Unit 4 Evolution Flashcards
Define evolution
any net directional change or any cumulative change in the characteristics of organisms or populations over many generations
Define phylogeny
the branch of biology that deals with phylogenesis.
What is a clade?
a group of organisms believed to have evolved from a common ancestor, according to the principles of cladistics.
Define gene pool
the stock of different genes in an interbreeding population.
Define species
a group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding. The species is the principal natural taxonomic unit, ranking below a genus and denoted by a Latin binomial,
What is divergent evolution? Give an example.
In divergent evolution, two or more distinct species share a common ancestor from which they diverged. A common example is a modern elephant and woolly mammoth.
What is convergent evolution? Give an example.
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. flying squirrel and the other one.
Describe struggle for existence.
the competition in nature among organisms of a population to maintain themselves in a given environment and to survive to reproduce others of their kind.
Who was responsible for adopting the theory of evolution?
Charles Darwin
Why were Darwin’s ideas so controversial at the time?
it threatened the prevailing views of the Anglican Church and society at large.
Briefly describe what natural selection is.
the process through which populations of living organisms adapt and change.
True or false - In general, the more derived genetic characters two species share, the more recently they shared a common ancestor and the more closely they are related in evolutionary terms.
True
What does allele frequency mean?
Allele frequency, or gene frequency, is the relative frequency of an allele at a particular locus in a population, expressed as a fraction or percentage.
What are analogous structures? Give an example.
Analogous structures are features of different species that are similar in function but not necessarily in structure and which do not derive from a common. wings
What are homologous structures? Give an example.
Homologous structures are similar physical features in organisms that share a common ancestor, but the features serve completely different functions. An example of homologous structures are the limbs of humans, cats, whales, and bats.
