IB Biology Option D D3 Human Evolution.

IB Biology Option D D3 Human Evolution

D.3.1 Outline the method for dating rocks and fossils using
radioisotopes, with reference to 14C and 40K. _____ is a naturally occurring isotope of carbon with a half life of ________ years. Constantly being made in the atmosphere when cosmic rays cause ________ to fuse with _________ nuclei and “kick out” protons Formation Decay

radioisotopes, with reference to 14C and 40K. 14C production is in equilibrium with its decay to ____ The 14C is incorporated in _____________ which is then taken up by _____. In the end all living things have the same ratio of 14C to 12C When an organism dies it no longer takes in 14C. So over time the ratio of ____________ changes. This is measurable and can be used to estimate age. The limit for accurate determination of age is about ____________

radioisotopes, with reference to 14C and 40K. ____ is an isotope with a half life of ____________ 40K decays to ____. When 40K is released from a volcano in _____, all of the argon gas is driven off. So brand new rocks effectively have a ratio 40K: 40Ar of _______ Over time the lava may be weathered and eroded and incorporated into _____________________. The measured ratio of _________ can be used to date rocks ________________ years old with an accuracy of around __________ years

When to use which isotope? ____________
D.3.1 Outline the method for dating rocks and fossils using radioisotopes, with reference to 14C and 40K. When to use which isotope? ____________ - K-40 - For older samples, over 100,000 years old - C-14/C-13/C-12 - For young samples, from 1000 to 100,000 years old - _____ C14 recent death; ______ C14, old!

D.3.2 Define half-life. Half-life = ______________________________________ _______________________________________ What is the half life for each of the isotopes represented by these curves?

D.3.2 Define half-life. ______

Grasping ______________ limbs
D.3.4 Describe the major anatomical features that define humans as primates. human gibbon gorilla Grasping ______________ limbs

D.3.4 Describe the major anatomical features that define
humans as primates. ________Vision

leading to reduced olfaction
D.3.4 Describe the major anatomical features that define humans as primates. Monkey _________ ________ leading to reduced olfaction Monkey Squirrel vs. Doggie Human

Generalized _________
D.3.4 Describe the major anatomical features that define humans as primates. Human Baboon Gorilla Generalized _________ Moo Cown

D.3.4 Describe the major anatomical features that define
humans as primates. Others: Forelimbs able to ____________ ____________ allows wide range of arm movement (re. the above two points: if you have a gentle and patient pet dog, give it a rub on the tummy and then move it’s forelegs, they really only move in one plane) ___________ reproduction - long ____________ - usually ______ offspring at a time _____________ – relative to body size _____________ – more complex, more folds Better _____________ – more of the photoreceptors have their own sensory neurons ___________ dependency

Modern primates are divided into two subgroups:
Prosimii ( meaning “ “): includes

Modern primates are divided into two subgroups:
Anthropoidea ( ): includes Anthropoid primates arose at least 45 million years ago in Africa or Asia. Anthropoids have Monkeys differ from apes by having

Monkeys are divided into two groups:
Found in Central and South America Some have ( ) New World Old World

monkeys New World Old World
Found in tropical parts of Africa and Asia: Most are arboreal though (these are quadrupedal – walk on all fours) None have New World Old World

Old World monkeys shared a common ancestor with the
Old World monkeys shared a common ancestor with the , group consisting of ( ) In addition to monkeys, the anthropoid suborder also includes four genera of apes: Hylobates (gibbons), Pongo (orangutans), Gorilla (gorillas), and Pan (chimpanzees and bonobos)

Modern apes ( ) are our Locomotion:
Humans and have a common ape-like ancestor and share very similar DNA ( ) Locomotion: (gibbons and orangutans) – movement through (chimpanzees, bonobos, gorillas) – have adapted to life on the ground – quadrupedal walking in which they fold their digits when moving Brachiation, Knuckle-walking, and the absence of a tail are thought to have been a preadaptation to bipedalism (walking on two legs)

