chapter 22: descent with modification

zoology: dr tenneson: lecture notes: chapter 22: spring 2022: evangel university

what was the book that charles darwin wrote?

the origin of species

what were darwin’s 2 major points in his book, The Origin of Species?

descent with modification & natural selection

what year was darwin’s book, The Origin of Species, written?

1859

timeline of people involved with natural selection/common descent studies around darwin’s time:

\

1. hutton: principle of gradualism (_______)
2. malthus": survival of the ____ (ex: poor people died & the rich thrived)
3. lamarck: hypothesis of _____ (hypothesized that giraffes started out with short necks but stretched them out over time)
4. charles darwin is born
5. cuvier: identified _____
6. lyell: published Principles of Geology
7. darwin traveled around the world for 5 years
8. darwin wrote his essay on ____ with modification
9. wallace sent darwin his hypothesis on NS (he came up with NS independently of darwin, but their conclusions were the same)
10. darwin published The Origins of Species

uniformitarianism. fittest. evolution. extinction. descent.

what 3 commonly held views did The Origin of Species challenge?

species constancy, recent creation, humans being unique

Aristotle

* philosopher from _____.
* views species as _____ & _____.
* Aristotle's idea was that living things could be assigned a hierarchical position on a diagram that would represent their degree of perfection. what is this diagram called?

greece. fixed & unchanging. scala naturae

linnaeus

* thought adaptations were evidence of what?
* founder of _____.
* invented _____ _____.
* same in every language
* \

god created each species for a purpose. taxonomy. binomial nomenclature.

who founded taxonomy & invented binomial nomenclature?

linnaeus

cuvier

* first ______
* opposed _____ism
* advocated for _______ism
* believed in what type of earth?
* established _____ as fact

paleontologist. gradualism. catastrophism. ancient. extinction

who was the first paleontologist

cuvier

who established extinction as fact?

cuvier

lyell

* supported ______
* believed in what type of earth?
* geologist
* collaborated with darwin (he influenced darwin, so darwin embraced uniformitarianism)

uniformitarianism. ancient

lamarck

* first detailed theory of ____
* inheritance through _____ characteristics (use & disuse causes structures to change size)
* viewed evolution leads toward perfection (______)

evolution. acquired. teleological

who first detailed the theory of evolution?

lamarck

who believed in inheritance through acquired characteristics (use & disuse causes structures to change in size)?

lamarck

if lamarck was right about inheritance through acquired characteristics, then the seeds of a _____ tree would produce very small trees as well. but this does not happen - they turn into regular trees.

bonsai

wallace

* parallel theory as darwin’s
* motivated darwin to quickly publish
* describe Wallace’s Line

he noticed that in the north islands, the organisms were similar to asian organisms. & in the south islands, the organisms were similar to australian creatures. it’s an imaginary line

who was the person that had a parallel theory to darwin & motivated darwin to quickly publish?

wallace

malthus

* observed ____ offspring produced than survived
* idea of competition for survival (AKA:???)

more. survival of the fittest

who observed that more offspring are produced than survive?

malthus

who had the idea of competition for survival, or survival of the fittest?

malthus

gradualism

* define gradualism.
* geologists Hutton & Lyell:
* changes in earth’s surface can result from continuous actions still operating today
* exerted a strong influence on darwin’s thinking
* advocated ______ism

profound change can take place through slow but continuous processes. uniformitarianism

what 2 geologists advocated for gradualism?

hutton & lyell

descent with modification

* define descent with modification
* the history of life is like a ____.
* multiple branching from a common trunk.
* represent the diversity of living organisms

all organisms are related through descent from a common ancestor. tree.

natural selection

* are new traits created?
* what determines which traits will be selected?
* define mutations
* does natural selection = macrevolution?
* what is the in-class example that dr. tenneson used to describe natural selection?

no. environment. change in DNA that’s passed down to the next generation. no. horns on rhinos help them fight predators, so they’re more likely to survive & pass that trait to their offspring.

