Knowt
Untitled Flashcards Set
Cons Bio Study Guide
Taxonomy- classification of species
Biological Species Concept- can mate and produce fertile offspring
Phylogenetic Species Concept- same ancestral lineages
Morphological Species Concept- look the same
Prezygotic Barriers- can’t be fertilized (lock and key, mating behaviors, sperm can’t reach egg)
Postzygotic Barriers- Zygote is produced but something goes wrong
Hybrid inviability- zygote forms but doesn’t develop
Hybrid sterility- offspring can’t reproduce, ex: mule
Hybrid breakdown- next generation after offspring can’t reproduce, ex: liger
Selection pressures:
Directional- for one extreme, against the other
Stabilizing- for moderation, against both extremes
Disruptive- for both extremes, against moderation
Hybrid species- offspring produced from two distinct species
Speciation- Becoming a species, lineage diverging
Sympatric Speciation- Becoming a species without geographic barriers
Allopatric Speciation- Becoming a species with geographic barriers
Hybridization- Two species reproducing an offspring
“Natural” processes- two species hybridizing without human intervention
Anthropogenic process- two species hybridizing caused by humans
Benefits- increased range of tolerance, increased chance of survival
Threats and issues- decreased biodiversity, loss of species, hybrids may not be protected as endangered species
Genomic vulnerability- how much genetic change must occur to maintain optimal fitness under the changing climate
Conservation Interventions- humans aiding in conservation
Assisted migration- humans moving animals and plants
Altered genetics-
Altered fitness- changed genetics causing an increase or decrease in a species’ chance of survival
Genetic swamping due to extensive introgression of non-native genes- hybrids outperform original species and take over the gene pool
eDNA- DNA found in environment, good for biodiversity research and surveying
Global Patterns- closer to equator, warmer water → more biodiversity
Terrestrial- closer to equator, stable environment, water availability
Freshwater, aquatic- warmer water, closer to shore
Elevation, Latitudinal- lower elevations, lower latitudes
Temporal, seasonal, annual- seasonal migrations
Maritime vs Continental- coastal areas are influenced by ocean currents, rain shadows have less biodiversity, coastal areas are more temperate
Alpha Diversity- number of species in an ecosystem on a landscape
Beta Diversity- the difference between species between two ecosystems
Gamma Diversity- The sum of all species over the entire landscape
Richness vs Diversity- richness is the number of species present, diversity is the number and abundance of each species
Phylogenetic vs Functional- phylogenetic diversity measures evolutionary history and functional diversity measures the traits of species
Changing distributions of ant implications- becoming more similar to each other, less biodiversity, greater chance of whole population wipeout
Biogeography- study of distribution of species in geographic space over geologic time
Plate Tectonics- pangea, same species in multiple places
Continental Drift- pangea
Equilibrium Theory of Island Biogeography- farther, smaller islands have less biodiversity
Biogeographic Regions
Biodiversity Hotspot- ≥ 1,500 endemic vascular plants and habitat is ≥ 70% reduced from its original size
Endemic species- specialist, native species
Trends- 6 richest hotspots have lowest proportion of vegetation remaining, 10.9% are protected areas, Madagascar & Indian Ocean Islands and Atlantic Forest are among the least protected
Priorities- important because species are irreplaceable, Madagascar & Indian Ocean Islands, Sundaland
HIPPCOD- habitat loss/fragmentation, invasive species, population growth, pollution, climate change, over exploitation, disease, these 7 are how we are framing the threats
Extinction Vortex- process that declining populations undergo when a mutual reinforcement occurs among biotic and abiotic processes that drive population to extinction, ex: continental drift → inbreeding
Escalator to Extinction- climate change drives specialist species up mountain/upstream to colder temperatures, but they will eventually run out of space
United Nations Convention on the Law of the Sea- countries have sovereignty 200 mi offshore
Tragedy of the Commons (Commodity)- everyone wants to use a public resource, overuse and desire for self gain
Carrying Capacity- the highest stable amount of a population that an area can sustain
Fishery- place where people catch fish commercially
Fishery Stock- group of fish/shellfish that are caught in a fishery, can be multiple species, identified by location
Collapse of fisheries- Overfishing causes fish populations to deplete, no fish to catch!
Anadromous Spawning- Hatch in freshwater, grow in saltwater, reproduce in freshwater
Catadromous Spawning- Spend most of lives
Diadromous Spawning- navigate between fresh and saltwater during their lives
What’s the problem with hatchery fish?- spread diseases when released,
Total Allowable Catch- max amount a fisher is allowed to catch in a year based on max sustainable yield- not really sustainable because it’s about extracting the most not what’s best for the fish
Exclusive Economic Zones- where countries regulate fishing
Illegal, unreported, and unregulated (IUU) fisheries exploitation at sea- happens outside exclusive economic zones or illegally inside them
North Atlantic Subpolar Gyre- farther populations collapsed earlier
Atlantic Salmon case study- paper blames IUU fishing but this is probably an oversimplification because also affected by climate change, fish escaping farms and spreading disease, food availability at sea, marine predators
Papers
Padial & De la Riva 2020
Padial and De La Riva describe how there are new recent trends in classification and taxonomy, as scientists are increasingly grouping and subgrouping species with new discoveries through species delimitation, and the paper argues whether these changes are justified or not.
