Human Evolution

Are there any grooves in the knee/femur of African apes?

no much of a groove, rather flat straight edge. Australopithecus Afarensis and humans have groves at the end. This helps the knee cap to stay in place when the knee is flexing and bending.

As we get back further in time, what do we discover about our ancestor?

our ancestor looks nothing like a chimp at all. Chimps have been evolving for 6-8 years since we shared a common ancestor. So ancestor did not look like a chimp at all.

Lucy had grasping feet, this indicates what? (fingers in toes of Australopithecus Afarensis bit more curved vs human toes)

she might have spent little time in the trees, or a characteristic left behind from a previous ancestor ( so no time spent in trees).

What were the brain sizes of Australopithecus Afarensis?

slightly larger than the previous ancestors (Sahlanthropus and Ardipithecus) at 450-500 cc.

What two groups does A.Afarensis branch into ?

1. Australopithecus 2. Homo

After Putting together all the uncovered skeleton of Ardipithecus Ramidus, what can we conclude?

- Can see a vertebral column, same in all primates - Hands very supple, great for grasping tree limbs not strong enough to support body weight, not a knuckle walker. - Skeleton recovered predicted to be female - Ardy - Comparing feet with chimps and humans, we see a clear separated toe, used to grab

How were the teeth of Ardy aka Ardipithecus

- Had teeth that weren't Ape or Human like, had small canines and bigger teeth in the back. Canines in the front bigger than human so teeth were intermediate.

In 1973 what did Donald Johanson and his expedition discover in the far region of Ethiopia?

A valgus knee, and immediately knew what it was (knew organism was 3.4 mya). Came back a year later to discover the Lucy skeleton in 1974.

Provide the year existed and brain capacity of the following: 1. Sahelanthropus Tchadensis 2. Ardipithecus a) Kadabba b) Ramidus 3. Australopithecus Afarensis 4. Australopithecus Africanus 5. Australopithecus Boisei 6. Australopithecus Robustus

1. 6-7 mya with case 320-380 cc 2. Kadabba 5-6mya and Ramidus 4.4 mya ; 300-350 cc 3. Lucy 3.6-2.9 ..... 4. A. Africanus 3-2mya with brain 430-500 cc 5. A. Boisei 2.5-1.4 mya with brain 500-550 cc 6. A. Robustus 2.2-1.4 mya ....... 4-6 cousins/hominids not direct relatives

What are the different types of Australopithecines and Homo ?

1. Australopithecus; Africanus, Robustus 2. Homo; Habilis, Erectus, Sapiens

Summary of Ardipithecus Ramidus

1. Did not have ape like teeth, but had small canines, teeth intermediate between chimps/humans 2. Little Sexual dimorphism 3. Wrist not adapted for branching on branches and knuckle-walking on ground 4. Pelvis top like a human (bipedal) and bottom like chimp

What is the Summer of the Characteristics of Sahelanthropus Tchandenisis?

1. Skull - small and chimp like in size 2. Brain - about 320-380 cc 3. Brow Ridge - continuous and thick 4. Face - less prognathism than chimp/ more than human 5. Teeth - intermediate, small canines than chimp but longer than human. Cheek teeth larger than chimp with more enamel (ate less fruit and more tough vegetable matter) 6. Foramen Magnum - (Hole in bottom of skull) - Oval, shape of true upright walking bipedal organism- hominids

When did Raymond Dart finally convince the science community that these organisms Australopithecine Africanus had human/ape characteristic and were human ancestors existing long before Neanderthals?

1940's

When was Lucy found? and what was so special about this discovery

1973-1974 and it was never believed that a bipedal organism could exist such a long time ago (4-2.8 mya).

How old are Ardipithecus ? and do we see knuckle walking?

4-5 mya and no knuckle walking, knuckle walking evolved in chimps/gorillas since we diverged from Ardipithecus.

What type of skeleton do we have of Ardipithecus?

40% bones and 35% individual pieces

What is the starting point of human evolution?

6-7 million years ago with the discovery of Sahelthropus Tchandenisis

What can be noted about the heads/skulls of Australopithecine and a chimp?

A lot of prognathism, bottom jaw sticks out - Prominent brow ridge, very low forhead and small brain caise

Which two groups have a crest/ridge at the top of their skulls like a gorilla?

A. Robustus and A. Boisei. Muscles working the upper jaw go up the side of the face and anchor at the crest, allowing for tremendous powerful chewing jaws and huge teeth.

Compare Australopithecus Robustus and Gorillas

A.Robustus had giant huge molars like gorilla but didn't have giant canines. Gorillas also don't have huge molars in the back

What is characteristic of a valgus knee?

Angling of femur from base of condyle and grooves at the end of femur.

