Evolution

ClipBird Lab

Biology

Evolution Unit

Day 5

ClipLand Scene

Here we see a new species called ClipBirds.

They were tragically split into two populations---the East ClipLand and the West ClipLand.

How are these birds alike? How are they different?

http://www.ucmp.berkeley.edu/education/lessons/clipbirds/scene.pdf

Food Values

Food Values in Megacalories

Megacalories Needed

Marblefruit 10

Big Tootfruit 5

Tiny tootfruit 2

To Survive To Reproduce

Big bill 80 160

Medium bill 50 100

Small Bill 25 50

ClipBird Populations

West Clipland

East Clipland

1st Season 2nd Season 3rd Season 4th Season

Big Bill

Medium Bill

Small Bill

1st Season 2nd Season 3rd Season 4th Season

Big Bill

Medium Bill

Small Bill

Discussion

What happened to these populations? What factors had an impact on their

lifestyles?

Vocabulary

Adaptation- inherited trait that increases a population’s chances of survival and reproduction in a particular environment.– What types of adaptations did we see here?

Vocabulary

Niche- habitat and the role a population plays in that habitat. Includes where organisms live, what and how they eat, how they raise their offspring, and what their predators are.– What were the examples of the niche that we saw

in this lab?

News Reporters

You are a news reporter and are writing a story on Charles Darwin and his theory.

Need to answer the 6 questions of Who, What, When, Where, Why, and How.

Have today during class to find your information. Hand in by tomorrow.

Background Information

In Mediaeval times, people believed in Spontaneous Generation.

Idea that living things could come from non-living things.

Example of Spontaneous Generation Observation: Every year in the spring, the Nile

River flooded areas of Egypt along the river, leaving behind nutrient-rich mud that enabled the people to grow that year’s crop of food. However, along with the muddy soil, large numbers of frogs appeared that weren’t around in drier times.

Conclusion: It was perfectly obvious to people back then that muddy soil gave rise to the frogs.

Redi’s Experiment

In 1668, Francesco Redi, an Italian physician, did an experiment with flies and wide-mouth jars containing meat.

One jar was covered with a stopper, one was covered with gauze, and one was left open.

Redi’s Data

In the uncovered jars, flies entered and laid eggs on the meat. Maggots hatched from these eggs and grew into more adult flies.

Adult flies laid eggs on the gauze on the gauze-covered jars. These eggs or the maggots from them dropped through the gauze onto the meat.

In the sealed jars, no flies, maggots, nor eggs could enter, thus none were seen in those jars. Maggots arose only where flies were able to lay eggs.

Redi’s Conclusions

Only flies can make more flies

This experiment disproved the idea of spontaneous generation for larger organisms.

Louis Pasteur

In1864 Louis Pasteur, disproved spontaneous generation in microscopic organisms.

Pasteur boiled broth in various-shaped flasks to sterilize it, then let it cool. As the broth and air in the containers cooled, fresh room air was drawn into the containers. None of the flasks were sealed — all were exposed to the outside air in one way or another.

Louis Pasteur’s Findings

Broth in flasks with necks opening straight up spoiled while broth in swan-neck flasks did not, even though fresh air could get it.

Broth in flasks with cotton plugs did not spoil, even though air could get through the cotton. If the neck of a swan-neck flask was broken off short, allowing bacteria to enter, then the broth became contaminated.

Who is Jean-Baptiste Lamarck? 1809- French Scientist who reasoned that

fossils of extinct animals were the ancestors of those living today.

Developed a theory of evolution Organisms are constantly striving to improve

themselves. Use it or lose it! Most-used body structures are

maintained, while others waste away. Inheritance of acquired characteristics.

Discussion—So What Are the Important Aspects of Darwin’s Theory? Natural Selection

Sexual reproduction causes variation within a species, some of which are favorable.

There is a struggle for exsistance.

Not all young produced in each generation can survive. (Nature overproduces)

Individuals that survive and reproduce are those with favorable variations.

Discussion—So What Are the Important Aspects of Darwin’s Theory? Geological Change is slow.

These gradual geological changes can influence plant and animal life over time.

This Theory is called Gradualism Artificial Selection

Selective breeding of domestic animals and crops to gain most desirable characteristics.