____________; similar to _____________ Australopithecus: A. afarensis
D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. approximate dates distribution Ardipithecus ramidus 5.8 mya – 4.4 mya ____________; similar to _____________ Australopithecus: A. afarensis 4 mya – 2.5 mya _________________; “Lucy” A. africanus 3 mya - <2.5 mya __________________

________, India, ________, Indonesia, Africa
D.3.5 Outline the trends illustrated by the fossils of: Homo: H. habilis 2.4 mya – 1.6 mya Olduvai Gorge (Tanzania), Kenya, Ethiopia, South Africa; simple _____________, fire, ______-dwelling H. erectus 1.8 mya – 100,000 ya ________, India, ________, Indonesia, Africa H. neandertha-lensis 200,000 – 30,000 ya Europe, Western Asia; ____________ than modern human!  H. sapiens 140,000 – 70,000 ya Africa, Europe, Asia; ______________; tool technology/weapons

Ardipithecus ramidus 5.8 – 4.4 Mya Distribution: Ethiopia
Believed to be Most fossils of this species are teeth so it is difficult to be sure about physical features Probably similar to chimpanzees but canines were more hominid-like Possible View fossils (Ardi revealed tab):

Australopithecus afarensis
3.9 – 2.9 Mya Climate changing. Antarctic advance 5 Mya Distribution: Ethiopia, Kenya, Tanzania Cranial capacity: Height: 1.07m Australopithecus afarensis is one of the longest-lived and best-known early human species—paleoanthropologists have uncovered remains from more than 300 individuals! Found between 3.85 and 2.95 million years ago in Eastern Africa (Ethiopia, Kenya, Tanzania), this species survived for more than 900,000 years, which is over four times as long as our own species has been around. It is best known from the sites of Hadar, Ethiopia (‘Lucy’, AL 288-1 and the 'First Family', AL 333); Dikika, Ethiopia (Dikika ‘child’ skeleton); and Laetoli (fossils of this species plus the oldest documented bipedal footprint trails). During the time they lived (Pliocene epoch) the antarctic ice cap came and went with the seasons and fluctuations in climate. Towards the end of this period (2.6 mya) the ice became permanent and grassland and tundra thrived. Similar to chimpanzees, Au. afarensis children grew rapidly after birth and reached adulthood earlier than modern humans. This meant A. afarensis had a shorter period of growing up than modern humans have today, leaving them less time for parental guidance and socialization during childhood. Au. afarensis had both ape and human characteristics: members of this species had apelike 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 human brain), and long, strong arms with curved fingers adapted for climbing trees. They also had small canine teeth like all other early humans, and a body that stood on two legs and regularly walked upright. 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. © 2008 Paul Billiet ODWS

(footprints 3.6 Mya old) /climber dental arcade but reduced canines Arboreal / terrestrial Famous fossil “ ” was found in Ethiopia in 1974 – about 40% complete fossil A. afarensis possibly gave rise to both Australopithecus africanus and other australopithecines Australopithecus afarensis is one of the longest-lived and best-known early human species—paleoanthropologists have uncovered remains from more than 300 individuals! Found between 3.85 and 2.95 million years ago in Eastern Africa (Ethiopia, Kenya, Tanzania), this species survived for more than 900,000 years, which is over four times as long as our own species has been around. It is best known from the sites of Hadar, Ethiopia (‘Lucy’, AL 288-1 and the 'First Family', AL 333); Dikika, Ethiopia (Dikika ‘child’ skeleton); and Laetoli (fossils of this species plus the oldest documented bipedal footprint trails). During the time they lived (Pliocene epoch) the antarctic ice cap came and went with the seasons and fluctuations in climate. Towards the end of this period (2.6 mya) the ice became permanent and grassland and tundra thrived. Similar to chimpanzees, Au. afarensis children grew rapidly after birth and reached adulthood earlier than modern humans. This meant A. afarensis had a shorter period of growing up than modern humans have today, leaving them less time for parental guidance and socialization during childhood. Au. afarensis had both ape and human characteristics: members of this species had apelike 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 human brain), and long, strong arms with curved fingers adapted for climbing trees. They also had small canine teeth like all other early humans, and a body that stood on two legs and regularly walked upright. 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. © 2008 Paul Billiet ODWS

