evolution Flashcards
Why are viruses sometimes considered to be “alive”?
they can reproduce and mutate/evolve
Why viral infections are usually difficult to treat with drugs.
no clear target for drug - virus in host and uses its resources. unaffected by antibiotics & other treatment methods used for bacteria.
hypotheses for the evolutionary origin of viruses.
evolved from cells since they require host cell to reproduce. they evolved into one which uses directions to reproduce etc.
ancient/before cells: from “primordial gene pool” - rna said to be first genetic material.
Why the effectiveness of anti-viral drugs is likely to decrease over time
viruses mutate/evolve quickly as their lifespans are short. drugs will soon encounter viruses that are resistant
Principles underlying evolution by natural selection:
heritable variation, non-random reproduction or survival, change in genotype of the population
What is heritable variation and how does it relate to natural selection?
it is the variation of what is passed from parent to offspring. helps natural selection alter frequency of alleles in the gene pool.
Rationale for using multiple drugs simultaneously to treat viral infections
it will take more nucleotides for a virus to develop resistance. viruses are unlikely to develop resistance to all the drugs.
Evolutionary origins of HIV and how does this show that eradicating viral diseases is difficult?
from virus that infected primates - chimpanzee. the virus evolved allowing it to spillover between both species (at least 5 times!!). It constantly evolves.
what is “scala natura” thinking.
aristotle’s ladder-classification system. non-living at bottom, humans and god at top. his system merged with biblical account of creation. organisms created by god and never change/go extinct. no new species.
Why is scala natura not compatible with modern evolutionary theory
modern evolutionary theory believes species can evolve while scala natura goes against this.
What evidence supports the idea of descent with modification from a common ancestor
geology and the fossil record, the geographic distribution of species, and comparative morphology
how does geology and fossil records support the idea of descent with modification from a common ancestor.
fossils found were similar to current species, but not the same. earth’s moving plates convinced Darwin that life can change as well.
how does geographic distribution of species that support the idea of descent with modification from a common ancestor.
species similar to each other were found in diff parts of the earth. species on an island would be similar to mainland species. Darwin thought that after being separated both species changed over time.
how does comparative morphology support the idea of descent with modification from a common ancestor.
species had similar bone structures which server diff purposes. some animals had structures that were now of no use (vestigial) but were similar to other species’.
Give examples of homologous traits (comparative)
human arm, bat wing, and seal flipper. pelvis of human, dog, and cat. tailbone of monkey and human.
