Transcript The Fossil Record - Fulton County Schools

The Fossil Record
The evolution of a structure, behavior, or
internal process that enables an organism to
respond to stimuli and better survive in an
environment. A trait that gives an organism an
advantage in the struggle for survival.
Adaptation in species develop over many
generations and can be physiological or
structural.
Mimicry Lab
Can a human tell the difference
between three types of
candies?
Milk chocolate M&M – mmmmmmmm yummy good!
Skittles – tasty but will make you sick every time
Dark chocolate M&M – you DIE!!
Organisms have ___2___ of many traits and sometimes the
environment can ___1___one ___2___over another. Other times a
__1__can occur and a ___2___will appear that gives an organism
___3___in the environment. Those with the ___1__have a
__1___and often live long and___2___. These organisms have a
high level of ___2___ in the environment in which they live. As these
organisms continue to______1____, passing on the __1___for
the__2___, the frequency of those___3___ increases so that over
time the species will__2___. This process is known as_____3____.
A species ___3__ to its environment can take___1___. This is known
as___1___. __3___evolve___2___ adapt.
1
2
•Evolution
•natural variations
•favored trait
•change
•genetic mutation
•variation
•alleles
•favored trait
•favor
•produce more offspring
•reproduce
•new trait
•survival advantage
•organisms
•thousands or millions of years
3
•Species
• an advantage
•natural selection
•fitness
•alleles
•adapting
Punctuated Equilibrium
Gradualism
Can
They
Reproduce?
Western Meadowlark
Eastern Meadowlark
The biological
species concept is
based on interfertility, rather than
physical similarity.
SPECIATION
A species is defined as being reproductively
isolated from other species.
TEMPORAL ISOLATION
BEHAVIORAL ISOLATION
HABITAT ISOLATION
MECHANICAL ISOLATION
GAMETIC ISOLATION
The Mechanics –
attempts to reproduce may be
made but because anatomy is
incompatible reproduction can’t
occur
SPECIATION
Allopatric speciation, a species
emerges due to geographic isolation
Parapatric speciation adjacent
populations become distinct species. Come
in contact along a common border but
prefer to mate with own kind – weak
hybrids
Sympatric speciation species form
within the range of a parent species.
Something other than geographic isolation
Geographic barriers can start
the process of speciation
Ammospermophilus leucurus
Ammospermophilus harisi
Two species of garter snakes
live in the same area but
because one lives mainly in
water and the other is
primarily terrestrial they rarely
encounter each other.
Gamete Isolation –
The gametes do not form a zygote
Chromosomal changes due to mutations
More common in plants
Western
Spotted skunk
&
Eastern
Spotted skunk
Share a habitat
but mate at
different times of
the year
Western = summer
Eastern = winter
Courtship
What lights your fire?
Many species have elaborate rituals for attracting
a mate – what works for one species doesn’t
necessarily work for others
Species that were once similar to an ancestral
species become increasingly distinct adapting
to different environmental conditions
Unrelated species occupy similar environments in
different parts of the world. Develop similar
characteristics due to similar environmental pressures.
MASS EXTINCTION
It’s all over!!