RBC’s lack mitochondria and nuclei – they use glycolysis to produce ATP and only live about 3 months before being replaced. Microorganisms that can live without oxygen, such as the lactobacilli that turn milk products into yogurt and cheese, use fermentation to generate ATP.
Because the fossil record show abrupt appearance and “stasis” (no change), the evolutionary theory of “punctuated equilibrium” was developed by Gould and Eldredge, which basically says we don’t see evolution in the fossil record because it happens fast in small isolated groups. It is an argument from lack of evidence. The Cambrian Explosion makes a shipwreck of their nice neat chart. Rather than seeing simple life forms such as worms and jellyfish appear to be folowed by trilobites and fish and the like, we instead see representations of all major phyla appearing AT THE SAME TIME! This obvious slap in darwin’s face has caused not a few Darwinists to famously modify the theory. Punctuated equilibrium, or “punk eek,” suggests that life exists with only minor adaptations within established kinds [observable microevolution, which no one disputes], but then goes rapid changes in short spurts which leave behind no transitional forms!
Could be evidence for descent with modification Could be evidence for a single intelligent “creator”
Do similar embryological forms show common ancestry or a common designer? Ludwig Rutimeyer, a professor of zoology and comparative anatomy, at the University of Basel, reviewed Haeckel&apos;s work and Haeckel&apos;s mistakes were brought to the attention of the professors at Jena (Rutimeyer 1868). Charged with fraud by five professors and convicted by a university court at Jena, he agreed that a small percentage of his embryonic drawings were forgeries. Haeckel alleged he was merely filling in and reconstructing the missing links when the evidence was thin. During the trial, Haeckel confessed that he had altered his drawings, but excused himself by saying: “I should feel utterly condemned and annihilated by the admission, were it not that hundreds of the best observers and biologists lie under the same charge. The great majority of all morphological, anatomical, histological, and embryological diagrams are not true to nature, but are more or less doctored, schematized and reconstructed”.
Case Study: Developmental Homologies In 1868, a scientist named Ernst Haeckel published drawings of early vertebrate embryos which he manipulated to look more similar than they actually were. This was because he held preconceived views about evolution. Haeckel’s drawings were eventually recognized as fraudulent, but they are still found in some biology textbooks as good evidence for common ancestry. Haeckel’s ideas continue to spread misconceptions today. In humans at one month, there are throat pouches in the skin near the neck. These are sometimes labeled as ‘gillslits’, suggestive of a fish ancestry. In fish, these pouches do develop into gills. But in humans and other organisms, the middle ear canals develop from the second pouch, and the parathyroid and thymus glands come from the third and fourth. These labels are therefore quite biased. Other common misconceptions include the idea that a human embryo has a ‘yolk sac’ like a chicken and a ‘tail’ like a primate. These parts have now been identified as the blood-forming sac and the coccyx: an important point of muscle attachment necessary for our upright posture.
Darwin didn’t know about DNA – it hadn’t been discovered yet. Most people of his time believed that things you learned and experienced during your lifetime could be inherited by your offspring. Darwin believed there had to be a system to pass down physical traits and he was right. Since Watson & Crick discovered how nucleic acids transfer genetic material in 1953, a whole new field of genetics has exploded in the realm of science.
Before 1970, taxonomists classified all forms of life into two kingdoms: Animalia and Plantae. Bacteria, fungi, and photosynthetic protists were considered plants, and the protozoa were classified as animals. In 1969, Robort H. Whittaker proposed a five-kingdom classification scheme that is widely used today, and which we follow in this text. Whittaker identified two kingdoms of primarily unicellular microorganisms based on whether they showed prokaryotic or eukaryotic cellular organization. The kingdom Monera consists of generally single prokaryotic cells, whereas the kingdom Protista consists of generally single eukaryotic cells. All of the organisms in the remaining three kingdoms (Plantae, Fungi and Animalia) are eukaryotic, and most of them are multicellular. They may be classified further on the basis of their way of acquiring nutrients. Members of the kingdom Plantae photosynthesize, and members of the kingdom Fungi secrete enzymes outside their bodies and then absorb the externally digested nutrients. In contrast, members of the kingdom Animalia ingest their food and then digest it, either within an internal cavity or within individual cells. Recently, a sixth kingdom has been proposed. Many microbiologists argue that the cell structure of the Archaea is so different from that of prokaryotic and eukaryotic cells that they should occupy their own kingdom. Following the fashion, this text adopts the updated six-kingdom classification system (Fig. 1.1). 6 Kingdom Classification System Kingdom Eubacteria: true bacteria (formerly in kingdom monera) Kingdom Archebacteria: extremophiles (formerly in kingdom monera) Kingdom Protista (same)
Patterns of Evolution
Patterns of Evolution
Changes Over Time
In your lab notebook, please answer as best you can:
Bonus: What is the geologic column?
