1. The greatest show on earth!
Evolution
The greatest show on earth!

2. Theories Evolution is a theory
Not “JUST” a theory
Remember, a theory explains why things happen; are supported by a large set of facts, observations, and experiments; and can make predictions about what we could expect to see
Evolution fits all of those criteria, and is therefore, a scientific theory.

3. Development of Evolutionary theory
The idea of evolution was built over time by several people.
The theory is still being refined today although the main principles have remained the same since first published in 1859.

4. Lamarckian Evolution
Most evolution discussions start with Jean-Baptiste Pierre Antoine de Monet, Chevalier de Lamarck
Jean-Baptiste Lamarck for short.
Lamarck proposed that living things changed through 2 theories:
The Theory of Need
If a living things needed something it could change its physical characteristics to create that. It’s offspring would then inherit that trait.
The Theory of Use and Disuse
If a living things used a trait frequently it would keep that trait. If it did not use something it would lose that trait.
The beneficial or lost traits would be passed down (or not passed down) to the offspring.

5. Lamarckian Evolution Clearly Lamarck was not correct in his theory.
What are some reasons you think of that would prove him incorrect?

6. Charles Darwin
Charles Darwin was a British naturalist – observer of nature
He observed plants and animals to note their similarities and differences
He was also an avid collector of living organisms
Particularly barnacles
He also tried to eat a majority of the species that he studied.

7. Charles Darwin
In 1831, Darwin left on the H.M.S. Beagle to travel to several points across the globe and study living organisms.
They stopped in Africa, South America, the Galapagos Islands, Australia, and Madagascar (among other places)

8. Charles Darwin On his trip, Darwin noted:
Geological similarities in Africa and South America
Geological upheaval revealing fossil of animals and plants that were extinct
Fossils of extinct animals that resembled modern animals
Variation among species in similar locales
Changes in similar species in different locales

9. Charles Darwin
Most notably, Darwin studied the finches of the various Galapagos Islands
He noted that the finches looked very similar to finches from South America’s mainland but were different in other ways
He also noted that the finches has specialized diets
They also had specialized beaks.

10. Charles Darwin
Darwin spent the next two decades back in England gathering evidence, experimenting, and observing.
In 1859 he published On the Origin of Species outlining his Theory of Evolution by Natural Selection

11. Alfred Wallace
Although not as well known as Darwin, Alfred Wallace independently developed the same theory in a different location
Wallace studied in Borneo and the islands of Indonesia for four year.
While there he collected samples and made many observations
On his return journey, Wallace’s ship caught fire and he lost most of the work that he collected.

12. Alfred Wallace
Alfred Wallace independently came upon the idea of evolution by natural selection and sent a article to Charles Darwin outlining his idea in 1858.
Darwin corresponded with him but also realized he must publish his work in order to receive credit for the idea he came upon nearly two decades earlier.

13. Evolution Evolution is the unifying theory in biology
“Nothing in biology makes sense except in the light of evolution.” – Theodosius Dobzhansky
Using the principles of evolution, we can look at every aspect of the biological world through an evolutionary lens

14. Evolution
Evolution is the change in heritable characteristics in a population of living things over successive generations.
Heritable characteristics – traits that get passed down from parent to offspring
Population – a group of organisms of the same species
Successive generations – a number of offspring over time
Evolution is the change in traits within a group of the same species as they have many children/offspring over time.

15. Evolution
Evolution is the theory that explains how species on Earth change over time and how they can eventually give rise to new species.
Essentially, it explains why living things are the way they are, and why they were what they were.
Evolution is the underpinning theory of all Biology

16. How Evolution Works
Evolution can be explained using a few main points:
Every individual is unique
Every individual passes on it’s traits when it reproduces
Every individual is under selection pressures to survive

17. 1. Every Individual Is Unique
A species is a group of organisms that can produce fertile offspring
Every member of a species is a little bit different
This makes some living things really good a certain things and really bad at certain things

18. 1. Every individual is unique
These are all rabbits of the same species
They are actually of the same parents
There is a large amount of diversity even amongst the group of rabbits. They differ in:
Colour
Markings
Size
They could also differ in intelligence, speed, biochemistry, strength, metabolic efficiency, etc.

19. 2. Individuals Pass on Traits When they Reproduce
Offspring tend to have the same or similar traits to their parents
This is because of heredity.
Each species (without selections pressures)
would have a completely random sample of traits

20. 2. Individuals pass on traits when they reproduce
The traits in an individual are taken from the gene pool.
Gene – a part of DNA that determines a trait (for now…until we find a better definition)
Gene pool – the available genes in a population
Each individual can be thought of as a sampling of the genes in a gene pool

21. 2. Individuals pass on traits when they reproduce
When an individual dies without reproducing, its genes are taken out of the gene pool

22. 3. Every Individual Is Under Selection Pressures To Survive
“Life is tough. Deal with it.” – Mr. Sandor, 2017
Every living thing has stuff trying to kill it
Toxins, lack of resources, predators, parasites, competition with others, famine, drought, changes in the environment, etc.
In order to reproduce, you must survive these pressures

23. 3. Every Individual Is Under Selection Pressures To Survive
Some traits will allow you to survive more easily
Some traits may be detrimental to survival
Some traits make no difference to your survival
If an individual has traits that do no allow it to survive, it will not reproduce
If it does not reproduce, its genes are removed from the gene pool
If its genes are removed from the gene pool, those traits may be lost

24. 3. Every Individual Is Under Selection Pressures To Survive
Over time, the available traits in the gene pool change
As the available traits in a gene pool change, so do the observed traits in a population
Boom – evolution!

25. 3. Every Individual Is Under Selection Pressures To Survive
Lets say in nature that something is causing it to be difficult to survive when you show the ‘White Wing’ trait
As those members of the population die, the ‘White Wing’ gene will become less prevalent
So will the trait
Suppose each butterfly had 2 offspring:

26. 3. Every Individual Is Under Selection Pressures To Survive
Now look at the population
Suppose this pressure against ‘White Wings’ continues

27. 3. Every Individual Is Under Selection Pressures To Survive
We can imagine this trend continuing for many many generations
Overtime, the population will essentially become almost all brown and orange butterflies

28. Natural Selection
Natural Selection is how evolution occurs within nature
Nature “selects” through the action of the various pressures on living things.
Hence, natural selection. It is the selection process of nature.
Natural Selection filters out the ‘random’ traits and animals are ‘selected’ by their ability to survive and reproduce.
Keep in mind, nature doesn’t actually, consciously, pick which things survive.

29. Natural Selection Natural selection is usually stated in 4 points:
Overproduction – in a population, more individuals are produced each generation than survive
Struggle for Existence – Due to over production, organism must compete for limited resources
Variation – Each individual is different. These traits get passed down during reproduction
Survival of the Fittest – Individuals with characteristics that allow them to adapt in their environment are more likely to reproduce.

30. Evolution
Evolution gave rise to all of the diversity that exists in the world
It is how life tackled simple problems like “How to get energy from molecules” to “How to adapt a reptile into an Antarctic bird”
Evolution shows us our relation to every living thing on Earth as it shows that we all came from one individual starting point.

32. “Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” On the Origin of Species Charles Darwin