There are a lot of scientists who are very against these changes, as they believe they are unnecessary and unjustified, and believe that the differentiation of species should only be when there is significant evidence and need. These changes also often come from scientists with selfish perspectives who just aim to name a species, publish a paper, or get cited.
Although these changes may be seemingly small and for the wrong reasons, they are necessary, as species delimitation is good for comprehending species diversity and especially for the organisms themselves, as it allows for increased regulation over classification, which supports the IUCN, and not delimiting may lead to novel, diverse species being grouped into a larger classification.
Brauer et al. 2023
The article begins by addressing how people believe hybridization is wrong, as it can create offspring that are unable to reproduce, but Brauer combats this by explaining how this is usually only a problem with human intervention, and when hybridization occurs naturally, it can be a very efficient tool for combating climate change.
Brauer then describes his experiment, in which he surveys the populations of narrow endemic rainbowfishes- the fish that live at high altitudes in cool conditions- and other various species related to Melanotaenia splendida and their hybrids. These species began encroaching on NER habitats, causing NERS and M. splendida to hybridize and create an increasingly large new population. Brauer then tested these species and hybrids for how they will adapt to climate change based on future predicted climate, and determined that the hybridized species were much more likely to survive and we much less vulnerable to climate change. This is because NERs are very specialized and will not survive without very specific conditions, but M. splendida is very generalized, and can survive in a vast array of habitats.
Brauer then goes into explaining why this discovery is important. He describes how hybridization is perhaps one of the most efficient solutions to combat species going extinct due to anthropogenic effects, specifically climate change. If vulnerable species hybridize with species with a large range of tolerance, they will have a greater chance of survival. This is significant, as humans have a massive impact on the collapse of ecosystems due to species going extinct.
Hirashiki et al. 2021
Hirashiki spends a lot of the article debunking the conservationist belief that there is significant, large amounts of data proving hybridization is a threat, when in reality, there is minimal proof that hybridization has negative effects, and in fact, there is some proof hybridization can be beneficial, especially when compared to losing a species forever.
Another heavily discussed controversy is that hybridization is seen as extremely detrimental specifically in the field of conservation biology because of the history of conservation biology and racism, like genetic purity, mixing etc. Evolutionary biologists have historically been more receptive to hybridization, seeing it as a good evolutionary mechanism, but conservation biologists treat it as a way to decrease biodiversity, which has not been proved.
The main point of the article was that hybridization should be considered in a nuanced perspective rather than a wholly black and white argument, as even though hybridization may pose risks to biodiversity, it also could be very beneficial to ecosystems with organisms struggling to adjust to climate change.
Loewen et al. 2022
In Loewen et al., the scientists aimed to asses the levels of biodiversity and species richness along the edges of geographic temperature gradients in Western Canada and the United States. They predicted that species richness would decline with increasing elevation and latitude and that larger body sizes would be more prevalent in colder lakes.
Loewen et al. found that species richness did decline at higher elevation with colder waters, proving that temperature limits biodiversity. They also found that with the warmer temperatures in lower elevations, but not latitudes, that food chains were larger and more diverse and that there were more predators in these lower, warmer, more productive zones.
Castro et al. 2021
Castro et al begins by discussing the clade Didelphidae of marsupials and how there was a gap in the fossil record for a related clade of marsupials during the paleogene era, and he goes in by discussing how understanding Didelphidae evolution, we can better understand larger marsupial evolutionary patterns.
He reveals that the Didelphidae clan originated and developed in Amazonia before reaching South America, and that the biodiversity of the Amazon allowed for great diversification. He also discusses how this results in the Amazon being viewed as a good source to discovering the evolution and history of other lineages, like how it helped bring this hypothesis about these marsupials.
Hrdina and Romporti 2017
Hrdina and Romportl, with their paper, aim to spread awareness of the increasing need to preserve biodiversity through reporting on how biodiversity hotspots are depleting, as they used to cover 16.7% of the Earth's surface, and now only cover 2.4 % of the surface.
They also mention the most at risk and important hotspots, being Madagascar and the Indian Ocean Islands, Sundaland, and the Philippines and Caribbean Islands. They classify hotspots as having 1,500+ endemic vascular plant species and having lost 70%+ of their primary habitat.
Finally, they emphasize what we must do to preserve our biodiversity hotspots, by restoring degraded habitats and decreasing fragmentation to ensure that the species extinction rate does not exceed the species discovery rate.
Hu et al. 2020
Hu discusses how forest loss and increasing agricultural land use, resulting in habitat fragmentation, has negative impacts on biodiversity, and land coverage loss is one of the main threats to biodiversity globally, especially regarding extinction and species richness/abundance. He also discusses how this affects hotspots most prevalently and how these results cannot be taken lightly.
He also discusses that although new forests are growing at a quicker rate globally, new forests do not provide the same benefits as older, richer, denser forests on biodiversity, so the growth of new forests can not be seen as a solution.
