Modern Evolutionary Theory. Darwin and Mendel Supports Darwin’s concepts of variation and natural selection Explains the genetic basis for variations.

Slides:

Advertisements

Similar presentations

Darwin and His Theory of Evolution by Natural Selection

Advertisements

Natural Selection, Adaptation, and Evolution

The History of Evolution

Natural Selection SC.912.L Describe the conditions required for natural selection, including: overproduction of offspring, inherited variation, and.

Charles Darwin’s Big Ideas!

1 Review Define the terms genes pool and relative frequency Predict Suppose a dominant allele causes a plant disease that usually kills the plant before.

Evolution of Populations

Darwin and His Theory of Evolution by Natural Selection

11.1 Genetic Variation Within Population KEY CONCEPT A population shares a common gene pool.

The History of Evolution

A Closer Look At Darwin’s Idea of Natural Selection

Study Guide Review!!!! Also use the Vocabulary Review PPT to help understand these important evolution concepts.

Chapter 3.4 (pages 88-89). Key concepts: Identify three kinds of adaptations that help organisms survive. Describe the four parts of natural selection.

1. Natural selection can only occur if there is variation among members of the same species. WHY? Variation in a population results from mutation and.

TOPIC: Evolution AIM: Explain the today’s theory of evolution.

15-1 Notes: Adaptations and Natural Selection

14.3 Natural Selection the Mechanism for Evolution 14.3.

Aim: How does evolution occur by natural selection?

1.Behavior geneticists study the genetic basis of behavior and personality differences among people. 2.The more closely people are biologically related,

Natural Selection SC.912.L Describe the conditions required for natural selection, including: overproduction of offspring, inherited variation, and.

IB Biology Topic 5.4 Evolution. Topics Define evolution Outline the evidence for evolution provided by the fossil record, selective breeding.

Aim: How does adaptative variation lead to the survival of an organism?

Natural Variation & Artificial Selection. Natural Variation & Artifical Selection Darwin, through many observations, explained evolution by natural variation.

EVOLUTION UNIT Natural Selection & Biological Resistance.

EVOLUTION …via Natural Selection. Organisms produce more offspring than can survive.

Aim: How does evolution occur by natural selection?

Darwin proposed natural selection as the mechanism of evolution Ch

8-5 Notes: Natural Selection. SO HOW DID ORGANISMS BECOME SO WELL ADAPTED TO THEIR ENVIRONMENT?

How did such tremendous diversity of life come to exist on this planet?

Darwin’s Evolution A Theory of Evolution. How did the giraffe get its long neck ? Lamarck had an idea… Lamarck had an idea… Organisms acquire traits.

Welcome ! Today our 2nd to last unit

KEY CONCEPT A population shares a common gene pool.

Objective: Understand the Key Events in Darwin’s Life

Aim: How does evolution occur by natural selection?

The Process of Natural Selection

Click this button to play

Mechanisms of Evolution

Quick Review: What is evolution?

Natural Selection & Biological Resistance

EVOLUTIONARY THEORY JEAN BAPTISTE LAMARCK.

Evolution of populations

KEY CONCEPT A population shares a common gene pool.

Evolution: Natural Selection

Natural Variation & Artificial Selection

KEY CONCEPT A population shares a common gene pool.

Evolution of populations

KEY CONCEPT A population shares a common gene pool.

KEY CONCEPT A population shares a common gene pool.

Natural Selection = mechanism for evolution

What has caused SUPERBUGS (antibiotic resistant bacteria) like MRSA?

September Journal: What is a theory? Are theories always true?

Natural Selection & Evolution

This is Evolution.

KEY CONCEPT A population shares a common gene pool.

EVOLUTION: DARWIN vs. LAMARCK

3 Ways Evolution Happens

KEY CONCEPT A population shares a common gene pool.

Microevolution Change within a species, organisms adapt to survive in their environment Micro - evolution is "driven" by natural selection Natural selection.

History of Biological Diversity Evolution: Darwin’s travel

Populations Change Over Time through Natural Selection

III. Darwin’s Theory of Natural Selection

Natural Selection.

Evolution Notes.

Modern Evolutionary Theory

KEY CONCEPT A population shares a common gene pool.

KEY CONCEPT A population shares a common gene pool.

SURVIVAL OF THE FITTEST

A population shares a common gene pool.

KEY CONCEPT A population shares a common gene pool.

Presentation transcript:

Modern Evolutionary Theory

Darwin and Mendel Supports Darwin’s concepts of variation and natural selection Explains the genetic basis for variations Variations can give individuals an advantage over others in their struggle for resources; any trait that helps an organism survive and reproduce is said to have adaptive (survival) value (example snowshoe bunnies, polar bears)

2 Ways Variation Occurs Variation is caused by segregation (separation of chromosomes into different gametes) and recombination (crossing over) during meiosis. In other words, variation is caused by sexual reproduction. Variation is also caused by mutations which are changes in the genetic material.

Chunk! How is the Modern Theory of Evolution different from Darwin’s? What does “adaptive value” mean? What are two causes of variation? Define segregation. Define recombination.

Natural Selection and Resistance Natural selection can also be responsible for insects developing resistance to insecticides. For example, a few roaches in a population may have a random mutation Random mutation does not have adaptive value in regular environment…

Resistance …That allows them to live unaffected when an insecticide is sprayed. The other roaches in the population without this mutation would die.

Resistance Since this mutation makes the bugs more fit for their environment (one that includes a pesticide), these roaches live and reproduce, passing the resistance to their offspring.

Resistance Note: the insecticide did not CAUSE the resistance. It just acted as a selecting agent showing which roaches were more “fit”.

Evolution? Compare the traits of the original population and the surviving population. originalsurviving

Resistance The development of penicillin-resistant strains of bacteria occurs in a similar fashion

Chunk! Why was there variation in the original population? What was the effect of the mutation without spray present? What is the effect of the mutation with spray present? Why is saying the roaches are “immune” to the spray incorrect? What is the proper term?

What caused the resistance? Why is the pesticide called a “selecting agent”? What do the most fit roaches do? What is this an example of? What does the bug clipart in the corner represent?