1. 7/8 World History Week 3 The Peopling of Earth

2. Monday Do Now Objectives
What do you know about the Big Bang? What do you know about the earliest humans? Give as many details as you can think of.
I will understand how the universe started.
I will understand how the process of evolution works.
I will identify key features of Australopithecus.

3. Key Terms Term Definition Sentence Big Bang
The current scientific theory about how the universe was created from a single explosion 13.8 billion years ago.
Scientists continue to study the Big Bang and its effects to better understand the universe and how it works.
evolution
The process of a species changing little by little over a long period of time to adapt to new environments.
Even though lions, tigers, and cats were all the same creature millions of years ago, evolution turned them into three very different species today.
continent
A large area of land that is separated from others by a combination of physical geography (land shape, oceans, etc.) and human cultures.
There are currently considered to be seven continents on Earth.
Australopithecus
The earliest known species of direct human ancestors.
Even though Australopithecus was very short and monkey-like, they walked on two feet and evolved to become modern humans over millions of years.

4. The Big Bang
Over the course of the 20th century, many famous physicists, including Albert Einstein, Edwin Hubble, and Stephen Hawking, all helped shape our scientific understanding of the beginning of the universe.
Together, their work has shown that all the matter in the entire universe was contained in a single point until 13.8 billion years ago, when it suddenly exploded, spreading matter in all directions, forming brand new stars and galaxies.
Our own sun is estimated to have formed about 4.6 billion years ago, and the Earth shortly after, around 4.5 billion years ago. It took around another billion years for the very first life to form, the size of a single cell.

5. Evolution
As conditions on Earth changed over the next few billion years, getting gradually cooler and more stable, a wider variety of life forms were able to evolve. Around 66 million years ago, most of the large animals on Earth, including dinosaurs, suddenly died off, probably the result of a large asteroid impact.
Although this impact was disastrous for most reptiles, something about the new conditions on Earth allowed a new type of creature, mammals, to suddenly appear. With the ability to regulate their own internal temperature and give birth to live young, mammals have since become the dominant type of life form on Earth, including humans.

6. Continents
Just as animal species adapt and change over time through evolution, the surface of the Earth and the shape of its land also changes over time, in response to movement deep under the Earth's surface. The basic locations of continents that we can see today on the map mostly developed by about 5 million years ago, with a few significant changes in response to sea levels even within the last 50,000 years.

7. Australopithecus 3-4 million years ago Southern and Eastern Africa
Same group of species that includes modern-day chimpanzees and apes
Always walked on two feet, on the ground, instead of living in trees
Earliest known hominid species
The move to upright walking (called bipedalism) had three very important effects on the future evolution of the group:
1) walking upright required a different-shaped pelvis with a smaller opening, resulting in more difficult childbirth and a lower number of new babies born
2) walking upright allowed our arms and hands to be free, instead of helping us to walk and climb, which changed the configuration of muscles in them, allowing for more fine, controlled movements
3) whether or not it was a result of walking upright or having our hands free, or a coincidence, as hominids evolved, they got gradually larger brains (and skulls to fit them), allowing for more complexity of thought and organization

8. One of the most important Australopithecus discoveries happened in 1974, when a 40% complete skeleton of a female, nicknamed Lucy, was discovered in Ethiopia. It is the single most complete Australopithecus skeleton yet found. Females of the species grew to about 3.5 feet tall as adults, and males around 4.5 feet. Their brain was small compared to modern humans, but significantly larger than a modern chimpanzee's. Their proportions were more ape-like than modern humans, with shorter legs and long, strong arms, but they walked upright.
Analysis of their teeth and surroundings shows that they had a mixed diet consisting mainly of meat and fruit. Animals skeletons found near some Australopithecus skeletons also show clear evidence of stone tool use, to remove the meat for eating.
Right: Lucy in her modern museum display case at the National Museum of Ethiopia

9. What was the thing you found the most surprising today?
Exit Ticket
What was the thing you found the most surprising today?
Homework
Readings on Homo habilis and Homo erectus
Complete chart columns for the species

10. Study for Reading Quiz or Read silently.
Tuesday
Do Now:
Study for Reading Quiz or Read silently.
Objective:
I will identify key features of Neanderthals and Homo sapiens.

11. Reading Quiz
1. Put these species in order of when they lived (earliest to most recent): Homo erectus, Australopithecus, Homo habilis
2. What continent did Homo habilis live on? What continent did Homo erectus live on?
3. Which early hominid species had the most similar brains to modern humans?

