Transcript 07 Chapter-Adaptations

Table of Contents
Aim: What makes a Scientific
theory credible?
HW: Preview 190-200 NB 74
Do Now: When someone tells you a story,
how do you know whether to believe them or
not?
Ideas About Evolution
1
Hypothesis of Acquired
Characteristics
• In 1809, Jean Baptiste de Lamarck suggested
that characteristics, or traits, developed during
a parent organism’s lifetime are inherited by
its offspring.
• His hypothesis is called the “inheritance of
acquired characteristics”.
Ideas About Evolution
1
Hypothesis of Acquired
Characteristics
• According to this theory individual changes
made, would be passed on.
• Ex: exercise-muscular body
• Exposure to sun- Darker color skin
Lamark’s Theory did not have
evidence!
Charles Darwin
http://www.pbslearningmedia.org/resource/tdc02.sci.life.evo.lp_darwin/charles-darwin/
Video: Who was Charles Darwin
1. What characteristics made Darwin especially well
suited for science?
2. What did Darwin see and do on his five-year voyage
aboard the Beagle?
3. Why was the publication of On the Origin of Species
a courageous act?
Letters from Darwin
Questions to consider:
What kinds of questions was Darwin trying to answer?
What observations did he make?
What follow-up questions would you ask on these topics?
How did he use the evidence he collected to form hypotheses?
How did he use this evidence and much more to create a theory about evolution?
How was Darwin's scientific process similar to and different from that used by scientists today (e.g., Cameron Currie)?
More to consider:
Explain and discuss the reasons why Darwin was so persistent in his efforts to test plant seeds of various types for
viability after soaking them in fresh and salt water for long periods of time?
What evidence do these letters reveal about the way Darwin proposed and then tested hypotheses critical to his
developing theory?
There are many different definitions of "the scientific method" -- most of which are too cut-and-dried for general
consumption to be of much real value. Consider the following statement about the scientific method, and discuss
whether it seems to apply to Darwin's strategy as expressed in these letters: "The process of science making is
narrative. It consists of spinning hypotheses about nature, testing them, correcting hypotheses, and getting one's head
straight. En route to producing testable hypotheses, we play with ideas, try to create anomalies, try to find neat puzzle
forms that we can apply ... . Our instruction in science from start to finish should be mindful of the lively process of
science making, rather than being an account only of "finished science" as represented in a textbook." Bruner, Jerome.
1996. The Culture of Education, Cambridge, MA: Harvard University Press. p. 127.
Ideas About Evolution
1
Early Models of Evolution
• Change in inherited
characteristics over
time is evolution.
Science Probe
What are different types of
adaptations that help an animal
survive?
• HW: NB 74 (skim 190-197)
• Do now: Think of an animal and what is
special about it that helps it survive.
• You may use books to help you
Adaptations
• -A variations about an organism that helps
it survive
• 3 main types – body parts, body coverings
and behavior
• Species to survive: food/nutrients,
reproduce, defense, shelter, water
Body Parts
• How might these adaptations help?
• webbed feet, -swim, walk on slippery
lsurface
• sharp claws,defense, climing, feeding,
running
• whiskers,-sensors “HEAR or SEE”
• sharp teeth, defend and feed
• large beaks, open food, store food, feed
young
• wings,- fly- defense, migrate, get food
What behaviors might be
considered an adaptation?
Body Coverings
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•
•
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Hair
Stripes/spots
Bright colored feathers
Scales/plated body
Ideas About Evolution
1
Aim : What evidence did Darwin have to
support his theory?
• HW: NB 75.
Ideas About Evolution
1
Darwin’s Observations
• Darwin observed 13 species of finches on the
Galápagos Islands.
• He noticed that all 13 species were similar,
except for differences in body size, beak
shape, and eating habits.
• He also noticed that all the Galápagos finch
species were similar to one finch he had seen
on the South American coast.
Ideas About Evolution
1
Darwin’s Observations
• Darwin reasoned that the Galápagos finches
must have had to compete for food.
• Finches with beak shapes that allowed them
to eat available food survived longer and
produced more offspring than finches without
those beak shapes.
• After many generations, these groups of
finches became separate species.
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Hibernation
Migration
Raising young
Finding food
Communication
hide
Ideas About Evolution
1
Darwin’s Theory
• Darwin’s ideas became known as the
Theory of Evolution by Natural Selection.
• Natural selection means that organisms
with traits best suited to their
environment are more likely to survive
and reproduce. “survival of the fittest”
Industrial Revolution
Peppered Moth
Simulation http://www.techapps.net/interactives/pepperMoths.swf
Adaptations for Hunters
Black
White
Newspaper
Trial 1
Trial 2
Trial 3
Trail 4
Average
1.Which color was easiest to find?
2.How would this effect the survival rate
of this “species”. Why?
What does variation and
adaptations have to do with a
species survival?
• HW RD Notebook 76
Ideas About Evolution
1
Variation and Adaptation
• A variation is an inherited trait that makes
an individual different from other members
of its species.
• Variations result from permanent changes, or
mutations, in an organism’s genes.
Ideas About Evolution
1
Variation and Adaptation
• If individuals with
these variations
continue to survive
and reproduce over
many generations,
a new species can
evolve.
Ideas About Evolution
1
Variation and Adaptation
• An adaptation is any variation that makes an
organism better suited to its environment.
• Camouflage is an adaptation.
Ideas About Evolution
1
Changes in the Sources of Genes
• Over time, the genetic makeup of a species
might change its appearance.
• Many kinds of environmental factors help
bring about changes.
