Biology 100 Midterm 2 (part 1) Flashcards
Summarize the cultural and scientific contexts that led to Darwin’s development and publishing of his hypotheses.
Charles Darwin’s development and publication of his evolutionary theory, primarily natural selection, were significantly influenced by the prevailing scientific understanding of geology, the practice of selective breeding, and the ideas of population growth presented by Thomas Malthus, all within a cultural context that was gradually shifting towards accepting natural explanations for phenomena rather than solely relying on religious interpretations; his observations during the voyage on the Beagle, particularly on the Galapagos Islands, provided crucial empirical evidence that helped shape his theory.
Describe examples of and evidence for evolution by natural selection that can be seen in your daily life
In daily life, you can observe evidence of evolution by natural selection in things like: pest resistance to insecticides, antibiotic-resistant bacteria, variations in dog breeds, adaptation of local bird populations to different food sources, and even human traits like lactose tolerance depending on dietary habits; all of which demonstrate how organisms with advantageous traits survive and reproduce more successfully, leading to changes in the population over time
Identify the different kinds of evidence that support the theory of evolution
The main types of evidence supporting the theory of evolution include: fossil record, comparative anatomy (including homologous structures and vestigial organs), embryology, molecular biology (DNA analysis), biogeography, and direct observation of natural selection; all of which provide insights into how organisms have changed over time and share common ancestry
Explain how the geologic age of fossils can be determined in both relative terms (using layers of rock) and absolute terms (using radiometric dating)
The geologic age of fossils is determined by comparing their position within layers of rock (relative dating) to establish a sequence of events, while absolute dating uses radiometric techniques to calculate a precise age by measuring the decay of radioactive isotopes present in the rock or fossil itself, providing a numerical age in years.
Define macroevolution
Macroevolution is defined as a change in allele or gene frequency over the course of many generations.
Decipher the evolutionary relationships among biological organisms using a phylogenetic tree
A phylogenetic tree depicts the evolutionary relationships between different organisms by showing how they are believed to have diverged from a common ancestor over time, with closer branches indicating a more recent shared ancestry and longer branches signifying a more distant evolutionary relationship; essentially, the closer two species are on the tree, the more closely related they are considered to be
Describe the structure of viruses
A virus is primarily composed of a nucleic acid genome (either DNA or RNA) enclosed within a protein shell called a capsid, which protects the genetic material; some viruses also have an additional outer layer called an envelope, derived from the host cell membrane, surrounding the capsid; essentially, a virus is a simple structure with only these core components, allowing it to infect and replicate within a host cell
Identify the reasons why most biologists do not consider viruses to be alive
Most biologists do not consider viruses to be alive because they lack the ability to independently replicate or carry out metabolic processes outside of a host cell, meaning they cannot produce their own energy, grow, or maintain homeostasis on their own; essentially, they are only able to reproduce by hijacking the cellular machinery of a host organism, making them dependent on another living thing to function.
Define invasive species
An invasive species is a non-native organism that can cause economic or environmental harm, or harm to human, animal, or plant health.
Explain the effects that introduction of an invasive species can have on a community of native organisms
When an invasive species is introduced into a new ecosystem, it can significantly disrupt the balance of native organisms by outcompeting them for resources like food and habitat, leading to population declines, altered community structure, and even potential extinction of native species; this can happen through direct interactions like predation, competition, and disease transmission, while also indirectly impacting the ecosystem by modifying habitat conditions or altering nutrient cycles
