Topic: Evidence of evolution

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:

1. explains the essence of the process of evolution of organisms and presents sources of knowledge about its course.

General aim of education

You will learn direct and indirect proofs of biological evolution.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to explain that living organisms are evolving;

• to provide pieces of direct and indirect evidence of evolution.

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 divides the class into groups and each of them recommends preparing a short presentation about one of the following parts of the lesson: Fossils and transitional forms; Indirect proofs of evolution.

• Students present the results of work in groups. After completing the student's presentation, students from another group can ask questions and discuss with them on the topic discussed. The teacher acts as a moderator, making sure that the discussions are not unnecessarily prolonged and that the student's statements are supplemented as necessary.

• The teacher presents an interactive illustration „Comparison of different vertebrate embryos at the same stage of development”. He explains that in the course of embryonic development, the human body undergoes numerous changes, during which, among others, the external tail disappears and the skull elements (eg mandible, ear bones of the middle ear) form from gill archs. The analysis of these changes allows us to determine with great approximation how the evolution of vertebrates has progressed..

• Students, working individually or in pairs, carry out interactive exercises to check and consolidate knowledge learned during the lesson. Selected people discuss the correct solutions for interactive exercises. The teacher completes or corrects the statements of the proteges.

Summary

• The teacher asks a willing student to summarize the lesson from his point of view. He asks other students if they would like to add anything to their colleague's statements.

• At the end of the class, the teacher asks the students questions:

  • What did you find important and interesting in class?

  • What was easy and what was difficult?

  • How can you use the knowledge and skills you have gained today?

  Willing/selected students summarize the lesson.

Homework

• Using a Polish language dictionary, define the meaning of evolution and explain what biological evolution is..

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

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Evidence of evolution

Evolution is the process by which organisms gradually change their body structure and behaviour, which results in creating new species.

Evidence is provided directly by fossils and transitional forms.

Fossils are created when deceased organisms are not eaten by scavengers or decomposed, but end up in oxygen‑deprived conditions, covered up by a layer of sand or clay. Such conditions enable organic tissue, both soft and hard, to absorb mineral salts over time, such as calcium carbonate. Usually, only the hardest parts of organisms are fossilised—bones, teeth, horns, shells, carapace, eggshells and tree trunks. It is a much less common occurrence with soft tissue.

Another type of fossil are imprints of leaves, tree bark, feathers and animal tracks, which were pressed against a soft surface first, and then filled with rock that fast solidified. Based on animal track imprints, we can learn what size were the specimens of various species and how they moved.

Transitional forms are fossils of species that combine traits of old and new forms. One of such fossils, which prove that reptiles were the ancestors of birds, is the Archaeopteryx. It combines reptile and bird traits.

An animal that combines traits of reptiles and mammals is the currently existing platypus, which is considered a living fossil: a contemporary organism that whose body structure is very similar to that of its long‑extinct ancestors.

The evolution of living fossils has been a very slow process, which is why they have remained almost unchanged. Their appearance and behaviour is a great source of knowledge about similar organisms that lived in the past. Other living fossils include horsetail, scorpions, and horseshoe crabs.

The most convincing proof for a relationship and between organisms and a common ancestor is the cell structure, a similar chemical composition, and similar basic cellular processes. The building blocks of all living organisms include proteins, fats, carbohydrates, and nucleic acids. The genetic code is universal, which allows for the assumption that all species originate from common ancestors that used this code. By comparing nucleotide sequences in DNA of various species, it is highly possible to determine their relationship; the fewer differences, the closer the organisms are related.

Based on Comparing of anatomical structure traits of currently living organisms, conclusions can be drawn that indirectly confirm the common descent of analysed species.

Another piece of proof for interspecies relationship are vestigial organs, remnants of organs that used to be perform important bodily functions in ancestors, but are now nigh or entirely useless. Human vestigial organs include the appendix, coccyx, and muscles for ear wiggling.

• Direct evidence of evolution include fossils and transitional forms.

• Comparative anatomical studies of currently living organisms provide indirect evidence of evolution.