Evolution Before Darwin

Question 1

What is evolution?

Answer 1

heritable change in a population or species over generational time from the divergence of lineages from a common ancestor

Question 2

What 3 things does evolution involve?

Answer 2

1. it is creative = it can increase the fitness of a population over time, it is not JUST the elimination of inviable forms
2. evolutionary change is open-ended, it is not striving towards a goal or restricted to a natural stopping point
3. species are related by descent and they have common ancestors

Question 3

What were 8 obstacles to evolutionary thinking pre-Darwin?

Answer 3

1. essentialism
2. generational continuity in every day life
3. literal interpretations of religious texts or believe in divine creation
4. natural theology
5. incomplete fossil record
6. the plenitude principle
7. fear of evolutionary thinking - amoral and societal chaos
8. misunderstanding of evolution

Question 4

How was essentialism an obstacle to evolutionary thinking before Darwin?

Answer 4

essentialism implies that species do not change over time, they have fixed characteristics

(Aristotlian - species are just imperfect reflections of some ideal eternal form)

Question 5

How was everyday generational continuity and lack of radical disconinuity an obstacle to evolutionary thinking before Darwin?

Answer 5

reproduction over 1-2 generations doesn’t show us radical change in characters

ex. kids usually look like their parents, not like complete strangers

Question 6

How were literal religious text interpretations and divine creation an obstacle to evolutionary thinking before Darwin?

Answer 6

teleological thought and divine creation prevented a lot of religious people from accepting science

especially during times when the paradigm was religious

Question 7

How was Natural Theology an obstacle to evolutionary thinking before Darwin? What was natural theology?

Answer 7

it was a new concept in the 18-19th centuries for TELEOLOGICAL interpretations of organismal function (dates back to ancient times)

related to divine creation

Question 8

Who was William Paley?

Answer 8

he was the most significant natural theologian in England in 1802 after his publication of ‘Natural Theology’

he had powerful arguments for his time about function

ex. the watch and human eye

looking at a watch, you know someone created it with a specific function in mind and interdependent parts - the same must be true for the human eye. it was not randomly created

Question 9

What was Darwin’s connection to William Paley?

Answer 9

Darwin later occupied the same dorm room as Paley, but also learned from his Natural Theology book

Question 10

How was the incomplete fossil record an obstacle to evolutionary thinking before Darwin?

Answer 10

it allowed room for arguments about the missing pieces - Cuvier thought that if evolution was occurring, why aren’t we seeing intermediate organisms in the fossil record?

he believed evolution should be abrupt and not gradual, so there should be obvious differences throughout the record (which there wasn’t)

Question 11

How was the plenitude principle an obstacle to evolutionary thinking before Darwin? what was it?

Answer 11

plenitude principle: all species that can exist, do exist

Creation was fully stocked and there cannot be gaps in creation

this is a theological/teleological argument

Question 12

How was fear an obstacle to evolutionary thinking before Darwin?

Answer 12

people were scared that evolutionary thinking would cause amoral behaviour and societal chaos because it contradicts the bible

it implies humans are ‘animals’ and might start behaving like them if they accepted evolution

Question 13

What is an example of the societal chaos that accepting the notion of evolution did actually cause in the 19-20th centuries?

Answer 13

Social Darwinism:

people accepted the idea of evolution by natural selection to justify their cutthroat competitive, capitalistic attitude toward less well off people

winners and losers exist and no remorse

Question 14

What was a secular argument against evolution?

Answer 14

anti-Social Darwinism

leftwinged people were against evolution because it allowed Social Darwinists to justify their remorseless behaviour

Question 15

How was misunderstanding evolution/science/words an obstacle to evolutionary thinking before Darwin?

Answer 15

not understanding a concept generally prevents people from accepting it or accepting it for inaccurate reasons

ex. popular thought of a phylo tree might be that a common ancestor became a fungus which became a sea star which became a giraffe but that is not true

ex. popular thought might think that ‘theory’ in ‘theory of evolution’ is just a guess and not an actual fact represented by a swack load of evidence as it means in science

Question 16

How do Linnaean hierarchies and natural groupings indicate evolutionary change?

