Exam 2

Question 1

Lamarck

Answer 1

Lamarck founder of invertebrate paleontology and evolutionary theorist. Thought species might improve over time because of inherent drive towards perfection.

Question 2

Cuvier

Answer 2

Cuvier established the fact of extinction of past lifeforms. Studied fossils and noticed that many fossil species had no living counterparts. Developed the theory of catastrophism. Researched vertebrate and invertebrate zoology and paleontology.

Question 3

Buffon

Answer 3

Buffon’s idea that species change over time has become the cornerstone of the modern of evolutionary theory.

Question 4

Explain catastrophic events that affect life on Earth and how life adapted to the changes.

Answer 4

Catastrophic events happen by the geologic forces shaping the Earth’s surface. Remain species repopulated the earth.

Question 5

• Describe the historical background of the development of evolutionary theory in the 19th century. Include the role of Charles Darwin and Alfred Russel Wallace.

Answer 5

o Darwin formulate the theory of natural selection. He wanted enough evidence to prove his theory. Wallace supplied Darwin with birds for his studies and helped Darwin publishing his own ideas on evolution.

Question 6

• Explain all the contributions made by Darwin.

Answer 6

o Used observations, life had changed over time via geologic evidence & fossil evidence.
o Darwin provided a mechanism and substantial evidence to explain how evolution works.\
o Selection of gene breeding was called artificial selection. This produces observable changes that individuals may see through his lifetime. Over time generations.

Question 7

• Explain Darwin’s finches and the role of the mockingbird in his observations of natural selection.

Answer 7

o The mockingbird/finches discovering from observations were that their adaptation to varying island habitats through gradual separation into differing species.

Question 8

• Discuss the observations of Charles Darwin leading to the theory of natural selection.

Answer 8

o Genetic variation, overproduction of offspring, struggle for existence, and differential survival & reproduction.

Question 9

• State the requirements for natural selection and evolution in a population.

Answer 9

o The gene pool has to survive by the environment to be inherited to the following population.

Question 10

• Discuss natural selection, artificial selection, and sexual selection.

Answer 10

o Natural selection selects traits in organisms by the environment survival process

Artificial selection is done by selecting the animals and plants to be bred and produce more desirable characteristics in the next generation.

Sexual selection is where the females decide on which male to mate with.

Question 11

• Explain how Charles Darwin used artificial selection, comparative anatomy and comparative embryology to understand and explain evolutionary mechanisms

Answer 11

o Artificial selection, comparative anatomy, and comparative embryology show how Darwin’s process by investigating the homologies, inherited similarities, and organisms bone structure change over time in evolution.

Question 12

• Describe the conditions that are necessary for natural selection and evolution to occur.

Answer 12

o Reproduction, heredity, variation in fitness or organisms, variation in individual characters among members of the population.

Question 13

• Name and describe the four processes of natural selection. Apply this knowledge to examples.

Answer 13

o Genetic variation – presence of differences in sequences of genes between individual organisms.
o Overproduction of offspring – each generation has more offspring than can be supported by the environment
o Competition for resources – the use of the same resource by individuals of the same species or of different species.
o Differential survival and reproduction – non-genetic changes that occur during an organism’s life span, such as increase in muscle mass due to exercise, cannot be passed onto the next generation and are not examples of evolution.

Question 14

• Define fossil.

Answer 14

o Remains or impressions of a prehistoric organism. Evidence of the past life

Question 15

• Describe the processes of fossil formation.

Answer 15

o When a plant or animal dies in a watery environment and is buried in mud and silt. Preserved in amber, permafrost, peat bogs

Question 16

• Explain where fossilization is likely to occur and why only certain organisms are likely to be found as fossils.

Answer 16

o Organisms that are in water are more likely to become fossils. Bones are more likely to be found than soft tissue.

Question 17

• Explain how relative and absolute dating work in general and apply this knowledge to examples.

Answer 17

o Relative dating
 Comparison of layer sequence in which fossils are found
 Cannot use rock layers have been disturbed by geological processes

o Absolute dating
 Quantitative method
 Radiometric dating – use of isotopes

Question 18

• Explain and estimate the age of fossils.

Answer 18

o Relative dating by comparing similar rocks and fossils of known ages and absolute dating by determining a precise age of a fossil by using radiometric dating decay or rocks associated with it.

Question 19

• Outline the major events in the evolution of life on earth and briefly describe the evidence for each.

Answer 19

o Earth forms about 4.55 billion years, 3.5 billion bya the first prokaryotes (single-celled), 2.1 bya first eukaryotes (single-celled), 1.2 bya first multicellular eukaryotes
o Cambrian explosion in 542-511 mya, defined animals and phyla of the modern period.
o 500 mya colonization of land by fungi, plants, and animals

Question 20

• Describe the evolution of oxygen-producing photosynthesis and its effects on early life forms.

Answer 20

o Cyanobacteria is a prokaryotic cell, bacteria, that produces photosynthesis, earliest form of life on earth 2 bya.
o The process by which light energy is used to assemble sugars from carbon dioxide and water.

Question 21

• Discuss the relationship of cyanobacteria and stromatolites to evolution.