How does this affect us now?

Vocabulary to Know

Terms Natural Selction Variation Gradulism Artificial Selection Spontaneous Generation

People and Theories Darwin Jean-Baptiste Lamark Louis Pasteur Francesco Redi

Add all of these terms and people to your evolution foldables!!

Lucy Activity

Where did humans come from? Who are we related to?

Lucy, ancient hominid fossil, helps us to bridge the gap in human evolution.

Primate Family Tree

Old World African Old World

Monkeys Gibbon Orangutans Human Apes Monkeys

Anthropoids

HominoidsHominids

Lucy

Let’s find out more about Lucy by reading Digging up the Past

Lucy Discussion

Comparing hominids from Lucy’s lifetime to your own, do you think there have been more changes in physical characteristics of the body (such as hands, feet, head, posture) or more changes in how hominids lived (types of shelter, ways of getting around, ways of gathering food)?

Did Lucy use her structures the same way that we use our own structures today?

Lucy Discussion

Which aspects of your description were based on evidence?

Which aspects of your description were inferences related to evidence?

Which aspects of your descriptions were guesses?

Evidence for Evolution

Evolution of Humans

Wrong—There is no direct lineage!!

So is this correct???

No, there is no direct lineage!!

So what is right??

Old World African Old World

Monkeys Gibbon Orangutans Human Apes Monkeys

Anthropoids

HominoidsHominids

We have a common ancestry!

How do we know this?

Scientists have come up with multiple ways to show evidence for this theory of evolution.

1. Comparative anatomy

2. Comparative physiology

3. Fossils

4. Immunity resistance

Evidence for Evolution: Comparative Anatomy

Homologous StructuresStructures that have a common origin but

not necessarily a common function.

Evidence for Evolution: Comparative Anatomy

Vestigial StructuresStructure in an organism that seem to have

little to no obvious purpose.

Examples in humansTail boneWisdom teeth

Evidence for Evolution: Comparative Anatomy

Analogous StructuresStructures are similar in appearance and

function but are different in anatomical development and origin.

Evidence for Evolution: Comparative Physiology

DNA Comparison95 of our DNA genome matches the DNA

genome of chimpanzeesEnzyme Comparison

Evidence for Evolution: Fossils

Fossil RecordMore simple organisms appeared first

Carbon DatingUses the decay of carbon over time to tell

how long the fossils have been in the ground.

allows us to organize once living things by age and type.

Indicates a change through time

Evidence for Evolution: Resistance

Insects have become resistant to different types of farm chemicals

Bacteria has become resistant to different types of antibiotics

Natural Selection selects towards mutations that are resistant.

Evidence for Evolution: OOPS!

Comparative EmbryologySimilarities in development

= genetic similaritiesThis is no longer believed

to be true!!

Population Genetics

Speciation Evolution of one or more species from a

common ancestor -- New species created

Species is a group of similar-looking organisms that can breed with one another and produce fertile offspring

Population Genetics

Divergent Evolution (Allopatric Speciation) Geological barrier separates members of the

population Two different species evolve

Population Genetics

Convergent EvolutionNatural selection produces analogical

adaptations in response to environmental conditions.

Two similar species

Population Genetics

Coevolution Environmental factors

cause two species to evolve together.

Special relationships between organisms.

Ex. Flowers and bees.

Population Genetics

Adaptive Radiation An open habitat

creates many different evolutionary tracts for one species

Many diverse species from one common ancestor.

So…How Does This Really Happen?

Evolution in Genetic Terms: The change in allele frequencies over time.

Population Genetics

Mutations: change in genetic information of a cell

Population Genetics

Gene Pool: Combined genetic material of all the members of a given population.

Allele Frequencies: Percentage of appearance of a single allele in a gene pool.

What is the Allele Frequency of blue eyes in this class?

So How Do Adaptations Happen?

Natural selection allows an individual with desirable traits to live and pass on the genetic information.Person with correct DNA will pass off their

genes to next generation

Population Genetics

Genetic Equilibrium:

If the allele frequency is constant the allele has reached equilibrium. It will not change unless something big happens to the population.

Population Genetics

Genetic Drift: random change in allele frequency in a population due to chance events.