- a sequence of rock layers that combines all the known fossils and
rock formations on Earth arranged from oldest to youngest
1. Name two factors that increase an organism’s chance of fossilization.
• Hard parts (shell/bone), quick burial (slows decomposition), location of
death (dry/cold vs. harsh or warm/wet)
1. When all members of a certain species die, they are said to be…
1. Are fossil molds & casts found in ice, tar, sedimentary rock, or amber?
1. An opinion that prevents the objective analysis of a set of facts is a…
1. What is dendrochronology?
• Tree-ring dating (the technique of dating rock layers and fossils by cross-
dating the patterns of annual growth rings in tree trunks)
What is Evolution?
• Simple: "change over time“
• Biological Evolution:
"descent with modification"
– many, many, MANY small
changes over LOOOOOOOOONG
periods of time that result in the
formation of many DIFFERENT
types of organisms
Types of Evolution
– Small changes within a species' set of genes
that result in phenotypic differences
– Decades or centuries (short time)
– Under certain environmental conditions,
can produce new, closely-related species
– descent with modification
– the process by which modern organisms have
descended from ancient ancestors due to
many small changes over millions of years
• A lineage-splitting event that
produces a new, separate species
is called speciation
– reproduced in lab experiments
– populations change so much that they no
longer can interbreed and exchange genes
– requires geographic isolation
• Macroevolution =
speciation on a grand scale
• Individuals DO NOT
evolve over time, but
Week 13 Lab
Paper Airplane AdaptationsObservation
-A mutation is a change in the nucleotide base sequence of a gene (in a
cell’s DNA) that results in the manufacture of altered proteins which determine
an inherited trait.
-Mutations are rarely beneficial and only passed to offspring if they occur in
germ cells or gametes.
-Adaptations are traits caused by mutations that increase an organism’s or
population’s survival and/or ability to reproduce.
-Evolutionary fitness describes a population’s ability to survive and
reproduce in its current environment.
-Natural selection describes how a more fit population may be “chosen”
by their environment to survive. (This is really an awkward way of saying that
a less fit population that lacks adaptations will probably not survive or pass on
-Biological evolution occurs over long periods of time within populations of
living things due to differences in the frequency and combination of genes that
determine or influence inherited traits.
Paper Airplane Adaptations
- For this activity, paper
airplanes will represent
organisms of the same
species. Paper clips will
represent food, which the
organisms will be
competing for by trying to
reach the box. Certain
airplane designs may
provide an advantage for
the “organism” to reach
the food sooner and stay
alive. If your airplane is
the last to reach the box
in the center of the circle,
your organism will die
and you will have to sit
out for the rest of the
• Assembled from different
strata from around the
world with a bias towards
• Assumes sedimentation
occurs evenly and slowly
over millions of years
“the present is key to the past”
• Large gaps remain in the
fossil record – they may be
still hidden, have been
destroyed, or never existed
• Out of place fossils & lack
of transitional fossils is
The "Cambrian Explosion"
• Evidence in the fossil record shows that all major phylla were established in the
transition from Late Precambiran to Early Cambrian time
• In the creationist model, these animals represent descendants of original created
kinds that became extinct during the Flood of Genesis.
• Gradual evolution
struggles to account for
the sudden appearance
of so many types of life
at one time.
Equilibrium" is one
• It is puzzling why there
are little to no
"precursor" fossils to
all these varieties of
• A structure found in different species, but derived from a
common ancestral structure.
– The structure may or may not be used for the same function in
the species in which it occurs.
• skeletal structure
• similarities in
DNA, RNA, & the
proteins the code
• Structures that have different
mature forms but develop
from the same embryonic
• Limbs are structurally similar
but have different functions
• Recent developments in
biochemistry show "similarity
does not imply a genetic
• Neo-Darwinism sites the
similarities of genetics between
species as evidence of evolution
• Other scientists look DNA and see
the complexity and efficiency of
information transfer as evidence
for a single, intelligent “designer”
• The evolutionary
history of a species
• Relationship to other
species is based on :
– Fossil record
– Morphology (similar
– Embryological patterns
– Genetic similarities
• A cladogram is based on sorting similar organisms into groups called
clades that prioritize evolutionary relationships (phylogeny) over
traditional shared characteristics (Linnaean classification)
• Cladistics is a relatively new system of grouping that identifies similar
derived characteristics to represent evolutionary relationships.
• Organisms on the
descended from a
• The branching pattern
events (splits in two
where changes occur)
• Relies most heavily on
• This phylogenetic tree is VERY
• First true cells are thought to
have arisen from aquatic,