what is a homologous structure? how are these evidence for evolution?

What is a homologous structure? How are these evidence for evolution?

Biology Journal 4/30/2014

Compare and contrast intraspecific competition and interspecific competition in a Venn diagram.

Biology Journal 12/12/2013

What kinds of competition is going on in these pictures?

What could be some things that organisms compete for? Who do they compete against?What could happen if there is too much competition?

Biology Journal 12/10/2013

Biology Journal

In terms of natural selection, why did the dinosaurs go extinct?

Biology Journal

What is your reaction to this data?

How do you think the data would look in 50 years?

How do you think the data would look in 500 years?

Biology Journal

What could be some differences between artificial selection and natural selection?

What could be some of the end results on the creature that is “selected” in these two different ways?

Biology Journal

What could be some examples of environmental pressures?

What is the impact of these on natural selection?

Biology Journal

What are the 4 steps of natural selection? How does this picture show each of these steps?

Biology Journal

Do you think that the human race is still evolving? Why or why not?

(there is totally no specific, right answer, just a good explanation of your answer)

Biology Journal 5/1/2014

Bacteria are getting stronger all the time! Explain why this is happening in terms of natural selection. What could be done to slow this process down?

5.4 Evolution5.4.1 Define evolution.

Evolution is the cumulative change in the heritable characteristics of a population. If we accept not only that species can evolve, but also that new species arise by evolution from pre-existing

ones, then the whole of life can be seen as unified by its common origins. Variation within our species is the result of different selection pressures operating in different parts of the

world, yet this variation is not so vast to justify a construct such as race having a biological or scientific basis.

5.4.2 Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures.

5.4.3 State that populations tend to produce more offspring than the environment can support.

5.4.4 Explain that the consequence of the potential overproduction of offspring is a struggle for survival.

5.4.5 State that the members of a species show variation.

5.4.6 Explain how sexual reproduction promotes variation in a species.

5.4.7 Explain how natural selection leads to evolution. Greater survival and reproductive success of individuals with favourable heritable variations can lead to change in the characteristics of a population.

5.4.8 Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria. Other examples could include: the changes in size and shape of the beaks of Galapagos finches pesticide resistance industrial melanism heavy-metal tolerance in plants

Biology Journal 2/28/2014

What must 2 organisms be able to do in order to be considered the same species?

What could be some problems with this definition?

+ =

Donkey •Equus africanus, aka “ass”•64 chromosomes•Excellent at pulling or carrying weight

Horse•Equus equus•62 chromosomes•Fast, easy to train for a variety of tasks (riding, racing, pulling a carriage, warfare)

+ =Mule•No species name!•Sterile! (can’t reproduce)•63 chromosomes•Often has useful qualities of both horses and donkeys

Grizzly Bear•Ursus arctos•74 chromosomes•Lives in North American temperature regions

Polar Bear•Ursus maritimus•74 chromosomes•Lives in Arctic regions of Northern hemisphere

+ =Grolar Bear•No species name!•Can reproduce!•74 chromosomes•Found in wild and in captivity

Species ProblemPopulations move. Species evolve. DNA changes. Constantly!

Evolution

5.4 Evolution5.4.1 Define evolution.

Evolution is the cumulative change in the heritable characteristics of a population. If we accept not only that species can evolve, but also that new species arise by evolution from pre-existing

ones, then the whole of life can be seen as unified by its common origins. Variation within our species is the result of different selection pressures operating in different parts of the

world, yet this variation is not so vast to justify a construct such as race having a biological or scientific basis.

5.4.2 Outline the evidence for evolution provided by the fossil record, selective breeding of domesticated animals and homologous structures.

5.4.3 State that populations tend to produce more offspring than the environment can support.

5.4.4 Explain that the consequence of the potential overproduction of offspring is a struggle for survival.

5.4.5 State that the members of a species show variation.

5.4.6 Explain how sexual reproduction promotes variation in a species.

5.4.7 Explain how natural selection leads to evolution. Greater survival and reproductive success of individuals with favourable heritable variations can lead to change in the characteristics of a population.

5.4.8 Explain two examples of evolution in response to environmental change; one must be antibiotic resistance in bacteria. Other examples could include: the changes in size and shape of the beaks of Galapagos finches pesticide resistance industrial melanism heavy-metal tolerance in plants

What could be some things that limit population size?

