Paleontology Notes

What is Paleontology? The scientific study of life in the geologic past, especially through the study of animal and plant fossils Greek for "ancient" (paleo), "being" (onto-), and "study" (-logy)

In order to fully understand Human Evolution, we must understand our closest ancestors “If we look straight and deep into a chimpanzee's eyes, an intelligent self-assured personality looks back at us. If they are animals, what must we be?”  ― Frans de Waal

What makes an animal a primate? Hands and feet Features of hands and feet Grasping big toe Opposable thumbs Sensitive fingertips Flat nails

Adaptations of Primates

Adaptations of Primates Opposable Thumbs Practice Exercise: Write your name with your pencil without the use of your thumb. Also, try and tie your shoe and get something out of pencil case

Adaptations of Primates Grasping Hands Practice Exercise: Pick up a coin without using your thumbs

Limited olfactory senses What makes an animal a primate? Vision Forward facing eyes Binocular vision Stereoscopic Vision Information sent to both hemispheres of the brain Depth perception Color vision Limited olfactory senses

Adaptations of Primates Binocular Vision Practice Exercise: Determine your field of vision with your arms spread wide. Test your binocular vision using a pencil and a partner.

What makes an animal a primate? TEETH 2 pairs of incisors 1 pair of canine 2 pairs of premolars 3 pairs of molars

What makes an animal a primate? DEVELOPMENT Small liters Long pregnancy Long infancy Long juvenile period

What makes an animal a primate? BRAIN Large brain in proportion to body size

The Primate Family Tree

Groups of Primates Prosimians Monkeys Apes

Prosimians Why? What do you notice about their eyes? Aye-Aye Loris Lemur Why?

They are nocturnal Prosimians also: Are insectivores Have large snouts Are most primitive of primates

Tarsier – From Southeast Asia Tarsiers They are Prosimians but are more closely related to Old & New World Monkeys Larger brain than lemur and loris Flatter face than lemur and loris Tarsier – From Southeast Asia

Monkeys Two groups New World Old World Have tails

New World Monkeys Found in South and Central America Spider Monkey Howler Monkey Notice the functioning tail.

Old World Monkeys Found in Africa and Asia Baboons What are the TWO main differences between new and old world monkeys?

Difference between Old and New world Monkeys Old World New World Prehensile Tail Less intelligent Flat nose Nostrils are far apart and open to the side Thumb orientation lies in line with other digits.  Live mostly in trees NO prehensile tail More intelligent Nostrils are closer together and open downward or forward Thumbs are rotated and more opposable Live mostly on the ground

Gibbons From Asia Apes Orangutans From Asia

Apes Gorillas Chimpanzees From Africa From Africa

Apes No tail Large brain Can use tools Highly intelligent Long arms Can walk upright for short periods although not considered bipedal

Humans

What do we call primates who are bipedal? HOMINIDS

Hominids

how are Humans like Chimpanzees? Its in our DNA

Human and Ape DNA Lab

Part I When you hear the word evolution, what do you think of first? For many people, the first thing that comes to mind is the phrase, “Humans evolved from apes.” However, we did not evolve directly from modern apes. Instead, we evolved from a common ancestor with modern apes. This activity will give you the opportunity to observe differences and similarities in human and ape DNA.

Background Knowledge DNA is a double helix shape DNA is made of nitrogen bases that make up the “steps of the ladder” A and T, C and G always match up and are called “base pairs”

Background Knowledge A G G C A T T C C G T A One side of DNA is called the parent strand and the opposite side is called the complimentary strand For example: A G G C A T Parent strand T C C G T A Complimentary strand

Background knowledge A G T G A T C C G C A T T C C G T A Organisms that share matching bases are closely related in evolution. The more bases you match, the closer you are related. Sections that do not match show differences A G T G A T C C G C A T Parent strand of Human T C C G T A Complimentary strand of Organism X Don’t Match 4 unmatched bases and 2 unmatched sections

procedure 1. Diagrams called morphologic trees, are based on comparisons of organisms. Look at the morphologic tree in figure 1 and find the part of the tree that shows the relationships between gorillas, chimpanzees, and humans. You will notice that there are no lines showing relationships. 2. Develop three hypotheses to explain how these organisms are related. On the DNA Lab Answer Sheet, under Part I, make a diagram of your hypotheses by drawing lines from point A to each of the three organisms (G = gorilla, C = chimpanzee, H = human, A = common ancestor). 3. Circle ONE of the hypotheses as the one that you think best shows the relationship between humans, gorillas and chimpanzees.

example G C H A You can use this one on your paper but make sure to make up 2 more that are from your brain

Part II Modern research techniques allow biologists to compare the DNA that codes for certain proteins and to make predictions about how closely related the organisms are based on their DNA. You will use models of these techniques to test your hypotheses.

procedures 1. Using your DNA Lab Answer Sheet, “recreate” three strands of DNA. Use the provided DNA sequences and a color code like the one listed below: blue = adenine (A) green = guanine (G) yellow = thymine (T) red = cytosine (C) 2. Recreate the three DNA strands by filling in the correct color, coded for each base in the proper sequence of DNA given for each organism. The DNA strands for all three organisms represent a section of the gene that codes for the hemoglobin protein. Hemoglobin carries oxygen in red blood cells.

