SLO 2.1
Systematics
the study of diversification of living forms both past and present and the relationship among living things though time
Modern Synthesis
unification of natural selection and genetics. The modern synthesis united geneticist, naturalists, and paleontologists for the first time and laid the foundation for the explosion of research into evolution by natural selection that occurred after the second world wa
Aristotle
very first biologist, gave us the first written taxonomy
Sustainability
we can make enough for a species for a period of time but at the cost of the environment - Populations of most species stay relatively stable. Species produce more offspring than needed because not all survive.
Darwin's 2 Great Laws: 1. Natural Selection
diversity makes species better at adapting - organisms come as they are with a bunch of diversity (never could answer where all the diversity came from)
What are Charles Darwin's Two Great Laws?
1. Natural Selection: diversity makes species better at adapting 2. Common Descent: all species are connected by a common ancestor
Is Malthus, right? Has human population grown exponentially?
- Human populations have grown exponentially. - Humans have responded by making more food (overproducing) than we need.
Thomas Malthus
- Studied human societies and cultures - Economist, infinite growth of human population vs. finite growth of resources (influenced Darwin0 - Determined that only those who would adapt would survive (natural selection)
Thomas Malthus role in Darwin's Theory of Evolution
- was a sociologist and studied human societies and cultures - Came up with human populations have the potential to grow much faster than our resources. Population growth outstrips resources. - Darwin reads Malthus' work and figures it applies to all living organisms. Large populations, not everyone can survive
Problems with Darwin's theory
1. Complex structure with intricate parts; how can we explain complicated structures under Darwin's theory. 2. Explaining traits and organs of little importance 3. Loss of variation in populations
4 forces of evolution that change allele frequency
1. Mutations (alternations in DNA sequence) 2. Genetic drift (random changes) 3. Gene flow 4. Natural Selection
Charles Darwin
A Naturalist who didn't publish due to controversy. Galapagos Island on HMS Beagle
How is artificial selection different from natural selection? Is it faster or slower?
Breeders/ humans artificially select certain individual animals to reproduce. Traits would become proportionally more common in population over course of generations - Natural selection takes place because some individuals are better suited for human ideals
James Hutton and Charles Lyell
Came up with concept of Uniformitarism - Uniformitarism: some natural laws and processes that operate in the universe now as they have always operated - our physical laws of the universe are universal and don't change
Jean-Baptiste Lamarck
Created first hypothesis - Thought that the organisms passed down traits and believe that species were not connected in origin at all - Spontaneous generation - obsolete theory that states that living organisms can originate from inanimate objects
How do we know all species are connected?
DNA because if you insert a clone of DNA into bacteria, that bacteria reads the genetic code and makes human insulin. The genetic code between humans and bacteria is very similar about 99%. Genetic code is universal. All cells come from other living cells, so there cannot be spontaneous generation.
Alfred Wallace
English naturalist who wrote Darwin about his observations which concluded that life had evolved. Led to Darwin publishing his work. - Came up with parts of Wallace's theories
What theory is August Weismann credited with and how does this help to determine the nature of evolution (ie., the debate between natural selection v. Lamarckian evolution)?
Germ plasm theory: all animals are made up of cells and all cells come from pre-existing cells - contradicts Lamarck's idea of Spontaneous Generation
Which better explains the actual process of biological evolution?
Lamarck was right in a very limited sense. He hypothesized the independent origin for all species. Believed we can trace all the way back to one origin.
What are the two main differences between Lamarckian evolution and evolution via natural selection?
Lamarck: mechanism for evolution was that organism can inherit acquired traits. Lamarck also firmly believed in spontaneous generation. - Ex) I get my ears pierced so my children will be born with pierced ears. - Has to get into gene line to be passed on
What was the main insight of Mendelian genetics and what major "problem" of natural selection did it explain?
Mechanism of inheritance - Problem with natural selection; if variations blended with each other in each generation, they would eventually merge into a same great average and differences among individuals would disappear. ( ½ genes from mom, ½ genes from dad)
What was the significance of the "Voyage of the Beagle"?
Navigated the globe on the beagle and published books describing his findings.
Is height completely determined by parent's genes?
No, sometimes it also has to do with the environment
What are some of the experiences Darwin had during his travel around the world that shaped his ideas about evolution?
Observed collected and wrote about specimens he looked at. Stopped on the coast of Chile after an earthquake and ocean floors had risen. Saw fossils in foothills. Realized there was a longer period for the life of the earth. Observed the different beaks of finches which helped him conclude that life evolves.
Problems with Darwin's Theory 3. Loss of variation in populations
Organisms that reproduced sexually is done by comparing mixing paint. Eventually we lose colors of paint when we've started with a rainbow of colors.
What did Aristotle discover?
Scalae Naturae: "Nature's ladder" - Took all animals and placed them into four groups; land, sea, air, and underground. However it is a trivial system because it does not go deeper than what it is.
Spontaneous Generation
The belief that all living organisms came from a single spontaneous origin. Believed dead material was giving life to flies. People think that organisms just pop up. However, this is not very accurate. We have NEVER ever found an instance of spontaneous generation.
Problems with Darwin's theory 1. Complex structure with intricate parts; how can we explain complicated structures under Darwin's theory example
The eye- made up of complicated tissues and nerves. Fossils for eyes are very limited. We may not get to see a progressive and continuous evolution of the eye
Be able to talk about the Modern Synthesis in broad terms. Why did it take so long for science to unite the ideas of Mendel and Darwin?
The fusion b/w Darwinian and Mendelian genetics that resulted in a unified theory of evolution - Proposed new definition of evolution: "changes in allele frequencies within populations" - Genetic basis of evolution
Problems with Darwin's Theory 2. Explaining traits and organs of little importance example
Vestigial traits- like human tailbones. Makes sense when looking at evolution as a whole
What does the Green Revolution have to do with Malthus?
We are probably reaching the point of not being able to sustain human life. There's a lot of hope though. Nearly universally, when humans reach a standard of living, the people self-regulated reproductively. - Malthus was right, we may be close to sustainability limit.
Darwin's 2 Great Laws: 2. Common Descent
all species are connected by a common ancestor
Classification
arrangement of animals and plants in taxonomic groups according to their observed similarities - putting things into groups
The best explanation for the process of biological evolution would be
natural selection
Artificial Selection:
natural selection but with humans doing the selection instead of the environment. A species is manipulated by an outside force. - Ex) Ancestor of all dogs is a wolf. They look so different because of Artificial selection. Selective breeding made dramatic changes in dogs.
Norman Borlaug
one of the leaders of the green revolution - Increased food Production
Scala Naturae
places simple things at the bottom and more complex at the top (not accurate)
Green revolution
primarily in the 20th century, the vast changes in agriculture to maximize our growth. We've increased the number of acres to produce food. - We have been able to increase our food supply.
Taxonomy
science of naming, describing, and classifying species of living or fossil organisms
Science is
self-correcting
Phylogenetics
study of the visual representation of the evolutionary history of populations, genes, and species - figuring how all things are related; road maps
Methodological Naturalism
the earth is a flat disk and is surrounded by a dark glow with a fire around it
