Miami Arts Charter
- the study of the distribution of species and ecosystems in geographic
space and through (geological) time
- Evolution is modification over time
- Molecular biology is a branch of science concerning biological activity at
the molecular level. The field of molecular biology overlaps with biology
and chemistry and in particular, genetics and biochemistry.
- Molecular biology study genes in RNA and DNA as well as the molecules
that regulate these reactions and compare them against other species.
- All life has similar structures/molecules that can perform life’s basic
Observed Evolutionary Change
- most speciation takes millions of years
- take a mass of mutations accumulating over generations to create a
- But all it takes is some event that reproductively isolates one group of
individuals from another to cause genetic drift in a population
- evolution is easiest to observe in species with a quick generation turnover
Human Evolution: Our Early Ancestors
- Humans are primates
- Modern Human Species: Homo sapiens
- Share a common ancestor with modern day African apes, gorillas,
chimpanzees, and bonobo etc., 8-6 mya
- The fossils of early humans who lived between 6 and 2 million years ago
come entirely from Africa.
- 15-20 species of early humans
- Bipedalism, the ability to walk on two legs, evolved over 4 million years ago.
- Large and complex brain, the ability to make and use tools, and the capacity
for language, developed more recently.
- Many advanced traits, including complex symbolic expression, art, and
elaborate cultural diversity, emerged mainly during the past 100,000 years.
Humans Family Tree
- Sahelanthropus tchadensis is one of the oldest known species of humans
- Between 7 and 6 million years ago in West-Central Africa
- First appearance of Bipedalism
- Evidence: The foramen magnum (the large opening where the spinal
cord exits out of the cranium from the brain) is located further forward
(on the underside of the cranium) than in apes or any other primate
- Indicates that the head of Sahelanthropus was held on an upright body,
probably associated with walking on two legs.
- Femur bones shows evidence of bipedalism
- Probably climbed trees and walked upright
- Between 6.2 and 5.8 mya
- Ardipithecus ramidus a partial skeleton (like most)
- The foot bones in this skeleton indicate a divergent large toe combined
with a rigid foot
- Reconstructed pelvis show adaptations that combine tree-climbing and
- canine teeth like chimpanzee
- found alongside faunal remains indicating she lived in a wooded
- contradicts the open savanna theory for the origin of bipedalism
- states that humans learned to walk upright as climates became drier and
environments became more open and grassy.
Australopithecus afarensis AKA Lucy
- remains from more than 300 individuals
- Between 3.85 and 2.95 million years ago in Eastern Africa (Ethiopia,
- survived for more than 900,000 years, which is over four times as long as
our own species has been around
- oldest documented bipedal footprint trails
Au. afarensis Continued
- children grew rapidly after birth and reached adulthood earlier than
- Shorter period of growing up
- less time for parental guidance and socialization during childhood.
- both ape and human characteristics:
- Ape like face proportions (a flat nose, a strongly projecting lower jaw) and braincase (with
a small brain, usually less than 500 cubic centimeters, about 1/3 the size of a modern
- long, strong arms with curved fingers adapted for climbing trees
- small canine teeth, and bipedal.
- Their adaptations for living both in the trees and on the ground helped them survive for
almost a million years as climate and environments changed.
- Au. africanus had a rounder cranium housing a larger brain and smaller
- some ape-like features
- shoulder and hand bones indicate they were also adapted for climbing
- relatively long arms and a strongly sloping face that juts out from underneath the
braincase with a pronounced jaw.
- Pelvis, femur bone, and foot bones of Au. africanus bipedalism
- Discover 1924: The Taung child, found in 1924, was the first to establish
that early fossil humans occurred in Africa.
- very few remains of this species have been found
- 2.5 million year old ’Black Skull’ in 1985 helped define this species as the
earliest known robust australopithecine. P. aethiopicus
- has a strongly protruding face, large megadont teeth, a powerful jaw,
and a well-developed sagittal crest on top of skull, indicating huge
- Paranthropus robustus found in South Africa
- Paranthropus boisei- larger brain capacity
- only one really good fossil of this Homo rudolfensis
- KNM-ER 1470, from Koobi Fora in the Lake Turkana basin, Kenya
- Originally considered to be Habilis
- really critical feature: a braincase size of 775 cubic centimeters, which
is considerably above the upper end of H. habilis braincase size. At least
one other braincase from the same region
- also shows such a large cranial capacity.
- differs is in its larger braincase, longer face, and larger molar and
- Due to the last two features, though, some scientists still wonder whether this species
might better be considered an Australopithecus, although one with a large brain!
- one of the earliest members of the genus Homo
- slightly larger braincase and smaller face and teeth than in
Australopithecus or older hominin species
- retains some ape-like features, including long arms and a
- name means ‘handy man’, was given in 1964 because this species was
thought to represent the first maker of stone tools. Currently, the oldest
stone tools are dated slightly older than the oldest evidence of the genus
Homo habilis continued
- Discovery: 1960
- A team led by scientists Louis and Mary Leakey at Olduvai Gorge in
- The type speciman, OH 7, was found by Jonathan Leakey, so was
nicknamed "Jonny's child"
- combination of features different from those seen in Australopithecus
- declared these fossils a new species, and called them Homo habilis
- suspected that it was this slightly larger-brained early human that made the
thousands of stone tools also found at Olduvai Gorge.
- Early African Homo erectus fossils (sometimes called Homo ergaster) are
the oldest known early humans to have possessed modern human-like
- relatively elongated legs and shorter arms compared to the size of the
- adaptations to a life lived on the ground
- indicating the loss of earlier tree-climbing adaptations
- ability to walk and possibly run long distances
- expanded braincase relative to the size of the face
- complete fossil individual of this species is known as the ‘Turkana Boy’
- a well-preserved skeleton (though minus almost all the hand and foot bones)
- dated around 1.6 million years old.
- Microscopic study of the teeth indicates that he grew up at a growth rate similar to that of
a great ape
- Fossil evidence that this species cared for old and weak individuals.
- The appearance of Homo erectus in the fossil record is often associated
with the earliest handaxes, the first major innovation in stone tool
- Found in Asia
- the first species to have expanded beyond Africa
- highly variable species, spread over two continents
- possibly the longest lived early human species - about nine times as long as our
own species, Homo sapiens, has been around
- large browridge
- larger braincase
- flatter face than older early human species.
- First species to live in colder climates
- short, wide bodies were likely an adaptation to conserving heat
- lived at the time of the oldest definite control of fire and use of
- first early human species to routinely hunt large animals
- the first species to build shelters, creating simple dwellings out of
wood and rock.
- Year of Discovery: 1908
- Heidelberg, Germany, a workman found the type specimen of H.
heidelbergensis in the Rösch sandpit just north of the village of