Transcript Species Variation

SPECIES VARIATION
Obj.6 Describe
evidence of species
variation due to
climate, changing
landforms, interspecies
interaction, and
genetic mutation.
Adaptation- a characteristic that
improves an individual’s ability to
survive and reproduce in a particular
environment.
Adaptations may be physical
(change in appearance), such as a
long neck or striped fur. Adaptations
may be behaviors that help an
organism find food, protect itself, or
reproduce.
Scientists think that Earth has changed
over time. Scientists estimate that Earth
is 4.6 billion years old.
Scientists think that as populations have
changed over time(adaptations), new
species form other species die out (go
extinct).
Newer species descend from older
species.
Evolution- process in which populations
gradually change over time.
Evidence that organisms evolve can be
found by comparing living organisms to
each other and to the fossil record.
The process of evolution is indicated by
fossil records and common ancestry.
It was proposed that evolution happens
through a process called natural selection.
Natural Selection
- the process by which
individuals that are better
adapted to their environment
survive and reproduce more
successfully than less well
adapted individuals do.
THE FOUR PARTS OF NATURAL SELECTION ARE:
1. Overpopulation ( some eggs survival –other
do not)
2. Inherited Variation (Every individual has its
own combination of traits)
3. Struggle to Survive (some die because of
predators, starvation, and disease)
4. Successful Reproduction (those best adapted
to the environment have many offspring that
survive)
Speciation
- formation of new species as a result of
evolution
The three steps of speciation are:
1. Isolation (division) (part of a population
becomes separated from the rest)
2. Adaptation (the separated group may
evolve different sets of traits )
3. Division (two separated groups may
become very different; groups may not be
able to interbreed anymore)
EXTINCT
-DESCRIBES A SPECIES THAT HAS DIED OUT
COMPLETELY.
Most scientists think that the extinction of
dinosaurs happened because of extreme
changes in the climate of the Earth. These
changes could have resulted from a giant
meteorite hitting the Earth or forces within
the Earth could have caused many
volcanoes and earthquakes.
GENETIC RESISTANCE
-When an organism changes or
adapts to factors such as the
environment, antibiotics,
insecticides, and pollution to
survive.
Isolation
- refers to species being
separated.
Isolated populations can be unable to
interact with each other because of
geographic boundaries like an ocean or
mountain. They can develop unique
characteristics and cannot breed.
Two populations can be isolated if they feed at
different times or reproduce at different times of
the year.
Two or more populations may evolve differently
from each other.
ISOLATION (CONT.)
Isolation stops populations from
interbreeding so new species evolve.
SURVIVAL OF THE FITTEST
-When an organisms survives through
adaptations such as biologically, physically,
philologically, to enhance survival and
reproduction rates.
CAMOUFLAGE
Camouflage is the use of any combination of
materials, coloration, or illumination for disguise,
making animals hard to see by blending in with
their environment.
MIMICRY
The action or art of
imitating someone or
something, for
protection.
CHEMICAL DEFENSE
Chemical defense is
the use of chemical
compounds by plants
and animals to deter
herbivory and
predation
SYMBIOTIC RELATIONSHIPS WITH OTHER
ORGANISMS
Mutualism: both
organisms
benefit
Ex: Nemo and
the anemone
2. Parasitism: one
is helped (the
parasite) and the
other is harmed
(the host).
Ex: Tick on a dog
Or mosquito on a
human
SYMBIOTIC
RELATIONSHIPS:
3. Commensalism:
one benefits and
the other is not
helped nor
harmed.
Ex: Remora on
shark
HOW DO ORGANISMS IMPACT OUR
ENVIRONMENT?
By studying an organisms behaviors and
impacts in their environment, we can better
manage our planet.
If organisms prey on each other, the prey
population has to outnumber the predator
population in order for them to survive.
Organisms can modify the environment
positively and negatively.
Bacteria and fungi can positively modify
the environment by breaking down dead
and decaying materials, but they can
negatively affect organisms by causing
infections and sickness.
Plants give us food and oxygen but they
can overtake certain areas and become
invasive species.
An invasive species is a non-native plant
that invade and outgrow the local plants.
Some Invasive species of Alabama:
Popcorn tree
Cogon grass
Apple snail
Lion fish
WHAT ABOUT US?
Humans can negatively modify the
environment by building new roads,
buildings, cutting off rivers, polluting the
environment.
These things can change wildlife’s way of
living and can often lead to extinction.