BIO 2|DEVELOPMENT OF EVOLUTIONARY THOUGHT Flashcards
3 DEVELOPMENT OF EVOLUTIONARY THOUGHT
- CATASTROPHISM BY GEORGES CUVIER
- INHERITANCE OF ACQUIRED TRAIT BY JEAN-BAPTISTE LAMARCK
- THEORY OF EVOLUTION BY NATURAL SELECTION BY CHARLES DARWIN
French Zoologist and Paleontologist
Georges Cuvier (1769-1832)
states that the Earth has been shaped by sudden, often unpredicted, events that are short-lived but impactful. It proposes the idea that catastrophes are responsible for mass extinctions and other processes.
CATASTROPHISM BY GEORGES CUVIER
French Naturalist and Biologist
Jean-Baptiste Lamarck(1744-1829)
According to Lamarck, organisms alter their behavior in response to environmental change. Their changed behavior, in turn, modified their organs, and their offspring inherited those “improved” structures.
INHERITANCE OF ACQUIRED TRAIT BY JEAN-BAPTISTE LAMARCK
Naturalist, Geologist and Biologist
Charles Darwin (1808-1882)
“THE FATHER OF EVOLUTION”
defined evolution as “descent with modification,”
the idea that species change over time, give rise to new
species, and share a common ancestor.
THEORY OF EVOLUTION BY NATURAL SELECTION
The mechanism that Darwin proposed for evolution is
___________
natural selection
__________causes populations to become adapted, or increasingly well-suited, to their environments over time.
depends on the environment and requires existing heritable variation in a group.
Natural selection
H.M.S Beagle
Her Majesty’s Ship
1831-1836
In ___, Darwin published his famous book,_____. This book caused a lot of controversy, but it also gained a lot of support.
1859
On the Origin of Species by Means of Natural Selection
Darwin found that nearby islands in the ________ had similar but not identical species of finches living on them.
Galápagos
This mechanism was elegant and logical, and it explained how populations could evolve (undergo descent with modification) in such a way that they became better suited to their environments over time.
natural selection
Traits are often_____. In living organisms, many characteristics are inherited or passed from parent to offspring.
heritable
FOUR BASIC PRINCIPLES OF NATURAL SELECTION
- Variation
- Heritability
- Overproduction
- Reproductive advantage
Individuals have traits better suited to the environment than others. Individuals with adaptive traits give them some advantages and are more likely to survive and reproduce.
Variation
refers to the degree of
adaptation of an individual to its environment which is passed onto future generations.
Fitness
Variations in traits of individuals maybe passed on to their offspring.
Heritability
Organisms can produce more individuals than can be supported by the environment.
Overproduction
Some traits allow individuals to gain more advantage in terms of fitness.
Reproductive advantage
6 MECHANISMS OF EVOLUTION
- NATURAL SELECTION
- GENETIC DRIFT
- ARTIFICIAL SELECTION
- MUTATION
- MIGRATION
- RECOMBINATION
- usually predominates in large populations
- It results in evolution when
individuals with higher survival and reproductive rates pass on these traits
to their offspring. - operates according to the differential reproductive successes of individuals.
NATURAL SELECTION
- Random change in the frequency of gene. In each generation, some individuals may, just by chance, leave
behind a few more descendants than other individuals. - A large reduction in the size of the population increases evolutionary change by genetic drift is termed bottleneck.
GENETIC DRIFT
Some individuals may survive by ____. The offspring of these individuals carry the genes for the “lucky” and not necessarily the “better” individuals
luck
a technique in which the intervention of humans
allows only for selected organisms to breed and produce offspring.
ARTIFICIAL SELECTION
A change in the DNA of an
organism. ____________ is a
random event and it may
be beneficial or harmful.
Environmental factors may
influence the rate of __________ and not all
__________ result in evolution.
MUTATION
is the movement of
populations, groups or
individual species.
It enables gene flow.
MIGRATION
the movement of genetic
characteristics from one
population to another
gene flow
Exchange of segments between DNA molecules or
chromosomes.
RECOMBINATION
refers to largescale changes that occur over extended time periods, such as the
formation of new species and groups.
Macroevolution
refers to smallscale changes that affect just one or a few genes and happen in populations over shorter
timescales.
Microevolution
refers to the total collection of fossils discovered and studied by paleontologists and geologists.
The fossil record
are the preserved remains,
impressions, or traces of
ancient organisms or their
activities found in rocks and
sedimentary layers of the
Earth’s crust.
Fossils
Types of Fossils (8)
Petrified Fossils
Mold Fossils
Cast Fossil
Trace Fossils
Amber Fossils
Index Fossils
True-form fossils
Microfossils
These fossils form when organic materials are replaced by minerals, turning them into stone. _______ fossils can preserve the cellular structure of the original organism.
Petrified Fossils
_______ fossils are formed when the remains of an organism, such as a shell or
bone, dissolve or decay, leaving an impression in the surrounding rock. These
impressions are called molds.
Mold Fossils
are created when a mold
is filled with minerals or sediments, creating a replica of the original organism.
Cast Fossil
are essentially three dimensional copies of the mold
Casts
are indirect evidence of ancient life, including footprints, tracks, burrows, nests, and coprolites (fossilized feces). These fossils provide information about the behavior and activities of organisms rather than their physical remains.
Trace Fossils
is fossilized tree resin that can trap small organisms, such as insects or plant parts. The resin hardens over time, preserving the trapped organisms in incredible detail.
Amber Fossils
are fossils of organisms that lived for a limited geologic period and had a wide geographic distribution. These fossils are useful for
dating and correlating the layers of rock in which they are found, helping scientists determine the age of rock formations.
Index Fossils
are organisms that are
preserved entirely in their natural form.
True-form fossils
are tiny fossils that require a microscope to be seen. They include microscopic organisms like diatoms,
foraminifera, and pollen grains.
Microfossils
Anatomical Comparison of Organisms (3)
Homologous structures
Analogous structures
Vestigial structures
If two or more species share
a unique physical feature,
such as a complex bone
structure or a body plan, they may all have inherited this feature from a common
ancestor. Physical features
shared due to evolutionary
history (a common ancestor)
are said to be _____
Homologous structures
are common traits found in different groups of species which are anatomically different, and serve the same function, but evolved
independently in the different groups of species.
Analogous structures
is a biological structure
that has lost a major
ancestral function and is
usually drastically
reduced in size.
Vestigial structures
the study of the development of the anatomy of an organism to its adult form, provides evidence for evolution as embryo formation in widely divergent groups of organisms tends to be conserved. Structures that are absent in the adults of some groups often appear in their embryonic forms, disappearing by the time the
adult or juvenile form is reached.
Embryology
The spread and distribution of species of organisms in different geographical positions across the planet is known as ____________. The geographic distribution of organisms on Earth follows patterns that are best explained by evolution, in
combination with the movement of tectonic plates over geological time.
BIOGEOGRAPHY
Like structural homologies,
similarities between biological molecules can reflect shared evolutionary ancestry. At the most
basic level, all living organisms share:
* The same genetic material (DNA)
* The same, or highly similar,
genetic codes
* The same basic process of gene expression (transcription and translation)
* The same molecular building blocks, such as amino acids
Molecular Biology