Australopithecus africanus (Southern Ape of Africa)
3 – 2.25 Ma ___________ of climate reduced rainfall Further advance of _______________ 2.4 mya Development of scrubland and savannah ____________ cover retreats

Australopithecus africanus (Southern Ape of Africa)
Distribution: Southern and Eastern Africa Cranial capacity: _______ cm3 (Chimp = 400cm3) __________ 20 – 35 kg _________ skull _________ dental arcade Longevity: __ years maximum __________ of bone marrow/ brain cases

Homo habilis - the handy man
Mya E. Africa ; 1st hominid to have enough features to be placed in genus Homo significant part of the diet Cranial capacity: 600 – 800 cm3 (larger brain) Height: 1.20 – 1.35m (small) Simple fashioned tools –

Homo erectus – the upright man
1.8 to 0.5 Mya 0.9 Ma beginning of the Pleistocene __________ Oscillations between ______ and ______ periods Spread out of Africa (1.6Ma) throughout the old world are examples of Asian H. erectus dated at 200,000 years ago Scavenging to ________ Use of a _____________

Cranial capacity: ____________cm3 (H. sapiens = 1350 cm3) Use of _______ Height 1.55 to 1.8m Extended ____________ 1st molar at ___ years old (H. sapiens = 5.9y) Greater ___________  52 years Speech? (______ says: yes; ________ says: no) Improved tools: ____________

Homo erectus H. erectus used more advanced tools (Archeulian tools), wore clothes, used fire, lived in caves or shelters, and hunted and scavenged for food

H. erectus fossils may actually represent two species – Some researchers suggest that H. ergaster was an earlier African species, and H. erectus was a later eastern Asian offshoot These researchers believe that H. ergaster led to modern humans and H. erectus became an evolutionary dead end What is all this fuss about Broca's area and how does it relate to speech in Homo erectus? Broca's area, the new, deeper speech center, apparently creates a bulge in the surface of the brain. This bulge is the classical Broca's area but the bulge is due to the deeper speech center which as Walker and Shipman said, lies like a cat under the bed clothes. This bulge leaves an impression on the inside of your skull. Since skulls are fossilized, the earliest appearance of this bulge on the interior of the skull can be noted. Apes do not have a Broca's bulge.(Dean Falk, Comments, Current Anthropology, 30:2, April, 1989, p ) The earliest occurrence of Broca's bulge on the interior of the skull occurs in KNM-ER 1470 a 1.9 million year old Homo habilis. All Homo erectus' like modern man, have Broca's bulge imprinted onto the interior of the skull. This is something that no australopithecus nor ape possesses. There is another feature which is required for modern speech. It is the cranial flexion at the base of the skull. Jeff Laitman has shown that the cranial flexion was non-existent in Australopithecus, "substantial“ in erectus and fully developed with Neanderthal and modern humans. Erectus had a brain the size of a one-year-old modern human. The face of Homo erectus was not that different from its forebearers. It still had protruding jaws, no chin, thick brow ridges, and a long low skull. Its teeth were smaller than those of Homo habilis. This species grew to be up to 6 feet and they were slender which gave them ample surface area for sweating, an advantage in the tropics. Their hips were narrower than those of other hominids; this gave them great speed. They also had robust bones which helped them through a physically-demanding life. The hole in a vertebra, smaller than that of a modern humans, carried a spinal cord which was probably too small for true speech. Since Homo erectus was a meat-eater it did not need the powerful jaws that Homohabilis and earlier forms would have needed for grinding coarse vegetation. © 2008 Paul Billiet ODWS

