living environment quiz natural selection and taxonomy Flashcards
(43 cards)
the theory of natural selection was introduced by
darwin
(theory of natural selection) 1.
- populations evolve, not individuals
(theory of natural selection) 2.
- individuals within a population have variations (differences)
Darwin does not explain how these differences appear
(theory of natural selection) the modern theory of evolution adds the reasons for…
variation within a species. (sexual reproduction - genetic shuffling), and mutation
(theory of natural selection) 3.
- overproduction - populations produce more offspring than can survive
(theory of natural selection) 4.
- The organisms with traits that help them survive the environment win the competition (struggle for existence- survival of the fittest)
(theory of natural selection) 5.
5.Those that win the competition produce more offspring, and
pass on their winning traits, than those that do not win the
competition, have less desirable traits
(theory of natural selection) 6.
- Eventually the population will have more members with the
new, and favorable, trait that increases chances of survival,
populations evolves
(theory of natural selection) 7.
- The environment has determined which traits are helpful and
which are harmful, (environmental selection ).
mutation -
any change to
genetic material
sexual reproduction -
genetic shuffling (meiosis
and fertilization)
structural change -
Homologous structures that have been
developed or modified
functional changes -
a structure changes what it does. (Ex. Snakes - in some snakes the salivary glands became poison glands)
behavioral change
a change in how the
organism acts. (Usually
associated with mating behavior)
the two variation sources are
mutation and sexual reproduction
the 3 results from variation are
structural change, functional changes, and behavioral changes
(rates of evolution - factors) reproductive rate -
generally, the faster the reproductive
rate, the faster the rate of evolution.
(rates of evolution - factors) life span -
generally, the shorter the life span, the faster the rate of evolution
There are two hypotheses for types of rates of evolution
gradualism and punctuated equilibrium
Gradualism
Evolution is constantly going on and it is a slow and steady
process.
- If this is true, then there will be transitional fossils, “missing
links”, present. - In the time that life has been on the planet, it seems unlikely
that life could have evolved from a single cell into a
multicellular, complex life form, like humans, through this process
Punctuated Equilibrium
This hypothesis proposes that there are long periods of
stability, no change in species, broken up by brief periods of
rapid change, species changing quickly.
- Brief geological periods of rapid change could be 5, 275, or
10,000 years. - If this concept is true, there will be few, if any, transitional
fossils - In the time life has been on this planet, it would be possible
for life to have evolved from a single cell to a complex,
multicellular life form (like humans) using this model
taxonomy is
the science of classification
(taxonomy) Organisms were placed into categories based on _____ _______. Today when we place organisms into categories
we tend to use ______ _______
structural similarities
biochemical similarities