E1 - Intro to Evolution Flashcards
Who is Leclerc de Buffon and what did he belivie?
-He examined animal body structure and function and was puzzled by anatomical features that seemed to serve no purpose
-He believed that the species had been created in a more perfect form but changed over time
What did carl linneaus suggest?
that life changed over time
What did Erasmus Darwin suggest?
that all life might have evolved from a single original source
Chevalier de Lamarck proposed a mechanism for the evolution of species through 2 distinct principals:
Use and Disuse
Inheritance of Acquired Characteristics:
Use and Disuse
Structures that an individual used, became larger and stronger and structures that were not used, got smaller and weaker
Inheritance of Acquired Characteristics:
Individuals could pass characteristics onto their offspring that they had acquired over their lifetime
what was the problems with Lamarcks ideas
we know that traits can change over an individual’s lifetime, but that does not change their DNA or how their traits are passed on
For example, a giraffe cannot “stretch” its neck over its life and pass on the trait of a longer neck to its offspring
what book held convincing evidence that species have evolved
and also proposed a theory of how species evolved
Darwin’s On the Origin of Species
why did Darwin publish his book
received a letter from a young biologist named Alfred Russell Wallace outlining almost an identical theory Darwin became more anxious to publish
how did Darwin describe natural selection
described natural selection as a way in which the environment favours the reproductive success of certain individuals over others
- Evolution was simply the result of natural selection occurring over many generations
what was Darwins theories?
All healthy populations produce far more offspring than can survive
All individuals exhibited heritable variability
What did Darwin conclude from his theories
Some individuals will have better chance of success than others
Their traits are therefore more likely to be passed onto the next generation
Who coined the term “Survival of the Fittest” to describe process of evolution
Herbert Spencer
Why is “Survival of the Fittest” not true?
Being “fit” is not important, being more likely to have reproductive success is what is important!
-its the organism that is most adaptable to change that will survive
Evolution
Change in the gene pool over time from generaqtion to generation by such processes as mutation, natural selection and genetic drift
gene pool
The set of all genes or gentic information, in any population
ex: red hair and non-red head is 50%
-like a card deck that is reshuffled
-deck remains the same through generations, i.e 50% red
-if the frequency varies the evolution has occured
evolution in simple terms
change in the gene pool over time
5 fingers of evolution- little finger
- if population shrinks then chance can take over
ex, if a couple people survive a epidemic than their genes will represent the new gene pool
5 fingers of evolution- ring finger
reminder: mating (ring on ring finger)
- if indivduals choose a mate based on apperence or location the frequency may change
5 fingers of evolution- middle finger
reminder; “M” in middle finger should remmind you of mutatuons
- if new gene is added through mutation then it affects frequency
5 fingers of evolution- pointer finger
reminder: movment
-If a new indivdual flow into an area the frquency will change or even if they leave
- this is called gene flow
gene flow simplified
If a new indivdual flow into an area the frquency will change or even if they leave
WHAT DOES NOT LEAD TO ADAPTATION
- however, small populations, non-random mating, mutations and gene flow DO NOT LEAD TO ADAPTATION
what is the only process thay creates organisms better adapted to their local enviroments
natural selection
5 fingers of evolution- thumb
reminder; thumb up and down
- Nature votes thumbs up for adaptation that do well in enviroment
-votes down for adaptations that dont do well
-less adaptable genes are replaced with adaptable ones
microevolution
- refers to small change
macro evolution
larger change over longer time.
TRUE OR FALE: EVOLUTION IS ORGANISMS ADAPTING TO ENVIROMENT
FALSE
- INDIVIDUAL ORGANISMS DO NO EVEOLVE AT ALL
- RANDOM GENE MUTATIONS CAN OCCUR WHICH CAUSES CHANGE
TRUE OR FALSE: SURVIAL OF THE FITTEST
-FALSE
-EVOLUTIONARY FITNESS IS REALLY ABOUT HOW WELL SUITED ONE IS TO THE CURRENT ENVIROMENT
- ALSO SURIVIAL IS NOT HOW EVLOUTION OCCURS, REPRODCUTION IS
- IF AN ORGANISM DIES WITHOUT REPRODUCCING DOES NOT MEAN IT IS USELESS BECAUSE IT MAY HAVE DIED FOR SOMEONE ELSE TO TAKE ITS SPOT
TRUE OR FALSE: GENES WANT TO MAKE MROE COPIES OF THEMSELVES
-FALSE
-GENES DO NTO WANT ANYTHING
- NO OUTSIDE MECHANSIM THAT SELECTS WHICH GENES ARE BEST TO PRESERVE
-ALL THAT5 HAPPENS IS RANDOM GENETIC MUTATIONS
-THIS CAN RESULT IN MORE COPIES OF GENE BEING PASSED ON
immutable
unable to change
How do fossils help
- prove evidence of evolution by shwping that certain speices at time had certain traits
adaptation
a characteristic or feature
of a species that makes it well suited
for survival or reproductive success in
its environment
what can we take away from the black pepperd moth gizmo?
Nature favored adaptations that did well so for example before teh trees turned darkers the lighter moth population was thriving in population because they were camoflaging
-however, as teh trees got darker the moths that were darker, nature voted thumbs uo for the adaptation leading to their population to grow and survie
Biological evolution
process by which populations of organisms change over time.
