Module 1 - Evolution Flashcards
What was revolutionary about the Darwinian revolution?
challenged traditional views of a young Earth inhabited by unchanging species
What the definition of evolution?
Descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones; also defined more narrowly as the change in the genetic composition of a population from generation to generation.
What is the meaning of the pattern of evolutionary change?
data from a range of scientific disciplines, including biology, geology, physics, and chemistry. These data are facts and are observations about the natural world.
What is the meaning of the process of evolutionary change?
consists of the mechanisms that produce the observed pattern of change. These mechanisms represent natural causes of the natural phenomena we observe.
What impelled Darwin to challenge the views about Earth and its life?
Darwin’s revolutionary proposal developed over time, influenced by the work of others and by his travels
What was Aristotle’s views of evolution?
- viewed species as fixed (unchanging).
- Through his observations recognized certain “affinities” among organisms.
- He concluded that life-forms could be arranged on a ladder, or scale, of increasing complexity, later called the scala naturae (“scale of nature”).
- Each form of life, perfect and permanent, had its allotted rung on this ladder.
- Old Testament account of creation, which holds that species were individually designed by God and therefore perfect.
What was Carolus Linnaeus’s views of evolution?
- sought to classify life’s diversity
- developed the two-part, or binomial, format for naming species (such as Homo sapiens for humans) that is still used today.
- adopted a nested classification system, grouping similar species into increasingly general categories. For example, similar species are grouped in the same genus, similar genera (plural of genus) are grouped in the same family, and so on.
What is the benefit of fossils in relation to ideas of evolution?
- Darwin drew from the work from studying fossils
- fossils provide a glimpse into organisms populated Earth at the time that layer formed
- Curvier noted that older stratum = more differences in fossils
- concluded that Earth’s changes led to killing off species and led to biological changes
What were Lamarck’s hypotheses?
- Use and disuse: parts of the body that are used extensively become larger and stronger and those not used deteriorate
- The inheritance of acquired characteristics: organisms can pass along modifications to offspring
What are adaptations?
Inherited characteristics of an organism that enhances its survival and reproduction in a specific environment
What is natural selection?
a process in which individuals have inherited traits which tend to survive and reproduce at higher rates than other individuals because of those traits
What were the 3 main observations of the Origin of Species?
the unity of life, the diversity of life, and the match between organisms and their environments.
What is artificial selection?
- selective breeding of domesticated plants and animals to encourage the occurrence of desirable traits
- As a result of artificial selection, crops, livestock animals, and pets often bear little resemblance to their wild ancestors.
What are the main ideas of natural selection?
- Natural selection is a process in which individuals that have certain heritable traits survive and, because of those traits, reproduce at a higher rate than other individuals.
- Over time, natural selection can increase the frequency of adaptations that are favourable in a given environment
Can individuals evolve?
No! Individuals do not evolve, populations evolve over time
Can natural selection amplify/diminish identical traits?
No! Natural selection can amplify or diminish only those heritable traits that differ among the individuals in a population. Even if a trait is heritable, if all the individuals in a population are genetically identical for that trait, evolution by natural selection cannot occur.
What are the 3 key points of natural selection?
- A process of editing not a creative mechanism (cannot create resistant pathogens can select for them)
- Species that produce new generations in short periods of time lead to rapid natural selection a few years or decades
- Natural selection depends on time and place and favors genetically variable populations,
what is homology?
similarities in characteristics resulting from shared ancestry
What are examples of homologous structures?
Mammalian forelimbs, Even though they have become adapted for different functions, the forelimbs of all mammals are constructed from the same basic skeletal elements: one large bone, attached to two smaller bones, attached to several small bones, attached to several metacarpals, attached to approximately five digits, each of which is composed of multiple phalanges
What is a vestigial structure?
feature of an organism that is an historical remnant of a structure that served a function in the organism’s ancestors
i.e the skeletons of some snakes retain vestiges of the pelvis and leg bones of walking ancestors. Another example is provided by eye remnants that are buried under scales in blind species of cave fishes. We would not expect to see these vestigial structures if snakes and blind cave fishes had origins separate from other vertebrate animals.
what are pseudogenes?
A segment of DNA that structurally resembles a gene but is not capable of coding for a protein. Pseudogenes are most often derived from genes that have lost their protein-coding ability due to accumulated mutations that have occurred over the course of evolution.
what is convergent evolution?
the evolution of similar features in independent evolutionary lineages
