Warm Up

Describe the Law of Superpostition.

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• What do you think each of the following mean?

o Fossil o Comparative anatomy o Comparative embryologyo Comparative biochemistryo Geographic distribution

o Fossil

preserved remains or traces of animals,plants, and other organisms

o Comparative anatomy

Study of similarities and differences in the anatomy of different organisms

o Comparative embryology

Compares and contrasts embryos of different species

o Comparative biochemistry

structure, composition, and chemical reactions of substances in living systems.

o Geographic distribution

Distribution of Plants and animals

Evidence of Evolution

• Fossil • Comparative anatomy • Comparative embryology• Comparative biochemistry• Geographic distribution

Evidence of Evolution

Evolution

Fossils

Glyptodont

Fossils provide a record of species that lived long ago. Fossils show that ancient species share similarities with

species that now live on Earth.

Armadillo

Evolution

Derived traits newly evolved features

Feathers do not appear in the fossils

of common ancestors.

Ancestral traits primitive features

Teeth appear in ancestral forms.

Two classes of traits

Comparative Anatomy

Anatomically similar structures inherited from a common ancestor are called homologous structures.

• Analogous structures – same appearance, structure or function – evolved separately– do not share common ancestor.

• Homologous structures– Similar structures – Share common ancestor

Homologous or Analogous

Evolution

Show that functionally similar features can evolve independently in similar environments

Analogous structures

Evidence of Evolution

Evolution

Vestigial Structures

reduced forms of functional structures in other organisms.

Evidence of Evolution

Evolutionary theorypredicts that features of ancestors that no longer have a function for that species will become smaller over time until they are lost.

Evolution

Vestigial Structures

reduced forms of functional structures in other organisms.

Evidence of Evolution

Evolutionary theorypredicts that features of ancestors that no longer have a function for that species will become smaller over time until they are lost.

Evolution

Vestigial Structures

reduced forms of functional structures in other organisms.

Evidence of Evolution

Evolutionary theorypredicts that features of ancestors that no longer have a function for that species will become smaller over time until they are lost.

Evolution

Vertebrate embryos exhibit homologous structures during certain phases of development but become totally different structures in the adult forms.

Comparative Embryology

Evidence of Evolution

Evolution

Many different organisms share metabolic molecules

Common ancestry

Comparative Biochemistry

Evolution

Comparisons of the similarities in these molecules across species support the evolutionary patterns seen in comparative anatomy and in the fossil record.

Organisms with closely related morphological features have more closely related molecular features.

15.2 Evidence of Evolution

Chapter 15

Geographic Distribution The distribution of plants and animals Evolution is intimately linked with climate and

geological forces.

Rabbit Mara

Evolution

Types of Adaptation Adaptation

trait increases an organism’s reproductive success.

Camouflage

Mimicry

California kingsnake

Western coral snake

Evolution

Fitness is a measure of the relative contribution an individual trait makes to the next generation.

Traits with higher fitness become more common.

1 2 3 4 5 6 7 8 9 100

2

4

6

8

10

12

Fitness vs. Number of organisms

Fitness

# of

org

anism

s with

trai

t

Name the independent and dependent variables?

Independent variable

dependent variable

A. ancestral traitsB. analogous structuresC. homologous structuresD. vestigial structures

Identify the term that is used to describe anatomically similar structures inherited from a common ancestor.

EvolutionChapter 15

Chapter Diagnostic Questions

A. snake pelvisB.porpoise flipperC. human appendix

Which is not a vestigial structure?

EvolutionChapter 15

Chapter Diagnostic Questions

A. a tailB. bonesC. feathersD. teeth

Which is an example of a derived trait?

EvolutionChapter 15

15.2 Formative Questions

A. analogous structuresB. embryological structuresC. homologous structuresD. vestigial structures

Which features are similar in use and evolve in similar environments, but do not evolve from a common ancestor?

EvolutionChapter 15

15.2 Formative Questions

True or False

Organisms with similar anatomy share similar DNA sequences.

EvolutionChapter 15

15.2 Formative Questions

A. adaptationB. biogeographyC. gradualismD. speciation

At the heart of the theory of evolution by natural selection lies the concept of __________.

EvolutionChapter 15

15.2 Formative Questions

A. camouflageB. mimicryC. embryological adaptationD. vestigial structure

Determine which morphological adaptation the monarch butterfly exhibits.

EvolutionChapter 15

Chapter Assessment Questions

Evolution

Which is the best explanation for the similarities in the construction of these forelimbs?

A. Each forelimb is a similar modification derived from a different ancestor.

B. Natural selection has produced similar modifications in the forelimb.

Chapter 15

Standardized Test Practice

Evolution

C. They are functionally similar features that have evolved independently.

D. They are modifications of the forelimbs of a common ancestor.

Chapter 15

Standardized Test Practice

Which is the best explanation for the similarities in the construction of these forelimbs?

Closing Quiz

Contrast ancestral and derived traits.