Evolution quiz Flashcards
What are mutations
changes in the genetic material of an organism
what are the three mutations
neutral beneficial and harmful
what is a neutral mutation and an example
no effect on the organisms biological fitness
- attached or detached earlobes
what are beneficial mutations and an example
increases an organisms biological fitness to survive or produce
- webbed feet on a duck helps them swim faster
what are harmful mutations
prevents a gene to function properly, decreasing biological fitness
- allele or cystic fibrosis
what is biological fitness
an organisms ability to survive and reproduce
what is selective pressure and an example
environmental conditions that select certain characteristics of individuals and select against other charactertics - Moths turning black because of the industrial revolution
What is artificial selection and an example
Selective pressure exerted by humans on populations in order to improve or modify desirable traits.
Ex. Dogs are selectively bred for a purpose by humans.
four steps for artificial selection
- desired traits are identified
- they are bred
- offspring that only contains desired traits are bred.
- repeated over generations till its fully developed.
What is natural selection
A process that results when characteristics of a population or organisms change over many generations.
What are the 4 types of natural selection
directional, stabilizing, disruptive, and sexual selection
What is directional selection
selection that favors, increases, or decreases certain phenotypes coompared to the initial population increase.
- favors extreme variation
- shifts away from average
- common in artifical breeding
what is stabilizing selection
selection that favors the average phenotype
- individuals with extreme traits have lower fitness
- extreme traits are selected against
What is disruptive selection
selection that favors 2 or more variations of phenotype, that differ from initial populations
- opposite traits favored
- average traits are selected against
what is sexual selection and how many traits are favoured and why?
reproductive success increases an organisms fitness
- 1 trait is favored because it increases the organisms ability to reproduce
Female mate choices for sexual selection
bright colors, successful mating rituals, etc.
male v male competition comparisons for sexual selection
Male v male comp: males with large body size, features or strength.
what is directional selection selected towards and against and what is it common in?
- favors extreme variation
- shifts away from average
- common in artifical breeding
What is stabilizing selection selected towards and against and what do certain individuals have
- individuals with extreme traits have lower fitness
- extreme traits are selected against
What is disruptive
selection selected towards and against
- opposite traits favored
- average traits are selected against
Radiometric dating formula for age –> P
- n = Age/H-life
- P = 0.5n (number of h-lifes)
what is a half-life
the time it takes for 50 % of a parent isotope to decay to the daughter isotope.
Radiometric dating formula for P –> age
- n = Log P / Log 0.5
- age = n X h-life
what is adaption?
a structure, behaviour, or physiological process that helps organisms survive and reproduce in a particular environment.
example of adaption
an owl’s feathers for silent flight
