Topic: The era of aquatic animals, first terrestrial organisms…

Author: Leokadia Stalewicz

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 concept of organism evolution.

General aim of education

You will learn how the evolution of vertebrates has progressed

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to describe the conditions on Earth in chosen eras;;

• to present main phases of the evolution of plants and animals;

• to order chronologically the most important events in the history of life on Earth.

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 gives the topic, the goals of the lesson in a language understandable for the student, and the criteria of success.

• The teacher initiates a conversation introducing the topic.

  • What do you know about ...?

  • Have you ever met ...?

Realization

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

• The lecturer explains the concept of an explosion of life in the oceans and then appoints people who will discuss the following topics: The era of aquatic animals; The first terrestrial organisms; The era of reptiles; The era of mammals and birds.

• The indicated pupils discuss further topics. The other students after the end of each speech can ask the referring people questions and ask them for explanations. The teacher completes the students' statements, initiating after each of them a short discussion on the topic discussed.

• The lecturer presents and discusses the interactive illustration entitled „How were the organisms inhabiting Earth changing?.” Then he instructs the students to write on the board features common for at least two vertebrate clusters and features that distinguish individual clusters from each other. Students analyze these characteristics in terms of their significance for the evolution of life on Earth.

• 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 the students questions prompting them to assess their own work during the lesson. They can use the interactive board.

• At the end of the lesson the teacher asks: If there was going to be a test on the material we have covered today, what questions do you think would you have to answer? If the students do not manage to name all the most important questions, the teacher may complement their suggestions.

Homework

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

• Imagine that you have the opportunity to interview an academic - a specialist in the field of today's lesson. What questions would you like to ask him? Write them down.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

The era of aquatic animals, first terrestrial organisms…

Link to the lessonhttp://www.epodreczniki.pl/reader/c/140129/v/38/t/student‑canon/m/iZXIn74PMO#iZXIn74PMO_d5e334Link to the lesson

About 540 million years ago, the pace of the evolution of organisms was so fast that this period is sometimes called the explosion of life in oceans. Ocean waters filled with numerous and diverse species, among which there were cnidarians, annelids, crustaceans and molluscs, a bit later also placodermi appeared.

The bottom of the sea was inhabited by sponges and other marine animals living in sedentary environments such as corals and crinoids. Primitive cephalopods nautilida and ammonites were flitting in the midwater. The most characteristic animals of that period were the trilobites (belonging to arthropods), the ancestors of today’s crayfish.

The period between 416 and 359 million years ago is the time of the rise of groups of fish. Many evolutionary lines developed then, the first of which were the fish with cartilaginous skeletons, similar to the contemporary sharks and rays. Fish covered in scales with fossilized skeletons appeared later; many of these species survived until today.

Soon, among fish inhabiting shallow waters, species with strongly muscled paired fins developed, thanks to which they could crawl through the shallows. Single fins were no longer useful in this environment, and started to vanish gradually in subsequent generations. Moreover, the upper or the lower segments of digestive tract were gradually gaining the ability to extract oxygen from the atmosphere. Fish with similar characteristics to those described above, have given rise to the first terrestrial quadrupeds - amphibians.

For over 3 billion years, life had been developing almost exclusively in water. Forms such as fungi, plants and animals appeared on land just about 500 million years ago.

The first organisms that inhabited lands about 480 million years ago were plants similar to today’s mosses.

The rapid and abundant development of plants took place during the warm and humid climate of geological period called Carboniferous. Dense vegetation provided food and shelter to numerous invertebrates, which appeared on land already 440 million years ago and diversified greatly. They developed organs adapted to breathing oxygen from the atmosphere and chitin cuticle that protected them against drying. The lack of competition from vertebrates that were still absent on the land, resulted in countless species of insects, up to 1 meter long, flying around in the air.

When about 395 million years ago the first amphibians appeared, the abundance of arthropods and other invertebrates was an easily accessible source of food for them, while at the same time they were not threatened by the still absent mammals and birds. Amphibians quickly took over all terrestrial environments and evolved into diverse forms. Some of them, such as Acanthostega still lived in the aquatic environment; others, like Ichthyostega, crawled on land, using their widely spaced paws to push, while Seymouria were moving using their limbs located right under the torso, just like typical terrestrial quadrupeds.

After the many‑million‑years of their domination, most amphibians went extinct. The few remaining species gave rise to the amniotic animals - reptiles.

Reptiles were the first vertebrates to become independent from the aquatic environment. Their eggs, equipped with an embryo food supply and a strong, leathery or calcareous coating, could be laid anywhere on land. The animal leaving the egg was completely independent and protected from the loss of water by dry, thick skin.

The largest growth of reptiles took place between 250 and 66 million years ago. This period is called the Mesozoic Era, or the era of reptiles, because this is when these animals gained control over all available habitats at that time: the waters were dominated by Plesiosaurs and Ichthyosaurs, over the land and the water flew Pterosaurs, whose front limbs were transformed into wings, while the land was dominated by two‑legged predatory Tyrannosaurids and four‑legged herbivorous Sauropods, Stegosaurians, Triceratops. The age of reptiles ended 65 million years ago with their great and violent extinction, which killed not only reptiles, but also other animals (including aquatic) and most plants.

The extinction of most reptiles resulted in many free habitats and food sources that were exploited by rapidly diversifying mammals and birds. This was fostered by a world dominated by flowering plants with lush leaves, nutritious flowers and fruit.

First mammals, like their ancestors – the reptiles, laid eggs. In many mammalian development lines, however, a new way of reproduction has emerged - viviparity . Their teeth were also diversified, which enabled them to make better use of their food.

23 million years ago, more and more species of mammals lived on the continents, including hoofed mammals, predatory mammals, and the first primates - ancestors of modern monkeys and prosimians, from which lines leading to the hominids soon emerged. Some mammals started to repopulate the waters of the seas and oceans.

Birds have developed from reptiles belonging to one of the groups of dinosaurs. Important stages in the evolution of birds were the improvement of gas exchange, the transformation of the front limbs into wings and the covering of the body with light and flexible feathers. Soon after the major disaster 65 million years ago, new species of birds occurred, resembling those that live today.

• Life was created in the seas.

• In the history of life on Earth, you can find many examples of massive species extinctions.