EXAM 5, Introduction to Evolution Flashcards
Evolution in it’s simplest meaning is
change
In biology is has come to…
refer to genetic change over time in species or groups of species
Microevolution refers to
change in a single gene in a population over time
Evolutionists and Creationists…
alike accept the reality that populations change over time (microevolution)
Microevolution is…
observable
Macroevolution refers to…
the formation of new species or groups of related species
so new classes, orders, phylum…
While Evolutionists…Creationists…
Evolutionists accept macroevolution as a natural extension of microevolution, Creationists REJECT the concept that all organisms are interrelated by decent
Creationists…
accept that speciation within the created “kinds” may occur, but not the origin of one “kind” from another
using “kind” in a biblical sense
The emphasis of evolution…
meaning macroevolution, is the study of how new species and higher taxa are formed
Evolution as a Theory…
seeks to answer many questions related to the diversity of life, seeks to explain the origin of everything
Since question of origin seeks to answer questions about history of life on earth…
it may not be handled directly by the scientific method, since it cant answer questions about history
Scientific method…
relies on empirical thought
empirical thought means…
using observations of natural processes rather than nonphysical or spiritual points of view
Scientific method automatically
eliminates any reliance upon or reference to theology
(Pre-evolution) #1) Chinese, Greek, other early cultures…
a) life was created supernaturally (people were theists, involved gods)
b) organized from simple to complex
(Pre-evolution) #2 Greek philosophers (plato, aristotle)…
a) an ideal perfect world (essence) exists, in contrast to the apparent, imperfect world
b) therefore no need to change
since essence made everything perfect, would not accept evolution
(Pre-evolution) #3 early church
a) God’s creation is perfect
b)also influenced by greek philosophers
c) so species will neither disappear nor change
Factors promoting change of perspective
- Age of enlightenment
- fossil record
- geology
- Thomas malthus
(Promoting change of perspective) #1 Age of enlightenment..
(1700s) questioned Biblical inerrancy (belief that Bible is without fault)
(thinking of possibility of no god)
(Promoting change of perspective) #2 fossil record…
A.) Georges Cuvier documented extinctions
- he opposed evolution since he saw design in anatomy
- promoted catastrophism (earths history is shaped by local upheavals (flood, earthquakes)
- but did NOT embrace a biblical flood
extinctions was in contrast with what the church was teaching
B.) fossil sequence seemed to suggest a sequence of different organisms over time (ex. simpler on the bottom)
(Promoting change of perspective) #3 Geology…
A.) James Hutton - gradualism
- gradualism was slow, continual processes accumulate into a large effect/change
INFLUENCED DARWIN
B.) Charles Lyell - uniformitarianism
- “the present is key to the past”
- only the same processes occuring now explain what happened in the past
C.) conclusion: the earth must be very old
D.) Darwin reads Lyells book while in HMS beagle
(Promoting change of perspective) #4 Thomas Malthus…
A.) populations can increase faster than food or supplies
B.) So, results is survival of the fittest
DARWIN ALTHOUGH READ MALTHUS
(Evolutionary Theories) Jean Baptiste Lamarck (1801)…
proposed inheritance of acquired characteristics
- through use or disuse, parts of an animals body develop or degenerate
- these changes are passed on to offspring
this was eventually disproven (maybe epigenetics?)
(Evolutionary Theories) some background about charles darwin
- love for outdoors/nature
- began training as physician (boring and distasteful)
- turned to the ministry (most naturalists clergy)
- hired as ship’s naturalist (HMS Beagle, 5 year voyage around the world
(Evolutionary Theories) the beagle left in the year….when darwin was…
1831, 22 years old
(Evolutionary Theories) beagle most known for stop at
Galapagos islands
Darwin Key observation #1
similar but different species in different locations
question: did God create each one, or did some process produce this variation?
Darwin Key observation #2
fossil species similar to modern day species
Question: is the fossil the ancestor?
Darwin Key observation #3
Island species similar to but different from mainland species
example: Galapagos finches, different sized beaks for different purposes
example: marine iguana goes into water vs. green iguana, did it diversify by some natural process?
Darwin spent…
23 years developing his theory and preparing it for publication (1836-1859)
Meanwhile…
Alfred Wallace sent Darwin a paper on similar theory “On the Tendency of Varieties to depart indefinitely from the original type”
- they published their own papers separately, but they were presented together as scientific meeting in 1858
Darwin was pushed to publish the…in..