Looking at the bottom of the pelvis , there are two points in the pelvis of Homo Sapiens and Au. Afarensis from which the hamstring muscles come down and allow us to move forward/walk bipedal very efficiently. These two points aren't in the pelvis of which two organisms?

Ar. Ramidus and P. troglodyes

What are the two separate species of Ardipithecus?

Ardipithecus Kadabba (5.6 mya) Ardipithecus Ramidus (4.4 mya)

Which organism pushed our understanding of human evolution back to 4.4 mya ?

Ardipithecus Ramidus

Human teeth: no large canines in the front, but teeth get bigger as going back Chimps teeth: teeth in the front very large, with large canines, and teeth in the back very small. How were the teeth of Ar. Ramidus?

Ardipithecus Ramidus had intermediate teeth, with Slightly large canine bottom teeth in the front and large molar teeth in the back for chewing.

Even though Lucy isn't an ape, her name Australopithecus Afarensis means what? and why is the name that it is?

Australopithecus Afarensis means Souther ape from region of Ethopia. She is not an ape and not from the south but was discovered near other Australopithecines so they put her in the same genus. Lucy is a different species. (Once you name something, the name sticks).

What two genus could have represented the true ancestors?

Australopithecus Afarensis or Gari

What did Raymond Dart name his discovery?

Australopithecus Africanus ( Southern Ape form Africa)

What are two known cousins of the Species Homo ?

Australopithecus Africanus and Boisei

What is the average hight of Au. Afarensis?

Average height was about 5ft tall with 150 lbs Lucy was on the smaller end at 3.5 ft tall at 60 lbs

Besides the small brain, why else did the taung baby not look like a human but more of an ape?

Because of its prognathism, lower jaw sticking out.

Why is it believed that the genus Homo and the two Australopithecines (Africanus,Robustus) were thought to have lived cotemoraneously?

Because their lines parallel each other, for some reason we survived and they didn't.

How were the delicate organisms of Ardipithecus able to outcompete the more aggressive ones?

By leaving behind more offspring. - Support the female by bringing food, more nutrition means more healthy offspring and so on. - More fit if you produce more Viable offspring than competitor.

Compare and contrast the teeth of Chimps, Humans, and Lucy

Chimps - 2 large canines, 4 incisors in the front and gap (diastema) where canines fit - Back teeth straight line and not bigger than front teeth Human - No diastema, no canines, teeth rounded and teeth in back bigger Lucy - Bigger back teeth and orientation little rounded - had canine, bigger than human but smaller than chimp - a little diastema right of canine - Jaw intermediate between the two - diastema almost non existent and very small canine

How are the cusps in the teeth of humans, chimps, and Australopithecus Afarensis?

Chimps - 1 cusp Australopithecus Afarensis - 1 and beginning of 2nd Humans - 2 distinct cusps

Comparing the skull of a chimp with a modern human and Sahelthropus Tchandenisis what can we conclude?

Chimps have Canine teeth, where the bottom of the face sticks forward. - Modern human doesn't have large canine teeth and face is flat - Sahelthropus Tchandenisis doesn't have a flat sticking face or large canine teeth

Who proposed that our ancestors would be found in Africa?

Darwin

There was little sexual dimorphism in the species of Ardipithecus, what does this mean?

Dimorphism - males very different from females (i.e horns, antlers, aggressive displayed teeth)

What is special about the foot of Ardipithecus Ramidus?

It had a rigid foot allowing it to walk upright but also grab things. Its an intermediate foot between chimps and humans. Also had an intermediate pelvis characteristic of organisms that climb and walk upright.

Why is Louis Leaky so famous?

Famous Paleoanthropologist because he followed Darwins lead/suggestion that we came from Africa. Went to Africa in 1930's and looked for fossils in Olduvai George. Eventually found Homohabilus (handy man)

from the side view, what is noticeable of the femur size in chimps and Lucy ?

Femur isn't wide, not much burring surface while in Lucy (Australopithecus Afarensis) its very wide like a modern human with a lot of burring surface.

What was the fossils of rdipithecus Kadabba primarily composed of?

Fossils of teeth and jaw ( 5.6 mya)

Where were Neanderthals found?

Found in Germany in 1850's with large brains ( larger than modern humans).

What are the major differences between a human pelvis vs a Chimp pelvis?

Human pelvis is short and runs front to back and very deep. This allows for attachments of muscles in Gluteus Maximus and other muscles ( stand up right and move forward). Femur/upper leg bone angles in so center of gravity stays in the middle of the body. Chimp pelvis not deep and is wide but doesn't have places to attach muscles. Knees are very different and femur doesn't angle, rather goes straight up and down, so animal waddles side to side or knuckle walks.