Ideas About Evolution
1
Geographic Isolation A small
number of individuals are isolated from the
rest of the population
• Gene mutations can occur that add variations to
populations. Over time, the two populations can
become so different that they no longer can breed
with each other.
Ideas About Evolution
1
Gradualism
• The model that describes evolution as a
slow, (100’s of millions of years) ongoing
process by which one species changes to a
new species is known as gradualism.
Ideas About Evolution
1
Punctuated Equilibrium
• According to the punctuated equilibrium
model, rapid evolution comes about when the
mutation of a few genes results in the
appearance of a new species over a relatively
short period of time.
Try This
• 1.On a piece of paper write the word
“TRAIN”.
• 2.Add, subtract or change one letter to
make a new word.
• 3.Repeat step 2 with the new word.
• 4. Repeat 3 more times
• Make a family tree- that shows how your
first word changed over time.
Clues About Evolution
2
Aim: What evidence is there to
support the theory of evolution?
• Do Now: What is a fossil?
Clues About Evolution
2
Types of Fossils
• Most of the evidence for evolution comes
from fossils.
• A fossil is the remains, an imprint, or a trace
of a prehistoric organism.
• Most fossils are found in sedimentary rock.
Clues About Evolution
2
Types of Fossils
• The fossil record provides evidence that
living things have evolved.
Clues About Evolution
2
Relative Dating
• Generally; younger rock layers are
deposited on top of older
rock layers.
• Relative dating provides only
an estimate of a fossil’s age.
Clues About Evolution
2
Fossils and Evolution
• By looking at fossils, scientists conclude that
many simpler forms of life existed earlier in
Earth’s history, and more complex forms of
life appeared later.
• Fossil activity
How Scientists use fossils to
develop theories?
• What is a homologous structure?
• -Similar structure in different species
• What is a vestigial structure? Give an
example. A structure that doesn’t seem to
have a function anymore
• Tonsils, appendix, wisdom teeth
The Evolution of Primates
3
What do all primates have in common?
HW #65
TXT Read 206-209
NB p.80
The Evolution of Primates
3
Primates: Humans Monkey and
Apes
• Having an opposable thumb
allows you to cross your thumb
over your palm and touch your
fingers.
• This enables primates to :
Grasp, hold things
• An opposable thum
tree-dwelling prima
hold on to branches
The Evolution of Primates
3
Other Trait Primates have in common
• Binocular vision Let’s you see depth or
distance with your eyes.
• Flexible shoulders – give a greater range of
motion
The Evolution of Primates
3
Hominids
• About 4 million to 6 million years ago,
humanlike primates appeared that were
different from other primates.
• These ancestors, called hominids, ate
both meat and plants and walked upright
on two legs.
• Hominids shared some characteristics with
gorillas, orangutans, and chimpanzees, but
a larger brain separated them from the apes.
The Evolution of Primates
3
African Origins
• In the early 1920s, a fossil skull was
discovered in a quarry in South Africa.
The skull had a small space for the brain,
but it had a humanlike jaw and teeth.
• The fossil, named Australopithecus, was one
of the oldest hominids discovered.
The Evolution of Primates
3
African Origins
• An almost-complete skeleton of
Australopithecus was found in northern
Africa in 1974.
• This hominid fossil was called Lucy and
had a small brain but is thought to have
walked upright.
• This fossil indicates that modern hominids
might have evolved from similar ancestors.
The Evolution of Primates
3
Early Humans
• In the 1960s in a
region of Africa, a
hominid fossil,
which was more
like present-day
humans than
Australopithecus,
was discovered.
The Evolution of Primates
3
Early Humans
• The hominid was
named Homo habilis,
meaning “hand man.”
because simple stone
tools were found near
him.
• Homo habilis is
estimated to be 1.5
million to 2 million
years old.
The Evolution of Primates
3
Early Humans
• Based upon many fossil comparisons,
scientists have suggested that Homo habilis
gave rise to another species, Homo erectus,
about 1.6 million years ago.
• This hominid had a larger brain than Homo
habilis.
• Homo erectus traveled from Africa to
Southeast Asia, China, and possibly Europe.
The Evolution of Primates
3
Early Humans
• Homo habilis and Homo erectus are thought
to be ancestors of humans because they had
larger brains and more humanlike features
than Australopithecus.
The Evolution of Primates
3
Aim: How did humans evolve?
• .Do Now: How does this fossil differ from a
modern human skull?
The fossil record indicates that
Homo sapiens evolved about
400,000 years ago
• By about 125,000 years ago, two early
human groups,
– Neanderthals and Cro-Magnon humans,
probably lived at the same time in parts of
Africa and Europe.
VIDEO: http://vitalny.pbslearningmedia.org/resource/hew06.sci.life.reg.earlyhumans/homo-sapiens-versus-neanderthals/
Another
http://ny.pbslearningmedia.org/resource/tdc02.sci.life.evo.humev/evolving-ideas-did-humans-evolve/
The Evolution of Primates
3
Neanderthals
• Short, heavy bodies with thick bones, small
chins, and heavy browridges
• Family groups lived in caves and used wellmade stone tools to hunt large animals.
The Evolution of Primates
3
Cro-Magnon Humans
• 1.6 m to 1.7 m tall, the physical appearance of
Cro-Magnon people was almost the same as
that of modern humans.
• They lived in caves, made stone carvings,
and buried their dead.
The Evolution of Primates
3
Cro-Magnon Humans
• The oldest recorded art has been found on
the walls of caves in France, where CroMagnon humans first painted bison, horses,
and people carrying spears.
Jeopardy Review
• https://jeopardylabs.com/play/evolution-mrs-kelly