12. Check Homework

13. Review Homo habilis Homo erectus - 2.3 - 1.5 million years ago
- found in Africa
- larger brain than Australopithecus
- still had long arms compared to modern humans
- used simple stone tools
Homo erectus
- 1.6 million - 100,000 years ago
- found in east Asia
- larger brain than Homo habilis
- arms were similar in length to modern humans
- used stone tools and probably fire

14. Neanderthals
The first known Neanderthal skeletons date back to about 300,000 years ago, and are found throughout Europe and the Middle East.
Physically, they were fairly similar to modern humans, just slightly shorter and with more muscles. Their skulls and faces were the most different, with Neanderthals having sloping foreheads with a large brow ridge over the eyes, and wide noses.
The technology they used was quite advanced for early hominids, and it is known that they used fire for warmth and cooking, and animal skins for clothes.
Unlike early modern humans who lived at the same time, Neanderthals did not seem to produce any art or advanced clothing using sewing.

15. One of the greatest mysteries about Neanderthals is what happened to them. Within a relatively short time of modern humans moving into their territory, around 35,000 years ago, they disappeared. To explain why this happened, scientists have come up with several possible theories:
1) Neanderthals were systematically killed into extinction by modern humans
Although Neanderthals had relatively advanced technology, modern human technology at the time was even more advanced. The lack of Neanderthal cultural artifacts also suggests that they were probably not quite as intelligent or organized as modern humans, making it even more difficult to fight back. This theory could help explain why Neanderthals disappeared so suddenly.

16. 2) Neanderthals couldn't compete with modern humans living in the same environment
It's possible that modern humans were simply more efficient at hunting and gathering wild plants than Neanderthals, not leaving enough for them to survive long-term. Physical evidence shows that Neanderthals were not as good at running as modern humans, and they also seemed to have shorter lifespans on average, living only into their 30's and 40's, giving them less time to reproduce.

17. We know that this theory is at least partially correct because new DNA evidence from the last 10 years proves that most modern humans in Europe and the Middle East today have some amount of Neanderthal DNA (around 1-4% on average). This is not true in Africa or East Asia, where Neanderthals did not live. But because we do not know the size of the pre-existing Neanderthal population when modern humans arrived in their territory, it is difficult to know how much interbreeding contributed to their disappearance. Perhaps only a small number of Neanderthals interbred with humans and most were purposefully killed off, or vice versa.
3) Neanderthals interbred with the modern humans and disappeared as a distinct group

18. Homo sapiens
All living humans today are members of the species Homo sapiens. The earliest skeletons date to about 250,000 to 300,000 years ago and come from East Africa.
Homo sapiens were better-adapted to walking and running than any hominid before. With longer legs and fewer muscles, they were faster on the ground than any of their ancestor species. They quickly developed more advanced tools than any seen before and began spreading around the globe, first to the Middle East, then into India, Europe, and beyond, tending to stay in warmer, more tropical locations.
By the time they encountered Neanderthals in Europe around 35,000 years ago, Homo sapiens were already producing complex art and culture.

19. Readings on Neanderthals and Homo sapiens
Exit Ticket:
Which do you think is the most likely explanation for the disappearance of the Neanderthals?
Homework
Readings on Neanderthals and Homo sapiens
Complete chart columns for the species

20. I will trace the route of human migration.
Block Day
Do Now:
Name the 7 continents.
What continent did humans originally come from? (If you don’t know, make a guess).
Objectives:
I will trace the route of human migration.
I will understand the origins of skin color.

21. Reading Quiz
Put these species in order of when they lived (earliest to most recent): Neanderthals, Homo erectus, Homo sapiens, Homo habilis, Australopithecus
2. On which continent have the earliest Homo sapiens skeletons been found?
3. Name two ways in which Homo sapiens are different from earlier hominids.

22. Check Homework

23. Review Neanderthals Homo sapiens 300,000 - 28,000 years ago
found in Europe and the Middle East
larger brain than Homo erectus
used stone tools, fire, and wore clothing
disappeared quickly after modern humans arrived
Homo sapiens
modern humans
appeared around 300,000 to 250,000 years ago
originally from East Africa
larger brain than any hominid except Neanderthals
used advanced stone tools, fire, wore sewn clothing, and produced art
overtook all other hominid species

24. Why are humans closer to the equator more likely to have darker skin?
Exit Ticket:
Why are humans closer to the equator more likely to have darker skin?
Homework
Study for the Unit 1 test on Friday!