How does Succession Effect the Animals?

• Pioneer plant species favor herbivores, small and large

• As the forest grows, more predators move in

• As succession continues the diversity changes

Natural Selection• If an ecosystem changes,

the animal populations have to adapt or move

• Only the animals with the characteristics to survive will populate the new ecosystem

• Animals can gain new characteristics by chance genetic mutations

Examples of Natural Selection• Darwin’s finches

– Galapagos Islands– Similar finches on each island – The finches have a unique beak

shape– Specialized for food source on it’s

island• Mountain Sheep

– Coat color and texture– Dall Sheep of Alaska– Bighorn Sheep of Rocky Mountains– Desert Sheep of Mexico

Adaptation• A trait shaped by

natural selection– Coat color or thickness– Beak shape and length

• The better suited the greater its chances of survival and reproductive success

Camouflage• Morphological

adaptations that allow animals to blend with their environment

• Prey species• Juvenile animals• Female animals

Mimicry

• Morphological adaptations that make one species look like another species

• Harmless species looking like a harmful species

• Viceroy and Monarch butterfly

• Kingsnake and coral snake

Natural Selection and Resistance• The ability of an organism to

tolerate a particular chemical designed to kill it– Herbicides

• Roundup Resistant weeds– Pesticides

• Colorado Potato Beetle– Antibiotics

• Methicillin-resistant Staphylococcus aureus (MRSA)

Artificial SelectionThe selective breeding of organisms by humans

for specific characteristics

Three Types of Natural Selection

StabilizingDirectionalDisruptive

• Remember– These are examples of different populations of

the same species

Stabilizing Selection

• Selection against both extremes

Directional Selection

• Selection against one extreme

Disruptive Selection

• Selection against the mean

• Splits population into two groups