Answer 16

the increasing inclusivity as you move from a species to an order or family

members of a group have commonalities with more organisms/members of a larger, more inclusive group as you move up the hierarchy

groups get more broad

ex. domestic house cats have things which make them individual; but they have commonalities with tigers and lions; tigers, lions and house cats have stuff in common with other mammals; mammals have stuff in common with other chordates; etc

Question 17

Describe similarity due to function vs. similarity due to unity of type, and how these indicate evolutionary change?

Answer 17

similarity due to function:
- all flying animals have wings = function is the same, but morphology differs (ex. birds, butterflies, bats)

similarity due to unity of type (aka homology):
- all birds have wings, but not all birds fly = function differs (ex. penguins, emus)

to evolutionary change:
- why would all animals that can fly need different forms for their wings if they provide the same function of flight?
- why would birds that can’t fly have wings?
= descent from a common ancestor and divergence from that ancestor

Question 18

Who distinguished the difference between function vs. type similarities?

Answer 18

Cuvier

Question 19

How does the fossil sequence in the stratigraphical column and the acceptance of extinction indicate evolutionary change?

Answer 19

in the 19th century, extinction became more widely accepted

fossil sequence provides information on the temporal transition of morphology

Question 20

What are the 2 possibilities that can explain the sequence of fossils in the stratigraphical column?

Answer 20

1. Like Cuvier thought, organisms undergo periodic extinction events and new assemblages form cyclically
2. temporal inheritable transition (aka evolution)

Question 21

How did spontaneous generation (as an accepted process) indicate evolutionary change?

Answer 21

before it was disproven,

the idea that if bacteria and protozoa could arise by spontaneous generation and evolve into more complex beings, then the creation of an unchanging world makes no sense

Question 22

How did natural theology indicate evolutionary change?

Answer 22

even though it also implied a divine creator (anti-evolutionary), it did accept adaptation and focus on function - helped progress evolutionary thinking

Question 23

Why would outright rejecting supernatural explanations in biology be counterproductive?

Answer 23

we would have to explain how function appears naturally in organisms and that’s much harder = might stop some people from asking the questions needed to head in that direction

Question 24

How did inherited variability within species indicate evolutionary change?

Answer 24

observing variability within species allowed us to reject the concept that if species were created to be adapted to their environments, then we wouldn’t see any inherited variability

Question 25

How did observations of vestigial and inefficient structures indicate evolutionary change?

Answer 25

they indicated descent from a common ancestor

ex. wisdom teeth in small humans are superfluous and often removed - why do we still have them then? they are leftover from our ancestors

Question 26

How did time and environmental change indicate evolutionary change?

Answer 26

geology helped biology understand this one

geology showed evidence for environmental change over time - how could species created to be adapted to an environment remain adapted throughout environmental change?

Question 27

How did the idea of change over time indicate evolutionary thought in different disciplines?

Answer 27

solar system’s formation and evolution - where did planets come from?

the solar arrow of time - how long until the sun’s energy runs out? what powers it? where did the energy come from?

gradual geological changes occurring over long time periods

language evolution - similarities between Sanskrit, Latin, Greek languages suggested descendent from a common, now extinct language
- ex. words for mother and father are extremely similar in French, Latin and Farsi

Question 28

How did studies of language evolution influence other areas of study?

Answer 28

Darwin drew a direct parallel, intentionally, from this concept

Also, knowing the origin and derivations of words in different languages can help us understand travel and migration patterns, trade, and environmental conditions (does the word ‘ocean’ exist in that language?)

Question 29

What was the best argument for evolution? what explains it?

Answer 29

there exists similarity beyond functional necessity

this is explained by descent from a common ancestor

ex. siblings look more alike than cousins

Question 30

Who was Erasmus Darwin (1731-1802)? what did he contribute?

Answer 30

Charles Darwin’s grandfather

scientist, poet, physician

published ‘Zoonomia’ (1796) as a theory of evolution similar to Lamarck’s

Question 31

What evidence did Erasmus Darwin present in Zoonomia for his theory of evolution?