Tim White and team figured the difference in the two groups of Ardipithecus makes them into two different species. But if Ramidus is in the same genus as Kadabba, then how far does it push back the human ancestors?

If Ramidus is in the same genus as Kadabba, it pushes back human ancestors 5.6 mya

When Raymond Dart found the Taung Baby (Australopithecus Afarensis) why was he ridiculed when he claimed that these were our ancestors?

It didn't look like the fake at the time, (fake had a large skull,brain) where this had a very small brain

Sahelanthropus Tchadensis which was found 10 years ago in present day Chad. how long ago did it live? What was its brain size? Did it have any prognathism?

It lived 6-7 mya had a brain size of 320-380 cc Didn't have much prognathism (lower part of face sticking forward)

Ardipithecus Ramidus walked upright and climbed in trees, how do we know this?

It walked up right and climbed in trees very well, because it had a grasping toe like a chimp. Also had supple hands so not a knuckle walker.

How was the diet of Australopithecines?

It was intermediate - Chimps have cusps in their molars while humans have virtually no cusps in the molar. Australopithecus don't have much of a cusp in their molar either. This means that through chewing and grinding of fibers, tubers, nuts and hard stems, the molars of Australopithecines got flattened out.

How is the Hip in P. troglodytes different from other species?

Its not broad and short, its rather long and narrow, doens't provide a lot of contact surface, so the animal waddles from side to side.

What is the famous species of Au. Afarensis?

Lucy , 3.3 mya and completely bipedal

When was the most famous Australopithecus Afarensis found?

Lucy was found on November 30th 1974

Whats the most famous specimen of Au. Afarensis ?

Lucy which existed 3.8 - 2.8 mya

If we go back 6-7 million years, will we find an organism looking like a chimp?

NO !!! ancestor not a chimp at all. Many intermediate organisms linking humans and chimps that were bipedal at the time.

did Raymond Dart find Lucy?

NO he did not !!! He found the first Australopithecus Africanus

Can science prove anything definitively?

NO it can't

Do modern humans have prognathism?

No they do not ( we are the only mammals who's brain is above the face, most other mammals have face in front of the brain).

Initially it was believed that as we diverged our brains got bigger, but what changed first?

Our teeth

Why was there very little sexual dimorphism between the species of Ardipithecus?

Owen Love Joy (studied 40 years) stated - Males of Ardipithecus were less aggressive, spent more time with the females, more mating/pair bonding - No need for aggressive fighting for dominance over women, - Males bring food to females and get sex in return - More stable family relationship

Who was the 1st to find the 1st Australopithecine?

Raymond Dart (Med school professor) , uncovered the "Taung baby/child" from some rocks that were brough tto him

Who helped Raymond Dart with his discovery?

Robert Brook (Professor of Anatomy)

What was the Magazine that published the findings of Ardipithecus RAmidus and the environment it lived in?

SCIENCE, summarized findings of Ardipithecus Ramidus (over 15 years of research)

What were the brain sizes of Sahelanthropus tchadensis ? and Ardipithecus Ramidus?

Sahelanthropus Tchadensis had a brain size of 320-380 cc Ardipithecus Ramidus had a brain size of 300-350 cc

When observing the skull of Sachelanthropus Tchandensis, what do we discover?

The size of the skull is smaller than a chimp. The cranial capacity is 320-380 cc Prominent brow ridge Face was much flatter than expected

Why was the discovery of Sahelthropus Tchandensis so unique? What perceptions did we have that this discovery changed?

Scientists believed that as we go back further in time that our ancestor would look in between a Chimp and a Human. However the discovery of Sahelthropus showed us that we are wrong. It had no canine teeth and no prognathism like a chimp. Meaning that chimps may have diverged over time and developed canine teeth, knuckle walking

What is characteristic of Lucy's pelvis?

Short rounded Illium - Femur (upper leg bone) angles down, giving center of gravity in the middle - knee joint also typical of bipedal organism

From the cover of SCIENCE, we can see the sekeleton of Ardipithecus Ramidus uncovered. How much was uncovered and what?

Skeleton, lot of cranium, teeth, part of pelvis, leg, interesting foot, tremendous amount of hand.

What is the primary diagnostic characteristic to separate primates ?

Teeth

Darwin proposed that Africa would be our home ("which it is") but through sheer ignorance, the scientific community believed what?

That Europe or Asia was our home

What do the creationist care about ?

That humans were created by God fully formed on this Earth

How is the Pelvis (particularly the bottom part) of Ar. Ramidus ?

The bottom part of the pelvis is more like that of a chimp and the top is more like of a human/Au. Afarensis

What helped the scientific community of their prejudice?

