Describing + Arranging Organisms Flashcards
What were 4 important tasks of biological classification?
- compiling an inventory of diversity
- labelling species and groups with scientific names
- distinguishing species and creating a method of distinguishing them - deciding what reality we want species boundaries to reflect, if any?
- fitting species into higher (more inclusive/nested) natural groupings
How were species distinguished before evolution?
essentialism - ‘essence is prior to existence’; groups are defined by characteristics (‘essences’) that are shared amongst only members of a group and that these characteristics were set before development and are unchanging (anti-evolution)
species have fixed characteristics that are unchangeable essence and based on ideal forms
How were species distinguished after evolution?
population-thinking model - a population of a species are a group of organisms that share features because they are descendent from a common ancestor NOT because of a common ‘nature’
this integrates change of characteristics over time
Define and compare artificial vs. natural classification of species
artificial classification: group-defining attributes do not correlate with other attributes = selecting unifying characteristics first and then grouping
- ex. habitat, colour, number or shape of leaves
natural: group-defining attributes DO correlate with other attributes = grouping organisms based on similarities and then identifying shared characteristics
- ex.
What 2 fields did the first modern works in natural history deal with?
botany and zoology
What factors arose which compelled natural historians to go beyond the ancient authors?
Advancements in travel allowed people to observe that different organisms existed in different parts of the world - European people were ‘discovering’ new plants and animals
print also allowed descriptive botany and zoology to be supplemented by illustrations
What were zoologists mostly interested in?
function and adaptation
How did the main interests of zoologists contribute to evolution theory?
understanding the function of animals always for better understanding of relatedness and why organisms might have certain structures
also notable differences in function/variability made them wonder why
interest in how the functions work together
adaptation is directly related to evolution theory
What were botanists mostly interested in?
identification and classification
Who founded the modern science of biological systematics? how?
botanists because of their interest in identification and classification of plants
Why was it more difficult for botanists to contribute to evolutionary theory than zoologists?
function, adaptation and the significance of variability in plants is not always as clear as it is in animals
Who were the 2 most famous botanists of the ancient world?
Theophrastus - pupil of Aristotle
and
Dioscorides -physician of the Roman army
How many plants did both these 2 ancient botanists describe?
they each described ~500-600 plants
How many plants did botanists of the 16th century describe unknown to the Greeks?
~500, medicinal and non-medicinal
Why was it important to classify and describe plants?
plants have medicinal applications
What was mysterious about plants?
they can vary in their forms (ex. different leaf types) and functional biology was hard to apply because plant species have so many different types of structures
Who invented the herbarium?
Luca Ghini (1490-1556)
What is a herbarium?
a library of dried, pressed, preserved, labelled and organized plant specimen which store plants in living condition indefinitely as a reference and resource for studying
What was the significance of the herbarium? What are the contributions of herbaria today?
a herbarium stores and preserves a representative plant of a plant species and includes a record of occurrence in location throughout history
used for studying botany
- track population changes and movements
now:
- preserved DNA so later analyses could be used to determine relatedness
- reconstruct historical environments of an area
What caused the information-management problems for botanists in the 17th century? What questions arose from this?
the immense volume of described plants (up to 18,000) and the awareness that many groupings of the plants were natural
this caused botanists to address the way groups were being organized - ‘how can all this information be organized and accessed?’ to reduce redundancy and ease accessibility for research
Who was George-Louis Leclerc, Comte De Buffon (1707-1788)? What was he famous for?
French nobleman
Famous during his lifetime, he published 36 volumes in his work “Natural History” and an additional 8 volumes were added posthumously
He directed the Royal Botanical Garden which became the greatest natural history museum in the world
What was Leclerc/Buffon’s famous work?
the 36 (+8) volumed Natural History
What were some of the topics in Buffon’s Natural History?
geology
minerals
origin of life
embryology
physiology
biogeography
functional anatomy
systematics
mammals
birds
anthropology
sociology
cultural history
general and theoretical articles
posthumously: reptiles, fish, whales
What were Buffon’s contributions to classification? How does this relate to today’s concept?
he believed that only the species level of classification could reflect a biological reality and that higher taxonomic levels do not - this is pretty accurate to the biological species concept
species can be distinguished based on reproductive behaviour
What were Buffon’s contributions to biogeography? How does this relate to today’s concept?
Each form of life in each area of the world underwent a separate genesis by spontaneous generation which led to an unchangeable interior mould of each species
his idea that life is different in different regions with similar environments is fundamental to biogeography and the historical view of the distribution of organisms
Who is often credited for founding biogeography?
Leclerc/Buffon often, but also sometimes Darwin
What did Buffon mean by an ‘interior mould’ of each species?
An unchangeable essence with some mutable aspects of the mould (some evolutionary adaptation might occur as the earth changes)
What was the previous view before Buffon’s suggestion?
that after Noah’s ark let all the animals off the boat that species walked off and distributed themselves into their current places and distributions in the world
What is Buffon’s Law/What did he conclude about biogeography?
different regions in the world with similar environments will have different plants and animals because of spontaneous generation
How did Buffon’s view of biogeography differ from the old view of Noah’s ark?
the Noah’s ark view suggests that all species were created at the same time and have always lived in their same current places/distributions
Buffon’s view suggests that each species generated independently of other species
Why is Buffon thought of as the “father of evolution’ even though he wasn’t an evolutionist?
he thought:
the interior mould of a species in unchangeable - essentialist
but parts that exist outside of the interior mould are subject to some limited adaptive change
he also considered descent from common ancestor but ultimately rejected it because the science couldn’t show it
= we didn’t see new species created all of the time, he thought the world was much younger than it is and that evolution should be occurring faster than it does
= intermediate species don’t exist, which he suspected should if new species evolved from others
Why did Buffon reject descent from common ancestors as possible?
