Biological Evolution

Four friends were discussing the meaning of the term biological evolution. This is what they said.

Mario “I think it is another term for natural selection.”

Sally “I think it mainly explains how life started.”

Cameron “I think it mainly explains how life changed after it started.”

Paz “ I think it includes both how life started and how it changed after it started.”

Who do you most agree with? Explain what you think biological evolution is.

Biological EvolutionA group of friends were discussing biological evolution. This is what they said. Who do you most agree with? Explain

Jenna “Evolution is about creating a perfect species like going from something ugly to something beautiful.”

Steve “Evolution is mostly random which makes new species randomaly.”

Becka “Evolution is mostly not random .”

A group of friends were arguing about what would happen if a population of rabbits from Arizona, a warm climate were moved to Rosholt, a cold climate. This is their responses. What person do you most agree with and why? Explain your ideas about adaptation.

Bernie “I think all of the rabbits will try to adapt to the change”

Leo “I think most of the rabbits will try to adapt to the change”

Phoebe “I think none of the rabbits will try to adapt to the change”

Adaptation

Adaptation

Adaptation

Evolution and religionA group of friends were discussing biological evolution. This is what they said. Who do you most agree with? Explain

Jerry “I can’t believe in evolution because it is against my religion.”

Amber “Science is about observations and religion is about faith so they cannot be compared.”

George “ I heard that all people that believe in evolution are atheist.”

Who do you most agree with? Explain

Evolution terms

• Species- a group of organisms that can have fertile offspring.

• Population- a group of the same species• Evolution-process of populations changing

over time.

Evolution terms

• Variation- a difference in one organism to another of the same species

• Adaptation- a trait that helps an organism survive or reproduce better.

Evolution terms

• Selective breeding- breeding an organism for a specific trait/characteristic

• Natural selection- nature picking an organism for a specific trait/characteristic

What is thedomesticated plantfrom the originalwild plant?

Corn selection

Basics of SelectiveBreeding• There is variation in

the population• There is a selection• Reproduction• Overall change in

population. (still variation though)

What were those people thinking?

Compare the pictures of wild teosinte and domesticated corn. What trait variants in teosinte do you think would have been selected by ancient people? List at least three traits that you think might have been a target of selection.

The selective breeding of Corn

• A gene on chromosome #1 causes the ears of corn to be big and to grow on a few short branches. In contrast, the ears of teosinte are scattered over many small branches.

• A gene on the second chromosome causes more rows of kernels to grow, yielding more food per corn plant.

• A gene on the fourth chromosome causes corn kernels to have small, soft casings. Teosinte kernels have much larger, harder kernel casings that make them hard to eat.

• Look at the photo of the wild and domestic tomatoes.In a series of steps, explain how ancient people might have evolved a population of domestic tomatoes from a population of wild ones. Be sure that your explanation includes the concepts of variation, inheritance, and selection.

Natural selection• There is variation in traits.

For example, some beetles are green and some are brown.

• There is differential reproduction.The environment can't support unlimited population growth, not all individuals get to reproduce. In this example, green beetles tend to get eaten by birds and survive to reproduce less often than brown beetles do.

• There is heredity.The surviving brown beetles have brown baby beetles because this trait has a genetic basis.

• End result:The more advantageous trait, brown coloration, which allows the beetle to have more offspring, becomes more common in the population. If this process continues.

• If you have variation, differential reproduction, and heredity, you will have evolution by natural selection as an outcome. It is as simple as that.

Venn Diagram

• In you notebook compare the similarities and differences of Natural Selection and Artificial Selection using a Venn Diagram.

• If artificial selection is happening is there any reason that natural selection cannot happen?