Zusammenfassung der Ressource
Evolution and Biodiversity
- Classification of
Biodiversity
- The binomial system of names for species
is universal amoung biologists and had
been argreed and delevloped
- When species are discovered they are given a scientific
name using the binomial system
- Taxonomists classify species using a hirarchy of taxa
- Domain, Kingdom, Phyum, Class, Orders, Family, Genus, Species
- The domain for species is either Archaeans, Bacteria and
Eukaryota
- Human:
Eukaryota.
Animalia,
Chordata,
Mammalia,
Primate.
Hominidae.
Homo.
Sapiens
- Pine trees.
Plantae,
Pinophyta.
Pinospioda.
Pinales.
Pinaeae.
Pinus.
Pinus
- The genus and accompanying higher taxa consists of all the species that have evolved
from one common ancestral species
- Taxonomists sometimes reclassify groups of species when new evidence
shows that a previous taxon contains species that have evolved from a
different ancestral species
- Natural classification help in identification of species and allow the prediction of characteristics
shared by species with a group
- Cladistics
- A clade is a group of organisms that have evolved
from a common ancestor
- Evidence for which species are part of a clade can be
obtained from a base sequence of a gene or a
corresponding amino acid sequence of a protein
- Cladograms are tree diagrams that show the most probable sequence of
divergence in clades
- There is a positive correlation between the number of
differences between two species and the time since they
diverged from a common ancestor
- Traits can be Analogous or
Homologous
- Analogous structures are similar because of convergent evolution
- Homologous structures are similar because of similar ancestry
- Evidence from cladistics has shown that classification of some
groups based on structure did not correspond with the
evolutionary origins of a group or species
- Natural selection
- Natural selection can only occur if there is a variation
among members of the same species
- Mutations, meiosis and sexual reproduction cause variation between
individuals in a species
- Mutations is the original point of variation. As new
alleles cause mutations
- Every cell produced by meiosis has
a different combination of alleles.
By crossing over
- The fusion of male and female gametes create a single combination of
alles
- Adaptations of characteristics that make
an individual suited to it's environment and
way of life
- Species tend to produce more offspring than the
environment can support
- Individuals that reproduce pass on characteristics to
their offspring
- Those better adapted to the environment tend to
survive and produce more offspring
- Those less adapted to the environment tend to not survive and
not produce as much offspring
- Natural selcetion increases the amount of characteristics that make an individual
better adapted and decrease the amount of other characteristics leading to a
change within the species