Environmental Pressure: Anything (living or nonliving) in the environment that decreases an organism’s chances of surviving or reproducing.What could be some examples of this?

Predators Space / Habitat

Competition(Population density) Diseases

What can happen if environmental pressure gets too great?

The population must move to another area (emigrate), or die off (and can eventually go extinct in that area)

What could happen if environmental pressure is too little?

The population size grows exponentially until it reaches or exceeds the carrying capacity (the maximum number of organisms that can survive in an area)

Evolution is the cumulative change in the heritable characteristics of a population.

Changes happen gradually, and

accumulate over many generations

Can be inherited (passed form

parents to offspring)

Traits carried on genes (DNA)

A species, which is a large group interbreeding of

organisms

How could you possible get something as complex as an eye, or flight, or hands, or anything evolve slowly over time? We have the evidence in

living and fossilized organisms.

Evolution is the cumulative change in the heritable characteristics of a population.

All organisms have a common ancestry. Homologous structures are an evidence of this. The same structure has been passed down through the DNA and evolved to different functions.

These animals all must be related to a single species in the past.

Why do all of these completely different organs have exactly the same bone arrangement?

Because a common ancestor had those bones!

We also find fossils of all of the intermediate ancestors of all of these creatures as fossils!

Natural Selection has 4 Basic steps:

1. More organisms are born than survive.

Game = Frogger Difficulty Setting = Epic

Natural Selection has 4 Basic steps:

2. A population has genetic variation

What is the difference between sexual and asexual reproduction?

Which one introduces more diversity in the gene pool of a population?

Natural Selection has 4 Basic steps:

3. Organisms struggle to survive against environmental pressures.

Natural Selection has 4 Basic steps:

4. Organisms with advantageous traits are more likely to survive and pass on those traits.

In the 1800s, in the forests of England, there lived an insect called the peppered moth. There were two

phenotypes (appearances) of this insect.

A story of natural selection…

Tutorial and Game with Peppered Moths:http://www.techapps.net/interactives/pepperMoths.swf

The light colored moths made up 99% of the population.

Can you explain why in terms of natural selection?

A story of natural selection…

Then, the industrial revolution happened in England. And with it came a lot of unregulated pollution.

A story of natural selection…

When you don’t vote, your standard of living tends to get worse.

Tutorial and Game with Peppered Moths:http://www.techapps.net/interactives/pepperMoths.swf

Realizing the damage that was being done, reforms were eventually passed to limit pollution. The forest returned to the way is was before. What do you think happened to the peppered moth population?

Antibiotic resistant bacteria is a dangerous lesson in natural selection

Antibiotic resistant bacteria is a dangerous lesson in natural selection

Antibiotic resistant bacteria is a dangerous lesson in natural selection

Antibiotic resistant bacteria is a dangerous lesson in natural selection

Big Problems!

Antibiotic resistant bacteria is a dangerous lesson in natural selection

When we use pesticides on crops, they work great for a few years, and then become useless. Can you explain why?

Humans can manipulate and evolution by controlling who reproduces and with whom. This is called artificial selection.

Through thousands of years of artificial selection, humans turned wolves, majestic symbols of wilderness

and independence, into helpless, dumb poodles.

Artificial Selection

What did we artificially select these dogs to do?

Pit Bull

Siberian HuskyGreyhound

BloodhoundGolden

Retriever

St. Bernard ChihuahuaGerman

Shepherd

What could be some other animals we’ve artificially selected?

Black Angus Holstein Texas longhorn

Draft Horses Thoroughbreds Ponies

Artificial selection is how all of our crops and food animals have become big, resistant to the environment, delicious and nutritious!

Many times in history people have endorsed the artificial selection of people to “improve” the human race.

This is called “eugenics” and is essentially a justification for genocide or other human rights abuses.

In the 1936 Olympics, held in Berlin, Germany, team USA sent Jessie Owens, an African American track and field athlete. He won 4 gold medals, humiliating the Nazi Germans, who were eager to use the Olympics to demonstrate their race’s “superiority.”

Who’s the inferior race now?

What are the 4 steps of natural selection? How does this picture show each of these steps?

What could be some differences between artificial selection and natural selection?

What could be some of the end results on the creature that is “selected” in these two different ways?