Module 1 Flashcards
(15 cards)
What alternative theories for ori of earth excisted?
Gradualism
Punctuated equilibrium
Uniformitarianism
Catastrophism
Creationism
How did the TOE emerged?
The purpose of the travel was to collect and observe species in their local environment and described features that made them well-suited to the diverse environments. A collection that later gave indications of geological changes and supported that earth was not 1000 years old. The finches in Galapagos had to come from elsewhere and diversified and giving rise to new species on various islands. He noticed adaptations through different traits provided by higher fitness – beaks, and behaviors adapted to specific food – an essential part of understanding evolution. These adaptations came from natural selection – a process in which individuals with certain traits tend to survive and reproduce at higher rates.
He did not publish his work since he anticipated an uproar during the time, as God had created every living being. A single common origin of life and after that evolving following the principle of passing down heritable traits and natural selection of the individuals with the highest viability and fertility. Since they lived in various habitats, they gradually accumulated various modifications, adaptations, for their specific way of life, and over time resulted in the rich diversity of life we see today. Natural selection explained the observable patterns of evolution. He viewed the history of life as a tree – a branching process along with past extinction events that could explain the morphological gaps that existed between related groups of organisms
Roles of relevant people?
Cuvier (Paleontology): Older strata had dissimilar fossils compared to other more current lifeforms, and that some species disappeared, and new species appeared from one layer to next. Extinction must have been familiar but opposed to the idea of evolution. Each strata boundary represented an extinction event that destroyed species in that area and was then repopulated by different species from other areas.
Wallace: Had identical work and presented it during the same time but gave much of the credit to the main architect Darwin.
Malthus: Overproduce. Human suffering was correlated to food and other resources. The capacity to overproduce was a characteristic of all species. An advantageous trait leaves more offspring that survive and reproduce and result in a high frequency of the said trait in the next generation. Over time natural selection resulting from biotic and abiotic factors can lead to a higher proportion of favorable traits in the next generation, leading to a high degree of adaptions to the local environment.
Mendel: Gave principles of inheritance and a foundation of genetics that gave TOE the mechanisms of inheritance.
James Hutton and Charles Lyell (geology): were two geologists that applied principled of the earth’s geological features, which could be explained by gradual mechanisms and that same geological processes are operating today as in the past and at the same rate. The principles caught Darwin’s attention; if the geological changes resulted from sudden events, then the earth must be older than 1000 years since it is not static.
How did the fields changed the view of nature?
Instead of thinking about strata as gods’ decorations, or images of lost souls, the layers contained organisms from earlier periods. They started to classify fossils in a new way and then discovered patterns in strata, where the top and bottom layers were dissimilar. Then the pondering began, and two alternative explanations were formed: Cuvier’s theory (Paleontology) of periodic catastrophes, and Lyell’s theory of gradual sedimentation. The first one indicated that fossils replaced each other through the strata, believed to be extinctions and speciation events. Breaks between strata were caused by repeated catastrophes, followed by radiation of new species, and these patterns must explain how species change and develop through time.
James Hutton and Charles Lyell (geology) were two geologists that applied principled of the earth’s geological features, which could be explained by gradual mechanisms and that same geological processes are operating today as in the past and at the same rate. The principles caught Darwin’s attention; if the geological changes resulted from sudden events, then the earth must be older than 1000 years since it is not static. Applied to biology: slow and subtle processes could produce substantial biological change. The two also pondered over mechanisms of erosion and sedimentation, mountain formation, and continental drift, also provided a classification of rocks and minerals that lead to patterns in strata.
Biology - Carolus Linnaeus: He included binominal nomenclature for the naming of species and classified life’s diversity for God’s greater glory. A classification system where similar species created a genus and similar genera were grouped as a family to give them a pattern of their creation. He realized that new species could emerge through hybridization and stated that primae speciae had been created by god and that the diversity was could have been a result of speciation events and that the competition in nature was necessary element to uphold the balance in nature – wisdom of god. The field then emerged and used comparative anatomy as its 1st objective.
Natural selection and O –> I ?
Natural selection explains the patterns of evolution. Two observations and two inferences: Members of a population often vary in their inherited traits. All species can produce more offspring than their environment can support, and many of these offspring fail to survive and reproduce. Individuals with a specific inherited trait have a higher P of viability and fertility = fitness in an environment than others. The unequal fitness among individuals will result in the accumulation of favorable traits in the population over generations.
