BIO004 - Module 3 Flashcards
defined as a body of thoroughly tested and verified explanations for a
set of observations of the natural world.
Theory
Considered as the first scientific explanation of evolution and proposed by Jean Baptiste de Lamarck
Lamarckism and the Inheritance of Acquired Traits
If an individual transforms, heredity will adjust.
Lamarckism
“Organisms CHANGE OVER A PERIOD OF TIME as a result of changes in heritable physical or behavioural traits, which will allow an organism to better adapt to its environment and have more
offspring
Darwinism and Evolution through Natural Selection
Darwinian evolution encompasses several different, but mutually compatible, theories:
-Perpetual Change
-Common Descent
-Multiplication of Species
-Gradualism
-Natural Selection
The living world is neither constant nor perpetually cycling. It is always changing.
Perpetual Change
Organisms undergo transformation across generations throughout time
Perpetual Change
All forms of life descended from a common ancestor through a branching
of lineages
Common Descent
Species that share a recent common ancestry have more similar features than do species whose most recent common ancestor is an ancient one
Common Descent
The evolutionary process produces new species by splitting and transforming older ones
Multiplication of Species
reproductively distinct populations of organisms that usually, but not always, differ
from each other in form, and can no longer interbreed among other members of different
species
Species
The DNA of a population of a species will drift apart when separated by
distance because they will start developing their own unique trait in respond to their new environment and they will only share these new traits within their population. This leads to the formation of new species
Speciation
There is a continues exchange of genes between 2 or more populations of the same species, therefore preventing/slowing down the process of speciation.
Gene Flow
The large differences in anatomical traits that characterize different species originate through
the accumulation of many small changes in the genes over very long periods of time
Gradualism
Organisms are constructed to meet the demands of
their environments
Natural Selection
Propositions of Natural Selection
-Overproduction
-Variation
-Competition
-Selection
-Adaptation
An organism must make lots of offspring to maintain its population, but not all
will survive adulthood.
Overproduction
There will always be variations (difference in anatomical, behavioral, or
physiological traits) among the population. (“Everybody is different.”)
Variation
Because natural resources (like food and shelter) are limited, there is a struggle
for existence among members of a population. (“Survival of the fittest.”)
Competition
Variants/Traits that permit their possessor to adopt better to their
environments will survive to breed and pass on their characteristics. (“Some are
better than the others”)
Selection
The expected result of the accumulation the most favorable traits occurring in a
population leads to the production of new species overtime.
Adaptation
Evidences of Evolution
-Embryologic Development
-Comparative Anatomy
-The Fossil Record
-DNA Comparisons
-Distribution of Species
