Evolution

Evolution
Ecology I
Mr. Nettles

Class Motto

 Discipline fuels character!

 Character builds hope!

 Hope assures your future!

Agenda- Wed., February 29, 2012

b Warm-Up
b Presentations
b Lecture: Evolution
o A-Plus

Today’s Objectives

 Define natural selection, evolution, adaptation,
artificial selection, and resistance.
 Explain the process of evolution by natural
selection.
 Articulate the concept of adaptation.
 Explain the steps by which a population of insects
becomes resistant to pesticide.

Warm Up (Feb. 29)

) List the four major levels of ecological
organization in the correct order.

t What is a population?

t Why are habitats important?

“The Main Man”
• Charles Darwin observed
that organisms in a
population differ slightly
from each other in form,
function, and behavior.
• Darwin proposed that some
individuals, because of
certain traits, are more likely
to survive and reproduce
than other individuals.

Evolution by Natural Selection

• Natural selection is the
process by which individuals
who are better adapted to
their environment, survive
and reproduce more
successfully than less well
adapted individuals do.

• Evolution is a change in the
characteristics of a population
from one generation to the
next.

“Survival of the Fittest”
(nature selects)
• Darwin thought that nature selects for certain
traits, such as sharper claws, because
organisms with these traits are more likely to
survive.
• Over time, the population includes a greater and
greater proportion of organisms with the
beneficial trait.
• As the populations of a given species change, so
does the species.

Agenda- Thurs., March 1, 2012

M Warm-Up (Standardized Test Ques.)
d Lecture: Evolution
o Wrap-Up
o Extra Credit Assignment
• earn up to 35 points towards quiz grades

Warm Up (Mar. 1) Standardized Test Prep

Multiple Choice
1. What is the term for the area where organisms live
together with their physical environment?

A. biome
B. biosphere
C. ecosystem
D. population

Chapter menu Resources

Copyright © by Holt, Rinehart and Winston. All rights reserved.


Multiple Choice, continued
2. Which of the following describes the theory of natural
selection?

F. Organisms with desired traits are selected for
reproduction.
G. Heredity determines which organisms will survive
in their environment.
H. Traits are developed in organisms in response to
interaction with other organisms.
I. Organisms with strong survival traits are more
likely to pass the traits on in reproduction.




Multiple Choice, continued
3. What inherited trait increases an organism’s chance
of survival and reproduction in a certain
environment?

A. adaptation
B. characteristic
C. evolution
D. resistance



(nature selects)
• An example of evolution is a population of deer
that became isolated in a cold area.
• Some of the deer had genes for thicker, warmer
fur. These deer were more likely to survive, and
their young with thick fur were more likely to
survive to reproduce.
• Adaptation is the process of becoming adapted
to an environment. It is an anatomical (body
parts), physiological (functions), or behavioral
change that improves a population’s ability to
survive.

(nature selects)

Evolution by Artificial Selection

• Artificial selection is the selective breeding of
organisms, by humans, for specific desirable
characteristics.
• Dogs have been bred for certain characteristics.

• Fruits, grains, and vegetables are also produced
by artificial selection. Humans save seeds from
the largest, and sweetest fruits. By selecting for
these traits, farmers direct the evolution of crop
plants to produce larger, sweeter crops.

Evolution by Resistance

• Resistance is the ability of an organism to
tolerate a chemical or disease-causing agent.
• An organism may be resistant to a chemical when
it contains a gene that allows it to break down a
chemical into harmless substances.
• Humans promote the evolution of resistant
populations by trying to control pests and bacteria
with chemicals.

Pesticide Resistance

• A pesticide sprayed on corn to kill
grasshoppers, for example, may kill most of
the grasshoppers, but those that survive
happen to have a gene that protects them
from the pesticide. These surviving insects
pass on this resistant gene to their offspring.
• Each time the corn is sprayed, more resistant
grasshoppers enter the population. Eventually
the entire population will be resistant, making
the pesticide useless.

Wrap Up (Mar. 1)

Œ What is one fact that you learned today?

What is the most interesting thing that
you took away from the lesson?

o How will you apply what you’ve learned
to your life?

Evolution

Recomendados

Recomendados

Mais conteúdo relacionado

Mais procurados

Mais procurados (20)

Semelhante a Evolution

Semelhante a Evolution (20)

Mais de Transition Academy

Mais de Transition Academy (20)

Último

Último (20)

Evolution