Natural selection is the process where individuals with a specific trait have higher viability and fertility and are favored because of these traits. Over time there will be a higher frequency of these adaptations that are favorable in an environment. If environment changes or individuals move to a new environment, natural selection may result in adaptation to these new conditions and may give rise to new species. Populations evolve, not individuals. It only works if the trait differs among individuals. The environment varies between places and, and different traits for different environments.
The geological theory of strata & theory of plate tectonics and continental drift?
James Hutton and Charles Lyell were two geologists that applied principled of the earth’s geological features, which could be explained by gradual mechanisms and that same geological processes are operating today as in the past and at the same rate. The principles caught Darwin’s attention; if the geological changes resulted from sudden events, then the earth must be older than 1000 years since it is not static. Applied to biology: slow and subtle processes could produce substantial biological change. The two also pondered over mechanisms of erosion and sedimentation, mountain formation, and continental drift, also provided a classification of rocks and minerals that lead to patterns in strata.
Cuvier (Paleontology): Older strata had dissimilar fossils compared to other more current lifeforms, and that some species disappeared, and new species appeared from one layer to next. Extinction must have been familiar but opposed to the idea of evolution. Each strata boundary represented an extinction event that destroyed species in that area and was then repopulated by different species from other areas.
3 main problems in the TOE?
Did not know how variation arises
Did not know how the mechanisms of inheritance worked
Earth was too young for there to have been enough time for the observed variation of life
The problems were later solved together with Mendel and the observations of Lyell and Hutton that the earth was older than 1000 years.
How did the modern synthesis came about?
The Modern Synthesis describes the fusion of Mendelian genetics with Darwinian evolution that resulted in a unified theory of evolution. It is sometimes referred to as the Neo-Darwinian theory. It introduced several changes in how evolution and evolutionary processes were conceived. It proposed a new definition of evolution as “changes in allele frequencies within populations , “ thus emphasizing the genetic basis of evolution.
Four forces of evolution were identified as contributing to changes in allele frequencies. These are random genetic drift, gene flow, mutation pressure, and natural selection . Of these, natural selection—by which the best-adapted organisms have the highest survival rate—is the only evolutionary force that makes organisms better adapted to their environments.
The Modern Synthesis recognized that most mutations are deleterious (have a harmful effect), and that mutations that are advantageous usually have a small phenotypic effect. Advantageous mutations may be incorporated into the population through the process of natural selection. Changes in species therefore occur gradually through the accumulation of small changes. The large differences that are observed between species involve gradual change over extensive time periods.
First, mechanisms of evolution other than natural selection are recognized as playing important roles. Second, the Modern Synthesis succeeds in explaining the persistence of genetic variation, a problem that Charles Darwin struggled with. The dominant genetic theory of Darwin’s time was blending inheritance, in which offspring were thought to be the genetic intermediates (in-between versions) of their two parents. As Darwin correctly recognized, blending inheritance would result in the rapid end of genetic variation within a population, giving natural selection no material to work with. Incorporating Gregor Mendel’s particulate theory of inheritance, in which the alleles of a gene remain separate instead of merging, solves this problem.
Evolution?
By descent with modification. That earths many species are descendants of ancestral species that were different from present day species. A change in the genetic material of a population from generation to generation.
Gradualism?
A theory of that change comes about gradually or that variation is gradual in nature and happens over time as opposed to in large steps, compared to punctuated equilibrium, which proposes that once a species appears in the fossil record the population will become stable, showing little evolutionary change for most of its geological history. This state of little or no morphological change is called stasis. When significant evolutionary change occurs, the theory proposes that it is generally restricted to rare and geologically rapid events of branching speciation called cladogenesis. Cladogenesis is the process by which a species splits into two distinct species, rather than one species gradually transforming into another.
Uniformirarianism?
(Lyell and Hutton) This theory states that the forces and processes observable at earth’s surface are the same that have shaped earth’s landscape throughout natural history. That the earth is not static and therefore, should be older than 1000 years, also provided insight in the allopatric speciation due to the tectonic plates.
Catastrophism?
(Cuvier) The theory that the Earth has largely been shaped by sudden, short-lived, violent events, possibly worldwide in scope. In contrast to uniformitarianism, which slow incremental changes, such as erosion, created all the Earth’s geological features. It provided insights in the strata layers, that provided insight in how speciation could occur, by a mass extinction event.
Creationism?
The religious belief that nature, and aspects such as the universe, Earth, life, and humans, originated with supernatural acts of divine creation. That God had created everything and that every creation was perfect.
Observations supporting?
Fossils
Biogeography
Anatomical
DNA
2 main supports?
Intelligent designer and irreducible complexity
