arcky exam 1

PRIMATE ORDER

Human beings share similarities with fellow primates, There was a debate if human beings are primates and humans are 19 century humans as primates, Among animals and humans are regrouped among the primates, Because humans and other primates share essential features in common

Conceptual tools

More than 1 million species of primates but we do not know how many, remains to be seen, We view all living forms the same way, break that reality, One way to break the diversity of species is the distinction of specialized and generalized.

specialized and generalized

Some species live on one thing eg. plant , they are adapted to make a living in one environment. Whereas humans are flexible or generalized to live within different context and circumstance, humans do not relate to the world in the same way, diversity.

Specialized:

an organism that is adapted to live under very definite condition or we may also speak of a biological trait that is evolved for very specific function or unity, Eg. limbs of cows, camels, horses, Used to stand and walk around but a camel won't scratch its back, barely used for anything else besides moving around

Generalized

an organism that is adapted to live under various conditions and circumstances. Or we may also speak of a biological trait capable of several functions

Eg. flexible hands of primates

Life forms are not having the same relationship or experience with the outer world

Some life forms exploit narrow ecological niches

Others exploit broad ecological niches

meaning : from the viewpoint of life the world as a whole offers different living experiences

Economy of nature:

All species need resources to make a living, human economy is built on that economy. How our physical world is built around possibilities and ways to make a living in such an economy. Certain species extract different resources. How the species position themselves in the economy, As a whole earth is a ecological system, Some species occupy narrow spaces, The more the organism does the bigger the space it fills

Retention of five digits

pentadactyl, earliest mammals 65 million years ago looked like squirrels with fingers

Primates as a whole are generalized creatures, this is reflected in the 9 features

1. Retention of five digits (fingers) in the hands and feet

2. Flexible hands and feet with a good deal of prehensility

3. A tendency toward erectness particularly in the upper body.

4. A generalized dental pattern

5. A lack of specialized diet (omnivorous)

6. An increased emphasis on vision

7. Expansion and increasing complexity of the brain

8. A longer period of gestation, infancy, and extension of the whole lifespan

9. Adult males often associate permanent with the group

prehensility

grasping ability

standing upright

We are the only primate that are designed to spend out days ----, cats dogs relate to the world differently than we do as primates

generalized dental pattern

particularly of the back teeth (molars), our cats and dogs are not versatile in what they are eating, we eat fruit and vegetable which is reflected in teeth, teeth are not specialized they are flexible because we can eat both, animals with more specialized teeth only eat a specific food

vision in primates

important development of the visual areas in the brain) color is seeing 3 dimensions,

how can we explain the numerous similarities between primates?

Sharing a common ancestor, Life is characterized by an interesting feature: nature is lazy: life forms come in packs, Nature creates a blueprint for a number of species to arise

Horse like animals, dog like animals, cat like animals, mammals look alike, all different species but same blueprint

Order in organizing the by blueprint (family) then species

Nature produces variations around a number of themes. Blueprints are created then through the process of evolution and divergence slightly different forms are built, Horse like blueprint = horse donkey zebra, more inclusive blueprints- mammals

United mammals (features connecting the mammals)

Air breathing animals, Hair or fur, Sweat glands (withstand heat by perspiration), Three middle ear bones for hearing, A neocortex (upper layer of brain) region in the brain

Vertebrate blueprint:

backbone animals= mammals, birds, amphibians, reptiles, fish, have a spine

Invertebrates

no spine

Common blueprint for all life

Common ancestor of all life

Common ancestor of all life

vertebrates; invertebrates; plants but we lose the trace of what actually happened, this was half a billion years ago to 500-600 billion years ago, Bacteria life, boom in complexity half a billion years ago, then we have the complexity we have now

Blueprint

multiplication of different forms- then a smaller blueprint and things go on and on, Pattern in reality of the process of life on earth, We put order in them by classifying

Homologies

similarities of organisms based on common evolutionary descent structures are said to be homologous when their anatomical similarities are based upon common descent

illustrated through the same bones in almost the same position

why homologies happen

It is precisely because the pattern of evolution works according to the blueprint principle that is often possible to identify what is called ---- among life forms

