Chapter 16.1 Introduction to Evolution and Evidence • Vocabulary – Artificial Selection – Natural Selection – Homologous • Key Concepts – Who was Darwin and what was his theory on evolution? – How structural and physiological structures relate – Homologous Structures – Analogous Structures – Vestigial Structures physiological structures relate to evolution?
74
Embed
Chapter 16.1 Introduction to Evolution and Evidence · Chapter 16.1 Introduction to Evolution and Evidence ... Evidence for Evolution (16.1) ... Fossils: evidence of once ...
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Chapter 16.1 Introduction to Evolution
and Evidence
• Vocabulary
– Artificial Selection
– Natural Selection
– Homologous
• Key Concepts
– Who was Darwin and what
was his theory on evolution?
– How structural and
physiological structures relate – Homologous
Structures
– Analogous Structures
– Vestigial Structures
physiological structures relate
to evolution?
How many scientists are involved in developing the
theory of evolution?
William Bateson Carolus Linneaus
George Buffon Charles Lyell
Watson and Crick Thomas Robert Malthus
Hugo de Vries Ernst Mayr
Theodosius Dobzhanky Gregor MendelTheodosius Dobzhanky Gregor Mendel
Eldredge and Gould John Ray
J.B.S. Haldane George Simpson
Hardy and Weinberg G. Ledyard Stebbins
James Hutton Alfred Russel Wallace`
Thomas Huxley Alfred Wagner
Jean Baptiste Lamarck
What kinds of sciences did these
scientists study?
• Biology
• Paleontology
• Geology
• Genetics• Genetics
• Botany
• Naturalists
• Microbiology
• Biochemistry
• Molecular chemistry
• Ecology
• Chemistry
When did the theory of evolution
begin to develop?
• Late 1600’s with John Ray
– Major contribution was his writings called Historia Plantarum
• Rejected the system of • Rejected the system of dichotomous division where species were classified by a preconceived type of system
• Instead, plants were classified by similarities and differences from observation
• Coined the term “species”
• When did Darwin
write Origin of the
Species?Species?
– 1859
– So about 200 years
after Ray
Look at the drawings carefully then answer the following questions…
1) What is the main difference you notice about the Galápagos finches?
2) Why do you think this difference exists?
Natural Selection and the Evidence for Evolution (16.1)
• change over time: the process by which modern organisms have descended from ancientorganisms.
DEFINITION OF EVOLUTION:
The Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles Darwin
Portrait of Darwin in 1840 (Darwin 65 years old)
(31 years old)
• Born 1809 (England)
• Completed college after studying to become a doctor but could not stand sight of blood …
The Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles Darwin
stand sight of blood …
• Set sail on 5 year voyage on H.M.S., Beagle in 1831 as the natural historian for expedition.
• Made extensive drawings and notes
on the trip but also collected many
species of plants and animals.
• Began to OBSERVE that animals were well
adapted to their environments,
The Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles Darwin
adapted to their environments,
(wondered why were different animals found in areas that appeared to
be similar in climate? and some survived while others did not?)
• Argentina
• Australia
• Europe
All had grasslands but very different animals
• He collected fossils. – noticed some looked like living organisms
– others looked like nothing he had ever seen
The Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles DarwinThe Life of Charles Darwin
– others looked like nothing he had ever seen
before
• Were these related to the living (present day)
organisms?
• Why did some organisms disappear altogether?
Where are the Galapagos?
The Life of Charles DarwinGalapagos Islands
Organisms Darwin Observed on the Galapagos• Land Tortoise = different shaped carapace (shell)
depending what island they inhabited.
• Finches = different shaped beaks depending on environment in which they lived.environment in which they lived.
• he realized that characteristics of many animals and plants varied noticeably among the different islands of the Galapagos.
• On the journey home he began to pose the question…– Could animals on the different islands once
have been members of the same species?
Those Who Influenced DarwinThose Who Influenced DarwinThose Who Influenced DarwinThose Who Influenced Darwin
Hutton (Geologist)
– Geologic processes operate extremely slowly (take millions of years!)
– therefore, the earth is very old
Lyell (Geologist)
– Scientists must explain past events in terms of processes that they can actually observe
• processes that shaped the Earth millions of years ago continue to shape present day Earth
• this explained how geological features can be built or torn down over long periods of time.
Darwin wondered…
• If the earth could change over time, could life change as well?
• Also: it must have taken many, many years for life to change the way Darwin had in mind– This would only be possible if the earth was very – This would only be possible if the earth was very
old…
Those Who Influenced Darwin
Malthus (Economist)• proposed that war, famine, disease,
limits the growth of human populationslimits the growth of human populations• if populations continue to grow
unchecked, they will run out of resources (food/shelter)
Variation &
2 IMPORTANT CONCEPTS TO HELP US
UNDERSTAND THE PROCESS OF
EVOLUTION:
Variation &
Adaptation
VARIATION:
differences
between between
individuals in a
population
Give me an
example,
PLEASE!!
ADAPTATION: inherited
characteristic that increases an
organism's chances of survival
EXAMPLES OF ADAPTATIONS!
What are some
adaptations this
polar bear has?
How do they
help polar
bear’s survive?bear’s survive?
How are the adaptations of How are the adaptations of this bear different than those
of the polar bear?
What are some adaptations of a
cactus?
What about this desert plant?
What helps this kelp crab
survive? (It lives on the kelp
in the ocean.)
What the heck are these?
EVIDENCE FOR EVOLUTION
1) Fossils:
● evidence of once-living things (shells, casts,
bones, teeth, imprints)
● show a succession of forms through a vast span of ● show a succession of forms through a vast span of
time
● progressive changes based on the order they were
buried in sedimentary rock
few fossils / species � many fossils/ species
simple organisms � complex organisms
EVIDENCE FOR EVOLUTION
2) Biogeography and age of the earth:
● distribution of plants & animals
� 13 species of finches on the 13 Galapagos Islands
� 57 species of kangaroos…
all in Australia!
2) Biogeography and age of the earth:
● Radioactive dating tells us the earth is
about 4.6 billion years old
● Rate of motion of tectonic plates
3) Adaptations: Evidence for Evolution
● MIMICRY: one species resembles another
● CAMOUFLAGE: enables species to blend ● CAMOUFLAGE: enables species to blend with their surroundings
● PHYSIOLOGICAL: ability to resist disease or drought
4) “Artificial Selection”
4) Applied Genetics ("artificial selection"):
● Darwin noticed that farmers “selected” the best crops, animals – he wondered
● Darwin noticed that farmers “selected” the best crops, animals – he wondered if there could be a “selective” force in nature
● today we see DDT-resistant insects; antibiotic-resistant bacteria
5) Anatomical Structures: Evidence for Evolution
5) Homologous and Vestigial Structures
5) Homologous Structures =
shared common anatomical or biochemical traits
ex: " forearm bones”
• structures that develop from the same clumps of cells
– later develop into structures that have different forms and functions
• arms, flippers, & wings look very similar at the beginning of development, but differ as the animal matures
– The function differs as well!
5) Vestigial Structures:structures that no longer serve a purpose in an