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A group of interbreeding natural population that do not (usually) successfully mate or reproduce with other such groups (which occupy a specific niche)
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Asexual Species
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Fragmentation - Starfish
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An arm is removed, and grows into a new Starfish. Where the arm that was removed, a new arm will regrow on the old body.
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Budding - Yeast cells
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Buds come off of their organisms which, are genetically identical to them.
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When relatives mate
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Two different, yet closely relating species mate
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Horse + Donkey = Mules (mostly infertile)
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Russet-backed Thrush + Olived-backed Thrush (fertile offspring)
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Small group of cohesive individuals that share intrinsic cohesive mechanisms.
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Genetic cohesive mechanisms
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Gene flow and stabilising selection function to maintain species integrity
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Ecological cohesive mechanisms
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Abundance, demographic stability, strengths of interactions with other species
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Potential for genetic and/or demographic exchangeability.
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Downplays hybridisation (i.e. what separates species)
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Lineages that occupy and adaptive zone different in some way from that of any other lineage within its range, and which evoles separately from all other lineages outside its range
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Common ancestor but now diverged Ecological competition within its own species
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Adapting to individual niches
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Recognise each other for the purpose of mating and reproduction
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Linked to features used to recognise mates
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White peacock
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Females would not recognise him as the same speices. They may not mate with him.
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The Western meadowlark and Eastern meadowlark
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Look very similar but have a different song. They do not breed as their distinct song prevents them from recognising each other.
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Earth appears to be undergoing a 6th mass extintion
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Extinction is occurring faster than "background extintion" (which occurs between the mass extinction events)
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1 species extinct per 1 million species each year
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Rate of between 10-10,000 times faster than background extinction
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Recent data
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Lower estimate
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200-2000 species a year
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Upper estimate
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10,000-100,000 species a year
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Extinction comes after
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Decrease in poppulation size
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Decrease in population distribution
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We don't know how many species exist
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Impossible to estimate
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>Take samples and extrapolate up >Look at patterns in identication rates >Look at ratio - such as 1:6 vascular plants to fungi
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Bias towards species
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>Charismatic >Larger >Common species
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Least known or described
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>Fungi >Viruses >Bacteria
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1.5 million catalogued so far
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100k well known
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Eastimated to be 3-10 million species globally
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Anthropogenic hazards are hazards caused by human action or inaction. They are contrasted with natural hazards. Anthropogenic hazards may adversely affect humans, other organisms, biomes, and ecosystems.
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land development
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is altering the landscape in any number of ways such as: Changing landforms from a natural or semi-natural state for a purpose such as agriculture or housing Subdividing real estate
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overexploitation
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the action or fact of making excessive use of a resource.
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Species translocations and introductions
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Translocation: The intentional capture and release of animals to the wild to establish, reestablish, or augment a population.
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pollution
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the presence in or introduction into the environment of a substance which has harmful or poisonous effects.
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Cheatography n. The art of mapping complex subjects into clear, instantly navigable reference guides.