Evolution

not a theory it is a fact, theories may be argued about but the main thing is it happened, probably not by chance, Similarities across life forms have a common ancestor (thats half of it) if we have a limited number of blueprints we still have millions of species the other side of the equation is building those differences

We know why primates are united by

the sharing of many key generalized features: common ancestry, this is only half the story, Half fights to stay the same but this is bad because the environment keeps changing therefore your extinct if you cannot cope with the changes, build inside the equation for ways to get around the changes, differences are explained by adaptation

Common ancestry:

explains the similarities between forms

Adaptation:

explains differences between forms

why adaptation

No species have ever been able to occupy every space on the planet, No species has been able to exist in all places on the planet, must find a place within one section, Life is so diverse because in the first place the environment is diverse, moulds to the environment,

adaptation put simply

Planet earth is a fragment place offering different contexts for making a living, Life cannot distribute evenly, life takes shape, Life forms have to find a way to fit in this economy of nature, So many life forms to squeeze into a complex form

Evolutionary forces pressuring life forms to find a place in that world

Whole range of possible habitats and animals must find a way to inhabit

Different ecological areas of habitus

Challenge that the physical environment has there is the world filled to capacity at the same time, other species are always there trying to make a living. You must be able to cope with the physical environment and other species out there trying to make living., Either the physical environment kills you or other species, Complex ecosystems competing or relating

Why do we have to compete

Because some use the same resources therefore cannot share or else possible extinction

Direct competition:

physical aggression

African wasp killing bees in their own hives

Indirect competition

occupying territory

Baboons in africa roving in large groups

Preventing other species from invading your territory, were here, we occupy it, sends a strong message to competitors

If competition is a reality species must modify to survive

Getting access to resources (2 ways)

By developing anatomical adaptations or novelties

- Keen sight

- Moving fast

- Digesting food others cannot

By adopting specific behaviors

- Fleeting (danger=flee)

- Sending warnings through vocal signals

who created Theory of natural selection

Charles darwin (1809)

One the origin of species 1859

Theory of natural selection into five key ideas

1. All species are capable of producing offspring faster than the food supply increases

2.All living things show variation; no two individuals of a species are exactly alike

3. Because there are more individuals than can possibly survive there is a struggle for existence

4. Favorable variations are inherited and passed to the next generation

5. Over long periods of geologic time these successful variations produce great differences that result in the modification of species or the rise of new species thus evolution.

Because there are more individuals than can possibly survive there is a struggle for existence

Those with favorable variations in size, strength, running ability ect.. Will possess an advantage over others, advantages depend on the circumstances, In darwin's theory it is about the individual because there are more individuals than can survive, some must go out the window and some with the right variations continue, The good variations are passed to the next generation

Illustrations of biological diversity

Inherited, natural state of population and species, moth example, impacts their rate of survival, If one is at a disadvantage one color will be reduced from generation to generation

Concept of normal distribution

Biological diversity is inherent to life

is a way to classify diversity

Concept prey adaptation

Living organisms cannot modify themselves, Preadaptation, At specific moments in time you carry either the right or wrong variation just unlucky

Preadaptation:

an individual that lives through a changing environment is by pure chance well adapted to deal with the new conditions

Evolution cannot occur without

biological variations, No variation = no evolution = greater risk of extinction, Police insurance for survival - no guarantee, A feature must be genetically inherited to count for evolution

natural selection chooses features that are transmitted through the generations

Three levels of evolution

1. populations/ species phenotype phenotype is what we see

2. organisms/individuals - take the bear brunt - social species are social when we live as a bunch of individuals our survival can also depend on other species, primates are social species

3. genes/ gene pools genotype

Genes are carried by organisms confronting the reality of their environment

At what level does natural selection work? It is all fused together

Primates

social animals, live in social organizations the survival of each individual does not only depend on themselves, The struggle for survival and reproduction (passing on genes to the next generation) is modified by social interactions, In evolutions eye just as there are physical environments (forests) there are also social environments, Social environment defines the fate

Primates six types of social organization

1. Noyau,

2. Monogamy,

3. polyandry,

4. One-male group

5. Multimale group

6. Fision-fusion society

Noyau,

one female and her offspring usually a closed system, once reproduction complete male takes off

monogamy

one adult female one adult male and the offspring, creates greater protection for offspring, Caretaking offspring important to survival

Polandry

a single reproducing female and several sexually active males

One male group

a single adult male along with several females and their offspring

Multimale group

several adult males, numerous females and the offspring

Fision-fusion society

size and occupation of subgroups within a community vary from day to day, an approach that seeks to explain aspects of organisms anatomy and behavior by reference to the way that their life histories including their reproductive development behaviors post reproductive behaviors and lifespan have been shaped by natural selection

Life history

may reflection on how primates engage with the world, Strategy 1

Introduce as much organisms as possible through reproduction

Fish laying millions of eggs

No caretaking

Strategy 2

Take care of a single offspring to ensure its survival

Female chimps having single child every five years

Heavily caretaking

Which model is best in life history

Different ways to fit in the economy of nature

Millions of offspring vs single offspring 2 extremes

Many will die but there are so many that some will live, vs the one offspring that will live

Small and simple organisms

Rapid growth

Small body size

Single reproduction of millions

Many small offspring

short life span

Reproduce early in life

Every few month variation, fast pace

Large complex organisms

Slow growth

Large body size

Repeated reproduction (one kid)

Few large offspring

Long life span

Reproduction later in life

Focus on reproduction

Rapid turnover (generations)

Little energy invested in caretaking

Focus on caretaking (primates)

Slow turnover (generations)

A lot of energy invested in caretaking

The adaptive radiations of the primates

Geological epochs MYA (millions years ago)

Pleistocene 2

Pioxene 5

Miocene 24

Olixene 37

Excocene 58

Paleocene 65

What happened 65 million years ago

The earliest primates were squirrel like in shape

From one original form the primates multiplied in number to reach today about 200 species

Three SCENARIOS

1. Arboreal theory

2. Visual predation theory

3. Angiosperm radiation theory:

Angiosperm radiation theory:

primates adapt to feeding on all kinds of small objects in the same arboreal habitat ( flowers fruits gums and nectars)

Visual Predation Theory

primates developed adaptipns that permitted them to catch insects on tree branches it is about a source of food

Arboreal theory

theory stipulating that primates are what they are because they adapted to physical environment of tree living

Genealogy of living primates

Although life forms change over geological times it is nonetheless possible to gather a rough pictures of the evolutionary past grom looking at current living forms

Thus living primates still display all the major levels of organization they through during the last 60 million years

This is possible because primates are necessarily that old

Younger life forms carry a lot of info about the past

Levels of organization in primates 3 levels

Prosimians

Monkeys

apes(humans)

Little change > changed > super changed

Three different evolutionary grades

prosimians : retained by many features of the common primate ancestor

Monkeys

Apes: were most transformed when compared to the common primate ancestor

Evolutionary grade

a group of animals similar levels of organization

Primitive condition:

a species that looked very much like its ancient ancestors because it has evolved very little

derived condition

a species that is quite different from its ancient ancestor because it has gone through a lot of transformation

Morphological spectrum

change

the prosimians

70 species alive (200 extinct)

Two main groups: lemurs and lorises

Lemurs only live in madagascar vs lorises live in africa india thailand java ect

Continental drift = lemurs are only in madagascar = tectonic plates

Madagascar was connected to africa but split, fossils in africa but were extinct over competition so madagascar is a refuge for the lemurs

Lorises big eyes because they are nocturnal, time shift share makes them nocturnal to avoid competition

Key concepts adaptive radiation

the multiplication of the number of species in a short geological time period, is a descriptive one it does not explain how species actually split

Key concepts speciation

splitting of species: the evolutionary proce3ss that produces new species from previous ones, Normal distribution = average or biological diversity

Biological species concept

species are groups of actually or potentially interbreeding natural populations which are reproductively isolated from such groups

Anagenesis

transformation without splitting

Human species bound together by backgrounds

Cladogenesis:

transformation by splitting, 2 ecological niches ( two ways to make a living) they decided to split and make a living in 2 different ways, the glue holding the species together over time was interrupted and therefore you get two different species.