The discovery of Neanderthals (which weren't human) who had large brains in Germany

The human toe is fused together with other toes, allowing us to push off and walk up right. How then can we say that Ardipithecus Ramidus was a bipedal organism? (walked upright)

The foot of Ardipithecus Ramidus has a wide out toe like chimps but it also has a "osporonium" bone, (which isn't found in chimps/gorillas) but is found in Humans. This small bone in the foot helps to keep the foot rigid, allowing for push off pressure and ability to walk upright.

What else is important besides the angling of the femur and connection to condyle?

The groove in the bottom femur

What is the take home message of the pelvis of Ar. Ramidus? Is it an intermediate pelvis?

The pelvis of Ar. Ramidus is a mosaic of parts ( not an intermediate). Part of it allows it to walk bipedal very efficiently and the bottom part allows it to have its feet sticking forward and grasp on to tree,s climb trees very well. (Climb trees better than a human but not as good as a chimp).

What was Dart clever enough to see in the Taung baby? and conclude that it was a human ancestor?

The teeth were different from a chimp and the brain lobes were different from a chimp also.

If a valgus knee is noticed in humans an Australopithecus Afarensis, what is the knee in Chimps?

There is no angling in chimps, a straight line can be drawn up and

Why don't the Creationist want us to share a common ancestor?

They find it degrading and don't want us to be produced by natural processes. Want us to be God like and made by God in the image and likeness of their favorite creator.

Why was Raymond Dart not able to convince the scientific community that his discovery was a human ancestor?

They said the child was most likely a chimp and if a human is found, it will look like an adult chimp.

Australopithecus Afarensis were bipedal or not? and how were their teeth?

They were fully bipedal and had intermediate teeth between chimps/humans with slightly bigger brains than Ardi (Ardipithecus Ramidus)

the top portion of the ilium in Homo sapiens, Au. Afarensis and Ar. Ramidus is broad and short. Why is this important?

This portion provides a lot of contact surface for muscles necessary to walk upright i.e Gluteus Maximus ect.

Besides the finding of the earliest Homo genus = Homohabilus, what else is significant about this discovery?

Thought to be the earliest human to use tools (2mya)

How do the Chimpanzee teeth stay sharp?

Upper and lower canines fit together in the diastema and canines sharpen each other by grinding.

Australopithecus Afarensis was discovered by ? When did it appear in our linear?

Very famous species that appeared in the middle of our lineage from where we think we diverged. Discovered by Raymond Dart in 1925

How were the famous footprints in Laetoli Tanzania formed?

Volcanic eruption and ash deposited and rained again. The wet ash allowed for 2 Australopithecines to leave footprints (adult/child). More ash came over and solidified foot prints 3.4 mya.

Judging by the pelvic structure of Ardipithecus what can we conclude about its gender? (nick named Ardy)

Was a female and nick named it Ardy

Why did our teeth change first?

Way back when we had less sexual dimorphism, more pair bonding, teeth structure different. We walked up right, to free our hands to carry food to female.

What else do we have besides the knee and pelvis, allowing us to predict that there were organisms 2.8-4 mya (Australopithecus Afarensis) that were fully bipedal ?

We also have foot prints !

What was the weight of Ardipithecus?

Weight around 50 kg/ 110 lbs, larger than a monkey, its the size of a female chimp, stayed out of branches and tops of trees

If today you want to find the origin of a domesticated plant/animal thats been spread all over the world by humans, where do you go?

You go where there are wild plants/animals that look the most like the one you are interested in. I.e. Wheat come from Middle east,

How are Australopithecines related to the genus Homo?

cousins of homo, not directly related

What are A. Robustus and Boisei ?

an offshoot of human evolution

Why do we believe that tool use goes further beyond 2 million years?

because Homo Habilis (handy man) fossils date back 2 mya while the tools date back 2.4 mya, so either Homo Habilis goes back further or Africanus/Robustus also used tools.

Describe the Valgus knee ( charactersitic of bipedal organism)

bottom part of femur coming at an angle to match with the bottom part (condyle). An angle can be noted when a line is traced up the condyle and to the pelvis. Angling of femur = valgus knee.

Where do we have the footprints that indicate to us that there were fully bipedal organisms 2.8-4mya ?

discovered in Laetoli Tanzania by Mary Leakie in 1978

It was always assumed that what makes us human was?

having a large brain and be a knuckle walker like a chimp. It was believed that what set us off to becoming humans was the large brain first.

When was the genus of Ardipithecus first disocovered?

in 1994, took about 15 years to put together and compelte the analysis, present and finally publish in 2009

What is the species of Pan Troglodytes?

the Chimp

the Ilium in Australopithecus Afarensis is very deep and wide, unlike in chimps which is long and narrow. Why is a deep wide ilium important?

to attach the walking muscles to the ilium

Hominid is ?

upright walking Ape (bipedal)