Transcript Natural Selection

Natural Selection
Mutation can occur that may result in an
advantage or disadvantage. In a given
environment, those individuals with an
advantage tend to “survive” and reproduce
(pass on genes to the next generation).
Examples
Ex. 1 Peppered Moth in England
Mutation has lead to 2 color phases, black and
white. The white phase was much more
common, causing the moth to blend with the
light colored tree bark.
Factories burning coal caused the tree to
darken with soot.
The white population dropped and the dark
population rose in numbers.
Caused by better camouflage.
Ex. 2 Drug Resistant Bacteria
What do you know??
Ex. 3 Artificial Selection: a.k.a. Selective
Breeding
Human control of breeding that control
specific traits.
Breeding for appearance and/or functions.
Dogs are selectively breed to obtain desired
traits.
Natural selection: slow process
Artificial selection: much quicker, controlled
Black Footed Ferret: Is endangered, not yet
extinct.
Food: Prairie Dog
Habitat: prairie to farmland
Outcome: less food for the ferret
Preventing Extinction
Study the organism
habitat and the behavior and role within the
environment.
What does the species need to survive?
What can be done?
1. protect habitat
2. protect organism
3. captive breeding
4. zoological parks
Evolution
Theory that states changes the genes (traits)
in a specific organism, occurs over time.
Charles Darwin develop the original theory.
Has nothing to do with religion.
Extinction: Happens when NONE of the
species remains alive.
A natural process
Changing environmental conditions
Some species cannot adapt and will not
survive.
Natural causes of Extinction
1. climate changes
2. competition for food/territory
3. diseases
4. predators (rare)
How man causes extinction
Man is capable of causing rapid
changes to the environment. This practice
has caused the extinction of many species.
1. loss of habitat
2. pollution
3. uncontrolled hunting
4. introduction of an invasive species.
Dodo Bird WAS a large, flightless bird that
lived on a small island in the Indian Ocean.
Had no natural predators.
Humans colonized these islands with their
dogs and cats.
Hunting = Wiped out!!
Attack of the Clones!
• What is cloning?
• One of the main problems with understanding
cloning, is that there are many ways to define
cloning.
• Cloning: is creating an offspring that is
genetically identical to another individual.
In Biology, NUCLEAR TRANSFER is the type of
cloning.
Taking the nucleus from an adult cell and
transferring it to an egg cell that has had its
nucleus removed. This “egg” is then implanted
into a surrogate female.
One of the myths about cloning is that cloning
makes an exact copy of someone or something
 Remember that clones will only have the
same genetic material.
The nutritional, environmental and life
experiences are also large factors in the
development of an individual organism.
Arguments against
Cloning
1. Controversial subject; religiously, morally and
ethically.
2. Creating human life, a means to an end?
Reproducing vs Transplanting children?
3. Medical treatments – medications, transplant
organs, models for research?
4. Nutritional – GMO?!?! NOOOOOOOO!
Clone cows for more milk – would you let your
child drink that?
5. Growing old gracefully – how long do you want
to live??
FYI: Scientists are a long way from being able to
clone higher order animals at an acceptable rate.
Dolly, the sheep, (has died) – was the only
successful pregnancy out 277 implanted embryos.
What are your thoughts about cloning?