Transcript 16.1 Darwin`s Voyage of Discovery - OG

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Charles Darwin was born Feb. 12th,
1809
 Same year as Abraham Lincoln (what was
happening during this time period?)
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How was the scientific view of the
world changing? – World has changed
over time, and is constantly evolving
Developed scientific theory of
EVOLUTION:
 The process of change over time
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One of the most important
scientific voyages in history
5 year voyage on the HMS
Beagle
Visited what continents?
Africa, S. America, Australia
Collected many plant and animal
specimens, and took LOTS of
notes, drawings, and
observations
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Visited wide range of habitats
In S. America - rhea
In Africa - ostrich
In Australia - emu
All similar habitats, yet different
animals…
*Different, yet ecologically similar
animal species inhabited separate,
but ecologically similar habitats
around the globe
 Species vary globally!
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*Different, yet related animal species
occupied different habitats within a local
area (species vary locally)
Habitat varied on each of the islands
Ex: Tortoise shells differed for each island
Ex: Finch beaks differed for each island
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In addition to living specimens, Darwin also
collected preserved remains or traces of
ancient organisms, called fossils
He noted that some fossils of extinct
animals were similar to living species
Ex: Extinct glyptodont – today’s armadillo
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Darwin had many questions
Used his collections and observations to
fit the pieces of the puzzle together
Why did some organisms live in one place
and nowhere else?
Why did different flightless birds live in
similar grasslands in the Southern
Hemisphere, but not the North?
Used ideas of other scientists of his time
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During Darwin’s time, new field called
geology, study of rocks
Provided evidence about Earth’s
history – Earth probably not just
4,000 years old – much older!
Famous geologists – James Hutton
and Charles Lyell
Wrote that Earth is extremely old and
processes that changed Earth in the
past are the same now
Hutton’s concept of deep time – idea
that our planet’s history is so old we
cannot comprehend it
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French naturalist, Jean-Baptiste
Lamarck proposed that:
1. Organisms could change during their
lifetime by selectively using (or not using)
certain body parts (acquired characteristics)
2. Individuals could pass these acquired
traits on to offspring, causing “evolution” or
change over time
Are these hypotheses accurate?
English economist Thomas Malthus (1798)
Human population was growing
exponentially
 Hypothesis: if human population
grew uncontrollably, there wouldn’t
be enough living space and food for
everyone
 Limiting factors would cause certain
individuals to survive or not survive
 How did this help Darwin’s theory?
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Darwin studied changes produced by plant
and animal breeders
They knew some change could be passed on
to improve crops and livestock
Farmers selected trees that produced the
largest fruit or cows that produced the most
milk
Process called artificial selection, in which
nature provides variation and humans
select those they find useful