1. History of Evolution
• 1831, Darwin, naturalist on H.M.S. Beagle
• Galapagos, Coast of S. America
• James Hutton(1785)– earth is millions, not
thousands of years old
• Thomas Malthus (1798) – predicted that the
population of earth would exceed it’s resources
• Jean-Baptiste Lamarck(1809) – proposed that
inheritance was acquired (1st mechanism for
organisms changing over time)
2. Cont.
• Darwin (1831) – naturalist who proposed the
theory of evolution (1859) On the Origin of
Species
• Charles Lyell (1833)- proposed that the process
occurring now have shaped the earth for long
periods of time; published Principles of Geology
• Alfred Wallace (1858)– contemporary of Darwin,
speculated on evolution through natural
selection
3. Theory of Evolution
• Fitness – individuals ability to survive and
reproduce in it’s environment
• Adaptation – inherited traits/characteristics
that increase the chance of survival
• Artificial selection – humans manipulate
traits
• Natural selection – inherited over time by
the process of nature (can not be seen
directly)
4. • Over time organisms produce different
structures, establish different niches, or
occupy different habitats – descent with
modification
• Fossil record supported Darwin’s theory
• Fossil record shows how species have
changed overtime or died
5. Formation of Earth
• 4.6 billion years old (universe 15 billion)
• Elements arranged themselves by
densities creating the planet (radioactive
decay creates heat, core heaviest metals)
least dense formed early atmosphere (H
and N)
• Atmosphere was toxic to life as we knew it
(it was what we didn’t know could exist in
this environment, cyanobacteria)
6. Cont.
• 3.8 billion, earth cooled enough to allow
water to remain liquid, creating rain
• Under these conditions, organic
compounds were formed (building blocks
for life)
• DNA is transcribed into RNA then
translated into proteins
7. Oxygen-evolution
• 2.2 billion increase in oxygen allowed
organisms to evolve (move from water to
land)
• 2 billion eukaryotic cells (nucleus)
appeared, endosymbiotic theory proposes
that eukaryotes evolved from prokaryotic
communities
9. Cont.
• 90% of earths history occurred during
Precambrian (life only existed in the water)
• Paleozoic Era – abundance of marine life
• Cambrian – hard parts appear, most
animal phyla evolve
• Devonian – vertebrates appear
• Mass extinction occurs
• Mesozoic Era – rise of dinosaurs and
flowering plants
10. Cont.
• Jurassic – dino’s ruled the earth for 150
million yrs.
• Cretaceous – leafy trees, shrubs, flying
birds, large reptiles still dominant earth
• Mass extinction (meteor) wipes out half of
all plant and animal groups (including all of
the dino’s)
• Cenozoic Era – animals evolve adaptation
for land, water and air
11. Pattern of Evolution
• 99% of all species that have lived are now
extinct.
• Macroevolution – large scale evolutionary
patterns and processes that occur over long
periods of time
• 6 specific areas of macroevolution – extinction,
adaptive radiation, convergent evolution,
coevolution, punctuated equilibrium, and
changes in developmental genes
