Notes:

Evidence for Evolution

15.2 Evidence of Evolution

Evolution

The Fossil Record

Provide a record of species that lived long ago

and show how ancient species share

similarities with current species.

(Ex. Early and modern horses)

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Evolution

Derived traits: Newly evolved features that

do not appear in the fossils of common

ancestors. (Ex. Flight feathers)

Ancestral traits: More primitive features that

do appear in ancestral forms. (Ex. teeth and

tails)

Homologous structures: Anatomically

similar structures inherited from a common

ancestor. (Ex. vertebrate forelimbs)

15.2 Evidence of Evolution

Chapter 15

Evolution

Vestigial Structures:

Structures that

have lost all or

most of their

important functions

and are reduced in

size.

(Ex. human

tailbone; whale

pelvis)

15.2 Evidence of Evolution

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Evolution

Features that

evolve

independently, but

are similar in

structure and

function.

(Ex. Bat, bird and

insect wings; shark

and dolphin fins)

15.2 Evidence of Evolution

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Analogous structures

Evolution

Vertebrate embryos show similar structures

during certain phases of development.

(Ex. tails and bronchial arches)

Comparative Embryology

15.2 Evidence of Evolution

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Evolution

Similarities in DNA

and RNA help to

determine

evolutionary

relationships

between species.

Comparative Biochemistry

15.2 Evidence of Evolution

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(Ex. DNA of humans and

chimpanzees is 98% the

SAME)

Geographic Distribution

Evolution

The distribution of plants and animals around

the world shows that evolution is closely

linked with climate and geological forces.

(Ex. rabbits and pikas live in similar niches)

Rabbit Pika

15.2 Evidence of Evolution

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Evolution

Types of Adaptation

An adaptation is a trait shaped by natural

selection that increases an organism’s

reproductive success.

Fitness is a measure of the relative

contribution an individual trait makes to the

next generation.

15.2 Evidence of Evolution

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Adaptations through Natural Selection

Evolution

Camouflage

Allows organisms to

become almost

invisible to

predators/prey by

blending into their

surroundings.

(Ex. Owls coloration

matches tree trunks)

15.2 Evidence of Evolution

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Evolution

Mimicry

One species evolves to resemble another

species, often for defense.

(Ex. California kingsnake looks like venomous

Western coral snake)

Western coral snake

(red touches yellow – kills a fellow)

California kingsnake

(red touches black, safe from attack)

15.2 Evidence of Evolution

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Evolution

Biological Resistance

Bacteria become resistant

to antibiotics and insects

become resistant to

pesticides. Called

MICRO-evolution

because it happens in a

SHORT amount of time.

(Ex. MRSA, tuberculosis)

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FOSSILS QUIZ on THURSDAY

Includes questions from:

Notes: How Populations Evolve

Fossils Table on BACK of Notes