Evolution Evolution Evolution as an Idea Aristotle Living things are Immutable Buffon 17071788 Observed anatomical features that seemed to serve no purpose and wondered why they existed ID: 592853
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Slide1
Theories of Evolution
EvolutionSlide2
Evolution as an Idea…
Aristotle Living things are “Immutable”Slide3
Buffon (1707-1788)
Observed anatomical features that seemed to serve no purpose and wondered why they existed.Theorized that this was evidence that species have changed over time.Slide4
More Ideas…
Carl Linnaeus (1707-1778)
– Developed classification system that highlighted similarities between organisms.
Erasmus Darwin (1731-1802)
– Believed organisms change over time and the earth was millions of years old. All life originated
from a single source. Did not propose a mechanism for this. Slide5
Georges Cuvier (1769-1832):
a famous paleontologist who conducted the first detailed studies of
fossils
Fossils of very simple organisms are found in all depths of fossil deposits
Fossils of more complex organisms are found only at shallower depths, in younger rock
Fossils in the shallower depths are more likely to resemble living species
Rock layers contain fossils of many
species that do not occur in layers above
or below them.Slide6Slide7
Theory of
Catatrophism (Cuvier)
the
theory of
catastrophism
which states that the patterns of fossils could be accounted for by a series of global catastrophes (such as floods) that wiped out most species on Earth. These wiped out species were then replaced with a newly created set of species.
Slide8
Chevalier de Lamarck (1744-1829)
One of the first scientists to
propose a mechanism for evolution.
Lamarck’s
First Principle:
Use and disuse
He believed that structures an individual used became larger and stronger, while structures that were not used became smaller and weaker.Slide9
Use it or Lose it…
When
astronaunts
are in space, there is no gravity and therefore no resistance against muscles. They experience muscle atrophy....(disuse)Slide10
Inheritance of Acquired Characteristics
Lamarck’s Second Principle
He believed that individuals could pass on to their offspring characteristics they had acquired
during their
livesSlide11Slide12
Lamarck’s Contributions
All species evolve over timeA species evolves in response to its environment and becomes better adapted to that environmentChanges are passed on from generation to generationSlide13
Charles Lyell (1797-1875):
- The father of geology. He studied rocks and fossils and came up with the opposite conclusion to Cuvier.Slide14
Charles Lyell
He proposed the Theory of
Uniformitarianism
.
Earth has been changed by the same processes in the past that are occurring in the present
Geological change is slow and gradual
Natural
laws that influence these changes are constant and
eternal
Lyell’s theories directly challenged the belief in a very young EarthSlide15
Charles Darwin (1809-1882):
22 years old, he set sail along the HMS Beagle for a five year voyage. Slide16Slide17
Darwin
During his travels, he visited the Galapagos Islands
T
he
flora
(plants) and
fauna
(animals) on
the Galapagos Islands resembled to the ones on continental South
AmericaSlide18
Darwin’s NotesSlide19
Darwin
There were no amphibians or large mammals on the island, indicating that only species that could arrive by
air
or
water
lived in the Galapagos.
I
slands
had been populated by species that arrived from elsewhere; however, most of these species only resembled species in the mainland. Slide20
Darwin’s FinchesSlide21
Why’s Darwin a Big Deal?
Darwin along
with Alfred
Wallace
proposed natural selection as the mechanism of evolution. Slide22Slide23
Current Interest in Lamarckism
Epigenetics is the study of heritable
changes in
gene
activity which are
not
caused by changes in the
DNA
sequence.
Changes can occur response to environmental influenceshttp://www.youtube.com/watch?v=kp1bZEUgqVI
ARTICLE: http://discovermagazine.com/2013/may/13-grandmas-experiences-leave-epigenetic-mark-on-your-genesSlide24
Epigenetic Examples
Diet in HumansPregnant Woman who experience starvation have abnormally small babies. Their children (even if dietary needs are meet) have small Babies.
May be some epigenetic factors in obesity.