3.
All evolution is based on changes in the
information stored in DNA- information
that guides development and leads to
distinctive body forms, metabolic
products, and behavior patterns.
5.
A change of allele frequencies in a
population over a short period of
time.
The basis for all large-scale or
macroevolution.
Microevolution
6.
5 Agents of Change that can Alter Allele
Frequencies
1. Mutation
2. Gene Flow
3. Genetic Drift
4. Non-random Mating
5. Natural Selection
Microevolution
7.
Any permanent alteration in the makeup of DNA.
*they must be heritable
* base pair deletion, translocation, etc.
* most do nothing , a few are harmful, rarely are
they beneficial
*these mutations are not working to further
survival and reproduction
*these mutations are not likely to account for a
change in allele frequency
*these good mutations bring new genetic
information into the genetic pool
Mutation
8.
A change in allele frequency that can occur
when mating with members from another
population occurs.
*Migration- the movement of individuals
from one population into the territory of
another.
Gene Flow
16.
Individuals do not choose mates randomly
1. Assortive mating- individuals tend to mate
with those with the same phenotype.
2. Sexual selection- males compete for the
right to reproduce and females choose to
mate with males possessing a particular
phenotype
Non-random Mating
17.
Results in adaptation of a population to the
environment.
Survival of the fittest
Traits of those who are more successful in
reproducing will become widespread in a
population, the alleles that bring about these
traits will bring about these traits and will
increase in frequency from one generation to the
next.
Acts on individuals, but only population evolve
Natural Selection
18.
1. Directional selection- individuals on one end of a
phenotypic range are favored
2. Disruptive selection- when environment selects
individuals on both extremes
3. Stabilizing selection- favors more intermediate
forms , tending to reduce phenotypic variation
4. Sexual selection-enhances mating, can lead to
sexual dimorphism(distinction of males and females
by secondary sexual characteristics).
Types of Natural
Selection
19.
Intrasexual selection- same sex competing for mates
Intersexual selection- mate choice, females choose
“sexier” male.
Natural selection does not result in perfect organism.
Can act on variations in the populations. Also chance
events affects populations evolution history.
20.
It happens upper level of species and create a new
families, order, genra
Created by population fragmentation and genetic
divergence
Many microevolution are add in it.
Macroevolution
22.
is the existence of biological factors (barriers) that
impede two species from producing viable, fertile
offspring
Reproductive isolation can be classified by whether
factors act before or after fertilization
Reproductive Isolation
24.
Reproductive isolation between populations
generally increases as the distance between
them increases
For example, reproductive isolation
increases between dusky salamanders that
live further apart
25.
gene flow is interrupted or reduced when a
population is divided into geographically isolated
subpopulations
Different homeland
For example, the flightless cormorant of the
Galápagos likely originated from a flying species
on the mainland
Allopatric Speciation
26.
15 pairs of sibling species of snapping shrimp
(Alpheus) are separated by the Isthmus of Panama
These species originated 9 to 13 million years ago,
when the Isthmus of Panama formed and separated
the Atlantic and Pacific waters
Evidence of Allopatric
Speciation
27.
A. FORMUSOS A. NUTTINGI
Atlantic Ocean
Isthmus of Panama
Pacific Ocean
A. panamensis A. millsae
28.
Regions with many geographic
barriers typically have more
species than do regions with fewer
barriers
29.
speciation takes place in geographically overlapping
populations
Sympatric speciation can also result from the
appearance of new ecological niches
For example, the North American maggot fly can live
on native hawthorn trees as well as more recently
introduced apple trees
Sexual selection can drive sympatric speciation
Sympatric Speciation
30.
Sexual selection for mates of different colors has
likely contributed to speciation in cichlid fish in Lake
Victoria
Normal Light Monochromatic orange light
P. pundamilia
P. nyererei
31.
In allopatric speciation, geographic isolation restricts
gene flow between populations
Reproductive isolation may then arise by natural
selection, genetic drift, or sexual selection in the
isolated populations
Even if contact is restored between populations,
interbreeding is prevented
Sympatric speciation can result from polyploidy,
natural selection, or sexual selection
32.
In sympatric speciation, a
reproductive barrier isolates a
subset of a population without
geographic separation from the
parent species
33.
Microevolution happens on a small
scale, while macroevolution happens
on a scale that transcends the
boundaries of a single species. Despite
their differences, evolution at both of
these level relies on the same
established mechanisms of
evolutionary change