\*\*\* test question \*\*\*

\
write a summary of natural selection in your own words

offspring are genetically different. populations have limited resources, which leads to competition. only a small percentage survives. those organisms with favorable traits survive & reproduce. the favorable traits become more common in a population and lead to microevolution.

organisms are well adapted to their environments

* crypcis: praying mantis
* close fit between _____ & their _____.

organisms, habitat

what are the 7 evidences of evolution (macroevolution)?

age of earth, evidences for natural selection, biogeography, fossil record, comparative anatomy, comparative embryology, molecular biology

evidence of evolution: age of the earth

* while this in no way proves macroevolution, it is considered a _____.
* the longer earth has been around, the more time for species to evolve

prerequisite

evidence of evolution: evidences for natural selection

* the effect of _____ _____ on animals & plants is huge
* NS is logical & sensible
* NS is observed in real time on a ____ scale (leads to microevolution)
* provides a satisfactory explanation for the fossil record

artificial selection. small

observations of NS in the wild


1. darwin’s _____
* beak thickness increased in ____ years. this occurred over generations (microevolution)
2. soapberry bugs
3. pathogen drug & antibody resistance
4. songless crickets, hawaii

finches. dry

can individual organisms evolve by themselves?

no

NS in response to introduced plant species

* soapberry bugs use their “beaks” to feed on fruit seeds.
* in southern florida, they feed on a native fruit. they have longer beaks.
* in central florida, they feed on introduced fruit. they have shorter beaks.

\
* _____ plants appear to result in smaller than natural beaks.

introduced

evolution of drug-resistant bacteria

* *Staphylococcus aureus* is commonly found on the skin & doesn’t start out harmful.
* methicillin-resistant *Staphylococcus aureus* (MRSA) is a dangerous pathogen.
* methicillin antibiotics can lead to a selection of MRSA strains.
* MRSA is resistant to most antibiotics

\
what is the chain of events in getting MRSA but not taking the full antibiotic prescription?

skin infection → antibiotic prescription → quit meds early because it starts to clear up → infection returns → same antibiotic doesn’t help because bacteria have become resistant to it

explain the “bogus example” of the peppered moth

trying to prove that the moth population changed from light to dark color during industrial revolution. they attributed the color change to natural selection. the data/pictures were falsified because moths don’t perch on trees, moths don’t fly during the day, their predators hunt by sound & not color, & the moths were dead & glued to trees for pictures.

is sickle cell anemia inherited by the homozygous recessive or heterozygous recessive allele?

homozygous recessive

because sickle cell anemia is a lethal disease, why did natural selection not wipe it out?

because carriers of sickle cell anemia are highly resistant to malaria

what is the disease that causes mutations in hemoglobin but also confers malaria resistance?

sickle cell anemia

natural selection favors individuals that are ___zygous for the sickle cell allele

hetero

what is the study of the geographic distribution of living things?

biogeography

what supports evidences of continental drift?

fossil distributions

what creation view does continental drift often support?

ancient creation

define pangea

continents all together

during the mesozoic era, pangea was split into northern & southern hemispheres. what were these hemispheres called?

laurasia & gondwana

between the mesozoic & cenozoic eras, what were the 8 continents that formed from the northern hemisphere (laurasia) & southern hemisphere (gondwana)?

north america, south america, eurasia, africa, india, madagascar, antarctica, australia

how does the movement of tectonic plates provide proof for old earth creation?

the plates separate really slow

Magnetic Field Reversals:

* what used to be magnetic field North is now magnetic field ___.
* rocks are younger/older in certain areas.
* magnetics north pole won’t hit the north pole.
* moves really fast
* caused by magma flow

south

* how many marsupials does south america have?
* how many marsupials does Australia have?
* how many marsupials does north America have?

3, 2, 1

are the oldest marsupials found on the northern or southern continents?

northern

marsupials started out in ____ america & then spread. they spread fast enough to get to australia before the continents split.

north

armadillos:

* found only in the ___ world
* appear to have originated in south america
* continuing to migrate north

new

mesosaurs:

* triassic reptile
* 2 feet long
* same species found in africa & brazil

\
* was it aquatic or terrestrial?

aquatic

same organisms/rocks found in different continents → the continents were previously attached → continental drift happens slowly → possibly proof of ancient creation → possibly proof of _____

evolution

do the deepest rock layers have prokaryotes or eukaryotes?

