Week 10/Intro. to Life Science

Earth and Life Science

Introduction to Life Science

MS. PATRIQUE ERIKA CANCEL

10

Introduction to Life Science

Earth and Life Science
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●Explain the evolving concept of life based on emerging pieces of

evidence

●Describe classic experiments that model conditions which may

have enabled the first form to evolve

●Describe how unifying themes in the study of life show

connection among living things.

Earth and Life Science
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Life Sciences

Life Sciences is the scientific study of living things. It involves many levels
of investigation: from the study of the interactions of organic molecules to the
interactions of animals and plants with their environment.

Earth and Life Science
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https://www.youtube.com/watch?v=9gBH5xAk3G4

Earth and Life Science
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Branches of Life Science
● Anatomy (plant and animal)
● Biochemistry
● Biotechnology
● Botany
● Ecology
● Entomology
● Environmental Studies
● Genetics
● Medicine
● Microbiology
● Morphology
● Physiology (plant and animal)
● Sociobiology (animal behaviour)
● Taxonomy
● Zoology

Multiple Choice

Which one the a branch of Life Science?

• Biology
• Geology
• Physics
• Chemistry

Why study Life Sciences

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● To increase knowledge of key biological concepts, processes, systems and theories.
● To develop the ability to critically evaluate and debate scientific issues and processes.
● To develop scientific skills and ways of thinking scientifically that enables you to see the

flaws in pseudo-science in popular media.

● To provide useful knowledge and skills that are needed in everyday living.
● To create a greater awareness of the ways in which biotechnology and knowledge of Life

Sciences has benefited humankind.

Why study Life Sciences

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● To show the ways in which humans have impacted negatively on the environment and

organisms living in the environment.

● To develop a deep appreciation of the unique diversity of biomes In Southern Africa, both

past and present, and the importance of conservation.

● To create an awareness of what it means to be a responsible citizen in terms of the

environment and life-style choices that they make.

● To create an awareness of the contributions of South African scientists.
● To expose you to the range and scope of biological studies to stimulate interest in and

create awareness of possible specialities and fields of study.

● To provide sufficient background for further studies and careers in one or more of the

biological sub-disciplines.

Multiple Choice

Why we should study Life Science?

• We should study Life Science to understand living organisms and improve health and environmental sustainability.
• To focus solely on physical sciences without considering life forms.
• To learn about historical events in biology.
• To memorize scientific names of plants only.

Evolution of Life

Earth and Life Science
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The diversity of life on Earth today is
the result of evolution. Life began on
Earth at least 3.5 to 4 billion years ago,
and it has been evolving ever since. At
first, all living things on Earth were
simple, single-celled organisms. Much
later, the first multicellular organisms
evolved, and

after

that,

Earth’s

biodiversity greatly increased.

Evolution of Life

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https://youtu.be/de1hiS_XjWg

Darwin and the Theory of Evolution

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The idea of evolution has been around for centuries. In fact, it goes all the way back to the
ancient Greek philosopher Aristotle. However, evolution is most often associated with
Charles Darwin. Darwin published a book on evolution in 1859 titled On the Origin of
Species. In the book, Darwin stated the theory of evolution by natural selection. He also
presented a great deal of evidence that evolution occurs.

Evolution is a change in the characteristics of living things over time. As described by Darwin,
evolution occurs by a process called natural selection. In natural selection, some members of
a species, being better adapted or suited to their environment, produce more offspring than
others, so they pass "advantageous traits" to their offspring.

Over many generations, this can lead to major changes in the characteristics of the species.
Evolution explains how living things are changing today and how modern living things have
descended from ancient life forms that no longer exist on Earth. As living things evolve, they
generally become better suited for their environment. This is because they evolve
adaptations. An adaptation is a trait that helps an organism survive and reproduce in a given
environment.

Multiple Choice

What is Theory of Evolution all about?

• The Theory of Evolution states that all species were created simultaneously.
• The Theory of Evolution is about the fixed nature of species over time.
• The Theory of Evolution explains the origin of the universe and celestial bodies.
• The Theory of Evolution is about the process by which species change and adapt over time through natural selection and other mechanisms.

Fill in the Blank

Who is the father of evolution?

Darwin and the Theory of Evolution

Earth and Life Science
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Darwin and the Theory of Evolution

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https://www.youtube.com/watch?v=JOk_0mUT_JU

Evolutionary Theory After Darwin

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Since Darwin’s time, scientists have gathered even more evidence to support the theory of
evolution. Some of the evidence comes from fossils, and some comes from studies that show
how similar living things are to one another. By the 1930s, scientists had also learned about
genes. As a result, they could finally explain how characteristics of organisms could pass from
one generation to the next and change over time.

Using modern technology, scientists can now directly compare the genes of living species.
The more genes different species share in common, the more closely related the species are
presumed to be. Consider humans and chimpanzees. They share about 98% of their genes.
This means that they shared a common ancestor in the not-too-distant past. This is just one
of many pieces of evidence that show we are part of the evolution of life on Earth.

Evolutionary Theory After Darwin

Earth and Life Science
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https://www.youtube.com/watch?v=x73bsC7WIsE

Misconceptions About Evolution

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Today, evolution is still questioned by some people. Often, people who disagree with the
theory of evolution do not really understand it. For example, some people think that the
theory of evolution explains how life on Earth first began. In fact, the theory explains only
how life changed after it first appeared. Some people think the theory of evolution means
that humans evolved from modern apes. In fact, the theory suggests humans and modern
apes have a common ancestor that lived several million years ago. These and other
misconceptions about evolution contribute to the controversy that still surrounds this
fundamental principle of biology.

Multiple Choice

What is the misconception about the Theory of Evolution?

• Humans did not evolve from monkeys; they share a common ancestor.
• Natural selection means only the strongest survive without any adaptation.
• The Theory of Evolution states that all species are static and unchanging.
• Evolution suggests humans are directly descended from apes.

Misconceptions About Evolution

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https://www.youtube.com/watch?v=mZt1Gn0R22Q

Origin of Life

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https://www.youtube.com/watch?v=Kc_O_Qtd8YM

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