Transcript What is Evolution??

What is Evolution??
Evolution is a theory based on substantial
evidence.
Definition: All the changes that have formed
life on earth from its earliest beginnings to
the diversity that characterizes it today.
Pioneers of evolution include:
Darwin, Malthus, Lamarck, Lyell, Wallace
 Malthus (1766- 1834): Population growth theories
http://www.blupete.com/Literature/Biographies/Philosop
hy/Malthus.htm
 Lamarck (1744 – 1829): Lamarck developed two laws
to explain evolution: the law of use and disuse, and the
law of inheritance of acquired characteristics.
http://en.wikipedia.org/wiki/Lamarck
 Lyell (1797 – 1875): Wrote Principles of Geology- said
“The present is the key to the past” Understood the
forces of tectonic plates and that the world as we now
know it happened slowly over time.
 Wallace (1823 – 1923): Biogeography; first to form
theory of natural selection
Lamarck Law 1:
 (Use and disuse) In every animal which has
not passed the limit of its development, a more
frequent and continuous use of any organ
gradually strengthens, develops and enlarges
that organ, and gives it a power proportional to
the length of time it has been so used; while
the permanent disuse of any organ
imperceptibly weakens and deteriorates it, and
progressively diminishes its functional capacity,
until it finally disappears.
Lamarck Law 2:
 (Inheritance of acquired characteristics) All the
acquisitions or losses wrought by nature on
individuals, through the influence of the
environment in which their race has long been
placed, and hence through the influence of the
predominant use or permanent disuse of any
organ; all these are preserved by reproduction
to the new individuals which arise, provided
that the acquired modifications are common to
both sexes, or at least to the individuals which
produce the young.
So who was Darwin, anyway,
and why do we care?
 Darwin relied on years of close observations
and data to develop his theories on evolution.
 Most well known for descriptions of Galapagos
Finches.
 He concluded that birds were adapting to their
environment by having different beak sizes for
their available food source.
 Revolutionized the theory of evolution at a very
controversial time in history.
 Darwin proposed that species were evolving by
process of natural selection – a process by
which organisms best suited to their
environment reproduce more successfully than
other organisms.
 For natural selection to occur, has to be some
certainties about the population:
- Organisms have to reproduce
- Has to be variation within the population
- Traits have to have a genetic basis
- Trait provides advantage to organism
Some Vocab. To Know…
 Adaptation: an inherited trait that
increases an organism’s chance of
survival in a particular environment.
 Fitness: the ability of individuals to
survive to pass on their genes.
 Population: interbreeding single-species
group.
 Species: a group of organisms of a single
type that are capable of producing fertile
offspring.
Which moth
started to
appear after
the industrial
revolution?
Other evidence…
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Fossils
Anatomy
Embryology
Biochemistry
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