Homo neanderthalensis (our distant cousins?!)
to years ago Europe, Middle East, into Central Asia First discovered in Evolved from __________ populations perhaps via _______________________, then became extinct Adapted to the ________ conditions of temperate zone ____________may have warmed cold air

Cranial capacity: _____ cm3 (H. sapiens = 1350 cm3) ___________, long low skull Height: 1.67m _________ build Improved sophisticated tools Sometimes _______________ Made simple _____________ The existence of skeletons of the demonstrates that they – indication of

Much debate exists about whether the Neanderthals are a Many researchers believe that between Neanderthals and modern humans indicate that – Homo neanderthalensis and Homo sapien much debate exists about whether the Neandertals are a separate species from modern humans or a race of Homo sapien many researchers believe that anatomical differences between Neandertals and modern humans indicate that they were separate species – Homo neanderthalensis and Homo sapien tools included oldest known spear points (known as Mousterian tools) – more sophisticated than those of H. erectus existence of skeletons of elderly Neandertals and of Neandertals with healed fractures demonstrates that they cared for aged and the sick – indication of advanced social cooperation had rituals and buried their dead © 2008 Paul Billiet ODWS

Disappearance of Neanderthals about 30,000 ya is not well understood Humans with more modern features coexisted with Neanderthals for tens of thousands of years Neanderthals may have interbred with modern humans, diluting their features beyond recognition However, analysis of mitochondrial DNA from Neanderthal bones seems to indicate that they were an evolutionary dead end Possible that more modern humans out competed them much debate exists about whether the Neandertals are a separate species from modern humans or a race of Homo sapien many researchers believe that anatomical differences between Neandertals and modern humans indicate that they were separate species – Homo neanderthalensis and Homo sapien tools included oldest known spear points (known as Mousterian tools) – more sophisticated than those of H. erectus existence of skeletons of elderly Neandertals and of Neandertals with healed fractures demonstrates that they cared for aged and the sick – indication of advanced social cooperation had rituals and buried their dead © 2008 Paul Billiet ODWS

Homo sapiens – Modern Human
From 200,000 years ago to present Originating in _____________then went worldwide Reached Europe about __________ years ago _________ of the climate during the last glacial period from about ya led to their predominance over other species (e.g. H. neanderthalensis) ____________ _________ environment ________________ of species, farming

Cranial capacity: _______ cm3 (range 1000 to 2000 cm3) _____ of the body’s energy consumption for _____ of body mass __________ Extensive tool kit including new materials (bone, ivory, antler) ____________ thought 1st molar tooth ___ years old Longevity ___ years

Cro-Magnon culture in France and Spain typifies the early H. sapiens and made of materials other than stone (bone, ivory, wood) Developed sophisticated tools and art indicate that they

Identify and label the following hominid skulls:
**Skulls not to scale

Homo erectus Australopithecine Gorilla Modern human Neanderthal

From the previous two slides you can see:
D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. From the previous two slides you can see: _______________ of the brain case _______________ of the face loss of _______________ You can’t really see it but the hole in the bottom of the skull where the spinal cord exits the brain (__________ __________) is further forward in modern humans. This distributes the weight of the head over the spine so that modern humans do not need huge necks muscles.

D.3.5 Outline the trends illustrated by the fossils of Ardipithecus
ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens.

ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Homo sapiens Pan troglodytes (chimpanzee)

ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. The jaw has developed from a ___ into a ___ shape. Teeth have generally ___________ in size. (Chimpanzee provided for comparison)

ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Human hands are adapted for ___________ and fine manipulation. In contrast gorillas have short fingers for _________________ and gibbons have elongated fingers and reduced thumbs for ________________.