Answer 21

o Stromatolites are layered mounds, columns, and sheet-like sedimentary rocks.
o Formed by layers of cyanobacteria, single cell photosynthesizing microbe

Question 22

• Describe the first organisms and their role to the evolution to current life on Earth.

Answer 22

o Photosynthetic cyanobacteria, prokaryotes

o Known as anoxygenic

Question 23

• Describe Snowball Earth, the geological evidence, and its importance to the evolution of complex life forms.

Answer 23

o Earth was covered by ice from 600-700 mya, glaciers period end under extreme greenhouse conditions, climate shock trigged evolution of multicellular animal life and challenge assumptions regarding global change.

Question 24

• Outline the major events in the early evolution of animals and briefly describe the evidence for each.

Answer 24

o 1st animal fossils found in china 580 mya
o Ediacaran fauna, 575-535 mya
o Cambrian explosion/animals, 542-511 mya

Question 25

• Describe the main features of various animal body plans and their evolutionary significance. Apply this knowledge to examples.

Answer 25

o Body plan is a set of morphological features common to many members of a phylum of animals
 Ex. Vertebrate body plan, invertebrates consist of many phyla.

Question 26

• Differentiate Homeobox and Hox genes.

Answer 26

o Homeobox genes are a group of genes that encode for transcription factors that regulate the anatomical development of organisms
 Regulate morphogenesis
o Hox genes are a subset of homeobox genes that regulate the development of body axes and structures during embryonic development
 Regulate body segmentation and development of appendages

Question 27

• Discuss the impact of predator-prey relationships on animal evolution. Apply this knowledge to examples.

Answer 27

o Evolution can stabilize when the predator evolves and traits in one or both species under strong stabilizing selection. Adaptiopn may either increase or decrease the amplitude of those cycles. Its productive for the population cycle to follow through.

Question 28

• Discuss the characteristics of arthropods and apply this knowledge to examples.

Answer 28

o Segmented body, jointed appendages, exoskeleton made of chitin, 50%. of burgess shale fossils.

Question 29

• Discuss the characteristics of trilobites, including their body plan, lifestyles, and eyes.

Answer 29

o Early arthropod group, 50k species, has three parts of the body – head, thorax, tail
o Trilobite eyes are complex and each dot is a lens with sophisticated vision, sensitive to movement and is used for hunting and protecting.

Question 30

• Discuss the characteristics and lifestyle of sea scorpions.

Answer 30

o Eurypterids were large sea scorpions, large powerful pincers, top predators

Question 31

• Discuss the characteristics of velvet worms and their adaptations to life on land. Compare their adaptations to the adaptations of arthropods.

Answer 31

o Aysheaia shared common ancestor with arthropods
o Earliest land animals, soft permeable skin, breathing holes along sides . breathe air, found in present day in tropical habitats.

Question 32

• Describe the characteristics of the plant and animal fossils from the Carboniferous period. Briefly describe the oxygen content of the atmosphere and its impact on animal evolution.

Answer 32

o Meganeura was the earliest insect fossils, giant dragonfly, wingspan of almost three feet. Oxygen level were 35%
o 80% of all animal species today are insects, most successful arthropod group, three body segments.

Question 33

• Compare the advantages of an internal skeleton (endoskeleton) to an external skeleton (exoskeleton). Apply this knowledge to examples.

Answer 33

o External skeleton protects the outer surface of an organism and enables movement through muscles attached on the inside. Endoskeleton is internal skeleton composed of hard mineralized tissue that enable moment through muscles.
o Internal is better because it provides more protection from physical forces.

Question 34

• Contrast the types of digestion mechanism of organisms.

Answer 34

Extracellular digestion = outside of the cell and other animals
Intracellular digestion = inside of each cell
Digestion begins in a compartment continuous with the outside of the animal’s body.

Question 35

• Discuss the morphological symmetries of organisms.

Answer 35

o Radial symmetry – more than one way number to divide a body to get a mirror image, some invertebrates
o Bilateral Symmetry – one way to divide a body to get two mirror

Question 36

• Describe the Cambrian Explosion and its effect on animal evolution.

Answer 36

o Happened 541 million years with all major animal phyla started appearing in fossil record. Explains how animals started appearing in our period.
o Fossil record changed into wide variety of more complex animal groups, 80 mya the rate of evolution accelerated and diversity of life began to resemble that of today.

Question 37

• Explain the significance of the Burgess Shale to the Cambrian period.

Answer 37

o The best record of the Cambrian diversification is the Burgess shale in British Columbia, laid down in the middle-Cambrian when the explosion had been underway for mya.

Question 38

• Provide and explain arguments to support the biodiversity of the Cambrian period.

Answer 38

o The environment became more hospitable with a warming climate and rising sea levels flooding low-lying landmasses to create shallow marine life.
o Rapid evolution of new animal phyla grew

Question 39

• Discuss evolutionary problems that had to be solved in order for animals to move to land. Apply this information to examples.

Answer 39

o The head and neck needed to developed in order to make the transition between waterlife to landlife.
o Tetrapods evolve from a group of organisms.