COMMUNITY, COMMUNITY, BIODIVERSITY, BIODIVERSITY, EVOLUTIONEVOLUTION
Ecosystem is the top of life’s hierarchy
Ecosystem depends on the complex interactions between its community of organisms and environment
ECOSYSTEM LEVELEucalyptus forest
COMMUNITY LEVELAll organisms ineucalyptus forest
POPULATION LEVELGroup of flying foxes
ORGANISM LEVELFlying fox
ORGAN SYSTEM LEVELNervous system
ORGAN LEVELBrain
Brain Spinal cord
Nerve
TISSUE LEVELNervous
tissue
CELLULAR LEVELNerve cell
MOLECULAR LEVELMolecule of DNA
Figure 1.1
Basic Concept of Basic Concept of Community Community 1. Structure2. Species Interactions3. Succession4. Sustainability
Community structureCommunity structure
Community structure
Physical appearanceSpecies Diversity Species abundance Niche structure
BIODIVERSITY
Distribution of species Species InteractionMain component of Biodiversity
Biodiversity of the worldBiodiversity of the world
Preservation of biodiversity is important to humans for aesthetic, ethical and practical reasons
Biodiversity provides humans with food, clothing, shelter, oxygen, soil fertility, etc.
Biodiversity is vital to human Biodiversity is vital to human welfarewelfare
How biodiversity evolve?How biodiversity evolve?
EvolutionEvolution
The Fossil RecordThe Fossil RecordFossils
◦ Organism’s hard parts preserved Turned to rock Replaced by minerals Or preserved in amber
Fossil record◦ Fossils found, catalogued &
analyzed◦ Shows transitions◦ Incomplete
Three key ideas◦ Older fossils more different◦ Increasing complexity with time◦ Most species have gone extinct
The ways to explain evolutionary process
The Biochemical EvidenceThe Biochemical Evidence
DNA◦Similarities in Chromosomes and genetic
code.◦Similarities in essential Amino Acids,
gene structure and gene function◦Changes slowly◦Also compare amino acid sequences
Cytochrome C Humans and chimps identical Rattlesnake 86% overlap
Evidence from Anatomy:Evidence from Anatomy:Vestigial OrgansVestigial Organs
Vestigial organs◦ Internal features◦ No useful function
Example◦ Appendix: humans◦ Wings: penguins,
cassowaries, emu◦ Hind limbs: whales,
snakes, legless lizards◦ Similarities in embryo
of vertebrates
Whale
Snake
Penguin
Similarities in Vertebrate Similarities in Vertebrate embryosembryos
Chemical EvolutionChemical Evolution
Chemical evolution◦Process of combining rocks, water and gases
Miller-Urey experiment
Formation of cell◦Still unknown
Black SmokersBlack SmokersBlack Smokers
◦Deep-ocean floor◦Vents of mineral rich hot
water◦Diverse ecosystem
Most archaic bacteriaHydrothermal zones
◦Site of life’s origin? Protected Ideal chemical
environment
Many animals thrive in the extreme environment around hydrothermal vents
– Tube worms were unknown to science until hydrothermal vents were explored
– They live on energy extracted from chemicals by bacteria
The Window of The Window of OpportunityOpportunity
Chemical processes◦Occurred rapidly
Recent discoveries◦Schopf
Evidence of life 3.5 billion years ago
First Cell◦4.0-3.5 billion years ago
The First CellThe First Cell
First cell◦No competition◦Multiplied rapidly◦No reliable replication◦Adopt genetic material from death cells
create biodiversitySpecial characteristics
◦Four nucleic acids in DNA (??)◦20 amino acids
The Story of LifeThe Story of LifeFirst cell
◦ Natural selection mutations
Mutations◦ Most not beneficial
Environment◦ Impacts evolution
EukaryotesColoniesHard Shell
◦ Cambrian explosion
Natural selection terjadi dalam waktu panjang
Geological Geological TimeTime
Mass Extinctions and the Mass Extinctions and the Rate of EvolutionRate of Evolution
Rate of extinction◦ 10%-20% extinct in 5-6
million yearsMass extinctions
◦ 30%-90% extinct Mechanisms
◦ Asteroid◦ Volcanism *)◦ Continental Drift
Evolution ◦ Gradualism◦ Punctuated equilibrium
Darwin & WallaceNatural Selection
◦ Variation in populations Some variation heritable
◦ More individuals born than will survive◦ Organisms are adapted to abiotic (regional
climate) and biotic factors. ◦ The presence and success of a species in a
particular place depends upon its ability to adapt
