Evolution of Living Things

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Evolution of Living Things
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Adaptation

• Characteristics that helps an organism survive
  and reproduce in its environment

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• When disturbed, they inflate their bodies. A
  conspicuous spade-like tubercle on each foot
  pushes soil to either side as the frog shuffles
  backward into the ground. They spend much of the
  year underground, but come to the surface after a
  heavy rain to breed.

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Squirrel monkeys move through the trees by
leaping. They have thighs that are shorter
relative to their lower legs this allows more
jumping force. They distribute a musky glandular
secretion throughout their fur (especially on
tail) as scent to mark territory or to leave a
trail for others of the troop to follow as they
go through the trees. This odor turns away
hunters who might otherwise kill them for food.

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• Very agile. Furry pads on feet are good for rock
  climbing. Will actively dig for water, sometimes
  up to one meter deep however, they conserve body
  water by hiding in hollows under granite boulders
  during hottest part of day. Wallaroos are the
  kangaroo best adapted to heat and dryness.

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Heat sensors along the upper lip as well as its
keen sense of smell help it to find prey. As with
other snakes, the python's loosely hinged jaws
can be stretched far apart, enabling it to
swallow animals with bodies much larger in
diameter than the python's head. They are good
climbers and have prehensile tails.
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To open the Abalone shell they place a small rock
on their chest and smash the shell against it.
Sea otters are one of the few mammals, beside
humans, that use tools. They will use strands of
kelp to tie themselves into the kelp beds for a
secure night's sleep. Air trapped in their fur
keeps them warm and buoyant
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Adaptations Cockroach and chameleon
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Species

• Group of organisms that can mate with on another
  to produce fertile offspring

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Do Species change over time?

• Evolution process by which populations
  accumulate inherited changes over time.

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Evolution

• Could birds have evolved from dinosaurs?

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Evidence of Evolution

• Fossil Record provide a historical sequence of
  life
• Fossils are solidified remains or imprints of
  once living organisms

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Vestigial Structures

• Remnants of once useful structures.

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• Whales possess a femur and pelvis, but these
  bones are no longer useful to the mammals

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Comparing Organisms

• Comparing skeletal structures
• Comparing DNA
• Comparing embryonic structures

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• Comparing DNA

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• All organisms contain the same limb bones-
  humerus, radius, ulna, etc, but they evolved to
  look different over time in length.

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• Homologous structures are structures from
  different organisms that look similar because the
  organisms descended from common ancestors
  (according to evolution).

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Comparing Embryonic Structures

• Scientists look at embryos of different organisms
  and find that many embryos resemble one another.

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Before Darwin

• French Scientist Jean Baptiste de Lamark (
  1774-1829)
• inheritance of acquired characteristics
• Passed acquired traits to their offspring.

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How does Evolution Happen?

• Charles Darwin
• 1831 he went on voyage on the HMS Beagle for five
  years.
• He observed thousands of species and collected
  many different types of fossils.

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• Finches living on Galapagos Islands differed
  slightly from the finches in Ecuador.
• Darwin concluded from his years of research that
  individuals having advantageous variations are
  more likely to survive and reproduce than those
  without the advantageous variations Evolution by
  Natural Selection.

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Natural Selection

• The process by which organisms with favorable
  variations survive and reproduce at a higher
  rate.

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• Darwin learned from farmers and animal and plant
  breeders
• Selective breeding breed only individuals that
  have desired traits.

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• Darwin was aided in his research by the book
  Principles of Geology, written by Charles Lyell,
  where he learned the age of Earth.
• Darwin also learned from Thomas Malthus essay on
  the Principle of Population, which helped him
  realize that animal species often produced too
  many offspring, and starvation, disease, and
  predators affected their population.

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• Then in 1858, Russell Wallace (1823-1913) came up
  with the same idea, therefore, Darwin finished
  his book The Origin of Species in 1859.

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Theory of Natural Selection explains how a
population changes over many generations in
response to its environment.
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Formation of new species

• Speciation when two populations can become so
  different that they can no longer interbreed.

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• 1. Separation
• Populations become isolated from one another
• 2.Adaptation
• When the environment changes so may the
  population that lives there.
• 3. Division
• Two populations over time may become so different
  they can no longer interbreed