Evolution is the process by which Populations accumulate inherited changes over time.

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Evolution is the process by which Populations accumulate inherited changes over time.

Transcript of Evolution is the process by which Populations accumulate inherited changes over time.

Page 1: Evolution is the process by which Populations accumulate inherited changes over time.

Evolution is the process

by which Populationsaccumulate

inherited changes over time.

Page 2: Evolution is the process by which Populations accumulate inherited changes over time.

Includes three major ideas:

Theory of Evolution

All organisms developed from a single life form that lived on Earth billions of years ago.

All organisms share common ancestors.

All species arise from other species.

Page 3: Evolution is the process by which Populations accumulate inherited changes over time.

Scientist have found evidence that allorganisms on earth share a commonancestor…all organisms are related.

Similar bone structure in the

upper arm suggests these animals have a

common ancestor.

Common Ancestor

Page 4: Evolution is the process by which Populations accumulate inherited changes over time.

Mutations Natural

Selection

Two processes are necessary for populations to change over time.

Page 5: Evolution is the process by which Populations accumulate inherited changes over time.

Mutations are sudden changes in the DNA of a gene. These changes can be passed on from parent to offspring.

Some mutations are helpful. Some mutations are harmful. Some are neither helpful or harmful.

Mercury-Poisoning Mutation

Harmful: Albinism is an inherited mutation.

Albinos lack protective skin pigments therefore are prone to skin cancer and do not see well in

bright light.

Helpful: such as a mutation that causes

bright color patterns in flower petals…all the

better to attract pollinating insects.

Mutation

Page 6: Evolution is the process by which Populations accumulate inherited changes over time.

Finches from the Galápagos Islands

H.M.S. Beagle

Five year voyage of H.M.S. Beagle (1831-

1836)

In 1831 Charles Darwin (22 years old) voyaged on the HMS Beagle

to the Galapagos Islands where he made many observationsabout the different species of plants and animals.He was most interested in the birds that livedin the different Islands. In 1859 he wrote a bookcalled “On the Origin of Species”. In it Darwinpresented his theory of evolution by natural selection.

Charles Darwin

Page 7: Evolution is the process by which Populations accumulate inherited changes over time.

“Survival of the Fittest” Traits are selected Traits must be passed from one generation to the

next Changes occur in response to the environment

Natural selection is a process in which organisms

that are better able to survive and reproduce in an environment are more likely to pass their

traits on to future generations.

Natural Selection

Page 8: Evolution is the process by which Populations accumulate inherited changes over time.

An adaptation is a characteristic or trait that helps an organism survive in its environment.

Adaptation plays a major role in natural selection.

An adaptation makes an organism more suited to its environment, and therefore more likely to survive and pass on its traits to the next generation.

Adaptation

Page 9: Evolution is the process by which Populations accumulate inherited changes over time.

Some adaptations are body parts. Other adaptations are behaviors.

A tiger’s teeth are adapted for tearing and chewing. A tiger’s fur

helps it blend into tall grasses.

Feathers are adaptations used for flight. A bird’s beak is adapted to

the food it eats. What type of food do you think this bird eats?

Adaptations

Page 10: Evolution is the process by which Populations accumulate inherited changes over time.

Leaves of green plants are adapted to absorb sunlight. Flowers are

adaptations that attract insects that can help a plant reproduce. How do

you think a plant’s stem helps it survive?

A cactus is adapted to life in a desert. Its thick stems store water. A waxy coating on the

plant reduces water loss.

Adaptations Cont.

Page 11: Evolution is the process by which Populations accumulate inherited changes over time.

A sea turtle retreats into its shell when it senses danger. What are

some other adaptations of sea turtles?

A dandelion’s seeds are easily dispersed

by the wind. How do you think this adaptation help the plant’s species?

How do you think this insect adapted to

living in or near trees?

Adaptations Cont.

Page 12: Evolution is the process by which Populations accumulate inherited changes over time.

Peppered MothsThe European peppered moth often rests on the trunk of trees and is found in two colors: one light and one dark. Before 1850, most peppered moths were light. After 1850, industry created pollution that blackened the tree trunks. Light moths became rare, while the once-rare dark peppered moths became more common.

Page 13: Evolution is the process by which Populations accumulate inherited changes over time.

Which moths are better adapted to the tree that they are on?

Adaptations of Peppered Moths

Page 14: Evolution is the process by which Populations accumulate inherited changes over time.

The light variety of the peppered moth

on a birch tree trunk.

The dark variety of the peppered moth

on a birch tree trunk.

Unpolluted Birch Forest

Page 15: Evolution is the process by which Populations accumulate inherited changes over time.

The light variety of the peppered moth on a soot-blackened tree

trunk.

The dark variety of the peppered moth on a soot-blackened tree

trunk.

Polluted Birch Forest

Page 16: Evolution is the process by which Populations accumulate inherited changes over time.

Evolution Mini Assessment Review

__________ is the process by which populations accumulate inherited __________ over __________.

Evolution changestime

Three Major Ideas of the Theory of Evolution:

Organisms developed from a single life form that lived on Earth billions of years ago.

Organisms share common ancestors. Species arise from other species.

Page 17: Evolution is the process by which Populations accumulate inherited changes over time.

Two processes are necessary for populations to change over time:1. __________ 2. ___________

MutationsNatural Selection

__________ are sudden changes in the ______________ of a gene. These changes can be passed on from parent to offspring.

MutationsDNA

Evolution Mini Assessment Review

Page 18: Evolution is the process by which Populations accumulate inherited changes over time.

Evolution Mini Assessment Review

__________ in 1859 wrote a book called “On the Origin of Species”, it was about __________ by __________ selection.

Charles Darwinevolutionnatural

__________ is a process in which organisms that are better able to survive and reproduce in an __________ are more likely to pass __________ traits on to future generations.

Natural selectionenvironmentfavorable (good traits)

Page 19: Evolution is the process by which Populations accumulate inherited changes over time.

Evolution Mini Assessment Review

An __________ is a characteristic or trait that helps an organism survive in its environment.

Adaptation

A species can become __________ if its environment changes to quickly.

extinct