Dadswell 2022
Dadswell et al. discussed the significant and large decline in the North Atlantic salmon population since 1985, citing much of North American and Western Europe fishery adult declines and population decreases.
They explain that some may believe that this decline is cyclic, as their has been cyclic abundances and declines within the adult North Atlantic Salmon population due to the AMOI and NAOI, especially in salinity fluctuations.
Dadswell et al. claims that this decline in the North Atlantic Salmon population cannot be due to natural cyclic fluctuations, as populations have never declined this significantly, and the cycle would have reset during those 35 years. Dadswell cites hydroelectric dams, DDT, industrial pollution, etc for these declines, especially in eliminating juvenile habitat and arresting salmon migration patterns.
Morrow 2024
Morrow is a comparative case study between the histories of the Atlantic bluefin tuna and cod industries, and how they have impacted the populations of the ocean, as these industries rely heavily on overfishing and exploitation of the oceans. Morrow uncovered that 87% of fisheries are fully overexploited and depleted, and the ocean has lost over 90% of predatory fish species.
These losses can be attributed to the usage of "maximum sustainable yield," which does not actually call for the sustainable maintenance of the ocean, but equates to exactly the amount of fish the industry can take out without destroying the entire species. This means that although the species are not completely gone, the ecosystems are collapsing. These continuous tragedies of the commons combined with the capitalist mindset will result in a complete ecosystem downfall.
Butchart 2025
The red list index is a good measure of how conservation efforts impact levels of extinction between species and also for applying extinction trends to policy.
Unfortunately, although the red list index has huge potential to be extremely useful, there are various limitations to usage of the red list index, as it does completely depend on the accuracy of the IUCN red list, and also is only representative of mammals, amphibians, corals, and cycads.
To combat these problems, the red list index needs more funding so that it can expand further to create more accurate estimates and documentation to further its desire to decrease extinction rates by tenfold by the year 2050.
Trew and Maclean 2021
Trew and Maclean first discussed how crucial biodiversity hotspots are and how they are declining, resulting in 50% of Earth's species being confined to 1.4% of Earth's area, and also how this is due to hotspots being sources of extremely specialized species with very narrow ranges.
They discuss how montane species are a good example of this, as mountainous regions have high spatial climate variability, and so even if the lower elevations and latitudes have higher productivity, these mountains are home to extremely large amounts of highly specialized species, alongside coastal areas, and both of these will be affected by the warming globe, as decreased upwelling will cause warmer temperatures along the coast.
One of the main goals of this article was to illustrate just how vulnerable these hotspots are to climate change, as they host many endemic species with very narrow niches, and therefore will be highly affected by climate change.
Quizzes
Which of the following is NOT a correct statement about Biodiversity Hotspots
Representatives of the 36 Biodiversity Hotspots can be found on every continent
According to the Castro et al. reading, marsupials originated in __________.
Amazonia - Colombia
In 2-4 sentences, clearly define "species diversity".
Species diversity is the combined measure of the number of species in an ecosystem and the abundance of these species. It counts how many species are represented in an ecosystem and how many individuals there are per species in comparison to the total number of individuals from all species in the ecosystem. This is in contrast to species richness. which is just the total number of species in an ecosystem.
According to the ranking system of the Hrdina and Romportl paper, the most important Biodiversity Hotspots are____________.
Madagascar and Indian Ocean Islands and Sundaland
Briefly, in 2-4 sentences, clearly explain the strict criteria for identifying a Biodiversity Hotspot
One of the criteria to be a biodiversity hotspot is that the area must have over 1,500 endemic, vascular plant species. Another necessity to be established as a biodiversity hotspot is that the area must have lost 70% or more of its original, primary habitat, meaning it can't have more than 30% of its original habitat intact.
Which of the following is correct about Coywolves?
The Coywolf would not be considered a distinct species from the Coyote (Canis latrans) and the Red Wolf (Canis rufus) under the Biological Species Concept.
The key result of Brauer et al. 2023 paper on the genetics of different species of rainbowfish in Australia was that hybrid populations between several narrow range endemic species exhibited reduced vulnerability to projected climates compared to pure narrow endemics.
False
According to Padial & De la Riva 2020, species are simply lineages of organisms with similar characteristics and all lineages are considered species
False
Given a species scientific name of the Coyote (Canis latrans), what is the term latrans named in taxonomic nomenclature? Note that the guest lecture by Greg Setliff and myself (Waldien) used slightly different terminology, but both are acceptable.
Specific epithet
In 3-4 sentences, clearly explain the difference between the Biological Species Concept and the Phylogenetic Species Concept. A complete answer will explain each concept and then identify the important difference discussed in class.
The biological species concept defines a species as two organisms that can mate, reproduce, and produce fertile offspring. In contrast, the phylogenetic species concept defines a species as organisms that share a unique ancestry line on a phylogenetic tree. These differ, as the biological species concept focuses more on reproduction and mating in the present, while the phylogenetic species concept is good for determining past species that may have gone extinct, as we would not be able to study their reproduction.
