Evolution and Genetics
Unit 2
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Evolution: Theory and Fact
Genetics

Biochemical or Molecular Genetics

Population Genetics and Mechanism of Genetic Evolution

The Modern Synthesis
◦ Mendel’s Experiments
◦ Independent Assortment and Recombination
◦ Cell division
◦ Crossing over
◦ Mutation
◦ Natural selection
◦ Random Genetic Drift
◦ Gene flow
◦ Punctuated Equilibrium
Outline

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What are some
ways we adapt to
our environment?
What ways are
cultural and what
ways are biological?
Evolution

Originally, believed
humans came from
the story of Genesis
from the Bible
◦ Creationism
◦ Characteristics of life
forms could not change
◦ Biblical scholars James
Usher and John
Lightfoot traced
creation to October, 23,
4004 B.C. at 9AM
Evolution
In your table groups, read through the
Biblical account of creation
 Is this a scientific theory? Why or why
not?

Activity Time

Carolus Linnaeus
developed the first
comprehensive
taxonomy
(classification)
◦ Grouped life forms on
basis of similarities
and differences in
their physical
characteristics
Evolution
Fossil discoveries in
18th and 19th centuries
started to raise doubts
about creationism
 Modified explanation
combining creationism
and catastrophism
arose

◦ Fires, floods, and other
catastrophes had
destroyed ancient
species
◦ After each destructive
event, God created again
Evolution

Alternative to
creationism and
catastrophism was
transformism or
evolution
◦ Species arise through a
long and gradual
process of
transformation or
descent with
modification
◦ Charles Darwin best
known
Theory and Fact

Charles Darwin
influenced by Sir
Charles Lyell, father
of geology
◦ Introduced idea of
uniformitarianism
 Natural forces at work
today also explain past
events
 Cast doubt on theory
that Earth was only
6,000 years old
 Darwin applied to living
things
Theory and Fact


Darwin offered theoretical
framework for
understanding evolution
Proposed the theory of
evolution with natural
selection as the
mechanism to explain
diversity, origin, and
similarities
◦ Theory is a set of ideas
formulated by reasoning
from a known factor to
explain sometimes.

Natural selection is the
selection of favored forms
through differential
reproduction
Theory and Fact

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
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Genetics
Genetics: science that emerged after
Darwin that helps us understand the
causes of biological variation
DNA molecules make up genes and
chromosomes which are basic
hereditary units
Mutations in DNA provide much of
the variety on which natural selection
operates
Mendelian genetics studies ways
chromosomes transit genetic material
through generations
Biochemical genetics examines
structure, function, and changes in
DNA
Population genetics investigates
natural selection and other causes of
genetic variation, stability, and
change in breeding population

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
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You will be put into 3 groups
Each group will be given a different topic –
Mendelian genetics, biochemical genetics,
and population genetics
You will look over the information and create
a summary of the important points
You will then teach those points to the rest of
the class
Everyone will record their notes on the
provided graphic organizer
You will only be given today and some time
tomorrow to do this
STOP – Activity Time

Today’s view on evolution is
known as the “modern
synthesis”
◦ Combination of Darwin’s theory
of evolution and Mendel’s
genetic discoveries
◦ Microevolution – genetic
changes over few, several, or
many generations but without
speciation
◦ Macroevolution – refers to
larger-scale or more significant
changes in a population or
species, usually over a long
time period which results in
speciation
 Speciation – the divergence of
one ancestral species into two
or more descendent species
Modern Synthesis

Model of evolution that
points to the fact that
long periods of stability
may be interrupted by
evolutionary leaps
◦ Could be caused by
extinction of another
species followed by
invasion by another
 Example: Sea species
dies out because water
dries up, while a closely
related species survives in
deeper waters. Later,
when water levels rise
again, protected species
goes to first area
Punctuated Equilibrium