Download Biological Evolution

Biological Evolution
Four friends were discussing the meaning of the term biological evolution.
This is what they said.
Mario “I think it is another term for natural selection.”
Sally “I think it mainly explains how life started.”
Cameron “I think it mainly explains how life changed after it started.”
Paz “ I think it includes both how life started and how it changed after it
started.”
Who do you most agree with? Explain what you think biological evolution
is.
Biological Evolution
A group of friends were discussing biological evolution. This
is what they said. Who do you most agree with? Explain
Jenna “Evolution is about creating a perfect species like
going from something ugly to something beautiful.”
Steve “Evolution is mostly random which makes new
species randomaly.”
Becka “Evolution is mostly not random .”
Adaptation
A group of friends were arguing about what would happen if a population
of rabbits from Arizona, a warm climate were moved to Rosholt, a cold
climate. This is their responses. What person do you most agree with and
why? Explain your ideas about adaptation.
Bernie “I think all of the rabbits will try to adapt to the change”
Leo “I think most of the rabbits will try to adapt to the change”
Phoebe “I think none of the rabbits will try to adapt to the change”
Adaptation
Adaptation
Evolution and religion
A group of friends were discussing biological evolution. This is what they
said. Who do you most agree with? Explain
Jerry “I can’t believe in evolution because it is against my religion.”
Amber “Science is about observations and religion is about faith so they
cannot be compared.”
George “ I heard that all people that believe in evolution are atheist.”
Who do you most agree with? Explain
Evolution terms
• Species- a group of organisms that can have
fertile offspring.
• Population- a group of the same species
• Evolution-process of populations changing
over time.
Evolution terms
• Variation- a difference in
one organism to another
of the same species
• Adaptation- a trait that
helps an organism survive
or reproduce better.
Evolution terms
• Selective breeding- breeding an organism for a
specific trait/characteristic
• Natural selection- nature picking an organism
for a specific trait/characteristic
What is the
domesticated plant
from the original
wild plant?
Corn selection
Basics of Selective
Breeding
• There is variation in
the population
• There is a selection
• Reproduction
• Overall change in
population. (still
variation though)
What were those people thinking?
Compare the pictures of wild teosinte and
domesticated corn. What trait variants in
teosinte do you think would have been selected
by ancient people? List at least three traits that
you think might have been a target of selection.
The selective breeding of Corn
•
•
•
A gene on chromosome #1 causes the ears of corn to be big and to grow on a few
short branches. In contrast, the ears of teosinte are scattered over many small
branches.
A gene on the second chromosome causes more rows of kernels to grow, yielding
more food per corn plant.
A gene on the fourth chromosome causes corn kernels to have small, soft casings.
Teosinte kernels have much larger, harder kernel casings that make them hard to
eat.
• Look at the photo of the wild and domestic
tomatoes.In a series of steps, explain how
ancient people might have evolved a
population of domestic tomatoes from a
population of wild ones. Be sure that your
explanation includes the concepts of variation,
inheritance, and selection.
Natural selection
• There is variation in traits.
For example, some beetles are green and some are brown.
• There is differential reproduction.
The environment can't support unlimited population
growth, not all individuals get to reproduce. In this
example, green beetles tend to get eaten by birds and
survive to reproduce less often than brown beetles do.
• There is heredity.
The surviving brown beetles have brown baby beetles
because this trait has a genetic basis.
• End result:
The more advantageous trait, brown coloration, which
allows the beetle to have more offspring, becomes more
common in the population. If this process continues.
• If you have variation, differential reproduction, and
heredity, you will have evolution by natural selection as an
outcome. It is as simple as that.
Venn Diagram
• In you notebook compare the similarities and
differences of Natural Selection and Artificial
Selection using a Venn Diagram.
• If artificial selection is happening is there any
reason that natural selection cannot happen?