BIL 160 Study Guide - Spring 2018, Comprehensive Midterm Notes - Synapomorphy, Oxygen, Zygote
12 Oct 2018
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Department
Course
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BIL 160
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Intro to Evolution
• Evolution- change over time
• Organic Evolution- genetic and phenotypic change of living organisms over time
Misconceptions About Evolution
• “Evolution is only a theory”
o Organic evolution isn’t a theory
o Evolution is a process by which living organisms change from one generation to
the next
o This misconception fails to separate 2 important things
▪ Extant species evolved from ancestral forms (an observable phenomenon
supported by copious physical evidence
▪ Natural Selection is a major mechanism by which this change occurs
(Darwin’s Theory)
• Acceptance of evolution as an ongoing, natural process implies an ideology
• Evolution describes the origin of life on earth
o Evolution is not the process by which life has changed since its origin. The origin
of life and the evolution of life are two separate concepts
o Darwin’s theory of evolution by means of natural selection does not explain or
address the origin of life; it only explains how life changed once it arose
• Evolutionary theory implies that life evolved, and is evolving, by chance
o While random processes (genetic drift) do contribute to evolution, natural
selection is a non-random process that can result in evolution happening in a
particular “direction” (ie. Creating populations of organisms that are adapted to a
particular environment)
• Evolution is progress: evolving organisms are getting better
o Evolution is a process that has no value system. Organisms evolve to fit in their
environments, which means diversity of form and function
o There is no one form or function that is superior to all others
• Individual organisms evolve during their lifetimes
o Individuals adapt as they live and age; only populations of organisms evolve,
from one generation to the next
• Evolution occurs only gradually, over very long periods of time
o Relatively small genetic changes can sometimes result in major phenotypic
changes; if these changes are passed to the next generation, they can magnify
(especially if they are adaptive), and major evolutionary modifications can occur
relatively rapidly
• Species are distinct natural entities that can be clearly defined and recognized
o The biological definition of a species is a group of similar organisms that can
interbreed in nature to produce fertile, viable offspring. Not always a clear line
between the species
o Hybridization between groups humans have defined as “species” can sometimes
produce fertile, viable offspring
• Genetic drift only occurs in small populations
o Very large populations can also undergo random genetic change from one
generation to the next
find more resources at oneclass.com
find more resources at oneclass.com
o Some alleles will be passed on, and others may disappear
o The global population of humans alive is genetically different than 10,000 years
ago because of simple genetic drift
• Our species is no longer evolving
o Pathogens, parasites, and environmental factors all can affect individuals and they
can cause differential reproduction among individuals of different genotype
• Because evolution is slow, humans cannot influence it
o Humans are influencing evolution as we speak
o Ex: our activities that produce pollution and climate change are driving evolution
of species that can reproduce quickly enough to evolve in response
Evolution and Biodiversity
• Species- a population or series of populations within which free gene flow occurs under
natural conditions (a group of similar organisms that can interbreed in nature to produce
fertile, viable offspring
• Conspecifics- are members of the same species
• Population- all members of the same species living in a defined locality
• Biodiversity- variety of living species on earth
• 1.2-1.7 million species of eukaryotes
• More than half of animal species are insects
• Edward O Wilson has estimated that there may be 5-50 million species of eukaryotes on
earth
o 5 x 1020 prokaryotes
Genetic Variety
• Genome is the full DNA sequence of an organism
• A diploid organism has two copies of its genome in each of its diploid cells, one from
each parent
o The 2 copies are not necessarily identical
• Nuclear genome- the genome in a eukaryotic nucleus (usually 2 non-identical copies)
• Organelle genome- the genome in a mitochondrion or chloroplast (may be multiple,
identical copies)
• Different species have different numbers of RNA coding genes
o Bacterium- 1,000
o Typical mammal- 20,000
o Ferns and flowering plants > 400,000
Biodiversity is Disappearing
• Most species that have existed on earth are now extinct
• Current rate of extinction qualifies as a mass extinction
• Homo sapiens are cause of species loss
o Habitat loss
o Invasive exotic species
o Pollution
o Population Explosion
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Intro to evolution: evolution- change over time, organic evolution- genetic and phenotypic change of living organisms over time. Organisms evolve to fit in their environments, which means diversity of form and function: there is no one form or function that is superior to all others. Genetic evidence suggests that it"s a hybrid between a coyote (canis latrans) and a timber wolf (canis lupus) Intellectual stirrings in the renaissance: biology was still studied in a framework of natural theology, the notion that science should be dedicated to studying nature in order to figure out the grand. If kimura"s neutral mutation model is true : there should be more neutral mutations found in pseudogenes than in protein or. Voyage of the beagle: father robert darwin believed nothing good will come out of being a naturalist, so he sent charles to med school at 16 at the university of edinburgh with his older brother.