He argued that:
we didn’t see new species created all of the time, he thought the world was much younger than it is and that evolution should be occurring faster than it does
and that intermediate species don’t exist, which he suspected should if new species evolved from others
What is meant by the “arrow of time?”
refers to the concept of the one way direction or asymmetry of time
reviewing history is important to the study of life because life is a historical process - events have unfolded over time and previous events change the potentialities of future events
What did Buffon introduce to the study of life (biology)? How was this different from previous thought?
history!
he recognized that it was important to consider biology or the study of life as a series of unfolding processes and potentialities over time
before Buffon, biologists hadn’t considered life as a historical process or as a historical subject
What are The Epochs of Nature (1778) and who wrote them? How did they contribute to the concept of biology as a historical study?
Buffon, who else?
they were his ‘arrow of time’ / way to describe the historical processes which led to life today
he proposed 7 periods of the history of life
List Buffon’s 7 Epochs
- Comet hit the sun, causing debris ejection
- Some debris cooled to form planets, like Earth
- Oceans formed and marine life spontaneously generated
- Waters retreated and the continents formed
- Animal life spontaneously generated on land
- The continents broke apart
- Humans spontaneously generated and took over
Even though he had no evidence, how did Buffon think of the idea that the waters retreated?
he knew of marine fossils found up in the high mountains, so he concluded water must have been there at some point
What were Buffon’s Epochs NOT a reference to?
biblical explanations of the study of life
the water retreating was not the Noah’s ark flood - he did not buy into this idea
the appearance of humans was not related to the biblical framework
Was Buffon religious in his works?
no, he may have been persoanlly (who’s to say) but he did not include a biblical framework in his history of life Epochs
What did Buffon use as an indicator of the Earth’s age?
the Earth’s temperature and rate of cooling - because he thought it had been cooling since its formation (an arrow of time)
How old did Buffon think the earth was? How did he determine this? How did this conflict with the story of genesis?
~75,000 YA
this was older than what genesis suggested
he did this by heating spheres and calculating their rate of cooling and then projected it onto the Earth
What was the significance of Buffon’s work to later evolutionary thought?
Adaptation by environmental changes
Because earth is cooling, organisms would have to adapt to colder temperatures/migrate to warmer climates
aspects of species can adapt
species must be reproductively isolated -
How did Buffon’s ideas challenge essentialism?
he postulated that organisms were more malleable than essentialism suggests
Why were Buffon’s ideas pervasive throughout society?
he was popular and well revered
Who was Carl Linneaus (1707-1778)?
He was a manager of scientific information - he wanted to organize the vast amount of knowledge collected to prove how much was accumulating
A plant explorer who described and collected many plants
He also was a student of relationships of organisms
Was Linnaeus an evolutionist?
no he never accepted evolutionary thought in his published work
What were Linnaeus’ major contributions?
He developed the standard of binomial nomenclature and was the first to use it consistently
How did the invention and consistent use of binomial nomenclature assist the organization of species?
Linnaeus’ consistent use of binomial nomenclature allowed the naming of species to be separate from the description of species (ie., the name of a species does not need to be descriptive of the species)
it also significantly shortened the name for species and made it much easier for writers and readers to follow papers
What is an example of an old name for which Linnaeus reintroduced with a binomial name?
Canna folilis untrinque accuminatus nervosis which Linnaeus called Canna indica
What type of classification system did Linnaeus develop? What features were they based on?
a nested hierarchical system
he classified plants based on sexual features
Why was it contentious for Linnaeus to classify plants based on sexual features?
some botanists did not believe plants were sexual and it contradicted ancient wold (Aristotle’s scale of nature) understanding
How did Linnaeus’ groupings of organisms differ from Aristotle’s Scale of Nature?
Linnaeus’ system is nested and hierarchical, with groups becoming more and more inclusive
whereas Aristotle’s was not nested, it was discrete units of hierarchy (exclusive)
Linnaeus’ was based on sexual features, whereas Aristotle’s was based on external form
T of F: Linnaeus understood the importance of natural groups, so he was able to form natural groups in his own taxonomy
false, he didn’t know enough about plants to form strictly natural groups
How did Linnaeus inspire the cataloguing of biodiversity?
although he attempted to form natural groups, he knew that they weren’t strictly natural but he paved the way for future people to do this by filling in gaps and discovering new species
How did Linnaeus’ system influence evolutionary thought in a positive way?
nested hierarchy suggested relatedness and relationships
displayed some continuity over time
allows for evolutionary and common ancestry interpretations and adaptations
How did Linnaeus’ system influence evolutionary thought in a negative way?
He thought that species, as a group, or groups, were like walled bins with unmergeable boundaries - you can’t go from one to the other and that was why there were no intermediate forms > this is challenging to fit into the idea of relatedness
Which 2 nests of Linnaeus’ classification system were natural groups? Why?
Genus and species
He recognized that there were features that made them natural groups, even if he didn’t know how
How did Linnaeus base the nesting of classes? Did this lead to natural groups ?
they were based on the number of groups which did not always leadto natural groups but was still a way to classify information - he knew this
Which other famous botanists or scientists did Linnaeus inspire?
Darwin
Who invented biological keys?
Lamarck in 1778
What are biological keys? Why was this invention important?
like the dichotomous key
they are a system for identifying specimens of known organisms by a series of 2 fold questions
allowed researchers to find out which species something belonged to without having to dig through copious amounts of literature and species descriptions - helped narrow it down basically
