TEST 1 - BIODIVERSITY Flashcards
IB Definition: Biodiversity
Change in the allele frequency of a population’s gene pool over successive generations.
Change Over time
change in inherited characteristics of a species.
Biological evolution
The commutative changes in a population from one generation to next.
Law of Fossil Succession
Fossils are dated by determining the age of the rock. Fossils of living organisms appear to show evolution.
Selective Breeding
Darwin: Humans select desirable traits in domesticated animals.
Artificial Selection
Foundation of selective breeding:
- Mating of organisms with fav traits. Erasing traits with negative characteristics. DOES NOT further variation of species. CAN cause evolution.
Homologous Structures
Similar structures due to common ancestry. DIVERGENT. EX: Pentadacyl Limb, arm bones, finger bones, legs, etc.
Analogous Structure
A feature with similar function and superficial structural similarity, but with different fundamental structure and evolutionary origin. CONVERGENT.
Divergent Evolution
Occurs when an ancestral species splits into two reproductively isolated groups, causing each group to develop different traits due to their respective selective pressures and natural selection.
Convergent Evolution
The process by which distantly related organisms independently evolve analogous traits due to similar selection pressures.
Artificial Classification
Classifying organisms on the basis of few, self-evident features.
Adaptive Radiation
Single species give rise to several related species. DIVERGENT. EX: Finches of Galapagos Island.
Speciation
The process by which new species form, where one species is split into two or more species. It occurs at population level. Reproductive isolated. Geographic isolated.
Natural Selection 5 Parts
- Production of more offspring than the environment can produce
- Struggle for survival
- Variation will exist among offspring produced.
- Natural Selection will favor offspring that: posses the best traits, are most fit, survivers will reproduce and pass on their favorable traits.
- Over many generations… gene pool changes.
Variations
Permanent change in the nucleotide sequence of the genome
Frame Shifts
Deletion, insertion, substitution of bases.
Random Mutation
Occurs during:
- DNA Replication
- Viral infection
DOES NOT occur often
Selection Preassures
Biotic: Predation, disease, competition, parasites.
Abiotic: Moisture, temperatures, altitudes, sunlight.
Melanistic Insects (Polymorphism)
- Peppered Moth (Biston Betularia)
- Selection Pressure: Predation by birds.
- Variation: Alternative alleles for a gene (transient)
Beaks of Finches (Adaptive Radiation)
- Galapagos Islands
- Selection Pressure: increased competition for food
- Environmental Change: Drought (1977): plants produced larger seeds, larger beaks and stuff.
Antibiotic Resistances
The bacteria Staphylococcus Aureus.
The Binomial System
- Carl Linnaeos (1735)
- Two name system, universal system
- Homo sapiens - human
- Canis familiaris - dog
Biological Species
Group of organisms with shared traits.
Number of Chromosomes
Cause diversity
Karyograms
Image where chromosomes are organized in pairs: Size, banding pattern, centromere position.
Karyotypes
Count chromosomes during the early stage of nuclear divison
Ecosystem diversity
Range of different habitat or number of ecological niches per unit area in an ecosystem. EX: woodland (High diversity), desert (low diversity).
Species diversity
The variety of species per unit area. This includes both the number of species present an their relative abundance.
Genetic diversity
Range of genetic material in a gene pool or population of a species. A large gene leads to a a high genetic diversity.
Causes of Ecosystem loss
- Global Climate change
- Habitat destruction
- Pollution
- Invasive Species
- Over harvesting
Causes of current biodiversity crisis
- Hunting and Over-exploitation
- Urbanization and land loss
- Deforestation and land clearance
- Pollution of land and sea
- Spread of invasive species.
How to gain evidence of Biodiversity crisis
- Determining the size of population over the years.
- Range of species in an areas
- Diversity of species in an ecosystem.
- Richness and evenness of diversity in an ecosystem
- Extend of degradation of an ecosystem
- Number of threatened species within a taxonomic group.
Biodiversity conservation
In Situ Conservation: National Parks, Biosphere reserves, Nature Parks or wildfire sanctuary.
Ex Situ Conservation: Seed banks conservation, Home gardens, Botanical genders, zoos, aquariums.
