Transcript Lizard Tortoise Pig Human

Introduction to Evolution
Ms. Sing
Do Now

In your notebook, answer the following
questions


What is evolution?
What evidence has been collected to support
evolution?
What is evolution?

Change over time
More specifically, change in gene
frequencies of populations over time

Which is an example of evolution?

Situation 1:
Imagine a year or two of drought in which there are
few plants that these beetles can eat .
All the beetles have the same chances of survival
and reproduction, but because of food restrictions,
the beetles in the population are a little smaller than
the preceding generation of beetles
Which is an example of evolution?

Situation 2:
Most of the beetles in the population (say 90%)
have the genes for bright green coloration and a few
of them (10%) have a gene that makes them more
brown.
Some number of generations later, things have
changed: brown beetles are more common than
they used to be and make up 70% of the
population.
Which is an example of evolution?
Situation 1
Situation 2
Situation 2
because it
demonstrates a
change in gene
frequency
Evidence of Evolution
Evidence of Evolution

1. Geological Records
 Scientists study records found in
fossils
 Fossils are remnants or traces of
an organism
Fossils are often found in
sedimentary rock

Scientists assume that each
layer is older than the layer above it

Evidence of Evolution

2. Comparative Anatomy


Based on observations of basic structural
similarities between organisms
Homologous structures: are anatomical parts found
in different organisms
that are similar in
structure and origin

They may have
different functions
Evidence of Evolution

3. Comparative Embryology

Study of early embryonic development of
various organisms suggests a common
ancestor
Lizard
Tortoise
Pig
Human
Evidence of Evolution

The early embryos of fish, reptiles, birds, and
humans closely resemble each other
Evidence of Evolution

4. Comparative Cytology


All living things are made up of cells
Cell organelles (nucleus, mitochondria, etc.) are
structurally and functionally similar in most
organisms
Evidence of Evolution

5. Comparative Biochemistry


All living things contain DNA and RNA as well as
proteins and enzymes
The greater the biochemical similarity, the closer
the relationship
Who am I?
HMS Beagle
Charles Darwin (1809- 1882)

Natural Selection is the result of


The overproduction of offspring
Variations among offspring




How?
The struggle for survival (competition)
Adaptive value of certain variations
Survival and increased reproduction of those
best adapted to a particular environment
moth animation
Peppered Moth Game
Reflection

On a piece of paper write

2 things you learned during the lesson

1 thing you did not understand during the lesson