Natural Selection and the Natural Selection and the Development of Complex LifeDevelopment of Complex Life
The evolution of insecticide resistance is an example of natural selection in action
Chromosome with geneconferring resistanceto insecticide
Additionalapplications of thesame insecticide willbe less effective, andthe frequency ofresistant insects inthe populationwill grow
Survivor
Insecticideapplication
Darwin also saw that when humans choose organisms with specific characteristics as breeding stock, they are performing the role of the environment
– This is called artificial selection
– Example of artificial selection in vegetables derived from wild mustard and dog pedigree
Dogs varieties
The Evolution of Human BeingsThe Evolution of Human Beings
One possible model of the
somewhat bushy path of human evolution. The letters correspond to the following species:O-Homo sapiensN-Homo neanderthalensisM-Homo heidelbergensis & Homo rhodesiensisL-Homo erectusK-Homo ergaster, Homo antecessor & H. mauritanicusJ-Homo habilus I-Homo rudolfensis H-Australopithecus garhi G-Paranthropus boiseiF-Paranthropus robustusE-Paranthropus aethiopicusD-Australopithecus africanusC-Australopithecus afarensis B-Australopithecus anamensisA-Ardipithecus ramidus
Orrorin tugenensis, Sahelanthropus tchadensis, & Ardipithecus kaddaba 7
Primitive human speciesPrimitive human species
– Humans exhibit extreme physical diversity
Modern human speciesModern human species
Species InteractionsSpecies Interactions
Species interactionsSpecies interactions
There are five basic types of interactions between species:1. interspecific competition2. predation3. parasitism4. mutualism5. commensalism
These interactions tend to regulate the populations of species and can help them survive in changes environmental conditions
The competitive exclusion principle
– Populations of two species cannot coexist in a community if their niches are nearly identical
Hightide
Chthamalus
Balanus
Lowtide
Ocean
Succession
Communities in transition (ecological Communities in transition (ecological succession) succession)
Communities constantly change in response to change environmental conditions.
The gradual change in species composition of given area is called ecological succession
There are two types of ecological succession :1. primary ecological succession2. secondary ecological succession
Primary Primary ecological ecological successionsuccession
SustainabilitySustainability
Human attitudes and environmental awareness are of utmost importance in the search for solutions to utmost importance in the search for solutions to the biodiversity crisis
Sustainable development in an Sustainable development in an ultimate goalultimate goal
Evolution and Modern Evolution and Modern Human LifeHuman Life(Extra Slide)(Extra Slide)
The excessive use of antibiotics is leading to the evolution of antibiotic-resistant bacteria◦Example:
Mycobacterium tuberculosis
The evolution of antibiotic The evolution of antibiotic resistance in bacteria is a resistance in bacteria is a serious public health concern serious public health concern
Pathogenic bacteria can cause disease by producing◦exotoxins, such as
Staphylococcus aureus
◦endotoxinsLyme disease is
caused by a bacterium carried by ticks
Some bacteria cause diseaseSome bacteria cause disease
These bacteria photosynthesize in a plant-like way◦They often “bloom” in polluted water
Cyanobacteria sometimes Cyanobacteria sometimes “bloom” in aquatic “bloom” in aquatic environmentsenvironments
The species that causes anthrax can be used as a biological weapon in war or in acts of terrorism
Many prokaryotes are environmentally important in Earth’s chemical cycles◦We exploit decomposers in sewage treatment
Prokaryotes help recycle chemicals and clean up the Prokaryotes help recycle chemicals and clean up the environmentenvironment
Rotatingspray arm
Rock bedcoating withaerobicbacteriaand fungi
Liquid wastes Outflow
Prokaryotes hold a great potential for solving environmental problems such as oil spills and toxic mine wastes