prokaryotes

do deeper rock layers have simpler or more complex organisms? what about more superficial rock layers?

simpler, complex

Fossil Record:

* remains/traces of organisms in the past
* are the oldest fossils prokaryotes or eukaryotes?
* if organisms were created at the same time, they’d be in the same rock layers

prokaryotes

what are 2 examples of transitional forms found through fossil records?

whales (terrestrial to aquatic) & reptiles to amphibians

catastrophic flood is generally considered insufficient to explain the distribution & abundance of discovered fossils. what does the majority opinion say better explains it?

uniformitarianism

what do most fossils consist of?

hardened mineral casts

what are examples of trace fossils?

footprints & burrows

fossil formation:

* layers of deposited ____
* younger stratum with more recent fossils
* older stratum with older fossils

sediment

what are 3 ways that the fossil record is incomplete?

favors large species, widespread species, & preservation of hard parts

the fish/amphibian transition: fish began to have the same ____ as amphibians

bones

what is an Acanthostega?

organism with terrestrial & aquatic features. has fish-like gills & limb skeleton. it’s in the transitional stage

reptiles → birds:

* older feather-bearing fossils had ___-___ feathers.
* flight feathers are found only in more recent fossils.
* aside from feathers, these creatures were reptilian.
* bird fossils lacking these reptilian features don’t appear until the most recent geological strata

non-flight

what was the whale’s ancestor called?

pakicetus

what is astralgus?

ankle bone

similarity in ____ bone lead to the belief that the ancestor of whales is a goat-like animal called a Pakicetus

ankle

does a pakicetus have 1 or 2 double humps in it’s ankle bone?

2

what is the ankle structure of most mammals?

1 single hump & 1 double hump

what is the ankle structure of cetacean fossils & artiodactyls?

2 double humps

what are the 3 organisms with 2 double humps in their ankles?

pakicetus, pig, deer

what is an example of an organism that has 1 single hump & 1 double hump in their ankle?

dog

this reptile had a mammal-like jaw

therapsid

the more ____ 2 species are, the more they will compete

similar

what did the image of the hominid fossil record show?

skulls

define ateleological

NOT goal oriented

survival or extinction depend on ____ of the species to the habitat

adaptation

diagram of the evolution of the horse:

* what does the image show/prove?
* the horse started out with multiple toes. how many does it have now?

ateleological evolution, 1

define homologous structures

anatomical resemblances that represent variations on a structural theme present in a common ancestor

define analogous structures

similar function caused by convergent evolution

how does common ancestry explain homology

same bones in forelimbs, whether they walk, fly, or swim

how does convergence explain analogy?

2 kinds of animals in separate parts of the world have similar structures. this isn’t necessarily due to them being related. it’s likely due to them occupying similar environments & adapting similar functions

define vestigial structures

anatomical features that have no known function. thought to be a remnant of an ancestral use. are not beneficial or harmful

extinct whales had hind limbs & ____ bones

pelvic

vestigial structures: whale pelvis --

* living whales lack hind limbs, but they do possess pelvic bones.
* fossil whales had both.
* what do creationists suggest about this?

not vestigial structures. they have an unknown function

why doesn’t natural selection cause new structures to appear?

because it can only modify what’s already present (not bringing new genetic trait). it does cause mutation

define evolutionary novelties

naturalistic explanation of evolution of novel features

define exaptations

structures that evolve in one context but become co-opted for a different function

define comparative embryology

vertebrate embryos go through similar stages of development & it indicates common ancestry

what is haekel’s ruse?

false data said all vertebrate embryos looked/were the same

small changes in genes can result in massive _____ changes.

appearance

define heterochrony

changes in rate & timing of developmental events

heterochrony: changes in rate & timing of developmental events.

* can have impact on ____ shape
* can alter timing of reproductive development

body

define paedomorphosis

sexually mature species may retain body features. may have been juvenile structures in an ancestral species

what’s an example of paedomorphosis?

an aquatic organism retains lungs but only uses gills

define homeotic genes

genes that control the placement & organization of body parts

can homeotic genes cause significant morphological change?

yes

define hox genes

class of homeotic genes. provides positional information during development

what happens if hox genes are expressed in the wrong location?

body parts can be produced in the wrong location