Lecture 1 Flashcards
What is bio diversity?
Diversity of species
- the variety of species present in a particular region
-measured by the number and relative frequency of species in a given area
Evolution
Genetic diversity
-total genetic information contained within all individuals of a population, species or group of species
Ecosystem diversity
-the array of biological communities in a region, along with the abiotic(or physical) components, such as soil, water and nutrients
Modern extinction rates
1000x
During the next 100 years it is expected to rise to 10,000X
6th mass extinction caused by?
Homo sapiens
Greatest threats to species
Habitat destruction
Invasive species
Population growth and increasing use of resources
Pollution
Climate change
Over exploitation
Why is genetic diversity important
Measured as the number and relative frequency of alleles in a species
Better chance of a species surviving
Why should we care about biodiversity
Ecosystem services
-any benefit that humans derive from ecosystems(i.e that support human and economies)
-material benefit
Regulation of eco system processes
-non material benefits(art, recreation, tourism)
_____________are more stable in their provisioning of ecosystem services
Diverse ecosystems
What is the intrinsic value of biodiversity
Species have a right to exist even if they are harmful and not useful to humans
Why study evolution
Evolution is one of the UNIFYING THEMES IN BIOLOGY it provides a framework to guide research across many sub disciplines of biology
-to understand the big picture of biology you have the understand life on earth in terms of both its history and its future
Why study evolution pt. 2
Evolution is happening now!
Evolution gives rise to biodiversity
What is evolution
A change in the characteristics (allele frequencies)of a population over time
Natural selection is one mechanism for evolution
Darwin’s theory of evolution through natural selection
- Species are related by common ancestry.
- Characteristics of species can be modified from generation to generation. Darwin called this process “descent with modification”.
When does natural selection occur (2 points)
When individuals within a population vary in characteristics that are heritable (i.e., that can be passed on to offspring).
• Putting it another way: when there is genetic variation in a population with respect to some characteristic.
2. When, in a particular environment, certain versions (alleles) of these heritable traits (genes) help individuals survive better or reproduce more than other versions.
• If certain heritable traits lead to increased success in surviving and producing offspring, then those traits will become more common in the population over time.
Example of natural selection
Antibiotic resistance in bacteria
• Genetic variation exists in a population of bacteria within an infected person (shown by colors here).
• Some individual bacteria (blue) in the population possess traits that allow them to tolerate antibiotic drugs.
• Infected person is prescribed antibiotics → the drug attacks and kills the entire population, except for those bacteria with the resistance traits (these individuals are selected for).
• The surviving population will now all be resistant to the drug → reproduce → pass the antibiotic-resistant traits to all offspring.
• The population has evolved because all individuals now have the antibiotic-resistant traits, whereas before it was rare (i.e., change in frequency of the resistant traits [alleles] in the population).
Individuals do not evolve what does?
Populations
Natural selection acts on?
Individuals
Natural selection leases to speciation which leads to?
Bio diversity
Natural selection is the ______ mechanism that gives rise to adaptation
ONLY
What is adaptation
Adaptation: a characteristic that enhances the survival or reproduction of organisms that possess it relative to alternative characteristics.
What is ecology
Ecology is the scientific study of the distribution and abundance of organisms, and the interactions between organisms and between organisms and their environment.
• “The purpose of ecology is to provide knowledge about the way the world works and provide evidence on the interdependence between the natural world and people.” (BES, 2013)
Why does ecology matter
Ecology provides an understanding of the processes that support and maintain life.
• Humans are part of ecology.
• We directly interact with other organisms AND depend on the interactions of other organisms to survive.
• As human impacts on the Earth continue, ecology is becoming a more prominent field in biology.
• Ecology has applications in…
• Conservation of species, biodiversity, and natural areas.
• Predicting the effects of pollution and climate change.
• Agriculture
• Harvest management (e.g. fisheries, game species, forestry)
• Pest control
• Public health and disease control