Skeleton, locomotion and posture
D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Skeleton, locomotion and posture Human knees aligned under the body’s ___________ __________ because femurs are angled __________. Human legs _____________________ when walking. Human spine has additional ________ to keep centres of mass of head and trunk aligned for bipedalism. Big toe ______________ in humans, which allows for an arched foot. Ratio legs:arms __________ for humans than other apes Human pelvis ____________

ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. _________, also called juvenilization or pedomorphism, is the retention, by adults in a species, of traits previously seen only in juveniles.

Some human characteristics thought to be a result of Neoteny:
D.3.5 Outline the trends illustrated by the fossils of Ardipithecus ramidus, Australopithecus including A. afarensis and A. africanus, and Homo including H. habilis, H. erectus, H. neanderthalensis and H. sapiens. Some human characteristics thought to be a result of Neoteny: Lack of body hair Small teeth and reduced numbers of teeth Prolonged growth period Long life span Flat face and thin skull bones Lactase production in adults Epicanthic eye fold Small nose Longer trunk relative to arms and legs

A. afarensis & A. africanus ~ 3mya A. africanus & H. habilis ~2mya
D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. Doesn’t necessarily mean they lived together/near each other...just means _______________________________ A. afarensis & A. africanus ~ 3mya A. africanus & H. habilis ~2mya H. neanderthalensis, H. erectus, and H. sapiens ~100,000 yrs ago

Did these species interact?
Very few Australopithecines, for a million years so there was time for chance encounters There is evidence that (according to IB!) World population was only in the tens of thousands and

D.3.6 State that, at various stages in hominid evolution,
several species may have coexisted. 1960 Up the ladder The idea that one species smoothly evolves from one into another is regarded today as an ___________________ Unfortunately it is a very persistent view that continually resurfaces in cartoons Australopithecus Homo erectus Homo sapiens Public Domain Images

several species may have coexisted. Branching out The 1960s and 1970s were a fertile period for _____________ in Africa The idea developed that ______________ __________________existed at the same time developed Homo sapiens Homo erectus Homo habilis Australopithecus africanus A. robustus A. boisei Australopithecus afarensis “Lucy” Added 1974

D.3.6 State that, at various stages in hominid evolution, several species may have coexisted. Changing status As more specimens were found a clearer idea developed of the relationships between them Homo sapiens Homo erectus Homo habilis A. africanus A. robustus A. boisei Australopithecus afarensis

several species may have coexisted. 2001 From a tree to a bush ? 1 Ma 2 Ma 3 Ma 4 Ma Homo sapiens Homo erectus Homo habilis A. africanus P. robustus Paranthropus boisei Australopithecus afarensis Australopithecus anemensis Ardipithecus ramidus P. aethiopicus Homo rudolfensis H. ergaster H. heidelbergensis Homo neanderthalensis A. garhi

2003 DEEPER ROOTS ? 1 Ma 2 Ma 3 Ma 4 Ma 5 Ma 6 Ma 7 Ma Gorilla gorilla
Homo sapiens Homo erectus Homo habilis A. africanus Paranthropus robustus Paranthropus. boisei Australopithecus afarensis Australopithecus anemensis Ardipithecus ramidus P. aethiopicus Homo rudolfensis H. ergaster H. heidelbergensis Homo neanderthalensis A. garhi Orrorin tugensis Gorilla gorilla Sahelanthropus tchadensis “Toumai” Pan trogolodites

D.3.7 Discuss the incompleteness of the fossil record and the
resulting uncertainties about human evolution. Reasons for the incompleteness of the fossil record: fossils only form when buried under sediment before _________________ occurs; animal bodies are usually eaten by _______________, decomposed by _________, or broken down chemically of remains fossilized, most remain buried in __________ / remain unfound; Measurements imprecise b/c _________________ of organisms at death (juvenile  adult)

resulting uncertainties about human evolution. Reasons for the incompleteness of the fossil record: hominid fossils that have been found may or may not be ____________________ of hominid history; hominid fossils that have been found are usually _________, and the remainder of the organism must be __________/ inferences may or may not be correct; only _____________of individuals fossilize, leaving many questions concerning the rest of the individual’s phenotype

Two opposing hypotheses exist about the origin of modern humans:
1. “ ” hypothesis – states that to Europe and Asia, displacing the more primitive humans living there

2. “ ” hypothesis – states the
each population evolved in its own distinctive way but occasionally met and interbred with other populations, thereby preventing complete reproductive isolation

resulting uncertainties about human evolution. The large gaps in the human evolution fossil record are consistent with ______________ ____________________ The following four slides show how the gaps are filled over time with new discoveries. The graphs plot cranial size against the age of the fossil.

