chapter 18 Macro evolution Flashcards
Macro-Evolution
Major differences in allele
frequency that result in so
much genetic change that
a new species is formed
Micro-Evolution
Minor differences in allele
frequency within a population
of the same species
Theory of Natural Selection
(Wallace and Darwin) Individuals with
favorable genotypes
suited for their
environment are
more likely to
survive, reproduce
and pass on their
genes to the next
generation
Inheritance of acquired
characteristics
(Jean Baptise de Lamarck) Organisms
acquire traits during their
lifetime (this is different than darwin’s theory) that they can
then pass down to future
generations
What is an example of inheritance of acquired characteristics?
Giraffes having short necks then stretching them out to get to food. Continual stretching caused the necks to stay long (within the lifetime)
Evolution by Natural
Selection
Organisms
with genotypes that
code for favorable traits,
live to reproduce and
pass their genes to
future generations
What is the difference between Darwin and Lamarck’s theories?
Lamarck theorized favorable traits developing in a lifetime and will be passed down to offspring. Darwin focused on having a genetic basis behind evolution through his theory of natural selection.
What are the five natural selection assumptions?
- Organisms carry different genetic
information - Organisms produce more offspring
than can survive - Among organisms there is a
struggle for survival (competition) - Individuals with favorable
characteristics have a higher rate
of survival and produce more
offspring - Favorable characteristics become
more common
Adaptation
a heritable trait that helps an
organism’s survival and reproduction in its
present environment
phenotype
physical characteristics (selection works on the phenotype)
Genotypes
are the genes that
code for a specific phenotype
How do bacteria develop this response and resistance against vaccines?
- Due to natural selection bacteria that have beneficial traits that protect them against the antibiotic survive they are able to reproduce (positive effect and increased fitness)
- Bacteria that do not have favorable characteristics die and do not reproduce (negative effect)
Aristotle…
was the first taxonomist
dividing organisms into land, sea, &
air dwellers
John Ray…
was the first to use Latin for
naming
* First to give a biological definition
of the term “species”
Carolus Linnaeus…
developed the
modern system of naming known as
binomial nomenclature, a two-word
name (Genus & species)
Linnaeus Taxonomy: Hierarchical Classification
Each level (taxon)
groups organisms
that share more
physical
characteristics
than the level
above
K - kingdom
P - Phylum
C - class
O - order
F - family
G - genus
S - species
Binomial Nomenclature
- A two-word name (Genus & species)
- Linnaeus’ groupings focused on
shared physical characteristics, now
scientist use molecular techniques
to classify living organisms - we only use it for animals now
Morphological
Species Concept
Based on analysis of
diagnostic traits
distinguishing one species
from another
- Species can be
distinguished anatomically
by one or more distinct
physical characteristics, but some organisms do not
have many measurable
distinguishable traits.
Evolutionary Species
Concept
distinguishes species
from one another based on
morphological (structural)
traits.
- It implies that members of a
species share a distinct
evolutionary pathway, but since fossils don’t give info about color, soft tissue anatomy or behavioral traits, they aren’t of much use
Phylogenetic
Species Concept
is used to identify
species based on a
common ancestor.
- It is based on a single
ancestor for two or
more different groups.
- example: the kinds of different giraffes seen in africa
Biological species concept
If two individuals can mate with each other and produce viable fertile young, then they are species
two individuals can mate but the offspring is unfit (unable to reproduce etc). This is an example of what would not be a species based on this concept
reproductive isolation
the inability for species to mate due to various barriers (genetically, geographically, etc)
Pre zygotic mechanical isolation
Reproductive isolation before fertilization
example: bee not being right shape to steal pollen from flowers, thus those flowers are not going to reproduce
Post zygotic Mechanical isolation
After fertilization
example: horse + donkey = mule that cannot reproduce
