2. NILAI PENTING BIOSISTEMATIKA DALAM BIOKONTROL
Identifikasi merupakan langkah awal dalam biokontrol;
Sering terjadi salah identifikasi karena adanya spesies
kembar dan atau polymorfisme serta proses adaptasi
evolusi (perubahan jenis pakan, habitat dll)
Minimal terdapat 2 kelompok organisme yang terlibat
(target dan agen); Perlunya penentuan spesies-spesies
target secara tepat dengan karakter-karakter molekuler –
ekologinya. Perlunya mencari musuh-musuh alami di
habitat yang sama dengan spesies target atau pada habitat
lain
Pengembangan teknik biokontrol modern (aplikasi
biopestisida – rekayasa genetik) perlu karakter-karakter
biokimia - molekuler
3. What is biosystematic?
• Taxonomy is the study of classification, its principles,
procedure and rules
• Classification is the ordering of organisms into classes or
groups
• Systematics is the branch of biology that’s concerned
with the comparative study of organisms and all
relationships among them
• Biosystematics is the application of genetics (and
cytogenetics) , statistics and chemistry to the solution
of systematics questions in order to provide explanations
abaout the diversity of organisms within the frame of the
theory of evolution
4. Types of relationships
between organisms
• relationships of descent (phylogenetic
relationships)
• relationships of similarity (phenetic relationships)
• spatial or geographical relationships
• trophic relationships
5. The force of chnge to the variability of different
generation (phylogenetic variability):
• mutation
• recombination
• selection
• gene flow
•Random phenomena
7. Macroevolution is the origin of new taxonomic
groups, as opposed to microevolution, which is
genetic variation between generations within a
species.
What is a species?
1. Biological species concept
- A species is a population or group of populations whose
members have the potential to interbreed with one another
and produce viable offspring, but who cannot produce viable
offspring with other species. The biological species concept is
based on inter-fertility, rather than physical similarity.
8. Speciation - process by which a new species
originates.
- Involves the creation of a population of organisms that are
novel enough to be classified in their own group.
- Two processes by which this can occur:
- Anagenesis is the accumulation of heritable traits in a
population, that transforms that population into a new species.
- Cladogenesis is branching evolution, in which a new species
arises as a branch of from the evolutionary tree. The original
species still exists. This process is the source of biological
diversity.
9.
10. The problem with the idea of biological species
concept --> How do you get organisms to breed to
see whether viable offspring are produced? There
are…
Alternative concepts of species
a. Ecological species concept
- Species are defined by their use of environmental
resources; their ecological niche (e.g. species that
are defined by their food source such as butterflies
with certain flowers).
11. b. Pluralistic species concept
- Factors that are most important for the maintenance of
individuals as a species vary. These factors include
reproductive isolation, i.e. not being in the same area so
mating is precluded.
c. Morphological species concept
- Species are characterized according to a unique set of
structural features. This is still the most widely used
concept by taxonomists.
d. Genealogical species concept
- Recognizes species are sets of organisms with unique
genetic histories. This idea is based often on molecular
analyses such as DNA sequences.
12. Modes of speciation
1. Allopatric speciation
- Allopatric speciation describes speciation that takes place
in populations with geographically separate ranges. Gene
flow is interrupted and new species evolve.
2. Sympatric speciation
- Sympatric speciation describes speciation that takes place
in geographically overlapping populations. Chromosomal
changes and nonrandom mating reduce gene flow.
Remember: Species arise when individuals in a population
become isolated one from the other.
