Topic: The similarity between humans and apes

Target group

8th‑grade students of elementary school

Core curriculum

General requirements

I. Knowledge of biological diversity and basic biological phenomena and processes. Student:

2. explains biological phenomena and processes occurring in selected organisms and in the environment.

Specific requirements

VI. The evolution of life. Student:

3. it presents similarities and differences between human and apes as a result of evolutionary processes.

General aim of education

You will learn what features distinguish a human from among the other primates

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• indicate similarities and differences in the construction and behavior of man and chimpanzee;

• exchange traits that only occur in humans;

• justify human belonging to the animal world;

• describe Australopithecus, an agile, upright, Neanderthal man and their achievement;

• point out examples of factors that influenced the emergence of bipedalism and strong brain development in human ancestors.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• exposing

  • exposition.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Before classes

• Students get acquainted with the content of the abstract. They prepare to work on the lesson in such a way to be able to summarize the material read in their own words and solve the tasks themselves.

Introduction

• The teacher explains the aim of the lesson and together with students determines the success criteria to be achieved.

• Then he writes the subject of the lesson on the blackboard or interactive whiteboard. Students write it in notebooks.

Realization

• The teacher asks students to read the abstract themselves, paying particular attention to the illustrations.

• The instructor recommends students to indicate these features on the basis of which the human being can be classified as the primate. Next, the students indicate the traits on the basis of which a man can be classified as vertebrates and features on the basis of which a man can be counted among animals..

• The teacher asks volunteers, on their own example, to indicate traits that differ from other animals, in particular from other primates. The teacher completes the student's statements as needed. Presenting the illustration titled „Comparison of human and chimpanzee skull structure” in detail discusses the difference between the construction of a chimpanzee skull and the construction of a human skull.

• Participants familiarize themselves with the content presented in the interactive illustration. Then the teacher discusses the issues with the students.

• The teacher explains the origin of man and the genesis of bipedalism and upright posture.

• The teacher initiates a discussion on the class forum about the relationship between man's bipedal posture and the development of material and non‑material culture.

Summary

• The teacher asks students to carry out the recommended interactive exercise themselves.

• The teacher briefly presents the most important issues discussed in class. He answers the additional questions of the proteges and explains all their doubts. Students complete notes.

Homework

• Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

• Develop a lap book containing issues learned during the lesson and bring your work to the next class.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

The similarity between humans and apes

The species Homo sapiens is, together with apes and prosimians, classified as belonging to the order (taxonomic rank) of primates. Humans are most closely related to apes, such as gorillas, chimpanzees, orangutans and gibbons. The degree of relationship is measured by the number of common genes. In the case of Homo sapiens and chimpanzee the degree of relationship is the highest: our DNA and the DNA of chimpanzees are 98% identical. This means that relatively recently (as compared to the age of the Earth), we and chimpanzees shared a common ancestor. Similarities between two species prove close relationship to each other. These similarities can be observed in:

• physique – for instance, our eyes are pointed forwards, we have prehensile hands in which thumb can touch the pads of all other fingers, enabling us to make complex and precise movements and manipulate objects; like apes, we don't have an external tail;

• protein structure – plasma proteins of humans and chimpanzees are nearly identical, and the hemoglobin in both species has the same sequence of amino acids;

• social behaviour – we live in family groups, take care of our offspring for a long time, have many ways of expressing emotion and create strong bonds with the other members of our community.

Humans are characterised by their erect, bipedal posture. Their prehensile hands are extraordinarily agile, making using tools possible and allowing for very precise movements. Human body hair is defined as vestigial. It remains only in some places, and the rest of our skin surface is bare and has many sweat glands, which prevent overheating.

Human teeth are small, the fang doesn't protrude beyond other teeth. The last of molars often errupt late in a human's life and sometimes doesn't grow in at all. Such dentition allows for the intake of soft, pre‑processed (cooked) foods, it isn't, however, fit for feeding on raw meat and hard plant parts. Because of this, the facial part of human skull is, unlike ape skulls, flat. As human skull leans on the spine instead of hanging in front like in the case of present‑day quadruped apes, it doesn't require bone keels or visibly uneven parts, to which the powerful muscles necessary for raising and moving the skull would be attached.

Another essential feature of the human skull is its high forehead and large neurocranium volume. In humans, its volume is about 1350 cmIndeks górny 3³ (1/40 of body mass) and in chimpanzees - 400 cmIndeks górny 3³ (1/120).

Equally extraordinary is the human brain: large in comparison to the rest of the body, with a heavily folded cerebral cortex. Human brains contain a speech centre. A well‑developed brain allows us to gain self‑awareness (I am me, now I'm thinking about... I feel..., I can...). A large brain, self‑awareness and the growing‑up period lasting more than ten years, during which young humans require being taken care of by adults, all have allowed for the development of many forms of social life as well as the creation of tradition, science, culture, technology and led to us becoming independent from environmental factors.

The history of our genus began in Africa. About 10 million years ago in the East side of the continent a gradual climate change occurred, leading to the disappearance of forests and the appearance of savannas. Our quadruped ancestors were gradually losing their tree‑dependent environment as well as the food sources, which best suited their needs.

Apart from seeds, grasses and insects, which were all difficult to digest, savannas also offered nutritious meat‑based food – small mammals and carrion. Observing the surroundings, which was necessary for spotting food sources, frequently required standing on two legs and raising the animal's head above the high grass. Bipedalism was advantageous in one more way: upright posture was better than quadruped posture at preventing overheating. When it comes to bipedal animals, sunlight directly heats a smaller body surface – only the head. To protect the brain against overheating, the skin of our heads is covered with hair to this very day. This hair layer (especially if the hair is very curly, woolly) serves as thermal insulation.

Two‑legged movement meant that arms no longer needed to support the body. From that point on, hands could be used for shelling seeds, carrying food, making tools as well as carrying newborns, which could no longer hold onto fur, as our ancestors no longer had it.

4 million years ago, natural selection led to the appearance of the bipedal Australopithecus, which was probably the ancestor of humans. Austrolopithecus' brain was approximately 20% larger than that of his ape ancestor. This meant longer pregnancy, more difficult birth and longer childhood, during which the offspring was helpless and the mother required assistance, e.g. being supplied with food. It is likely that the division of responsibilities that existed in later human forms was already present in Australopithecus communities: males acquired meat, while females were gatherers, toolmakers, and took care of the offspring.

• Homo sapiens, like apes and prosimians, is a primate.

• The first species in the Homo genus first appeared about 3 million years ago.

• In the past there were several species of the Homo genus on the Earth e.g. Homo habilis, Homo erectus and at least two subspecies of Homo sapiens: Homo sapiens neanderthalensis and Homo sapiens sapiens.

• Many factors contributed to the appearance of bipedalism and the increase in brain volume:

  • climate change led to the adaptation to life on a steppe, such as adopting upright posture;

  • because arms no longer had to support the body, they became better at making precise movements, for example useful when making tools;

  • carnivority, including scavenging, allowed for an increase in the body mass and brain volume; the loss of body hair helped in long hunts for hairy prey;

• A well‑developed brain allowed for the creation of culture, art, science and technology and made it possible for our species to become largely independent from environmental factors.