Answer 31

1. mammals are a natural group which are descended from a common ancestor
2. artificial selection allows us to modify species over a short period of time
3. vestigial characters can only be explained by descent (ex. appendix, wisdom teeth)

Question 32

Explain Erasmus Darwin’s cause of evolutionary change: acquired inheritance

Answer 32

he thought that an individual can improve itself during its lifetime and send those improvements to the sex genes and to its offspring

ex. a great piano player will provide musical talent to their offspring

Question 33

Explain how Erasmus Darwin’s concept of descent from a common ancestor was deistic?

Answer 33

he thought that warm-blooded animals descended from ‘one living filament, which the great First Cause endowed with animality”

something/someone presented a living filament with animality = suggests creationism

Question 34

Who was Lamarck (1744-1829)? what was he known for?

Answer 34

known for ‘getting it all wrong’

he was creative and flexible and had intellectual and physical courage

a contemporary of Cuvier

an accomplished botanist until 50 yo and then became an invertebrate zoologist at Museum of NH

Question 35

WHat major contribution did Lamarck make to biology?

Answer 35

the biological key

coined the words ‘biosphere’ and ‘invertebrate’

he formed a lot of natural groups as influenced by Linnaeus

published the first picture of branched evolution

Question 36

What were Lamarck’s 19th century evolutionary ideas?

Answer 36

he believed in evolution because:

1. Linnaean hierarchies suggest relationships
2. reality of environmental change suggests evolution must occur for life to survive
3. evolution solves the problem of theological extinction because new species evolve to replace the extinct ones = ‘saves god from geology’

Question 37

How did Lamarck attempt to ‘save god from geology?’

Answer 37

by supporting his belief in evolution with his belief that evolution solves the theological problem of extinction = new species evolve to replace old, extinct ones

Question 38

What were the 2 causes of evolution Lamarck proposed in his 3 books?

Answer 38

mainly: there is an innate (not external) tendency for organisms to increase complex; novel complexity is inherited (acquired inheritance) and evolution is linear

secondarily: use and disuse - if it is used, it is inheritably bigger and stronger, if it is disused, it is lost

Question 39

Impressively, in his mid 70s, which of his ideas did Lamarck change his mind about?

Answer 39

he put the use and disuse argument as his primary cause of evolution and secondary as innate drive toward complexity

he also agreed that all animal life descended from a common ancestor

Question 40

describe the balance sheet of Lamarck’s work?

Answer 40

support evolution:
- branching
- indefinite change
- natural theology was flawed because time and enviro change

impeded:
- unscientific
- not really accepting it as natural, still trying to fit into theological framework

Question 41

Patrick Matthew (1790-1874)

Answer 41

well-travelled, well-read Scottish landowner - not a scientist

like Hutton, he observed the land around him and wondered if he was selecting the best trees to be harvested was he effecting his population of trees

Question 42

What prevented Patrick Matthew from being credited for the concept of natural selection in his book that was published 28 years BEFORE the Origin of Species?

Answer 42

his book was titled “On Naval Timber and Arboriculture” and had nothing to do with evolution but there was a very clear description of natural selection and common descent in an appendix

no one knew about him either, he was not well connected and no evolutionary scientist would think to read his book as part of their studies

Question 43

Who was Robert Chambers and what is the Vestiges of the Natural History of Creation (1844)?

Answer 43

a publisher, amateur geologist, encyclopediast but not a scientist

a book published anonymously which was posthumously credited to Robert Chambers which that evolution occurs as a part of the general Law of Development of the Universe (a reference to physics) = the universe as a whole evolves

Question 44

What did Chambers present as evidence for the universe as a whole evolving as part of the Law of Development of the Universe?

Answer 44

1. the fossil strata showed temporal sequence (change over time)
2. comparative anatomy showed type unity
3. comparative embryology showed similarities in stages of development
4. progression from simple to more complex within a group (since been debunked)

Question 45

How did Chambers think new life arose?

Answer 45

frequent spontaneous generation events

after which, species evolved based on variable stopping points along embryological development (ie., new species remain as embryos for longer during development)

ex. if an embryo goes from A to B but stops at B it develops into fish, if it goes past B to C, it develops into amphibians and so on

Question 46

Why was Chambers and his book unpopular with biologists? Why was it popular with intelligent, liberal-minded public?

Answer 46

it was full of errors of fact bc he wasn’t a scientist

it was a best-seller nonetheless because his arguments for evolution were good, but his mechanisms sucked