Post on 09-Sep-2018
8.11C – Explore how short and long term environmental changes affect organisms
and traits in subsequent populations
Watch and Think https://www.youtube.com/embed/ysa5OBhXz-
Q?feature=player_embedded
What are your thoughts now?
If organisms (a biotic factor) can
influence an ecosystem, can an abiotic
factor, or factors do the same?
Venn Diagram Words to use
1. Climate Change2. Drought3. Hurricane4. Can cause extinction5. Can recover from change in a short time6. Floods7. Can cause permanent change to ecosystem8. Ice Age9. Volcanic eruptions10. Can cause the genes of an organism to change11. Can cause the genes of an entire population to change12. Forest Fire
Venn Diagram Words - Answers
1. Climate Change-LT2. Drought- LT3. Hurricane-ST4. Can cause extinction-LT5. Can recover from change in a short time-ST6. Floods-ST7. Can cause permanent change to ecosystem-LT8. Ice Age-LT9. Volcanic eruptions-LT10. Can cause the genes of an organism to change-ST11. Can cause the genes of an entire population to
change-LT12. Forest Fire- Both, depends on the severity and effects
on populations.
Adaptations Adaptations – are structures or
behaviors that increase an organism’s ability to survive in a given environment
Changes in the environment can affect survival of individual organisms and entire species.
Individual organisms live or die according to their inherited adaptations
Extinction occurs when species are unable to adapt to environmental changes
How did scientists learn about evolution? Evolutionary thought, the conception that species
change over time, has roots in antiquity, in the ideas of the ancient Greeks, Romans and Chinese. As well as medieval Islamic science.
Premier scientists were:
In the early 19th century, Jean-Baptiste Lamarck
1858 Charles Darwin and Alfred Wallace published a new evolutionary theory that was explained in detail in Darwin's On the Origin of Species.
Darwin proposed a theory was based on the idea of natural selection
Darwin’s Voyage In December 1831, Charles
Darwin set sail from England on a five year trip around the world
Darwin’s observations of plants and animals along the way led him to develop the theory of evolution by natural selection
Galapagos Islands In 1835, the Beagle reached
the Galapagos Islands
He noticed similarities and differences between organisms on the island and on the mainland
Darwin Reaches the Galapagos
Similarities and DifferencesMarine Iguanas of the Galapagos
• Large claws for gripping slippery rocks, eat seaweeds
Green iguanas in South America
• Smaller claws for climbing trees, eat leaves
Adaptations Darwin studied the different
finches on the island
He noticed that each species had a different beak shape, which related to the type of food it ate
Beak shape is an adaptation
Adaptations are structures or behaviors that increase an organism’s ability to survive
Darwin’s Finches
Natural Selection The process by which individuals that are better
adapted to their environment are more likely to survive and reproduce than other members of the same species
Darwin identified factors that affect natural selection:
Overproduction
Competition
Variation
Overproduction Most species produce far more offspring than can
possibly survive
There would not be enough resources for all of them
Ex. Sea Turtles lay more than 100 eggs
Competition The members of a species
must compete with each other to survive
Life in the wild is competitive, organisms with the most beneficial traits will prosper. This is commonly known as “Survival of the Fittest”
VariationsAny difference between
individuals of the same species
Ex. Some newly hatched turtles are able to swim faster than others
Every species exhibits variation
Selection Darwin observed that some variations make
individuals better adapted to their environment
Those individuals are more likely to survive and reproduce
If their offspring inherit the trait, they will be more likely to survive and reproduce
After many generations, more members of the species will have the helpful trait
In effect, the environment has “selected” organisms with helpful traits to be the parents of the next generation
Selection Cont. Darwin proposed that over a period of time, natural
selection can lead to change.
Helpful variations gradually accumulate in a species, while unfavorable ones disappear
A change in environmental conditions can affect an organism’s ability to survive, and therefore lead to selection
Survival determines if a trait is favorable!
The Role of Genes in Natural Selection
Only traits that are inherited can be acted upon by natural selection
How might new species form? Geographic isolation – when some members of a
species become cut off from the rest of the species
A new species might form when a group of individuals remains separated from the rest of its species long enough to accumulate different traits
Geographic isolation may have occurred on a worldwide scale during continental drift
Underwater Masters of Disguise
New study! Lizards evolution shorter than thought possible:
http://www.utexas.edu/news/2014/10/23/anole-lizards-evolution-florida/?utm_source=facebook&utm_medium=referral&utm_campaign=UTAustinSocial
Environmental Changes Human impacts cab also cause changes in
environmental conditions:
Pollution
Acid rain
Deforestation
Climate changes
Succession
Why does it matter if we change the world?
Human impact can harm our world and it can be irreversible.
We are dependent on our planet in ways that we are often unaware of.
Can anyone name a “dependence” we have?
8.11D Recognize human dependence on ocean systems and explain how human
activities such as runoff, artificial reefs, or use of resources have modified these
systems
Oceans
Water covers nearly ¾ of the Earth’s surface
More than 50% of the world’s population lives within an hour of the coast
Oceans play a role in both climate and day to day weather
Human dependence on oceans The ocean is our life support system, giving us more
than half of the oxygen we breathe, regulating climate, and providing valuable resources
How is marine life dependent on oceans systems?
The amount of sunlight, wave action, water temperature, water pressure, salinity levels and pH levels are important to maintain marine populations
Human activities modify the ocean
Critical Ocean Issues:
Overfishing
Sea Temperature Rise
Marine Pollution
Ocean Acidification
Marine Habitat Destruction
Sea Level Rise
Marine Invasive Species
“Even if you never have the chance to see or touch the ocean, the ocean touches you with every breath you take, every drop of water you drink, every bite you consume.
What does this quote mean? How are we all connected to the ocean?
*HW – watch videos
Everyone, everywhere is inextricably connected to and utterly dependent upon the existence of the sea.” ~ Sylvia Earle (oceanographer)