ancestral: old traits inherited from a distant ancestor(primitive) Derived: newer more recently evolved traits inherited from a more recent common ancestor

Why are tarsiers difficult to classify taxonomically?

In general, tarsiers are among the smallest of the prosimians, and are relatively hard to distinguish from one another purely on differences in pelage

What are some Colobine and Cercopithecine characteristics?

Largely the difference between Colobines and Cercopithecines are their feeding adaptations. Colobines have a sacculated stomach that helps them digest leaves and cercopithecines have cheek pouches. Colobines have more space between the eyes, and their incisors are narrower than in the cercopithecines. Colobines have a deeper jaw which extends father below the joint. Colobines' molars have high sharp cusps, while cercopithecines' have lower, more rounded cusps. Colobines have a complex stomach, which is atypical for primates. It is divided into four chambers kind of like a cow's stomach, and it works the same way too; The first chambers are less acidic fermentation chambers. Full of bacteria, they break d own the leaves, digest the cellulose, and make it available for absorption. Cercopithecines, on the other hand, have a simple stomach with no chambers but they do have cheek pouches (and thus their name). These pouches open inside the cheek at the base of the teeth and extend down into the neck. Also called buccal pouches, they are used to stuff food into for storage. The two pouches together can hold about a stomachfull. The pouches are good for grabbing food quickly and then getting out of there. Then the monkey can eat it somewhere safe. Also, since they live in groups, there's competition over food so if you can grab a whole meal and get away you won't have to share it. Colobines have long tails, while cercopithecines' tails are variable but often short. Colobines have longer hind legs, related to being more arboreal; They do more leaping and climbing. This is also probably the reason for the long tail. Cercopithecines have similar arm and leg lengths. Colobines have short thumbs. (Brachiators generally have short or no thumbs, probably since they tend to get caught when swinging through foliage at great rates of speed.)

Lemurs & lorises? Where do they live and what are they?

Lemurs only live in Madagascar They are the lorises of India and Southeast Asia

Where do primates live? What are the major adaptive trends of the Primate order?

Most primate species remain at least partly arboreal. With the exception of humans, which inhabit every continent, most primates live in tropical or subtropical regions of the Americas, Africa and Asia.

Which primates might have prehensile tails?

New world monkeys

Compare New World vs. Old World Monkey features. Where do these groups live (both geographically and in terms of local environment)?

New world- American Old World- Africa and Asia

What are the characteristics of Strepsirhini?

Strepsirrhini or Strepsirhini (Listeni/ˌstrɛpsəˈraɪniː/; STREP-sə-RY-nee) is a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia

What are postorbital bars, postorbital closure, and which primates have which? What role might these structures perform?

The postorbital bar (raccoon) is a bone which runs around the eyesocket of strepsirrhine primates. This is in contrast to the higher primates, haplorrhine, which have evolved fully enclosed sockets to protect their eyes. The orbital closure (monkeys) is the bony wall of the orbit. Some primates have limited bony encasement of the orbit in the form of a postzygomatic bar, but in the anthropoids, it is almost complete. You can see!

Where do humans fall in the classification of primates?

humans are next to chimpanzees and gorillas

Which primates might have a tapetum lucidum and how could this structure be useful?

tapetum lucidum is night vision. Among primates only the prosimians, with the exception of the tarsiers and several diurnal Eulemur species, have a tapetum lucidum. this could sturcute could be helpful to seek out danger in the night.

What is the toothcomb, which teeth are found in it, and which primates have one?

A toothcomb (also tooth comb or dental comb) is a dental structure found in some mammals, comprising a group of front teeth arranged in a manner that facilitates grooming, similar to a hair comb. The toothcomb occurs in lemuriform primates (which includes lemurs and lorisoids), treeshrews, colugos, hyraxes, and some African antelopes.

What are the differences between bilophodont and Y-5 molars? Which primates have which types

Cercopithecoids old world monkeys have bilophodent and y-5 molars are in homoniods also old world monkeys Bilophodont refers to a type of tooth structure. 'Bi-' means two. A loph is a ridge. And -dont means tooth. Hence, a bilophodont is a tooth with two ridges. Bilophodont teeth are a sub-type of lophodont teeth. bicuspids are one form of bilophodont, but it is also a very common for a premolar or molar to take this form. In the case of molars the 'ridge' may present in the form of two cusps, or points, with a low connecting bridge between them. Many bilophodont molars have four cusps, and are useful for chewing leaves and insects. When classifying primates the bilophodont pattern is contrasted with the Y-5 molar pattern, in which there are five cusps. Despite the fact that selenodont teeth are made up up two ridges, they are usually not called bilophodont. When talking about molars in specific, it is common to refer to the connection of cusps by a ridge as bilophodont, but the elongation of a single cusp into a ridge as a selenodont.

What are the characteristic features of mammals? What are the characteristic features of primates?

primates are mammals

What are the two major taxonomic divisions of primates?

primates include prosimians and simians

What is the difference between clades, phylogenies, and taxonomy?

• A clade is a group of organisms that have originated from a common ancestor. Taxonomy is the field of biology that classifies living and extinct organisms according to a set of rules. A phylogenetic tree is a hypothesis that depicts the evolutionary relationships among groups of organisms; in detailed phylogenetic trees, branch points indicate when new species diverged from a common ancestor. • Species (or groups of species) and their most recent common ancestor form a clade within a phylogenetic tree. • Phylogenetic trees constructed by modern methods can depict the relationship between clades and taxonomic groups.

What does a phylogenetic tree represent? What do the nodes represent?

• Phylogenetic trees are usually based on morphological or genetic homology. o A comparison of anatomical traits can reveal an evolutionary relationship among species. o Analysis of genetic differences in among species can identify descent from an ancestral gene. o Modern genetic techniques employ "molecular clocks" to assist in the construction of phylogenetic trees. • The cladistic approach to phylogenetic trees emphasizes primitive vs. derived characteristics. o Shared, derived characteristics are used to construct a tree called a cladogram. o Determining the order in which characteristics appeared during evolution can be a challenge. each node with descendants represents the inferred most recent common ancestor of the descendants, and the edge lengths in some trees may be interpreted as time estimates. Each node is called a taxonomic unit. Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed.