EVOLUTION OF PRIMATES

How are Humans classified How are modern humans classified? Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: sapiens

I. Order: Primates A. Humans, monkeys, and apes belong to the Class: Mammalia Order: Primates B. All primates have

I. Order: Primates 1. Opposable thumb allows you to cross your thumb over your palm and touch your fingers. This means that you can grasp and hold things with your hands. An opposable thumb allows tree-dwelling primates to hold on to branches.

Tree-dwelling

I. Order: Primates 2. Binocular vision permits you to judge depth or distance with your eyes. In a similar way, it allows tree-dwelling primates to judge the distances as they move between branches.

I. Order: Primates 3.Flexible shoulders and rotating forelimbs also help tree-dwelling primates move from branch to branch. These shared characteristics indicate that all primates may have evolved from a common ancestor.

I. Order: Primates C. Primates are divided into two major groups. 1. Strepsirhines (STREP suh rines) “Wet noses” Examples: includes lemurs and tarsiers. 2. Haplorhines (HAP luh rines) “Dry noses” Examples: monkeys, apes, and humans

Lemur

Tarsier

II. Family: Hominidae Is a family in the order: Primates Is a family in the suborder: Haplorhines Genera of Hominidae Pongo (orangutans) Gorilla Pan (chimpanzees) Australopithecus Homo

They are humanlike primates that lived about 4 million to 6 million years ago. They ate both meat and plants and walked upright on two legs. Hominids shared some characteristics with gorillas, orangutans, and chimpanzees, but a larger brain separated them from the apes. III. HOMINIDS

Hominids refer to the family of Hominidae, but specifically to the genus Australopithecus and the genus Homo *Modern man is the only hominid left that is not extinct

3.85 and 2.95 million years ago In the early 1920s, a fossil skull named Australopithecus was discovered in South Africa. It was one of the oldest hominids ever discovered The skull had a small space for the brain, but it had a humanlike jaw and teeth. V. Genus: Australopithecus

IV. Genus: Australopithecus An almost-complete skeleton of Australopithecus was found in northern Africa in This hominid fossil was called Lucy. This fossil’s remains are thought to be between 2.9 & 3.4 million years old. This fossil indicates that modern hominids might have evolved from similar ancestors.

“South ape” Small brain NOT in the same genus as humans V. Genus: Australopithecus

In the 1960s in a region of Africa, a hominid fossil, which was more like present-day humans than Australopithecus, was discovered. V. Genus: Homo

A. Homo habilis 1.5 million to 2.4 million years old The hominid was named Homo habilis, meaning “handy man” because simple stone tools were found near him. Larger brain than Australopithecus

A. Homo habilis

1.89 million and 143,000 years ago Based upon many fossil comparisons, scientists have suggested that Homo habilis gave rise to another species, Homo erectus, about 1.6 million years ago. Homo erectus had a larger brain than Homo habilis. Homo erectus traveled from Africa to Southeast Asia, China, and possibly Europe. B. Homo erectus

“Walked upright” Stone tools Able to make fire

C. Homo ergaster It is believed Homo erectus left Africa and branched out across Europe and Asia. They eventually became known as Homo ergaster. The Homo erectus population that remained in Africa eventually developed into Homo sapiens.

C. Homo ergaster

D. Homo heidelbergensis 700,000 to 200,000 years ago Previously called Archaic Homo sapiens, marks another increase in hominid size about 800,000 years ago. The designation heidelbergensis covers a diverse group of skulls which share features with Homo erectus, Homo neanderthalensis and Homo sapiens.

D. Homo heidelbergensis

E. Homo neanderthalensis 200, ,000 years ago They probably are NOT direct ancestors of modern humans, but represent a side branch of human evolution. Some scientists classify them as sub species of Homo sapiens, named Homo sapiens neanderthalensis Neanderthals disappeared from the fossil record about 30,000 years ago. They were unable to adapt.