procedures 3. The Human DNA strand (below) represents the parent strand. Remember DNA exists as two stands, a parent strand and a complimentary strand. Human DNA strand: (position 1) A-G-G-C-A-T-A-A-A-C-C-A-A-C-C-G-A-T-T-A (position 20) A G G C A T Now you can finish the rest…

Procedures 4. The Chimpanzee and Gorilla cDNA strands (below) represent the complimentary strand that matches to the parent strand. Chimpanzee cDNA strand: (position 1) T-C-C-G-G-G-G-A-A-G-G-T-T-G-G-C-T-A-A-T (position 20) Gorilla cDNA strand: (position 1) T-C-C-G-G-G-G-A-A-G-G-T-T-G-G-T-C-C-G-G (position 20)

procedures 5. Compare the human DNA to the chimpanzee cDNA by matching the strands base by base. Remember, the DNA bases are complementary – adenine (A) will always pair with thymine (T), and guanine (G) will always pair with cytosine (C). 6. Count the number of bases that are NOT complementary (matches) and the number of sections of bases that are NOT complementary (matches). Record your data in table 1 on your Lab Answer Sheet, under Part II. Repeat steps 5 and 6 with the human DNA and the gorilla cDNA.

Part III Biologists have determined that some mutations in DNA occur at a regular rate. They can use this rate as a “molecular clock” to predict when two organisms began to separate from a common ancestor. Most evolutionary biologists agree that humans, gorillas, and chimpanzees shared a common ancestor at one point in their evolutionary history. They disagree, however, on the specific relationships between these three species. In this part of the activity, you will use data from Table 1 to answer discussion questions and determine which hypothesis from Part I is best supported by the analyzed DNA evidence. Answer these discussion questions on the back of your Lab Answer Sheet under Part III.

Hominid Evolution

How are humans different from other primates? Bipedal (2 legs)  skeleton is adapted for walking upright Human pelvis is vertical (holds skeleton upright) Gorilla pelvis tips ribcage, head, and neck forward Human spine is “S” shaped Gorilla spine is “C” shaped

Which are bipedal advantages and disadvantages? 1. 2. 3. 4. Bipedal Disadvantages A. Easier birth B. Less heat absorbed C. Walk further D. Can climb trees better E. Faster F. No back problems G. Use of hands for carrying H. Greater field of vision

Which are bipedal advantages? Walk further Use hands for carrying Greater field of vision Less heat absorbed Bipedal Disadvantages More difficult births Slower Back problems with age Cannot climb trees as well

Cranial Structure Foramen magnum  Hole in the skull where the spine enters Human: Spine enters at bottom of skull Gorilla: Spine enters near rear of skull

Opposable Toes Humans do NOT have opposable big toes (only opposable thumbs). Other primates have both opposable thumbs and opposable big toes so they can hold onto things with their feet as well as their hands.

Next- Complete the Human vs Ape Comparison Worksheet

What came first bipedalism or large brains?

What came first bipedalism or large brains? The fossil evidence shows that bipedalism came first. The oldest fossils of hominids had cranium sizes similar to the size of apes but showed evidence of walking upright.

When and where did Homo sapiens evolve? So far fossil evidence also points to East Africa Genetic evidence also points to East Africa as our origin.

How did hominids evolve? Geologic Change changed climate Climate Change changed habitats Habitat Change changed the Species

Geologic Change 8MYA all of central Africa was tropical 6MYA Great Rift Valley forms isolating East Africa North & South America are joined by Central America

Climate Change East African climate became cooler & drier due to mountain range Change in Atlantic ocean currents due to joining of North and South America

Habitat Change In East Africa tropical rainforests became savanna West Africa still existed as a tropical rain forest

Species Change Primates of East Africa adapted becoming bipedal No longer lived in forested areas so less reliance on trees Needed hands to carry food further Needed increased height to look over the grasslands

Place events in order under their correct change: Geologic; Climate; Habitat & Species Savanna grasslands form in East Africa Central Africa is all tropical (apes are diverse) East Africa became cooler & drier due to mountain range and change in ocean currents West Africa remained a tropical rainforest Bipedal primates evolve in East Africa Great Rift Valley forms isolating East Africa & connection of North & South America

If bipedalism came first, what caused brains to increase in size?

Climate change – unpredictable environment

Hominid Skull Lab

Meet your Relatives

Human vs. Gorilla

Forehead Large, Medium, Small, or none?? Apes Hominids

Sagittal Crest No crest Large (very pronounced) Large, Medium, Small, or None?? Sagittal Crest No crest Large (very pronounced)

Prognathism How big is its snout, or muzzle? Large, Medium, Small, or None??

Supra-Orbital Ridge Bony ridge (eyebrow bone) above the eyes Small or None Large Large, Medium, Small, or None??

Dental Arcade Arch or shape of the jaw (top or bottom) U – shaped (parallel) V – shaped (parabola)

Canines Large, Medium, or Small ?? 2 1 3 1 2 3

Facial Slope The angle of the face (measured in degrees)

Facial Slope How to measure This is not level

Facial Slope How to measure

Cranial Size The circumference of the brain Use the measuring tape around the skull