Unit 1: Evolution-Intro to Evolution Flashcards
Evolution Definition
The cumulative change in the heritable characteristics of populations that occurs over successive generations; a theory to explain (prove) how species change over time (slow) through adaptations and mutations.
Who cannot evolve?
Individuals
What are the smallest unit that can evole?
Populations
Why are populations the smallest unit that can evolve?
Populations can have a shift in their gene pool.
Why do populations evolve?
So that a population becomes better suited to its habitat.
What does a population becoming better suited to its habitat result in?
-Increased survival
-Better chance of passing on characteristics to offspring.
Over what period of time does population evolution take place?
Over many generations
How does a population evolve?
There is a shift in the gene pool so that a higher ratio of individuals have a particular adaptation.
Adaptation definition
A particular structure, physiology or behaviour that helps an organism survive and reproduce in a particular environment
What are some examples of adaptations?
E.g. camouflage, superb sense of smell, bill shape
What is Myth 1 about the theory of evolution?
If humans evolved into monkeys, why are there still monkeys?
This is also related to the misunderstanding that evolution follows a linear path, that everything is trying to be human. - NOT SO –
What is Myth 2 about the theory of evolution?
Myth 2: Scientists regularly debate whether evolution occurs.
-Debate only occurs is in social settings, and is philosophical in nature.
- If any debate occurs among biologists, it’s often regarding specifics - such as timing, or what animal is related to what, or when did a creature evolve and what is its origins.
-As a THEORY, evolution is supported by a large body of evidence and is used to EXPLAIN new observations.
What is Myth 3 about the theory of evolution?
Myth 3: A person cannot believe in God and in evolution.
There are many scientists who have religious beliefs. One does not necessarily preclude the other.
What is Myth 4 about the theory of evolution?
Myth 4: Survival of the fittest encourages the strong to destroy the weak.
Remember, “strong” and “weak” are relative. Organisms do not have to be strong to survive
What is Myth 5 about the theory of evolution?
Myth 5: As organisms evolved so structures became more sophisticated and intelligent
The Retina is essentially backwards with blood vessels and nerve on the surface, creating a blind spot at the convergence of the retinal nerve.
The pharynx is a tube that connects the oral cavity to both the trachea and the esophagus.
How many common meanings of the word “theory” are there?
Theory has 2 common meanings
What are the two meanings of the word, “theory?”
Everyday meaning
Scientific meaning
What does the everyday meaning of theory mean?
Everyday meaning = an educated guess
In science that is called a hypothesis or a prediction
What does the scientific meaning of theory mean?
Scientific meaning = an explanatory model that accounts for a VERY large body of evidence
Cell Theory
Atomic Theory
Theory of Gravity
Unlike tentative guesses, what is a a scientific theory founded on?
Founded on a large body of evidence that gives scientists great confidence in the theory
What does this not mean for these theories?
These theories are complete or perfectly accurate
What are all scientific theories considered as?
Tentative and open for revision and refinement as new evidence is gathered
What would scientists still be shocked to see?
HOWEVER scientists would be shocked to find:
An animal without DNA
An atom without electrons
Or an apple that ‘fell up’
When something is a fact, what does it suggest?
It is absolute, and not subject to change
What does science not like?
Absolutes
What is the definition of fact?
An observation that has been confirmed repeatedly and is accepted as true (although its truth is never final)
What term do scientists prefer to use?
Observations