“Neanderthal” NOT direct ancestors of modern humans Short heavy body with thick bones Small chin & heavy brow ridges Family groups lived in caves Hunted with well-made stone tools Their body demanded massive amounts of energy. Ate mostly meat

“Neanderthal”

Anatomical comparison of the skulls of Homo sapiens (modern humans) and Homo neanderthalensis (right)

200,000 years ago to today “wise man” Greatest brain to body ratio in primates Thinner skull, near vertical forehead Virtually no heavy brow ridges Smaller jaws and teeth Buried their dead F. Homo sapiens

Art & painted cave drawings Long developmental period Less body hair allowed for cooling down to occur much more quickly Greater surface area to volume ratio (leaner than Neanderthals) Less energy demands

1.Homo sapiens idaltu ?? 160,000 years ago ?? (means elder or first born) 2. Homo sapiens sapiens (modern man) Two sub-species

Homo floresienses The original skeleton, a female, stood at just 1 meter (3.3 feet) tall, weighed about 25 kilograms (55 pounds), and was around 30 years old at the time of her death 18,000 years ago. Died out 13,000 years ago Neanderthals died out 30,000 years ago Lived during the same time as Homo sapiens

Homo floresienses

TIME LINE Animals600 mya Fish/land plants500 mya Insects 400 mya Amphibians350 mya Reptiles300 mya Mammals200 mya Birds150 mya Primates60 mya Hominidae family20 mya Australopithecus genus4 mya Homo genus2.5 mya Homo Sapiens200,000 years ago Agricultural revolution/towns form12,000 years ago Civilization/Writing/Recorded history6000 years ago

TIME LINE BIG BANG13.8 bya Solar system4.7 bya Earth & Moon4.5 bya Earth cools, crust, atmosphere oceans form.4.0 bya Prokaryote life forms appear.3.8 bya Cyanobacteria appears (oxygenates atmosphere) bya (Mass extinction of anaerobic life) Unicellular eukaryotic organisms appear. 2.0 bya Multicellular eukaryotic organisms appear. 1.0 bya

TIME SCALE The time scale is divided into units called Eons billions of years Eras100s of millions of years Periods10s of million of years Epochs1000’s to millions of years

The Precambrian era lasted from Earth’s formation 4.6 billion years ago until 542 million years ago (mya). The first cells appeared in the Precambrian era.

The Paleozoic era lasted from 542 to 251 mya. Paleozoic is a Greek word meaning “ancient life.” Rocks dated from the Paleozoic era contain fossils of trilobites, snails, clams, and corals.

The Mesozoic era lasted from 251 to 65 mya. (Mesozoic is a Greek word meaning “middle life.”) This era is often called the Age of Reptiles.

The Cenozoic era began 65 mya and is still going on. Cenozoic means “recent life.” Fossils from the Cenozoic era are closest to Earth’s surface, making them easier to find.

Mass extinctions are periods of large-scale extinction. They seem to be part of the evolutionary process because after each, new life forms emerge. Asteroids may have played a part in previous mass extinctions. MASS EXTINCTIONS

PBS: Becoming Human 3 hour documentary

AMOEBA SISTERS Human Body Systems: The 11 Champions s&list=PLwL0Myd7Dk1F0iQPGrjehze3eDpco1 eVz&index=23

Does a bigger brain size mean greater intelligence?

What about brain to body ratio?

Greatest brain to body ratio SpeciesSimple brain-to body ratio (E:S) [1] [1] small ants1:7 [2] [2] tree shrew1:10 small birds1:14 human1:40 mouse1:40 cat1:110 dog1:125 squirrel1:150 frog1:172 lion1:550 elephant1:560 horse1:600 shark1:2496 hippopotamus1:2789

What about brain to body ratio? Maybe only when comparing species of the same order

What about brain to body ratio? Maybe only when comparing species of the same order

Why did humans become so much more intelligent than other members of the genus: Homo ?

Climate change (adaptability) Communication & cooperation Around the campfire

Bottleneck Effect All Homo sapiens sapiens come from only 600 individuals. Living in close quarters disease spread easily, the survivors had a high resistance to disease.

What is vitamin D?

Skin pigmentation? Melanin Albinism (born with genetic, recessive, many health isues) Vitiligo (auto immune, occurs over time, usually affects only skin and eyes)

What is vitamin D? How did vitamin D influence natural selection?