Adaptive radiation versus speciation

A speciation can occur without an adaptive radiation because the splitting of one species into two species does not involve enough diversification of form to be called adaptive radiation

The reverse however is not true. An adaptive radiation cannot occur without speciation for by definition adaptive radiation is a cascade of speciations occuring in a short period of time and originally involving single species

adaption zone left empty

extinction of dinosours 65 mya opened the door to mammels

prosimians verses anthropoids (monkeys vs. apes)

1. Larger body

2. larger size

3. more rounded skull

4. eyes completely in front = stereoscrope vision

5. complete back wall to eye orbit

6. only two incisors on each side of jaw bone

7. more complex social systems

8. more parental care

survey the monkeys

140 species, 70 extinct two main groups, monkeys had less extinction than apes and prosimians

1. new world monkeys

2. old world monkeys

new world monkeys

central and south america, three premolars, prehensible (tail can grasp) wooly and black spider

old world monkeys

africa and south asia, dental formula 2:1:2:3 and only 2 premolars, 2 incisors, 1 canine, 2 premolar, 3 molars

savannah baboons, verret, macaques

why do old and new world monkeys share similar traits even though they have been isolated to their areas for 30 million years

1. common ancestors

2. evolutionary convergence

3. adaptive versatillity

evolutionary convergence

similar adaptive selective forces, both in tropical arboreal environments led to anatomical and structural evolution in different yet parallel directions

adaptive versallity

versitile and efficient biological organization of the monkey architecture would have been under little pressure from natural selection therefore there was little reason to go through profound modification

apes: adative radiation 14 species of today

1 humans

2 chimp species

1 gorilla species

1 orangutan species

9 gibbon species

limitied geographical distribution

dying apes paradox

while all other apes are on the verge of extinction humans are thriving, is the destiny of mankind to 1. go extinct or 2. drive other species to extinction

ape radiation GIBBONS key features

southeast asia, no secual dimorphism, monogamous females, single births every 4-5 years, branchiation (hanging on branches), hylobates=genus

Ape radiation ORABNGUTANS

island of borneo and sumatra, extreme secual dimorphoc species females are smalled, genus= prongo, they basically have 4 arms

orangutans features

1. high round braincase

2. poorly developped bow ridges

3. deep face with small orbits set close together

4. unique prognathic (projecting forward) snout with large convex premaxilla (front face)

5. the mandibles has a high ascending ramus (temporalis musicles in upper jaw and supraorbital

Gorilla features

central africa, largest primates, one male group 9-10 females, territorial, knuckle walking, genus gorilla

chimps features

africa from senegal to tanzania, occupy many habitats, locomotion or knuckle walking, complex behavuior eg. hunting in males and tools, fission-fusion societies, males gregarious and females isolated around offsping, genus is pan

humans features

worldwide, body proportions, long legs and ipright pibedal gait, opposable thumbs, nakes apes, cranial anatomy is large with large brain alike 3 types of apes, small canines, chin, diet omnivor, genus homo

3 stages

prosimian - paleocene/early eocene 65-45 mya

primitive anthropod (monkeys and apes - early oligocene 45-25 mya

ape- miocene 25-5 mya

ancestors of living apes

gibbons possible phiopitheus dated 15-11 mya. gorillas no idea, chimps no idea, organs good candidates in sivapithecus 10-8mya, humans plenty of potential candidates

Tooth morphology clues about behaviors

Three complexes

1. The frontal teeth (incisors) first stage of eating by breaking into food

2. Canines: although canines play a part in processing food these are not strongly correlated to food because they also serve other functions 1. Feeding 2. Protection 3. social structure

3. Back teeth (molars/premolars) second stage of eating by crushing food

Insect eaters: tooth morphology

molar and premolar teeth with sharp cusps and very well developed shearing crests useful for the breakup of insect skeletons which can be hard common among primates, sharp cusps may mean they are an insect eater

gum eaters tooth morphology

specialized incisor teeth forwardly projecting (dental comb) for digging holes in bark not rare among prosimians

leaf eaters tooth morphology

small incisors (leaves require little incisive prep) and molar teeth will be well developed shearing crests but somewhat rounded cusps useful for breaking through fibrous leaves common among monkeys and apes