Midterm 1 Flashcards
Biodiversity
All the diversity that encompasses everything from genes, species, the functions of organisms and their interrelations, and the diversity among ecosystems.
Ecosystem services
The benefits that humans derive from a healthy ecosystem including clean drinking water, protection from floods, carbon sequestration, recreation, and food.
Economic reasons
This is really a subset of ecosystem services, but is more monetized. It includes all resources that are sold in an economy that are extracted from nature, including timber, animal products, drugs and medicines, and anything that can be sold.
Scientific discovery and knowledge
The more biodiversity there is, the more things there are to discover and explore to satisfy our natural curiosity, and the more benefits we might gain from these things in the future.
Cultural reasons
Biodiversity and nature are often tied up in how we view ourselves culturally and nationally. Indigenous cultures especially rely upon and have a deep connection to nature that cannot be separated from their sense of self.
Ethical reasons
Many people feel a moral responsibility and sense of custodianship to the planet to not only look after it but to minimize the harm we inflict upon it.
Aesthetic reasons
The sense that nature is beautiful and that it should be preserved or conserved for other people to enjoy.
Ecosystem
Community of living organisms in conjunction with the non-living components of their environment, interacting as a system.
What needs to be done in order to maximally protect biodiversity?
Conserve species, ecosystems and the interactions between ecosystems.
Factors of priority
In practice, we cannot save everything, so we need to prioritize. This may depend upon factors such as cost, the probability of success, and the importance of ecosystem/species.
What selective pressures resulted in the increase in our brain size?
Sociality, a variable environment, and the need to rely on feeding strategies that involved hunting and coordination.
Evolution of our species
200,000 years ago in Africa.
Hunting gathering
Predominant means of subsistence for most of human history.
Mega fauna
Fauna with massive sizes whose extinction is partially attributed to humans.
Agriculture
Millstone in human history which allowed for larger groups of people to permanently settle in an area. Eventually, agricultural societies replaced most hunter gatherer societies. Led to the domestication/breeding of plants and animals.
Industrial revolution
Trend towards urbanization caused by increase in industrial work.
Green evolution
Set of technology and management transfers that were put into place from the 1930s to the 1960s in which the yield of agriculture was greatly increased. However, there has also been a decrease in crop diversity.
Shannon-Weiner Index
H= -SUM[pi x ln(pi)] pi= proportion of individuals relative to total population
Evenness
E= H/Hmax H= SW value Hmax= Ln(total number of pop.)
Simpson index
D= 1-(SUM[ni*(ni-1)] / (N*(N-1))) ni= number of individuals of a species N= total number of individuals in pop.
Jaccard’s index
J= Sc / (Sa + Sb + Sc) Sc= number of individuals that are common in both pops. Sa= number of individuals unique to pop. A Sb= number of individuals unique to pop. B
Allele frequency
Number of copies of a given allele / total number of allele copies in pop.
Genotype frequency
Number of individuals with a particular genotype / total number of individuals in pop.
Heterozygosity
Number of heterozygous individuals / total number of individuals in pop.
Homozygosity
Total number of homozygous individuals / total number of individuals in pop.
Allopatric speciation
Split between original population into two distinct populations that over time evolve distinctly.
Peripatric speciation
Associated with founder effect, segment of population becomes accidentally separated from original population.
Parapatric evolution
Overlap of populations in a limited part of their ranges, creating genetic flow. Difference in conditions of each population allows to species to begin to evolve.
Sympatric speciation
Speciation of two largely overlapping populations due to reproductive isolation.
Adaptive radiation
Splitting off of multiple taxa in a relative short time. For example, species of fish that speciate when a lake cyclically recedes and forms small pockets of water.
Co-speciation
Diversification of species in parallel due to their relationship with one another.
Convergent evolution
Independent evolution of a similar trait or set of traits amongst taxa that did not acquire them from a common ancestor with one another.
Biological species concept
A species is a group of actually or potentially breeding individuals.
Natural background extinction rate
About 10-20 species each year
Mass extinction events
50 percent or more of all species go extinct in a relatively short time span.
Factors that influence extinction
Geographical range, local population size, habitat tolerance, and reproductive cycle time
Largest mass extinction
Permian
