b15: genetics and evolution Flashcards
(17 cards)
what is evolution
change in the inherited characteristics of a population over time through natural selection,
may result in a new species
who first proposed the theory of evolution by natural selection
Charles Darwin
what is the theory of evolution by natural selection
all species of living things evolved from a common ancestor that developed billions of years ago
describe Lamarck’s idea of inheritance
organisms change over their lifetimes and these characteristics can be inherited
why was the theory of natural selection controversial
- challenges the idea that god made all the earths animals and plants
- insufficient evidence at the time
- genes, inheritance and variation were not understood
what is specification
gradual formation of a new species as a result of evolution
what evidence supports the theory of evolution
- parents pass on their characteristics to offspring in genes
- fossil record evidence
- evolution of antibiotic-resistant bacteria
what did Mendel discover through breeding experiments on plants
inheritance of characteristics is determined by units (genes) passes on unchanged to offspring
what are fossils
remains of organisms from millions of years ago, found in rocks
how might fossils be formed
- parts of organism do not decay due to certain conditions
- traces of an organism are preserved
- parts of an organism are replaced by minerals
what are the benefits of the fossil record
can learn how species changed and life developed on Earth
can track the movements of species across the world
what is extinction
no individuals of species are still alive
what are the problems with the fossil record
- many early organisms were soft bodied so left few fossils
- gaps in fossil record as not all fossils have been found and some have been destroyed
what is the binomial system
naming of an organism by their genes and species
what classification system did Carl Woese introduce
three-domain system of Archaea, bacteria and Eukaryota
why can bacteria evolve rapidly
they reproduce at a fast rate
how do antibiotic-resistant strains of bacteria develop
mutations that allow the strain to survive and reproduce
