big idea: the environment selects the traits of its inhabitants
TRANSCRIPT
BIG IDEA:
THE ENVIRONMENT SELECTS THE TRAITS OF ITS INHABITANTS.
Biogenesis: › All living things come from other living things
Spontaneous Generation :› States that life can come from nonliving
matter
Evolution :› the development of new types of organisms
from preexisting organisms over time
Natural Selection: › Is the mechanism for “descent of
modification”
Adaption: › A trait that makes an organism successful
in its environment EX:
thicker fur coats in cold climates
Fitness: › Is a measure of an individual’s hereditary
contribution to the next generation
Homologous Structure: › structures that occur in different species and
originate from a common ancestor Example: human arm and whale’s fin
Analogous Structure: › Structures that are closely related but do not
derive from the same ancestor Example: Wings of butterfly and bird
Vestigial Structure:
› Structures that serve no function but that resemble structures with functional roles Example: Human appendix
Fossil: › Are the remains of an organism that died
long ago › EX:
Dinosaur bones
Control Group: › the group that doesn’t change
Experimental Group› the group that has the variable
Where does life come from?
A piece of meat was left out.
The next day flies and maggots were seen on the meat.
Where did the flies come from?› The thought the meat.
idea that life can arise from nonliving matter.
There is a “life force”
Francesco Redi
Lazzaro Spallanzani
Louis Pasteur
1668› Francesco Redi
One scientist that performed an experiment that disproved spontaneous generation
Control group:›Put meat in a jar uncovered.
Experimental group:›Put meat in a jar covered.
He let the jars sit out for a couple days Observes……
Flies found on the meat.
No flies on the meat.
Conclusion › Flies do not come from the meat.
Italian scientist 1768
› Performed another experiment that disprove spontaneous generation
Control Group:›Boil broth›Left flask open
Experimental Group:›Boil broth ›Sealed flask
Control: › Broth becomes cloudy bacteria present
Experimental: › Broth remains clearNO bacteria
The bacteria came from the air
French chemist
He disproved spontaneous generation
Invented the Pasteurization method
1862:
Boil broth in a curved-neck flask.› Curved-neck prevented large particles
from getting into the body of the flask.
After a year, › Broth in the not broken neck of
flask clear
› Broth in the broken neck of flask cloudy
Bacteria came from the outside air.
All living things come from the reproduction of other living things.
Change in an organism over time.
Jean Baptiste Lamarck Charles Darwin
French Biologist
Famous for his evolutionary theory of inheritance
1809
Two Theories 1. Use and Disuse 2. Inheritance of Acquired
Characteristics
Body parts that are used more grow stronger and bigger
USE
Body parts that are NOT used deteriorate
DISUSE
Physical traits that were changed in an organism are inherited by their offspring(s).
Giraffe’s neck› They gets longer as it stretches to reach food in trees.
NO!!!!!!
Variations that occur in the:› GAMETES cells are passed to offspring
› SOMATIC (body) cells are NOT inherited
British Naturalist
Set sail on the HMS Beagle
Famous for his studies
with finches on the Galapagos Islands
“Father of Evolution”
Went to the Galapagos Islands
He observed different types of finches
These observation lead to him developing his theory of evolution
British Naturalist Co discover of natural
selection Wallace and Darwin
presented their ideas to the public › Darwinism
States: 1. Descent with modification
2. Evolution occurs by the process of natural selection.
states evolution is the development of new organisms from preexisting organisms over time.
Over production:› In a population, more offspring are produced than can survive.
Competition
› Only some survive long enough to reproduce.
There is variation within a population
these variations are inherited and lead to differences in organisms
traits that are favorable and improve the organism’s ability to function and reproduce.
States that survivors pass on their variations.
Therefore….. a larger proportion in the next
generation will have those variations.
is a measure of an individual’s genetic contribution to the next generation.
Over time, small changes accumulate and populations change.
a group of organisms that can mate and produce fertile offspring.
1. Fossil Evidence 2. Anatomy3. Embryology 4. Molecular Evidence
Fossils:
› remains/traces of organisms that died long ago
› They are often found in strata
Strata layered rock
If undisturbed, › the lowest stratum is the oldest › the highest stratum is the newest
Relative Age: › found by comparing ages of strata
Absolute age › found by using radiometric dating
• Fossil record suggests that different species were present in the past than today.
What about the PACE of evolutionary
change?
Evolution that occurs slowly and continuously throughout time
Gradualism› Fossil record should
show many transitional species, they DON’T
Punctuated Equilibrium › Fossil records seem to
support this › However, the mechanism
is uncertain
States that for long periods of time, the existing species didn’t change Equilibrium
Then, in relatively short periods of time, there is an interruption in the equilibrium
New species emerge. The fossil record supports this!
studies the parts or structures of living things.
Similar internal parts
Different function in different organisms
This suggests descended from COMMON ANCESTORS
Ex:
› Human arm› Cat leg› Whale fin› Bat wing
Similar external form and function
Different internal forms and function
Suggests species came from DIFFERENT ancestral lines
Ex: › Bat Wing › Bird Wing › Insect Wing
Usually reduced iiin size and have no function.
› Suggests that the structure was once used by an evolutionary ancestor.
› Example: human appendix, tailbone.
study of embryos as they develop
Similarities of the development of embryos:
› suggests that the species have a common ancestor
when we analyze chemical similarities between organisms
Ex: a. DNA Comparison b. Protein Comparison
The more DNA is similar the CLOSER the relationship between the organims
Amino acids › The building blocks of proteins
Similarities of amino acids that make proteins suggest a relationship between organisms
EX: › In the protein cytochrome C, the difference
between amino acids is…… Humans vs. monkeys 1 difference Human vs. pigs 10 differences