Classification+of+Humans+DB

22.3 Classification of Humans (p.475-477) 1. How are humans classified from domain to species? -Humans are in the Domain Eukarya. This domain is classified by a membrane-bound nucleus in a cell. -We are in the Kingdom Animalia. The kingdom Animalia consists of other organisms that are multicellular, motile, and heterotrophic. -Humans are in the Phylum Chordata because of our nerve chord and pharyngeal pouches. -The class Mammalia includes humans because humans have hair and mammary glands. -We are in the order Primates which is characterized by a well-developed brain. -Humans are a part of the family hominidae because we are bipedal. -We are in the Genus Homo for our use of tools and our most developed brain, and finally we are in the -Species Homo Sapiens meaning we have speech centers of the brain that are well developed.



2. What are the characteristics of primates? Notable characteristics of primates include mobile limbs and hindlimbs. These limbs have hands and feet that each have five digits that help primates obtain food. They also usually include an opposable thumb and toe. Primates have binocular vision, meaning that they have eyes that have moved to the front of their face. They have stereoscopic vision which allows them to see depth, and they have three different cone cells which help them tell the difference between blue, green, and red colors. Pirmates have a large and complex brain that helps them control and process information received from their developed hands and eyes. Finally, primates have a reduced reproductive rate in order to have a longer period of time to develop learned behavior and social interactions. All of these characteristics make primates ideal for aboreal life, or life in trees.

3. What major differences exist between the chimpanzee skeleton and the human skeleton? Major differences in the chimpanzee and the human skeleton give humans upright stance. They include, a spine coming from the center of the skull in humans, not the rear of the skull. Humans have a longer S-shaped spine, and a wider pelvis and hip joint, but chimps have a curved spine. Humans have a longer neck of the femur and a modified knee joint unlike chimps. Finally, humans, but not chimps, do not have an opposable toe but instead have an arched foot. 22.4 Evolution of Hominids 4. Which fossil hominid is the oldest of the australopithecines? The oldest fossil of the australopithecines is the austrolopithecus afarensis which existed 4 million years ago.

5. Which hominid is the first to have culture? Explain. The first hominid to have culture was the Homo habilis. Exisiting between 2.0 and 1.9 MYA, Homo habilis had a large brain and ate meat and plants. They made stone tools and are thought to have been able to speak. They may have thus been able to communicate and share food, making them the first culture.

6. Which hominid was the first to migrate out of Africa? Homo ergaster was the first hominid to migrate out of Africa. It first appeared in Africa, then moved to Asia, and Europe.

7. How might Homo habilis, living 2 MYA, have differed from the austropithecines? Homo habilis most likely was more upright. They also had more developed brains. Austropithecines are described as being "human like below the waist" but "apelike above (the waist)". Homo habilis were more capable of social organization, and perhaps speech.



8. How might Homo erectus, living about 1.9-1.6 MYA, have differed from Homo habilis? Homo erectus was the first hominid to use fire and they had advanced tools. They had an even larger brain than Homo erectus. They would have been able to kill animals and obtain food more easily than Homo habilis. They would have been able to travel more easily for this reason. They were "big game hunters."

9. What is the out-of-Africa hypothesis and what bearing does it have on the evolution of humans? The out-of-Africa hypothesis claims that Homo sapiens developed out of Africa and later traveled to other areas such as Asia and Europe. The out-of Africa hypothesis would mean that all humans ,and thus all ethnic groups, came out of a single ancestor relatively recently. This ancestor would have existed no more than a million years ago.

10. How do Cro-Magnons, the first of the modern humans differ from the other species in the genus Homo? The Cro-Magnons hunted cooperatively and probably had a language. The Cro-Magnons lived in small groups and while the men hunted during the day, the women stayed at home with the children. They also had a culture with art, and they sculpted figurines and painted drawings.