Evolution

1
Evolution

• Review for UNIT TEST
• Hint, Wink, Nudge, Do a Dance

2
Inhabiting the Earth

• Big Bang Bacteria Plants
  Plant Eaters
  Meat Eaters

3
Darwin

• The process of Natural Selection the
  biological mechanism that promotes the evolution
  of a species.

4
(No Transcript)
5
Genetic Variation

• Needed for Natural Selection to occur.
• Can be caused by a mutation or genetic
  recombination.

6
Darwins Observations

• Darwin noted similarities between species living
  on the Galapagos Islands and those living on the
  Coast of South America.
• Finches, plants, iguanas

7
His Explanation

• Ancestors of similar species migrated from South
  America to the Galapagos Islands.

8
Adaptations

• Animals and plants develop characteristics that
  allow them to survive (eat, maintain homeostasis)
  and reproduce.

9
Competition
The land iguana and the marine iguana have
different adaptations and occupy different niches
in order to reduce competition between the two.
10
Invasive Non Native Species

• If a non-native animal is introduced to an
  ecosystem, the native species must adapt.

11
Coevolution

• Animals that evolved at the same time will have
  different adaptations that allow them to occupy
  different niches.

12
Evidence of a Common Ancestor

• Fossils (Transitional Forms)
• Carbon Dating
• Homologous Structures
• Vestigial Structures
• DNA Fingerprinting
• Embryo Development
• All of these show the relatedness among a species.

13
Carbon Dating

• The half-life of carbon 14 is 5,730 years. If
  an organism containing one gram of carbon 14 in
  its tissues died about 17,000 years ago, how much
  carbon-14 is left in its bones?

14
Relative Dating

• No! It is not dating your relatives.
• It is looking at rock layers in order to
  determine the relative age of the rock.

15
Homologous Structures

• Same structure, different function
• Evidence of a common ancestor

16
Embryology

• Embryology shows us the at early stages all
  vertebrates have the same characteristics
  common ancestor.

17
Transitional Forms

• Intermediate stages found in the fossil record
  between the common ancestor and the present stage
  of an organism.

18
Kettlewells Experiment

• Before the industrial revolution there were many
  white moths, and very few dark moths because
  the trees were white.

19
After the Industrial Revolution
The trees are covered in soot, so white moths are
more easily seen and get eaten, leaving dark
moths to survive and reproduce. Increase in dark
moths due to natural selection
20
Kettelwells Hypothesis

• Based on his observations, Kettelwell
  hypothesized that moths whose body color matches
  the color of the tree bark are more likely to
  survive.

21
Evolution of the Horse
Summary Horses have undergone several changes
that are evident in the fossil record.
22
Classification
Classification Kingdom Animalia   Phylum
Chordata     Class Mammalia       Order
Perissodactyla         Family Equidae        
  Genus Equus

• Kingdom
• Phylum
• Class
• Order
• Family
• Genus
• Species

23
What makes a species?

• In order for two organisms to be considered
  members of the same species they must be able to
  produce fertile offspring.

24
Hominid Evolutionary Tree
Able to determine the ancestors of human.
25
Evolution of Primates

• Paleontologists can distinguish an ape skull from
  a human skull by the size of the cranial cavity.
• Several species developed and then became
  extinct, leaving no descendants.
• Fossil evidence suggests that human beings did
  not evolve from modern apes.

26
Comparing Amino Acid Differences
Number of Amino Acid Differences when compared to
human hemoglobin 0 They are most closely
related to humans.
27
Artificial Selection

• When HUMANS intervene.
• Change the genes of plants or animals.