D.3.8 Discuss the correlation between the change in diet and
increase in brain size during hominid evolution. The benefits of a bigger brain include: More ___________________ Mastery of ______ Cooking Wamth Protection Greater_____________________ (less reliance on instinct and better able to learn and pass on knowledge necessary to adapt to an environment)

increase in brain size during hominid evolution. The cost of having a big brain: ___________ gestation period Years of development before young can __________________ Much more _________________ occurs post birth than for any other animal

increase in brain size during hominid evolution. In summary: Big brains are _______________________. The mother must take in lots of energy not only during pregnancy, but for a significant time after. Hominids needed to increase their __________________.

increase in brain size during hominid evolution. The solution to this energy crisis was to swap a diet of these:

increase in brain size during hominid evolution. For some chunks of this: The increase in brain size observed in hominid fossils has been closely correlated with an ____________________________________ A bigger brain made ________ and _______ easier

D.3.9 Distinguish between genetic and cultural evolution.
Genetic evolution refers to the genetic changes that have occurred during the evolution of hominids. e.g. increased brain size, spine shape, position of knee Cultural evolution is the changing of ideas held and actions carried out by societies and the transmission of these ideas through social learning from one generation to the next. e.g. the use of fire, agriculture, tools, weapons, religion, beliefs The cultural evolution has spanned millions of years in three major stages: the nomadic (hunting), agricultural (settled), and industrial ages. However, we have not changed biologically in any significant way. We could take a baby from 80,000 years ago, raise it in a modern environment and it would be indistinguishable from other humans in terms of intelligence and social capabilities.

Genetic (e.g. increased brain size, spine shape, position of knee) __________, parent to child only Body ______________ # ______________ ________________ Cultural (e.g. the use of fire, agriculture, tools, weapons, religion, beliefs) ______________________, passed on to many in the group/family, generation to generation ___________, Art Customs/rituals _____________

Comparison D.3.9 Distinguish between genetic and cultural evolution.
The product of _________ ___________ The product of _________. the transmission of _________ behaviour characteristics _____________ _____, not modified during the organism’s life time _______ during the life time Passed on through ___________ information Passed on to ___ (family), social group, population, within a generation and between generations ________ change _______ change

Importance of Genetic and Cultural Evolution
One way to measure the culture of a people is to look at the quality and complexity of their artifacts (tools and artwork) Species Example of Culture Tools Developed Simple choppers, scrapers and flakes of rock Hand axes, cleavers and picks Large flakes of uniform size produced from a core then trimmed to the desired tool Delicate blades for knives, drills Other materials added (bone, antler, and ivory Some tools are ceremonial

As brain size increased so did quality of tool-making There is a connection between genetic and cultural evolution Genetic evolution probably occurred first because need larger brain size to develop more sophisticated tools In the last 30,000 years, H. sapiens evolution has been largely cultural, not genetic Cro-Magnon man is physically the same as humans today

Since the Upper Palaeolithic period (40,000 – 10, 000 years ago), human culture has developed exponentially Cultural evolution sometimes lags behind genetic evolution Our current cranial capacity has existed for 140,000 years but major cultural advances do not appear until 35,000 years ago Cultural evolution has potential to revolutionize a human population much more quickly than genetic evolution H. sapiens has been able to evolve culturally far more than any of our ancestors without any major genetic evolution

IB Biology Option D D3 Human Evolution.

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