“Origin of species” in 1859
Darwin had…
- lots of data on variability within species
- no actual data on speciation (one species evolving into another)
- Darwins thoroughness receives more credit than Wallace
natural selection…
Darwin and Wallace proposed that existing species developed from the modification of pre-existing species
“theory of descent with modification through variation and natural selection
4 points of natural selection
- variation in traits occurs among individuals within a species
- this variation can be passed from parents to offspring
- more offspring are produced than can survive and reproduce
- individuals with traits which make them better suited to their environment tend to flourish and produce more offspring and contribute greatest to next generation (survival of the fittest)
natural selection has been criticized..
because of its circular reasoning…
Who survives and reproduces?
those with adapted/best traits
What are adapted traits?
those which allow individuals to reproduce and survive
Following are ___ purported evidences for evolution and then some challenges to that evidence
8
1) Fossils
- according to evolutionists, when fossils are compared according to their age/depth, successive evolutionary change is apparent
(1) Transitional fossils…
are claimed to show the gradual transition from one form to another
(1) Evolutionists believe..
fossils were produced slowly over hundreds of millions of years
(1) creationists believe..
most fossils were produced during the flood
(1) first evidence for this
fish to amphibian fossils
- tiktaalik raseae is claimed to show the transition from fish to amphibian
- unlike a true fish, it had a broad skull, flexible neck, eyes on top of head, fins with primitive wrist and 5 finger like bones
(1) evidence against tiktaalik rasaea
more recent discoveries of terrestrial footprints 18 million years (according to evolution) prior to tiktaalik rule them out as ancestors of the walking amphibians
amphibians already on world before tiktaalik
(1) second evidence for this…
Horse Evolution
horse ancestors are claimed to show gradual transition from a small animal with short legs and broad feet to much larger animal with longer legs, single toe, hoof, large molar teeth
(1) evidence against horse evolution
creationists counter that all of horses are horses
simply represents diversification within the horse kind, which occurred after the flood
thus, series may show microevolution, or speciation, but it does little to show that all species are interrelated through common ancestry
2) Biogeography is the study..
of the geographic distribution of living and extinct species
(2) it is claimed that biogeography indicates…
that species in a given area have evolved from pre-existing species
(2) example of this is
Australia lacks large placental mammals
(2) this is consistent with idea that
placental mammals arose somewhere else and were never able to migrate to Austrailia beacuse its isolation in the pacific ocean
(2) creationists would counter…
that the real role of biogeography is to trace the migration of animals after they left the ark after the flood
the lack of placental mammals in austria means that marsupials could travel faster than placental mammals (since they can carry their young) after the flood, and reaches australia before ocean levels rose, isolating the continent.
3) convergent (macro)evolution claims that…
different species form different lineages have separately evolved similar characteristics due to similar adaptive pressure from similar environments
(3) example of this is
giant anteater and echidna both have long snouts and long tongues to eat ants
(3) counter argument is
similarity in traits that adapt different organisms to the same type of environment may simply show a common design
if you see a design, it implies there is a designer, complexity cant arise due to change
(3) intelligent design movement
seeks to show that the complexity of life demands an explanation that includes an intelligence
4) selective artificial breeding occurs when
humans breed species of plants or animals for specific traits
(4) evidence for selective breeding
wild mustard plant has been bred to produce broccoli, brussels sprouts, cabbage, cauliflower
(4) argue that natural selection…
can do that same, take different things out of one
(4) argument against this is (creationist)
- point out artificial breeding always involves an intelligence behind the breeding plan
- use breeding plans to show the limits of selective breeding, beets were selected for increased sugar content, could not go beyond 17%
- evolution depends upon creation of new structures , not just modification of existing ones
5) Homologous Structures are…
said to have been derived from a common ancestral form, but have evolved different functions
(5) example of homologous structure
vertebrate forearm, with the same arrangment of bones, but serving different examples is primary example used
humans, turtle, bat, whale, have pretty much same bones, different functions
(5) evidence against this (creationist)
homologous structures have been found to be controlled by different genes
- if they are due to common ancestor, one would expect the same genes to control the structures in various organisms, but this is not the case
(5) darwin redifened homology…
to mean due to common descent
(5) to use this as evidence for evolution..
involves circular reasoning
6) presence of homologous/vestigial structures are..
another example of homologous structures
(6) vestigial structures are..
anatomical features that have no currently known function, but resemble structures found in their ancestors
6) evidence against homologous/vestigial strucutres
- once 100 structures in humans claimed to be vestigial
- many of these including pineal, pituitary, thymus, appendix are now known to perform valuable functions
- tailbones (coccyx) cited by text is an attachment point for muscles
- vestigial structure may not be useless, use for everything
7) Developmental homologies are
species that differe as adults may have striking similarities during embryonic stages of development
7) example of this i
human embryos have “gill ridges” like a fish, and a bony “tail”
7) evidence against that specific example
gill ridges or slits may be inferred in embryos due to superficial resemblance, but perform very different functions
8) molecular homologies ..
the nucleotide and amino acid sequences from closely related species tend to be more similar than those from more distantly related species
8) evidence against this
again, circular reasoning
who is most closely related?
those with similar sequences
who has similar sequences?
those who are more closely related
